For 2009, the MDX’s power rear tailgate feature is standard equipment with the Technology and Sport packages - previously the power rear tailgate was only available on the Entertainment Package. Additionally, the AcuraLink real-time traffic system includes an additional metropolitan market (Dayton, Ohio) and the MDX is offered in two new exterior colors- Bali Blue Pearl and Mocha Metallic.
The 2009 Acura MDX is powered by a 3.7-liter V-6 engine that delivers 6,000 rpm and 275 lb-ft of torque at 5,000 rpm. The engine is mated to a 5-speed automatic transmission.
The price for the 2009 MDX is: MDX, $40,790; MDX with Technology Package, $44,840; MDX with Technology Package and Entertainment Package, $46,590; MDX with Sport Package, $46,940; and MDX with Sport and Entertainment Packages, $48,690.
Full details in the press release after the jump.
Benchmarked against some of the best performance SUVs in the world and tuned on the Nürburgring racetrack in Germany, the MDX clearly establishes itself as a driver’s SUV. Outfitted with Acura’s Super Handling All-Wheel Drive™ (SH-AWD®) system and an available Sport Package with Active Damper System, the MDX yields a combination of handling and comfort that is truly on the cutting edge.
The 2009 MDX is equally daring in its styling and thorough in its safety and environmental responsibilities. The MDX has an expansive array of safety features included as standard equipment. The MDX’s 300-hp VTEC® V-6 makes as much power as some competitive V-8s, yet delivers ultra-low emissions and excellent fuel economy. Inside the 7-passenger interior, the MDX offers thoughtful luxury and an unmatched range of advanced technologies, including the Acura Navigation System with Voice Recognition™ and AcuraLink® Satellite Communication System with real-time traffic and a spectacular 10-speaker Acura/ELS Surround® Premium Sound System.
Altogether, the 2009 MDX embodies Acura’s commitment to performance, luxury, quality and style, along with an emphasis on safety and environmental care. The 2009 MDX is the seventh Acura project to be designed and engineered in the United States (including the 1997 CL, 1999 TL, 2001 CL, 2001 MDX, 2004 TL and 2009 TL) along with several award-winning Honda products.
MDX has been very important to Acura, accounting for about 30-percent of the division’s sales since the vehicle’s introduction as a 2001 model. Equally important, the original MDX attracted buyers from competitive luxury makes including BMW, Mercedes -Benz and Lexus , starting new relationships for Acura. The 2009 MDX competes in the Mid Premium CUV (Crossover Utility Vehicle) segment.
Focus groups with luxury customers were conducted in Seattle, Detroit, Chicago and Los Angeles. These cities were carefully chosen to explore how customers use their SUVs in cold climates, in areas that are traditional domestic-vehicle strongholds and in areas known for their trend-setting character.
Early in the study process Acura also benchmarked performance SUVs such as the BMW X5 - and polled their owners - to ensure that the second generation MDX would exceed its performance. Satisfying these highly discriminating customers means that the MDX would be well positioned to attract a wider group of potential buyers.
With the MDX, added performance and handling capabilities boost its appeal for performance enthusiasts, while the luxurious and functional interior continues to satisfy the needs of traditional luxury customers.
ENGINE & POWERTRAIN
Developing 300 horsepower and 275 lb-ft of torque, the MDX’s 3.7-liter V-6 output is competitive with many V-8 engines - without the fuel-economy penalty most V-8’s suffer. To widen the powerband and improve fuel economy, the 3.7-liter engine has VTEC® (Variable Valve Timing and Lift Electronic Control) valvetrain, a dual-stage intake manifold and an electronic Drive-by-Wire™ throttle system. EPA estimated mileage of 15/20 mpg* (city/highway) and a large 21-gallon fuel capacity mean the MDX has a long cruising range. The MDX is designed to meet the latest emissions requirements including strict EPA TIER 2 - BIN 5 and CARB LEV II ULEV standards.
A 5-speed automatic transmission with Sequential SportShift is designed to satisfy the most performance-oriented drivers. Tuned on the famed Nürburgring circuit in Germany, the Super Handling All-Wheel Drive™ (SH-AWD®) system provides handling precision that sets a new benchmark for SUVs.
SH-AWD® actively varies the torque distribution between front and rear axles - then between the left and right rear wheels - to provide maximum grip under all driving circumstances. Such torque vectoring operates seamlessly and allows the SH-AWD® to overdrive the outside rear wheel up to 1.7-percent faster than the front wheels to create a "yaw moment" allowing the MDX to better rotate around a corner while minimizing understeer.
BODY & CHASSIS
The 2009 MDX sets new standards for SUV styling, engineering, handling and safety standpoints. Its dramatic styling utilizes large surface areas, sweeping curves and decisive angles. Longer, wider and lower (and with a longer wheelbase) than the original MDX, the dimensions create a more athletic appearance.
In an effort to keep mass out of the vehicle, the MDX features widespread use of light weight materials such as high-strength steel, aluminum and magnesium. In addition, the Advanced Compatibility Engineering™ (ACE™) body structure is intended to bring new levels of front crash safety to the MDX.
Befitting its position as Acura’s flagship SUV, the MDX is equipped with Xenon High-Intensity Discharge (HID) low-beam front headlights, a dramatic array of Light Emitting Diodes (LEDs) in the rear tail lamps and center high-mounted stop light (CHMSL), and exterior mirror-mounted turn signals. The Acura signature front grille reflects a fresh look for the MDX. Careful aerodynamic tailoring reduces drag noise and high speed dynamic stability.
The 2009 MDX features a track-tuned chassis to complement its 300-horsepower VTEC® V-6 engine and Super Handling All-Wheel Drive™ (SH-AWD®). Engineers targeted the BMW X5 and Porsche Cayenne when developing the MDX chassis, and then tested and refined it at Germany’s famed Nürburgring circuit. The Active Damper System, available in the Sport Package, has proprietary fully active dampers that adjust (in less than five milliseconds) to road conditions on a real-time basis. The MDX is also at home off-road where its excellent engine torque, responsive suspension, and generous ground clearance enable it to cross-step through rough terrain.
For family recreation, the MDX tows as well as it goes. With a 5,000-pound tow rating, standard trailer pre-wiring, high-capacity radiator with twin cooling fans, transmission fluid cooler and Trailer Stability Assist, the MDX needs only a dealer-installed hitch and wiring to tow a substantial trailer.
The MDX features a luxurious yet functional interior. The cockpit environment is focused on the driver, and features a host of technologies to make driving simultaneously rewarding and relaxing. The interior styling and functionality perfectly coexist with a driver’s cockpit that features a 10-way power seat including power-adjustable lumbar support for the driver, electronic tilt and telescoping steering column, a 2-position custom memory system, and a Multi-Information Display (MID) that allows access to multiple electronic functions.
The interior design is as dynamic and contemporary as the exterior, with a "4+3 seating" concept that luxuriously hosts four passengers in the first and second row seats, while also offering comfortable accommodations for three additional passengers (one in the second row and two in the third row). The front passenger enjoys an 8-way power seat, while everyone on board will appreciate the MDX’s Tri-Zone automatic climate control system. All occupants will enjoy the 253-watt, 8-speaker Acura Premium Sound System with in-dash 6-disc CD/MP3/WMA changer, AM/FM tuner, and XM® Satellite Radio. An auxiliary jack for personal audio devices is also included. Standard convenience features include HomeLink®, Maintenance Minder™ and adaptive and flexible cargo space with six configurations.
The Advanced Compatibility Engineering™ (ACE™) body structure along with several passive-safety technologies help bring the 2009 MDX to the next level of safety. ACE™ more evenly distributes collision forces and helps maintain the integrity of the passenger cabin in the event of a severe frontal collision. The MDX is also less intrusive to smaller vehicles in a head-on collision thanks to a special frame member located below the front bumper that is designed to engage the front bumper of smaller vehicles.
The MDX is equipped with an active front head restraint system for front seat head restraints along with knee bolsters for the driver and front passenger. The driver and front passenger are also protected by dual-stage, dual-threshold airbag Supplemental Restraint System (SRS) and side airbags with front passenger Occupant Position Detection System (OPDS). Side curtain airbags help reduce the likelihood of injury to the occupants in all three rows of outboard seats A rollover sensor adds a further level of protection.
The 2009 Acura MDX furthers Acura’s commitment to "Safety Through Innovation" with pedestrian injury mitigation features such as a deformable aluminum hood and hood hinges along with breakaway windshield-wiper pivots.
Honda of Canada Manufacturing in Alliston, Ontario, is the assembly plant for the MDX. A special dynamic quality-control process is employed to ensure the highest possible level of attention to detail for every MDX produced. After assembly is completed, each MDX enters a special Acura Quality line. The ability to immediately respond to the smallest quality issue allows the MDX to excel in quality - and in customer satisfaction.
The 2009 MDX fuses the model’s traditional virtues of adaptable space, functionality, safety and environmental responsibility with a more exciting visual presence along with more accomplished handling and ride comfort.
Customers in the luxury SUV arena demand distinctive style. The 2009 MDX ups the game with standard 18-inch wheels and tires, standard Xenon High Intensity Discharge (HID) headlights and a distinctive front grille. Driving excitement is equally embraced with a chassis tuned at the Nürburgring circuit and on autobahns in Germany.
The exterior has bold, clean and advanced styling details with European cache, and it was styled to connect with enthusiast drivers from the moment they first see it. Sitting in the vehicle - and then experiencing it - makes the desire even more intense. Besides featuring a 300 horsepower V-6, the MDX includes Super Handling All-Wheel Drive™ (SH-AWD®), an available Active Damper System along with lightweight aluminum components used in the suspension and body. Convenience features such as an available power rear tailgate further improve functionality and luxury.
EXTERIOR DESIGN GOALS
One of the primary goals in designing the second generation MDX was to keep its traditional strengths but advance its performance and image. The clear direction for the MDX was to create a bold and innovative look that clearly conveyed the "Driver’s SUV" nature of the vehicle. The grille is free of molding breaks for a cleaner look and features dark silver satin plating.
The original MDX provided a fine blend of utility, luxury and style. The 2009 Acura MDX has powerful, dynamic styling that is a continuation of the themes that have been embodied in recent Acura products. Designers found inspiration in a high-powered mega yacht, which features an exceptionally bold, lean and contemporary design. The challenge was to apply the useful elements of the yacht design to an SUV, and designers found their answer in the adoption of large areas of clean surfaces and the addition of decisive line breaks and dynamic surface curvature. Large 18-inch wheels and tires not only benefit handling, but also create a muscular look. In front, the 2009 MDX has a distinctive, advanced Acura look. The platform is long, low and wide to enhance cornering and high-speed stability.
The MDX has a significantly wider track than its primary market competitors. As a result it offers dramatic appearance, packaging and utility advantages.
The 2009 MDX utilizes the Advanced Compatibility Engineering™ (ACE™) body structure, which distributes collision forces through the structure during a frontal collision while helping to retain the integrity of the passenger compartment. The MDX uses a large amount of high-strength steel to help reduce vehicle weight while simultaneously increasing strength. Alternative materials including aluminum and magnesium are also used throughout the vehicle, further reducing vehicle mass, which helps improve fuel economy and increase performance.
Attaining a high level of dynamic body rigidity is essential for precise handling, ride quality and quietness inside the cabin. By researching the body’s dynamic response to chassis loads resulting from everyday driving events, MDX engineers considered the unit body’s "dynamic stiffness" as an entire system — not just as a single component. Thus, body rigidity is not an end to itself, but rather it is an enabler for enhanced vehicle dynamics, riding comfort, and driving quietness.
Instrumented testing revealed that the "tailgate ring" - the open area surrounding the tailgate - is particularly important for handling, stability and ride. In the second generation MDX, this area has been markedly stiffened, providing the rear suspension with a more solid mounting and netting an improvement in handling precision. In addition, the MDX’s floor frames are wider than before for improved packaging and rigidity.
The use of high-strength steel contributes to rigidity, excellent crashworthiness and light weight. High-strength steel is specified in different grades for use in different parts of the vehicle. Some unit body areas using this material include the roof arches, floor cross members, tailgate opening and front rails and body sides.
In addition, about 4.1-percent of the 2009 MDX body components are constructed of aluminum. This material is ideal for certain components such as the hood and instrument panel support, where light weight is required but the strength of steel is not imperative.
The hood on the first-generation MDX was steel, and the weight savings of using aluminum instead of steel (for the 2009 MDX hood) is 15.5 pounds. Aside from using a unique metal conditioner and phosphate dip prior to painting, there are no unique production challenges for using an aluminum hood - and no ownership compromises either. To improve environmental efficiency, a factory separation line isolates different scrap materials, including aluminum, for recycling.
The aluminum instrument panel support saves an additional 10.5 pounds compared to a traditional steel unit. This support structure, which connects the A-pillars to the front floor crossmember, is a structural element consisting of cast parts, extrusions and sheet aluminum.
Acura MDX prototypes spent a total of seven weeks in the wind tunnel to test and develop its aerodynamic properties. The attention to detail in aerodynamic efficiency included the development of body side sills that help keep air from moving underneath the vehicle which can cause turbulence. Lift balance and the coefficient of lift were also addressed to keep the MDX stable at high speeds. In this area, internal testing revealed that the MDX exceeds the performance of the BMW X5.
Careful attention was paid to reducing wind noise inside the MDX cabin. An acoustic wind tunnel was used to identify and correct noise issues, resulting in the MDX’s best-in-class wind noise performance (at the driver’s ear point) according to Acura’s internal measurements.
An added benefit of wind tunnel testing was the ability to rotate the MDX sideways into the airflow. This allowed engineers to approximate even the most severe gusting side winds and solve unexpected and unwanted wind noise that could accompany such severe conditions.
The MDX’s moonroof is larger than used in the previous generation and is also the widest of any direct competitor. A finely tuned deflector ensures that the moonroof does not add objectionable wind noise when in the open position, even at highway speeds. Attention to detail in the sealing of the doors and tailgate also heightened the performance of the MDX’s overall wind noise level.
Engineers attacked noise from virtually every source inside and outside the MDX. Their primary goal was to reduce noise at its source. One creative noise-reduction technique is the use of composite seals in the exterior door panels. These composite seals actually serve two purposes - to reduce the transmission of noise through the doors and to shield the interior components from dirt and water while driving through rain or puddles. The new door insulators provide a substantial reduction in objectionable sound - up to five decibels on some roads.
The MDX’s door handles are sized for comfort as well as ease of use, regardless of whether the user is bare handed or wearing winter gloves. There are three door checker - the detent mechanism that holds the door partially open - positions instead of the usual two, thus providing a convenient "in between" position useful during tight parking situations. The door openings are finished with an attractive composite garnish that hides the doorsill when the door is open.
Normally only sports cars use windshields with highly compound curves. Deeply contoured glass is more complex and costly to make, thus it is usually reserved for low-production vehicles. Designers specified deeply curved acoustic glass for the MDX for its styling appeal as well as to improve aerodynamic efficiency and quietness. The 2009 MDX uses an acoustic glass front windshield that incorporates a unique PVB film to help quell wind and windshield wiper noise from entering the cabin. The rear glass is also a deep wraparound design - the deepest in the Acura product range.
The MDX has an auto up/down feature for the driver and front passenger’s 3.5mm thick side windows. The 2009 MDX offers 273-degrees of outward visibility compared to 266-degrees of visibility for the BMW X5, which is a significant accomplishment considering the increased size of the MDX’s head rests mandated by the government’s FMVSS 202 safety regulations.
All glass from the B-pillar rearward has a gray tint to reduce eyestrain and heat buildup inside the cabin. In addition, the outside rearview mirrors use a special blue glass (sourced from Germany) that provides bright imaging along with excellent glare resistance.
XENON HID HEADLIGHTS
All 2009 Acura MDX models include Xenon high-intensity discharge (HID) low beam front headlights with halogen high beams. The advantages of HID headlamps include greater lighting power, daylight-color light balance and reduced power consumption. In addition, the cut lines of the new HID headlights are extremely precise, providing maximum nighttime visibility without distracting other drivers.
The 2009 MDX features Daytime Running Lights (DRL), which automatically turn on with the activation of the ignition. An MDX fit with the optional Sport Package features an auto-leveling feature that keeps the headlights level regardless of how the vehicle is loaded with passengers or cargo.
To ensure a high degree of theft prevention, the HID headlights are attached to the unit body with multi-strand steel cables. Halogen fog lamps are also included as standard equipment on all MDX trim levels
Two Light-Emitting Diode (LED) arrays, comprised of 12 LEDs apiece, are used for the tail lamps of the 2009 MDX. Likewise, the Center High Mount Stop Lamp (CHMSL) features a single array of 16 LEDs. Advantages of the LED taillights include an elegant contemporary appearance, quicker turn-on time compared to a conventional incandescent bulbs and significantly greater service life. LEDs are also brighter, smaller, lighter and produce less heat than incandescent lights. The LED CHMSL was selected for its appearance and ability to produce the required lighting brightness while retaining slender physical dimensions. LEDs are also used in the MDX’s outside mirror housing-mounted turn signals, improving visibility during lane changes or turns.
Acura’s power tailgate system is included on MDX models optioned with Technology or Sport packages. The power tailgate can be operated via the remote key fob, from a button on the driver’s door panel, or from a button located inside the tailgate. The location of the motor in the MDX’s D-pillar (instead of in the roof) allows excellent headroom for the third-row seats. The tailgate can also be operated manually.
RESIN FUEL FILLER DOOR
The MDX fuel filler door is operated remotely from inside the vehicle via a switch on the driver’s door panel. The fuel-filler door is made of a composite resin material that is lightweight, dent resistant and corrosion proof. For a better appearance the inside of the door features a flangeless resin design.
The front and rear bumpers are constructed of a structural beam covered with a plastic fascia rated to withstand impacts of up to five mph without sustaining significant damage. An attachment point for a tow hook is located under a small cover on each bumper fascia. Removing the cover allows access to a threaded boss that accepts a steel eyebolt located in a holder in the jack storage area.
Inspired by the smooth finishes on fine pianos, Acura set out to achieve a mirror-smooth paint finish with a wet, glossy look. To advance the surface smoothness, "orange peel" - the finely undulating surface found on some paints resulting from the evaporation of the paint solvents - had to be all but eliminated. Seven environmentally safer waterborne exterior colors are available, and each uses a durable clear-coat finish that resists scratching and airborne pollutants. For 2009 the MDX is available with two new colors: Bali Blue Pearl and Mocha Metallic.
The core MDX themes of driving enthusiasm, intelligent functionality, technology and luxury are clearly evidenced in the interior. Acura’s flagship SUV blends sport sedan intensity with the best elements of SUV utility. In keeping with Acura tradition, the MDX integrates the latest technology into a seamlessly intuitive package that puts the emphasis on driving.
New attention to detail and luxury distinguish the MDX interior. Softer leather seating, highly supportive front bucket seats and a driver-oriented cockpit make it clear that the MDX is focused on the driver - but not at the expense of passenger comfort. The power driver seat adjusts 10 ways (8-way power seat with 2-way power lumbar support) for optimum comfort, and the front passenger seat is 8-way power adjustable. The second-row seats mirror the style and lateral support of the front seats, giving the MDX interior a unique 4+3 feel that highlights its blend of sport and utility. Convenience and cargo features abound, including under-floor storage in the cargo compartment and an available power-operated rear tailgate.
As Acura’s flagship SUV, the MDX offers a formidable list of standard equipment. A leather-wrapped multi-function steering wheel provides the driver with fingertip control of key functions in an interior environment that’s maintained by a Tri-Zone climate control system with humidity control. Backlit LED instrumentation with spun metal appearance trim and Acura’s legendary attention to control function and feel make the MDX driver seat the place to be. A standard 8-speaker Acura Premium Sound System plays nearly every type of current audio format, and it includes standard XM® Satellite Radio and an auxiliary jack for the easy connection of a personal audio player. With the Bluetooth® HandsFreeLink® wireless telephone interface (compatible with many Bluetooth® mobile phones), staying connected while on the road is not a problem. The system also allows for up to six compatible mobile phones to be electronically linked with the ability to store up to 50 phone numbers with unique voice tags.
The available Technology Package adds even more capability, and integrates perfectly into the MDX’s performance-oriented driving environment. The Acura Navigation System with Voice Recognition™ with rearview camera has a brilliant 8-inch display screen and includes the AcuraLink® Satellite Communication System with real-time traffic, which can help the MDX driver navigate around congested freeways. The Technology Package’s spectacular 10-speaker Acura/ELS Surround® Premium Sound System with multi-format 6-disc DVD-Audi o changer, AM/FM tuner and XM® Satellite Radio provides a state-of-the-art soundtrack. An MDX with the Technology Package can import up to 1,000 names into the Navigation system phonebook.
For even more luxury, the available Sport Package includes extra-soft perforated Milano premium leather seating surface inserts. The optional Entertainment Package includes a DVD Rear Entertainment System complete with a flip-down 9-inch TFT screen, dual wireless headphones, a wireless illuminated remote control, and 115-volt plug in the center console.
CONCEPT AND STYLING
The interior styling of the MDX is based on three key concepts: a driver’s oriented cockpit, 4+3 seating, and a dynamic and layered overall interior look.
To put the MDX’s various systems under the clear control of the driver, a "Driver-Oriented Cockpit" theme guided the design of the cockpit. Analog central instrumentation is supplemented with digital and graphic displays. The interface with the MDX’s many advanced systems is simple and intuitive. Sight lines are clear with important items placed within easy view.
Frequently used systems, such as the audio system and cruise control, have switches conveniently positioned on the steering wheel. The multifunction Interface Dial, which operates navigation system functions, is positioned just ahead of the shifter lever within easy reach.
The concept of 4+3 seating emphasizes the comfort, luxury and style of the front seats and the outboard second-row positions. These seats share the same styling theme, and have substantial side bolsters to provide secure lateral support when the MDX is cornering. The second-row center position and the two seating positions in the third row are used less frequently, and as such styled more stealthily. Nested headrests in these positions provide a clean appearance, and in the third row, allow the seat to be folded flat without the need to remove the headrests.
The MDX envelops its passengers with dramatic shapes that sweep from the center console, across the instrument panel and then into the door panels. Sculptural and warm wood-patterned trim creates a zone of luxury for the front passenger. Rich textures interplay with sleekly technical metallic accents in the MDX interior to create an atmosphere of luxury and advanced technology.
LEATHER-WRAPPED STEERING WHEEL
The MDX’s driver-focused control layout is evidenced in the steering wheel. Audio system controls are positioned on the left spoke, and cruise control switches are on the right spoke.
The five o’clock position on the steering wheel has switches that operate the Multi-Information Display (MID). The seven o’clock position is reserved for Bluetooth® HandsFreeLink® and Technology Package navigation system controls, including a push-to-talk button to activate the voice recognition system, which provides voice control over a wide range of features.
INTERIOR MATERIALS AND CRAFTSMANSHIP
The MDX pushes interior luxury to a new level with a range of thoughtful touches. Special care has been taken to create surfaces with a pleasing tactile feel. Door grab handles have a soft-touch grip, the instrument panel has a soft feel and a seamless passenger airbag cover, and passenger grab handles have a dampened motion. Quality is further revealed in the soft, low-gloss instrument panel top, detailed door panels, door sash garnishes and flush seatbelt upper anchors.
In keeping with its 4+3 seating arrangement, the MDX offers two types of seating. To provide a blend of sporting support and comfort for four passengers, the MDX has deeply-bolstered sport sedan seating in front and in the outboard second-row positions.
The front bucket seats and outboard rear seats have pronounced side bolsters to provide lateral support for aggressive cornering, along with abundant comfort for long drives. On the Sport Package, the front seats feature a new type of seat base foam that improves damping of small vibrations for improved comfort. Redesigned seat frames and power adjustment mechanisms reduce flex for a more solid feel. The driver seat is 10-way power adjustable (8-way power seat with 2-way power lumbar support) and is part of a 2-driver automatic memory system that includes settings for the exterior mirrors, climate control, and electronic presets. The front passenger seat is 8-way power adjustable. Both front seats are heated, and with the Entertainment Package MDX the second row outboard seats are heated as well.
For easy access to the third row of seats, the passenger-side second-row seat slides forward and the seatbacks flip forward.
All MDX models feature high quality leather seating surfaces as standard equipment for the first and second row seats that utilize a soft and flexible tanning system, solid embossing and color coating. The result is a softer, richer feel coupled with excellent durability.
In addition, the perforated Milano premium leather included in the Sport Package is the softest leather ever offered in an Acura. This full grain leather has not been corrected or altered and shows the natural leather grain. A soft, flexible coating system provides maximum softness while retaining excellent abrasion resistance. Breathable perforated inserts in the first two rows add to passenger comfort. With the premium Milano leather, leather application is increased to the second row center passenger area.
INTERIOR CONVENIENCE AND UTILITY
Thoughtful features abound in the MDX interior. The front center console has individual armrests for driver and passenger to allow for storage access without disturbing the other armrest. A pocket in the passenger side of the console provides room for small items. In the second row, the flip-down padded center console features pullout dual cup holders. All four doors offer storage pockets, and storage for sunglasses is provided in the front overhead console. Storage pockets and cupholders add convenience to the third row seating area. Under-floor storage, grocery bag hooks and cargo tie-down points boost cargo area usefulness.
CARGO CARRYING VERSATILITY
The MDX easily adapts to a variety of missions. In all, there are six possible configurations for the MDX’s three rows of seating. Behind the rear seats, there are 15 cubic feet of storage that’s easily accessible though the flip-up rear hatch (the hatch is power-operated in the Technology and Sport Packages). With the 50/50 third row seats folded flat (the headrests can be left in place), the cargo capacity jumps to 42.9 cubic feet. For the maximum cargo volume of 83.5 cubic feet, the 60/40 split-folding second row seats can also be folded down, producing a flat load floor in the rear.
Acura’s power tailgate system is included on MDX models optioned with Technology or Sport packages. The power tailgate can be operated via the remote key fob, from a button on the driver’s door panel, or from a button located inside the tailgate. The location of the motor in the MDX’s D-pillar (instead of in the roof) allows excellent headroom for the third-row seats. The tailgate can also be operated manually.
Significant engineering went into the MDX’s interior lighting to provide clear visibility, the right ambience and optimized illumination levels regardless of ambient lighting. The analog instruments are LED backlit, with high-contrast markings and a subdued blue accent hue. Transparent illuminated pointers provide clarity and a high-end look. Auto Interior Dimming automatically and progressively adjusts the instrument and navigation system (if so equipped) illumination to suit the ambient lighting conditions. The sensitivity is owner-adjustable to one of five different levels, or interior dimming may be switched off entirely.
The MDX has a progressive self-illuminating gauge package. When the door is first opened, the instrument lighting comes to life, and then brightens progressively when the ignition is switched on. The illuminated instrument needles and enunciator lights then come alive, indicating that the MDX is ready to drive. When the ignition key is switched off, the instrument lighting dims progressively.
For easy location in the dark, all of the MDX’s switches are illuminated, including those on all four doors and the steering wheel. Low-level blue LED ambient lighting in the ceiling illuminates the front center console and map lights are provided for the two front seats as well as for the two outboard second row seats. A dome light is provided above the third-row seats. All four doors have courtesy lights that are illuminated when the doors are open and the rear tailgate has a light that illuminates the area immediately behind the vehicle for easier cargo loading. The MDX interior lights feature "theater dimming," which can be set via the MID by the driver to any of three dimming times.
TRI-ZONE AUTOMATIC CLIMATE CONTROL SYSTEM
To maximize passenger comfort, the MDX has standard Tri-Zone automatic climate control that allows the driver, front passenger and rear zone to be set to different temperatures. Rear zone controls are conveniently positioned on the rear of the center console. With the touch of a button, the driver can synchronize the rear temperature with that of the driver area at any time.
When equipped with the Technology Package, the climate control benefits from GPS-linked, solar-sensing actuation. Based on its continuously updated vehicle position information, the navigation system determines the position of the sun relative to the driver and passenger. When in AUTO mode, this information is combined with input from the solar sensor located on top of the instrument panel to automatically adjust the temperature from side to side as needed to compensate for asymmetrical solar heating.
Humidity Control System
To help avoid window fogging, the MDX’s automatic climate control system has a cabin humidity control system. This new control system provides greater passenger comfort and minimizes the time the air conditioning runs. When set to operate in AUTO mode, a temperature and humidity sensor located in the front of the passenger cabin monitors the interior climate. If the system determines that there is a low probability of window fogging, it maintains a comfortable humidity level of around 20-percent.
If the system determines that potential window fogging conditions exist, it changes the climate control parameters to help keep the windows clear. In these situations, the air conditioning system is set to MAX, the air outlet mode is switched to HEAT/DEF and the fan speed is gradually increased to reduce the chances of window fogging.
MULTI-INFORMATION DISPLAY (MID)
A LCD Multi-Information Display (MID) positioned in the instrument cluster provides important vehicle information to the MDX driver. An illuminated control on the instrument panel lets the driver cycle through various screens, including vehicle mileage and trip mileage and trip computer functions including average and instantaneous fuel economy.
The Maintenance Minder™ system also alerts the driver of upcoming maintenance needs via the MID. The MDX has controls positioned near the steering wheel hub that allow the driver to cycle the display through multiple screens of information while keeping both hands on the wheel.
The overhead console incorporates a variety of useful features. Controls for the standard HomeLink® system are positioned here within easy reach. This latest generation of HomeLink® is simpler to program. Other overhead console features include sunglasses storage, controls for interior lighting and the power tilt/slide moonroof.
253-WATT ACURA PREMIUM SOUND SYSTEM
To give owners excellent sound quality along with the ability to enjoy a wide range of audio formats, the MDX comes standard with a 253-watt Acura Premium Sound System with AM/FM tuner, in-dash 6-disc CD/MP3/WMA changer and 8 speakers, including an 8-inch subwoofer.
Prominently positioned just below the center instrument panel vents, the MDX audio system has large-format controls that make the audio system easy to operate. The system sends a total of 253 watts of power through six channels and eight speakers. The instrument panel has a 1.5-inch soft-dome tweeter positioned on each side, with a 3-inch mid-range polypropylene cone speaker centered atop the dashboard. Mid/low-range 6.5-inch dual thickness polypropylene-cone speakers are positioned in each door, and an 8-inch subwoofer is located in a special tuned enclosure in the sidewall of the cargo compartment.
The audio system can play CD, CD-R/RW, CD-Text, and MP3/WMA discs, in addition to AM/FM radio bands. Embedded text information on CDs can also be displayed. To make a high-quality audio connection simple for owners who have personal music players, the MDX has an easily accessible auxiliary input jack with a nearby 12-volt power outlet. Speed-dependent volume control automatically adjusts as road speed increases to maintain a clear and comfortable sound level. The amount of compensation can be set to three different levels or turned off completely.
The MDX audio system includes XM® Satellite Radio, which provides more than 170 channels of digital program material and near-CD quality sound. Informational text on the programming appears on the audio system display. XM® Satellite Radio offers virtually uninterrupted coast-to-coast coverage of the 48 contiguous states and coverage to densely populated regions of Canada; service for Alaska and Hawaii is not available at this time. Three months of complimentary XM® service is provided with the MDX. When equipped with the Technology Package or Sport Package, the complimentary period also includes real-time traffic service. After the complimentary period, XM® Satellite Radio requires a monthly subscription.
10-SPEAKER ACURA/ELS SURROUND® PREMIUM SOUND SYSTEM
Engineered by multiple Grammy® Award-winning recording engineer and producer Elliot Scheiner, Panasonic and Acura, the available Acura/ELS Surround® Premium Sound System brings a new level of audio performance to the MDX. Included in the available Technology and Sport Packages, the system pumps 410-watts through 10 speakers, to provide a total of six discrete audio channels.
Audio Head Unit
Like the MDX’s standard Acura Premium Sound System, the Acura/ELS Surround® Premium Sound System is remarkably versatile. The 6-disc in-dash changer can play CD, CD-R/RW, CD-Text, and MP3/WMA discs. In addition, it can also play DVD-Audio discs (the system will not play DVD movies). The system also includes AM, FM and XM® Satellite Radio. It’s easy to connect a personal music player to the system via an auxiliary input jack with nearby 12-volt power. The auxiliary input jack is located at the rear of the center console in the Entertainment Package, and in the center console for all other packages.
Large-format controls make the system simple and intuitive to operate. A prominent display below the center instrument panel vents shows the current audio system status at all times, independent of the navigation system (which is also included in the Technology Package). Screens within the navigation system menus display the current audio system status, audio track listings and more. Items that appear on the navigation system screen can be navigated and selected via the interface dial, which is conveniently positioned on the console.
Acura/ELS Surround® Sound
Acura/ELS Surround® Sound gets its name from Elliot Scheiner’s industry-recognized moniker "ELS." His goal with the system was to capture and reproduce music the way it is heard in the recording studio. The key to accomplishing this is through the use of the extra data-encoded on each DVD-Audio disc, which has six channels of information instead of just two channels of stereo information. In addition, DVD-Audio material can be recorded at a much higher resolution than CD material. Produced and mastered for the surround format, DVD-Audio recordings give recording artists and producers dramatically more creative freedom and control. The Acura/ELS Surround® system makes the most of this added information, reproducing it with spectacular accuracy and power, without processing or modifying the artist’s original creativity.
The system delivers a remarkable listening experience even when not playing DVD-Audio discs in Acura /ELS Surround® Sound mode. Specially engineered equalization for each media type allows the sound quality to be optimized regardless of whether the system plays XM® Satellite Radio, conventional CDs, or any other format. The system also features selectable Dolby Pro Logic II signal processing that creates simulated 5.1-channel surround sound from CD, MP3/WMA, XM® or AUX. For optimum sound regardless of vehicle speed, the system includes automatic speed-dependent volume control.
Advanced electronics in the Acura/ELS Surround® sound system gave Scheiner the ability to precisely tune the acoustics of the MDX cabin and time of each of six audio channels (traditional systems use two channels) to achieve the truest possible reproduction. The Acura/ELS Premium Surround® system uses a 24-bit D/A converter and a 192 kHz sample rate for smoother sound.
High-energy Neodymium magnets are used throughout the speaker system for optimum sound quality and substantially reduced weight. The carefully optimized speaker positions create an uncanny surround sound experience particularly for front seat passengers. There is a 6.5-inch mid/low-range dual thickness polypropylene-cone speaker in each door and a 1.5-inch soft-dome tweeter near each A-pillar. A 3-inch mid-range polypropylene cone speaker is centered on top of the instrument panel, and two more are positioned just behind the second-row seats, positioned high and angled into the interior. A special 8-inch Super Low Distortion subwoofer with a new cone design is positioned in a tuned enclosure on the right sidewall of the cargo area so it does not intrude on passenger room or useful storage space.
BLUETOOTH ® HANDSFREELINK ® WIRELESS TELEPHONE INTERFACE
The MDX includes the Bluetooth® HandsFreeLink® wireless telephone interface. Designed to work with many Bluetooth®-enabled mobile telephones (sold separately), Bluetooth® is a radio frequency-based cable replacement technology that lets portable devices like mobile phones, laptops, PDAs and other devices communicate wirelessly. Bluetooth®-enabled cell phones that have the Hands Free Profile (HFP) are compatible with the MDX system.
After a one-time "pairing" process, the MDX can communicate wirelessly and securely with the driver’s cell phone when it is within approximately 10 feet of the vehicle. The phone must be on, but can be stored anywhere inside the MDX cabin - even in a pocket, briefcase or purse.
Bluetooth® HandsFreeLink® boosts convenience by allowing the driver to send or answer calls without taking hands from the steering wheel. The number of the incoming caller is displayed on the Multi-Information Display (MID) located in the instrument cluster and a ring tone is played over the audio system. A press of the steering wheel-mounted "Pick up" button mutes the audio system and the incoming caller can be heard over the audio system speakers. A microphone in the overhead console picks up the driver’s voice and algorithms built into the Bluetooth® HandsFreeLink® system cancel "echo effect" to reduce background noise and improve the transmission quality of the driver’s speech. Using fingertip controls mounted on the steering wheel to activate the system, phone calls can be sent hands-free by dialing the number by voice.
On all models with the navigation system, up to 50 names with one number per name can be stored with voice tags in the system’s Voice Tag Phonebook. For users with large phonebooks in their mobile phone memory, the available navigation system, working in conjunction with Bluetooth® HandsFreeLink®, can import up to 1,000 names with 10 phone numbers per name. Up to six different compatible mobile telephones can be paired with the Bluetooth® HandsFreeLink® system. Additional information can be found at www.acura.com/handsfreelink or www.handsfreelink.com.
ACURA NAVIGATION SYSTEM WITH VOICE RECOGNITION™
The MDX with Technology and Sport Packages are equipped with the latest generation Acura Navigation System with Voice Recognition™. This highly capable system - similar to the units in the RL and RDX - is designed for intuitive and quick operation.
Based on positioning data from up to 12 orbiting Global Positioning Satellites (GPS), the Acura Satellite-Linked Navigation System with Voice Recognition™ locates the vehicle’s position. If the GPS antenna is blocked by a tunnel, tall building or parking garage, an internal gyroscopic system and a speed sensor track the location of the vehicle to help keep the mapping information current and reliable until satellite reception is restored. A DVD database is located in the system’s ECU. Updated DVD data discs are available on an annual basis on-line or by calling a toll-free number.
The navigation system can be controlled by voice, or by the interface dial. For voice operation, the driver simply presses the "Talk" button on the steering wheel and says any of a number of preset command phrases. The system responds to 832 command phrases, as well as to spoken city and street names. Sophisticated voice recognition technology allows the MDX owner to simply speak city and street names aloud, and the system responds by displaying matches from the available database.
When the "Talk" button is pressed, the audio system is automatically muted, and an overhead microphone receives the command from the driver. Commands can be given in plain English, like "Display gas stations," "Find nearest hospital," or "Find nearest Chinese restaurant." You can choose to display points of interest on the map (like restaurants, or ATMs, for example), or have the system provide turn-by-turn navigation - all by voice. The extensive point-of-interest database includes phone numbers that can be dialed by using the Bluetooth® HandsFreeLink® system and the driver’s compatible Bluetooth® cellular telephone.
The Acura Navigation System with Voice Recognition™ and AcuraLink® real-time traffic can also be controlled via the interface dial by choosing menu options or spelling out a word (e.g., an address, business name or place) using the interface dial to select characters from an on-screen keypad.
ACURALINK® SATELLITE COMMUNICATION SYSTEM WITH REAL-TIME TRAFFIC
The MDX with Technology and Sport Packages comes with the latest generation of the AcuraLink® Satellite Communication System with real-time traffic. AcuraLink® allows for 2-way communication between Acura and the vehicle, providing customers with the latest information specific for their vehicle. In cases where communication to and from the Acura server is needed, the owner’s Bluetooth®-compatible cellular telephone is used (once the owner has paired it with the vehicle and enabled its data-transmission function).
AcuraLink® messages consist of a displayed text plus full details via Text-To-Speech that can be heard over the MDX audio system. Each message is prioritized by importance. High priority messages are displayed immediately upon receipt. Other messages trigger an icon on the navigation display. In all cases, the MDX owner can choose to read the message immediately, or archive it to be read later.
A variety of messages can be viewed in the MDX, including Maintenance Minder™ system (detailed information regarding the next required maintenance), Quick Tips (information to help maximize the benefit and enjoyment of MDX features), Feature Guide (supplements to the Owner’s Manual), Diagnostic Info (detailed information and instruction should an onboard system issue arise), and Dealer Appointment Reminders. Depending on the message type, the owner may contact their dealer, Acura Roadside Assistance, or the Acura Client Assistance Center using their Bluetooth® phone directly from the message. The MDX owner has complete control over the types of messages received. All AcuraLink® preferences can be set via the Owner Link® web site.
Since the system allows 2-way data communication between the MDX and the Acura Server, AcuraLink® can provide the owner with vital information that previously has been unavailable. For example, if a "CHECK VSA SYSTEM" warning light should appear on the MDX instrument panel, AcuraLink® will automatically send a trouble code to the Acura server (if a paired phone is in range and the user has authorized data transmission), which interprets the code, then sends a message back to the MDX, such as "AcuraLink server results: VSA and TCS may not operate. Regular brakes work." This way, the owner knows if a particular fault is serious enough to cancel a trip, if it can be dealt with later or if it requires special driving techniques. AcuraLink® messages as well as the data connection are enabled even if the monthly XM® service package is not in effect.
Real-Time Traffic Information
The navigation screen can display up-to-the-minute traffic information including flow (traffic speed where available), accidents, incidents, construction and weather on freeways in 77 major metro areas. The information is aggregated by NAVTEQ™ from multiple sources including police and highway patrol accident reports and transportation departments and then transmitted by XM® Satellite Radio satellites to the MDX where it is graphically displayed on the navigation system.
MDX drivers can select an icon on the map to see incident details. Traffic information is continuously updated, allowing drivers to avoid congestion en route and choose the best path to their destination. The system gives MDX owners a useful timesaving tool on freeways. Unlike radio or television traffic reports, the AcuraLink® real-time traffic system provides a constant flow of relevant information reflecting conditions along a driver’s chosen route. AcuraLink® real-time traffic data services are offered on a subscription basis for a nominal fee following the 3-month free trial period. In addition to the on-screen traffic information, MDX owners who maintain their XM® service also receive more general audio traffic information that runs on a 2-3 minute loop in selected metropolitan areas.
DVD ENTERTAINMENT SYSTEM (Available with Technology or Sport Package)
The MDX is available with an Entertainment Package that features a rear display screen. With a 9-inch flip-down Thin Film Transistor (TFT) screen mounted in an overhead console, the system provides entertainment for the second and third row passengers. Audio plays through the MDX’s speakers in Dolby Digital surround sound via two wireless Personal Surround headphones and through three audio jacks. The system also includes a separate LCD control screen that makes operation clear and intuitive. An AUX input jack in rear of the center console is provided for video game play or other inputs. A 115-volt, 100-watt outlet inside the center console to provides power for a video game console, laptop computer or other small electronic device. The system also plays the audio content available from the MDX audio system, complete with on-screen information. The RES can also operate independently, allowing the rear passengers to enjoy one type of programming, while the front passengers listen to another. The Rear Entertainment System main controls and DVD player are built into the center section of the MDX instrument panel, just below the audio system. An illuminated and removable, wireless remote control is also positioned in the overhead console for easy operation by second- and third-row passengers.
Given the MDX’s performance goals, its powertrain and driveline were required to advance on multiple fronts. The result is one of the most powerful normally aspirated 6-cylinder SUV powerplants currently available in America. In addition, the MDX returns competitive fuel economy and meets tough EPA TIER 2 - BIN 5 and CARB LEV II ULEV emissions standards. To put the power to the ground and provide agile, responsive handling, the MDX has standard Super Handling All-Wheel Drive™ (SH-AWD®).
The MDX’s sophisticated 3.7-liter VTEC® V-6 powerplant develops 300 horsepower at 6,000 rpm and 275 lb-ft of torque at 5,000 rpm. The MDX returns an EPA fuel economy rating of 15/20 (city/highway) mpg.
Compared to the previous generation MDX, the 3.7L engine gains 47 horsepower and 25 lb-ft of torque. Of that gain, 20 horsepower came from an increase in displacement and a new 11.0:1 compression ratio and 15 more horsepower are due to new intake port shapes, valve design and VTEC® tuning. The final 12 horsepower is credited to the 3.7L MDX’s high-flow induction and exhaust systems. Although more powerful, the engine is actually 17.2 pounds (3.7-percent) lighter than the 3.5L engine it replaced. Durability upgrades throughout the powertrain, including a high capacity radiator with twin cooling fans and a standard transmission fluid cooler accommodate the MDX’s 5,000-pound tow rating.
A 5-speed automatic transmission with Sequential SportShift is standard, giving the driver the choice of fully automatic operation or manual shifting via a special shift gate. With the electronically controlled Drive-by-Wire™ throttle system and transmission working together to execute shifts, the MDX delivers smoothly responsive acceleration.
The MDX has standard SH-AWD®, an exclusive all-wheel-drive system that actively distributes the optimum amount of torque not only between the front and rear axles but also between the left and right rear wheels. The effect of such "torque vectoring" is reduced understeer, superior cornering accuracy and more total cornering performance. For the MDX, SH-AWD® is enhanced with hill logic which automatically adjusts the front/rear torque split based on hill grade.
The 3.7-liter VTEC® V-6 in the MDX is the largest production engine in Acura’s history and it incorporates many of the refinements and improvements that have been developed in other Acura powerplants. The MDX engine has a smooth-firing 60-degree V-angle, compact overall dimensions, and it sheds 17.2 pounds from previous generation 3.5L engine. Aluminum alloy block construction including special aluminum cylinder sleeves saves weight and improves cooling, while VTEC® compatible cylinder heads operate four valves per cylinder for maximum power output.
A high-flow intake system, high compression ratio, close-coupled catalytic converters and high flow exhaust team to help the MDX engine produce strong torque.
The MDX’s lightweight, heat-treated die-cast aluminum-alloy block has unique cast-in-place aluminum cylinder liners. These high-silicon sleeves dissipate heat better than traditional iron liners. The aluminum sleeves also allow a closer piston-to-cylinder clearance for lower operating noise. A mechanical etching process during manufacturing exposes silicone particles embedded in the aluminum sleeves, which provide a hard piston ring sealing surface. The block also incorporates a deep-skirt design for rigid crankshaft support and reduced noise and vibration.
The MDX uses a forged-steel crankshaft for high strength with minimum weight. With their raised crowns, the MDX pistons raise the compression ratio (relative to the previous MDX) from 10.0:1 to 11.0:1. This elevated compression ratio is possible due to an oil jet system that sprays cooling oil on the underside of the piston crowns to keep temperatures in check. Steel connecting rods are forged in one piece and then the crankshaft ends are "crack separated," creating a lighter and stronger rod with a perfectly fitted bearing cap.
CYLINDER HEADS / VALVETRAIN
Like other Acura V-6 engines, the MDX powerplant uses single overhead camshaft (SOHC) cylinder heads. These lightweight components are made of pressure-cast, low-porosity aluminum, and improve overall packaging, enhance exhaust flow and allow the optimal positioning of a primary close-coupled catalytic converter on each cylinder bank. To save weight and reduce parts count, an exhaust manifold is an integral part of each cylinder head casting. Magnesium cylinder head covers save a total of 2.6 pounds.
The MDX features lightweight camshafts. Assembled from tubular steel shafts with splined steel lobes and journals that are pressed in place, this unique style of camshaft design is a first for Acura.
The MDX’s intake port design has an optimized shape that contributes to the MDX’s 300 horsepower output. Intake valves are 36mm in diameter (an increase of 1mm over the previous engine design), yet weigh 13-percent less due to a reduction in material in the valve head. The exhaust valves measure 30mm in diameter.
To ensure positive sealing, a 3-layer shim-type head gasket is used. A single Aramid-fiber reinforced belt drives the overhead camshafts.
VTEC® (VARIABLE VALVE TIMING AND LIFT ELECTRONIC CONTROL)
The MDX’s VTEC® (Variable Valve Timing and Lift Electronic Control) operates the 12 intake valves in two distinct modes. Operation of the intake valves changes to optimize both volumetric efficiency and combustion of the air/fuel mixture. At low engine speeds, the intake valves have low lift and are open a comparatively short period of time during cylinder filling. At high engine speeds where breathing is critical, the valves switch to a high-lift, long duration mode to deliver improved volumetric efficiency. The VTEC® changeover point occurs at approximately 4,500 rpm and is virtually undetectable to the driver.
When the engine reaches the VTEC® changeover point, the powertrain control module (PCM) triggers the opening of an electric spool valve that routes pressurized oil to small pistons located in the intake valve rocker arms. The pistons slide into position to lock together the three intake rockers for a given cylinder, which then follow a single high-lift, long-duration camshaft lobe.
HIGH FLOW INDUCTION SYSTEM
To improve engine breathing and engine sound, particularly at high rpm and large throttle openings, the MDX has a low-restriction intake manifold system. With a large diameter inlet, a pair of resonators and a low-restriction air filter element, the 3.7L MDX induction system flows an additional 14-percent more than the previous 3.5L system.
DRIVE-BY-WIRE™ THROTTLE SYSTEM
The MDX doesn’t use a conventional throttle cable, but instead has smart electronics that connect the throttle pedal to the electronic throttle-body. A programmed "gain" between throttle pedal and engine offers better drivability and optimizes engine response to suit driving conditions. The throttle profile of the new MDX provides low speed control, followed by progressively building response at higher speed for improved linearity.
The Drive-by-Wire™ throttle system evaluates the driving conditions by monitoring throttle pedal position, throttle-body opening position, road speed, and engine speed. This information is used to define the throttle control sensitivity. This gives the MDX throttle pedal a predictable and responsive feel that better meets driver expectations.
PROGRAMMED FUEL INJECTION (PGM-FI)
The MDX features a Multi-Point Programmed Fuel Injection (PGM-FI) system that continually adjusts the fuel delivery to yield the best combination of power, low fuel consumption and low emissions. Multiple sensors constantly monitor critical operating parameters such as throttle position, intake air temperature, coolant temperature, ambient air pressure, intake airflow volume, intake manifold pressure, exhaust-air ratios and the position of the crankshaft and cams.
2-PIECE DUAL-STAGE INTAKE MANIFOLD
The MDX uses a dual-stage intake manifold that is designed to deliver excellent airflow to the cylinders across the full range of engine operating speeds. The 2-piece manifold is also very light due to its cast magnesium design. The light-weight manifold combines with the new exhaust system to contribute 12 horsepower to the MDX’s 300 horsepower total.
The induction system significantly boosts torque across the engine’s full operating range by working in concert with the VTEC® valvetrain. Internal passages and two butterfly valves within the intake manifold are operated by the powertrain control module (PCM) to provide two distinct modes of operation by changing plenum volume and intake airflow routing.
At lower rpm these valves are closed to reduce the volume of the plenum and effectively increase the length of inlet passages for maximum resonance effect and to amplify pressure waves within each half of the intake manifold at lower rpm ranges. The amplified pressure waves significantly increase cylinder filling and torque production throughout the lower part of the engine’s rpm band.
As the benefits of the resonance effect lessen with rising engine speed, the butterfly valves open at 3,800 rpm to interconnect the two halves of the plenum, increasing its overall volume. An electric motor, commanded by the PCM, controls the butterfly valves. The inertia of the mass of air rushing down each intake passage helps draw in more charge than each cylinder would normally ingest. The inertia effect greatly enhances cylinder filling and the torque produced by the engine at higher rpm.
DIRECT IGNITION AND DETONATION/KNOCK CONTROL
The MDX’s powertrain control module (PCM) monitors engine functions to determine the best spark timing. An engine-block-mounted acoustic detonation/knock sensor "listens" to the engine, and based on this input, the PCM retards the ignition timing to prevent potentially damaging detonation. The MDX has a coil unit for each cylinder that is positioned above each spark plug’s access bore.
CLOSE-COUPLED CATALYSTS AND VARIABLE FLOW EXHAUST SYSTEM
The exhaust manifolds of the 3.7L V-6 are cast directly into the aluminum cylinder heads to reduce weight and to put the engine’s two primary catalytic converters as close as possible to the combustion chambers. The 600-cell per-square-inch, high-efficiency catalytic converters mount directly to the exhaust port of each cylinder head for extremely rapid converter light-off after the engine starts — thus lowering emissions output. A significant weight savings and reduction in parts count is realized by eliminating a traditional exhaust manifold and converter design.
Downstream of the close-coupled catalysts, a hydroformed 2-into-1 collector pipe carries exhaust gases to a single secondary catalytic converter located under the passenger cabin. This high-flow unit has a revised shape and a large 62mm outlet. Downstream of the underfloor catalyst, the system splits flow into a pair of underfloor chambers (the previous MDX used a single chamber) to give the exhaust note a more refined sound. Dual silencers near the rear fascia incorporate an exhaust pressure-activated valve to balance the engine’s need for proper exhaust backpressure at low rpm and free flow at high rpm. With the valve in each silencer closed, the exhaust sound level is muted for quiet cruising. When exhaust flow increases sufficiently due to high rpm and a large throttle opening, the silencer valves open and provide a secondary exit path inside the silencer chamber. In total, the MDX’s exhaust system refinements substantially improve flow potential.
The 2009 MDX meets tough EPA TIER 2 - BIN 5 and CARB LEV II ULEV emissions standards, and per regulations, is certified to this level of emissions performance for 120,000 miles.
A number of advanced technologies are factors in this excellent emissions performance. The cylinder-head-mounted close-coupled catalysts light off quickly after engine start up, and a 32-bit RISC microprocessor in the powertrain control module (PCM) boosts computing power to improve the precision of spark and fuel delivery. In particular, right after startup, better fuel atomization is provided by the high-efficiency multi-hole fuel injectors that more accurately deliver fuel to each cylinder.
The MDX’s Multi-Point Programmed Fuel Injection (PGM-FI) system monitors the state of the exhaust gas and tracks multiple engine inputs including intake manifold pressure, throttle position, intake air temperature, coolant temperature, and such. Based on these inputs PGM-FI continuously adjusts and optimizes the amount of fuel delivered to each cylinder.
ONE-TOUCH STARTER SYSTEM WITH HIGH-POWERED STARTER
To ensure consistent starting, the MDX has a one-touch starter system that maintains starter engagement until the engine starts, even if the driver releases the ignition switch.
AIR CONDITIONER SYSTEM EFFICIENCY
To provide greater driving range while maintaining a comfortable interior climate, the MDX has excellent air conditioner efficiency. By partially mixing cool cabin air with fresh air in the blower, the amount of compressor operation can be reduced by up to 40-percent compared to operating exclusively on exterior air. Over the course of a tank of fuel, this partial recirculation mode can extend fuel economy by as much as 4-percent. This function operates automatically when the HVAC system is in Auto mode.
NOISE, VIBRATION AND HARSHNESS CONTROL
The MDX powerplant is exceptionally smooth thanks to its 60-degree cylinder V-angle and compact, rigid and lightweight die-cast aluminum cylinder block. A forged crankshaft, die-cast accessory mounts and a stiff cast-aluminum oil pan also help reduce noise and vibration.
5-SPEED AUTOMATIC WITH SEQUENTIAL SPORTSHIFT AND GRADE LOGIC CONTROL
The MDX has a standard 5-speed automatic with Sequential SportShift and Grade Logic Control to maximize acceleration performance, fuel economy and driver control. Compared to the previous generation MDX, this sophisticated transmission features lower gear ratios for improved acceleration and towing power, upgraded shafts, gears, bearings and clutches to match the engine’s greater power output and increased cooling capacity to accommodate the MDX’s 5000-pound towing capacity.
Designed for a high level of durability and low maintenance, the MDX transmission has a strengthened aluminum case that carries both high-torque clutches and high-strength gears. A transmission cooler is positioned in the front of the MDX to help keep the transmission fluid temperature within tolerance, particularly when towing.
The Sequential SportShift 5-speed transmission can be operated in conventional fully automatic mode via a console-mounted shifter. The Grade Logic Control System and Shift Hold Control are integrated into the shift programming to reduce gear "hunting" and unnecessary shifting.
While traveling uphill or downhill, Grade Logic Control alters the transmission’s shift schedule, reducing shift frequency and improving speed control. Throttle position, vehicle speed and acceleration/deceleration rate are continuously measured, then compared with a map stored in the transmission computer. When the system determines the MDX is on a hill, the shift schedule is adjusted to automatically hold the transmission in a lower gear for better climbing power or increased downhill engine braking.In spirited windy road driving, where the throttle is quickly released and the brakes are applied (as might be the case when decelerating to enter a corner), Shift Hold Control prevents upshifts to higher gears (4th and 5th). This reduces disturbance to the chassis and ensures abundant power is immediately available without a downshift. On curving roads, Shift Hold Control significantly improves throttle responsiveness and reduces unnecessary shifting.
The Sequential SportShift transmission can be shifted into manual mode by moving the console-mounted gear selector lever laterally to a special gate to the left of the "Drive" position. When in manual mode, a forward push of the selector lever commands an upshift, while a rearward pull commands a downshift. The current transmission gear is shown in a digital display within the tachometer face. To heighten control and driver involvement, special shift logic in manual mode delivers quicker, firmer shifts than in fully automatic mode.
An array of features are active when the transmission is in manual mode to help protect the engine and drivetrain from inadvertent damage. The ECU cuts off fuel flow to the engine if there is a possibility of over revving. In the rare situation where the fuel cutoff alone is unable to prevent engine over revving (as could happen on a steep downhill) the transmission will upshift itself to prevent engine damage. Also, when downshifting, the transmission won’t execute a driver-commanded downshift that would send the engine beyond redline in the lower gear. Regardless of the selected ratio, the Sequential SportShift transmission will automatically downshift to first gear as the vehicle comes to a stop thus preventing pulling away from a stop in a higher gear.
5-POSITION SHIFT GATE
The MDX has an intuitive 5-position shift gate that simplifies the operation of the transmission. When operated in automatic mode, the transmission allows the driver to choose D (1st through 5th gear) or D3 (1st through 3rd gear). The D3 position selects only the first three gears for increased engine braking or reduced shifting during city driving.
COOPERATION BETWEEN 5AT AND DRIVE-BY-WIRE
Both shift speed and smoothness are improved by cooperation between the Drive-by-Wire™ throttle system and the electronically controlled automatic transmission. Since the engine can be throttled by the engine management system during upshifts and downshifts, the function of the engine and transmission can be closely choreographed for faster, smoother shifting. As a result, the peak g-forces (or "shift shock") are reduced significantly during upshifts and downshifts.
SUPER HANDLING ALL-WHEEL DRIVE™
The MDX has Super Handling All-Wheel Drive™ (SH-AWD®) as standard equipment. This innovative full-time all-wheel-drive system actively distributes the optimum amount of torque not only between the front and rear axles but also between the left and right rear wheels. This "torque vectoring" improves cornering traction and steering precision by creating a yaw moment that helps the MDX turn. In addition to providing exceptional performance on dry pavement, the MDX’s SH-AWD® system provides significant performance gains in snow and ice, as well as similar gains in off road performance. In fact, the SH-AWD® system knows when it is going up a hill and automatically shifts torque to the rear to improve launch traction - done before the vehicle starts to move.
SH-AWD® enhances stability on snow and ice in cooperation with the MDX’s VSA® system. During acceleration and cornering, SH-AWD® first maximizes available traction by "preemptively" moving torque to the wheels with the maximum load. However, if the available traction limits are exceeded, the SH-AWD® system can directly modify the drive torque distribution to stabilize acceleration and reduce the potential for oversteer.
Effect of SH-AWD®
By overdriving the MDX’s rear wheels up to 1.7-percent faster than the speed of the front axle, SH-AWD® can provide a "yaw moment" while accelerating into and through tight corners. The torque vectoring ability of SH-AWD® to directly create a yaw moment to allow the vehicle to track exactly as the driver intended is called Direct Yaw Control. This reduces unwanted understeer (or vehicle "push") during everyday driving and when the driver chooses to go for a spirited drive on a favorite stretch of mountain road.
Up to the available traction limits, direct yaw control delivers an uncanny level of precision and driver confidence. Since direct yaw control acts preemptively, VSA® brake and throttle interventions are less intrusive. In changing and challenging road conditions, SH-AWD® reacts to adjust drive torque more quickly than the VSA® can apply stabilizing brake torque.
During acceleration and cornering on slippery surfaces, a conventional 4WD vehicle distributes torque evenly between the two rear wheels. This may lead to loss of traction of the inside rear wheel as load is transferred to the outside wheel due to load transfer during cornering. However with SH-AWD® the side-to-side rear torque distribution varies according to the lateral g (and associated load transfer of the rear tires). For all situations including low-traction roads, the side-to-side torque distribution is naturally aligned with the tire vertical loads. This enhances traction and allows maximum utilization of the available road surface grip during acceleration and cornering.
Electronic Controls and Parameters - VSA®
Vehicle Stability Assist™ (VSA®) is included as standard equipment on the MDX. By continually monitoring the vehicle’s operating parameters (such as road speed, throttle position, steering wheel position, accelerating, braking and cornering loads), VSA® anticipates if the vehicle is approaching oversteer or understeer. To help correct either of these situations, VSA® first acts to transfer torque bias to the axle with the most traction. This preventative measure significantly reduces the number of brake and throttle interventions. The response is so quick that the instability may be corrected even before the driver knows it is occurring. Traction Control is integrated into the VSA® which helps the MDX accelerate smoothly on slippery surfaces. The VSA® can request the SH-AWD® to adjust its torque level, thus allowing direct yaw control of the MDX to maximize stability under all driving conditions.
SH-AWD® System Layout
The MDX’s SH-AWD® system is closely related to the system in the 2009 RDX. (The system in the RL sedan differs mechanically between the RDX and MDX systems, but is similar in principle.) A torque transfer unit is bolted directly to the front-mounted transaxle. Attached to the front differential’s ring gear is a helical gear that provides input torque to the transfer unit. A short horizontal shaft and a hypoid gear set within the case send power to the propeller shaft, which in turn carries it to the rear drive unit. The MDX rear axle is designed to turn up to 1.7-percent faster than the front axle.
Direct Electromagnetic Clutch Systems
Located on either side of the hypoid gear that drives the rear axle, two identical direct electromagnetic clutch systems control the amount of drive torque that reaches each rear wheel. These clutch systems can be controlled as a pair to alter the front/rear torque split or can be controlled independently to allow up to 100-percent of the total rear axle torque to go to one side of the vehicle. The fast acting clutches coupled with smart control logic means traction is maximized in most conditions, without the need for driver intervention.
An electric coil controls the pressure in each clutch device. The amount of available rear axle torque transmitted to each rear wheel can vary continuously, ranging between zero and 100-percent, depending on the conditions. Since the clutches are electromagnetically operated, the amount of drive torque delivered to each rear wheel can be controlled quickly and precisely, reducing wheel slip in low traction conditions.
The clutch packs and friction material are specially designed for the small amount of continuous slip between front and rear axles (created by the 1.7-percent speed differential), while ensuring the expected level of Acura durability. An oil-temperature sensor allows the ECU to estimate the clutch plate coefficient of friction (which changes with heat) in each clutch pack and then adjusts the current sent to the electromagnetic coil that controls the compensation of each clutch. To ensure that the amount of torque transmitted remains optimized as miles accumulate a coil provides a feedback loop that the ECU uses to adjust current to the electromagnetic clutches to compensate for clutch wear.
MAINTENANCE MINDER™ SYSTEM
An Maintenance Minder™ system monitors the vehicle’s operating conditions to eliminate unnecessary service visits while ensuring that the vehicle is properly maintained. When the Maintenance Minder™ system determines that maintenance is required, the driver is alerted via a series of messages on the Multi-Information Display (MID). The alerts occur well in advance of required maintenance for scheduling convenience.
This resettable system indicates when maintenance is due on many normal service parts and systems, including oil and filter change, tire rotation, air cleaner, automatic transmission fluid, parts replacement and more. The MID monitors operating conditions such as oil and coolant temperature along with total engine rotations to determine the proper service intervals. Maintenance alerts are presented when the ignition is first turned on, not while driving, unless an urgent need arises. The driver can also check the remaining oil life at any time through the MID.
From its inception the MDX targeted the dynamics and driving feel of its strongest European competitors. The essential elements of this engineering goal included steering, suspension, braking and overall dynamic performance, as well as noise, vibration and harshness (NVH) control.
At the beginning of MDX development, engineers tested European luxury SUV competitors including the BMW X5 , Mercedes-Benz ML350, Porsche Cayenne and Volvo XC90. These experiences provided real-world understanding of how these luxury SUVs functioned in everyday driving on their "home turf." Although later development testing was conducted in the United States, the DNA of the MDX was largely formed in Europe.
One essential tool that Acura used was the famed Nürburgring Nördschleife road circuit in Germany. This 13-mile course contains over 170 corners, numerous altitude changes and is considered the toughest natural road course in the world. Engineers used the Nürburgring as a "weakness finder" because it quickly exposes problems with a vehicle’s dynamics, making them easier to identify and fix.
In order to build in a combination of increased handling agility, increased stability and comfort, the current MDX’s wheelbase, tread width, and suspension technology were changed from the first-generation MDX. Engineers changed the lift and squat characteristics of the suspension to provide a flatter takeoff. Thanks to its extended wheelbase together with SH-AWD®, the 2009 MDX offers both exceptional high-speed stability and responsive handling.
The entire front chassis area was tuned to provide the best balance of handling precision, road isolation, and impact after-shake damping. MacPherson struts with inversely wound coil-over springs and forged-aluminum lower control arms reduce unsprung weight, while the front subframe "floats" on rubber mounts to provide road and engine isolation. The front suspension also uses newly developed hydro-compliance bushings to provide superior ride isolation as well as chassis vibration control. Suspension and engine mounts are specifically tuned to provide minimum vibration transfer to the occupants, and the front struts employ internal rebound springs to improve ride and handling. Anti-dive properties were revised to improve impact harshness and ride comfort.
The MDX’s rear suspension is a multi-link design mounted on a separate steel subframe. Squeeze-cast aluminum uprights (or "knuckles") reduce unsprung weight for improved response, while revised trailing-arm mounting points (compared to the previous MDX) reduce body squat during acceleration. Coil springs, dampers and an anti-roll bar are tuned for the optimum combination of ride and handling.
Rear subframe mounts and lateral control link bushing rates were significantly revised to create a discrete level of lateral force steer at the rear axle. Since the SH-AWD® system constantly varies drive torque at the rear axle, the longitudinal and lateral force steer properties were carefully developed for optimum response, stability and consistency.
ACTIVE DAMPER SYSTEM
Included with the optional Sport Package, the Active Damper System gives the MDX an elevated level of handling precision designed to satisfy the most discriminating drivers, while maintaining a smooth and controlled ride. Acura considered all of the available technologies before choosing electronically controlled, fast-acting Magneto-Rheological fluid dampers as the ideal technology to maximize ride comfort and handling in one integrated system.
The overall goal of the Active Damper System is to achieve outstanding levels of handling response while maintaining refined levels of ride comfort. This allows the driver intuitive vehicle control in a relaxed environment - free from neck straining head toss and other sudden vehicle motions. This is made possible by the quick response of the dampers and by the computer algorithms that keep the dampers a step ahead of the actual body movements.
Advantages of the Active Damper System include:
- Flat cornering feel with minimal body roll or pitch — even during spirited driving
- Responsive, precise and secure steering feel
- Elimination of unwanted under-damped body heave, roll and pitch motions
- Improved tire adhesion, vehicle stability and road isolation
Real-Time Damper Control
The secret to the MDX’s Active Damper System is its fast-acting shock absorbers. These dampers are built and tuned specifically for the MDX and offer the ability to individually adjust from minimum to maximum damping force in as little as five milliseconds (0.005 seconds). This ability hinges on the principle of electromagnetic induction. Each damper carries a unique coil that generates an electromagnetic field when current is passed through it. Proprietary damper fluid contains microscopic (on the order of 10 microns in diameter) ferric spheres that align when surrounded by the electromagnetic field, dramatically and instantly changing the effective fluid viscosity. Not only is the overall range of damping force available significantly more than that of a conventional damper, but there are hundreds of damping steps within that range.
The current that passes through the field coils is controlled by an electronic control unit (ECU) that uses special algorithms to determine the best damper setting for the road conditions. This, combined with nearly instantaneous reaction time of the dampers, allows damping control to occur before the vehicle’s tires or body are allowed to have any extraneous motion.
The Active Damper System will operate with low damping when the road is smooth and level and the vehicle is being driven at a constant speed. Such limited damping further reduces the amount of vibration and harshness that passes from the suspension to the body thus quieting and improving the vehicle’s ride quality.
Using the dampers’ 5-millisecond response time, the Active Damper System reacts to sudden changes in driver or road inputs. The high damping force achieved in this short time allows the dampers to aid the springs and stabilizer bars in roll and pitch control, greatly improving the handling of the MDX.
The result of the improved transient handling, road isolation, and body control is that the MDX with the Active Damping System noticeably reduces the driver’s workload when compared to other performance-oriented SUVs. The system is able to achieve the benefits of a sporty suspension without the traditional ride comfort tradeoffs. The overall benefit is more enjoyment, better control and less fatigue over the long haul.
Sport or Comfort Mode
The Active Damper System provides two driver-selectable settings - Sport and Comfort. Sport mode prioritizes handling response, vehicle body control and tire adhesion to allow for spirited driving with high levels of precision and composure. Comfort mode allows for a more relaxed driving experience by prioritizing road isolation and reduced passenger fatigue caused by road inputs. Either Sport or Comfort mode can be used in any type of operating conditions as preferred by the driver.
The Active Damper system maintains the same quality, durability and performance as all other Acura components, does not require any special maintenance and has no scheduled replacement interval.
POWER RACK & PINION STEERING
Of the luxury SUVs that Acura targeted in developing the MDX, the BMW X5 3.0i offered the best steering quality. Acura set out to exceed the BMW’s combination of linearity, precise feel and security at high speed with using torque-sensing, variable power-assist rack-and-pinion steering.
Acura engineers spent considerable energy studying steering "on-center" feel in an effort to elevate the quality of steering feedback the driver receives. Beyond offering the correct steering effort level, the MDX provides subtle transient steering feedback that is an integral part of its subjective handling quality. Notable geometry changes include increasing the rake and trail over the previous MDX to provide a stronger steering feel.
WHEELS AND TIRES
The 2009 Acura MDX has standard 18x8-inch 5-spoke aluminum wheels with P255/55R18 104H M+S all-season tires. The tires were specially developed for the MDX by Bridgestone and Michelin and offer a significant traction improvement in dry and wet conditions, while maintaining the previous MDX’s level of snow/ice traction. Michelin P275/45R19 summer tires are also available with the Acura accessory 19-inch aluminum alloy wheels.
Acura designers purposefully moved the wheels and tires to the high end of the competitive set. In 2009, the MDX has larger tires than all of its base-level AWD/4WD competitors and it is the only vehicle in the group with standard 18-inch tires.
4-WHEEL DISC BRAKES
The 4-wheel disc brakes on the 2009 MDX are the largest brake system ever featured on a production Acura vehicle. The brake system is engineered to provide best-in-class braking capability in dry conditions, as well as while driving in rain, snow or icy conditions.
Engineers benchmarked the existing MDX as well as the top competitors including BMW X5 and Porsche Cayenne for braking performance and pedal feel. The 2009 model has short pedal travel and firm pedal feel, in keeping with the direct feel that enthusiast drivers want. The ventilated front brake rotors are 13-inches in diameter with a thickness of 1.1-inches, while the solid rear rotors are 13.2-inch diameter units with a thickness of 0.43-inches. Dual-piston cast iron brake rotors are used in front and single-piston cast iron calipers are fit in back.
The MDX brake design is validated by a severe fade test utilized by the German enthusiast magazine Auto Motor und Sport and by rigorous testing at the Nürburgring.
VEHICLE STABILITY ASSIST™ (VSA®) WITH TRACTION CONTROL
Vehicle Stability Assist™ (VSA®) is included as standard equipment. By continually monitoring the vehicle’s operating parameters (such as road speed, throttle position, steering wheel position along with acceleration, braking and cornering loads), VSA® anticipates if the MDX is approaching oversteer or understeer. To help correct either of these situations, VSA® first acts to transfer torque bias to the axle with the most traction. This preventative measure significantly reduces the number of brake and throttle interventions. The response is so quick that the instability may be corrected even before the driver knows it is occurring. Traction Control is integrated into the VSA®, and it helps the MDX accelerate smoothly on slippery surfaces. In addition, the VSA® can request the SH-AWD® to adjust its torque level - thus allowing direct yaw control of the MDX to maximize stability under most all driving conditions.
TIRE PRESSURE MONITORING SYSTEM (TPMS)
An onboard Tire Pressure Monitoring System (TPMS) warns the driver if the air pressure decreases significantly in any tire. The system helps reduce the chance of damaging a tire or losing control of the vehicle due to low air pressure. This is important because a slow leak, such as one that might be caused by a nail or road debris, might not be easily detectable but could cause loss of grip and potentially, a blowout.
TPMS uses a sensor mounted on each wheel that continually monitors tire pressure and sends a coded signal to the TPMS electronic control unit (ECU). The process begins with a signal initiator located inboard of each tire on the chassis. The initiator sends a unique signal for each TPMS sensor. Then the TPMS sensor sends tire pressure data to the TPMS ECU, which compares the values for each tire’s pressure against an acceptable range of pressures.
When a tire’s pressure drops significantly below the proper level, a "check tire pressure" alert will appear on the Multi-Information Display (MID) alert screen. The system can display the air pressure in all four tires simultaneously via the MID, making it simple to locate a low-pressure tire.
At the driver’s preference, the MID can continually show the air pressure in all four tires. Regardless of whether the driver chooses to monitor the pressures, a warning will still occur if a tire drops below specification.
Acura took thorough measures to ensure that off-road enthusiasts would be satisfied with the MDX. The vehicle meets design criteria developed for the original MDX, which was based on research at different off-road areas across the country. This research was the foundation for specific minimum performance criteria for the new MDX, including travel through standing water nearly 19-inches deep, steep approach and departure angles (28-degrees front and 23-degrees rear), rocks, off road and paved grades up to 60-percent. Components located underneath the vehicle are tucked away to avoid damage in off-highway driving and the evaporative canister is protected by a high-strength steel guard.
The high-torque V-6 engine, SH-AWD® system with hill logic and computer-controlled traction capabilities help the MDX meet typical off-road challenges without the need for low-range gears. The MDX outperforms its predecessor without the need for a driver-selected 4WD "lock" mode.
SNOW AND ICE CAPABILITY
The same technologies that make the MDX capable off-road also enhance its performance in snow and ice. The SH-AWD® system with grade logic and computer-controlled traction capabilities work together with the standard M+S tires to maximize grip and driver control during winter driving conditions.
NOISE, VIBRATION & HARSHNESS (NVH)
The MDX uses an array of technologies to reduce noise, vibration and harshness (NVH) in the passenger cabin. Acura began by attacking vibration in the body during the engineering phase instead of simply adding materials to the body to damp it out later. Two examples of this process are new rear suspension mounting points, which are now attached to the unit body for greater rigidity and reduced vibration, and the stiffening of the front and rear subframes, which allowed the mounting bushings to be made softer.
Engineers paid strict attention to addressing two specific issues - concrete road noise and drumming - neither of which is acceptable to luxury customers. By nature SUVs are susceptible to drumming noises in the cabin interior because of their large open area. Where necessary, meltsheets are used in critical areas on the front bulkhead and floor, and lighter insulators are used on the bodysides, doors and roof. A new hybrid carpet and padding system further reduces noise intrusion by balancing the transmission loss and absorption properties of the carpet.
To verify that the results were on target, engineers dynamically shook the MDX body and measured vibration by scanning with lasers the floor to find the "hot spots". This provided exact information on where to focus efforts. As a result, the MDX is 20-percent stiffer and quieter than the previous version, registering just 64 dBA at 60 mph.
With a towing capacity of 5,000 pounds the MDX can tow a boat or camper trailer with equal confidence. Standard towing equipment includes a high-capacity radiator with twin 160-watt fans, an automatic transmission fluid cooler, a heavy-duty power-steering cooler and pre-wiring for an electric brake controller. A Towing Package is available as dealer-installed accessory and includes a hitch, receiver, ball and wiring harness.
One of Acura’s durability tests was towing a 5,000-pound trailer in Death Valley National Park during summer, including climbs up steep Townes Pass and Daylight Pass with outside air temperatures between 113º and 120º F. Testers also targeted the toughest boat ramp they could find - at Shasta Lake in Northern California. The ramp is extremely steep, and its length varies depending on the lake level. They also proved the MDX trailer-pulling skills elsewhere in California as well as in Kentucky and West Virginia.
TRAILER STABILITY ASSIST
Every 2009 MDX comes with standard Vehicle Stability Assist™ (VSA®) that includes special Trailer Stability Assist algorithms. Trailer Stability Assist interprets oscillation (or wag) in the vehicle/trailer combination while driving. This may occur if the trailer is not loaded correctly, or under certain speed and road conditions. Using a combination of torque reduction and individual brake application, Trailer Stability Assist activates to stabilize the vehicle after sensing oscillations of the vehicle and trailer system.
The 2009 Acura MDX continues the MDX’s commitment of advancing SUV safety. Standard features include dual-stage, dual-threshold front airbags, active head restraints for driver and front passenger, side curtain airbags and driver knee bolsters. In addition, the MDX features the Advanced Compatibility Engineering™ (ACE™) body structure, designed to disperse frontal collision forces and improve car-to-car collision safety.
Acura engineers term this compendium of safety features as "360 degree safety" as quite literally passengers are completely surrounded with safety features. The 2009 MDX meets the highest crash-test standards from the National Highway Traffic Safety Administration (NHTSA) and Insurance Institute for Highway Safety (IIHS).
CRASH PERFORMANCE TARGETS
The 2009 MDX passed all National Highway Traffic Safety Administration (NHTSA) and Insurance Institute for Highway Safety (IIHS) tests at the highest levels. NHTSA tests include NCAP frontal crash, SINCAP side impact, and Rollover Resistance, while IIHS tests include Frontal Offset, Side Impact (also known as SICE), and Rear Crash Protection indexes.
NHTSA test results:
- NCAP Driver - 5-Star
- NCAP Passenger - 5-Star
- SINCAP Front seat - 5-Star
- SINCAP Rear seat - 5-Star
- Rollover Rating - 4-Star
IIHS test results:
- IIHS Frontal Offset - GOOD
- SICE Side Impact - GOOD
- IIHS Rear Crash Safety - GOOD
- IIHS TOP SAFETY PICK
OFFSET REAR COLLISION
The new requirements for NHTSA’s FMVSS 301 include a more severe rear crash test. In the current test, a 3,015 pound deformable barrier sled strikes 70-percent of the vehicle’s width at 50 mph. In contrast, the previous FMVSS 301 used a 4,000 pound flat rigid moving barrier that struck the full width of the vehicle at 30 mph. The new test requires that the vehicle absorb more crash energy than before.
As the popularity of small size vehicles has soared recently, so has the risk of these large vehicles colliding head-on with smaller vehicles. The disparity in vehicle mass - as well as the higher bumper height of the larger vehicles - put the smaller vehicles at a disadvantage. For the MDX, however, engineers integrated a more stringent internal vehicle-to-vehicle collision standard to help correct this discrepancy.
ADVANCED COMPATIBILITY ENGINEERING™ (ACE™)
Like all 2009 Acura models, the MDX features Advanced Compatibility Engineering™ (ACE™) body design. ACE™ more evenly distributes frontal crash forces to help reduce cabin intrusion and deformation as well as to help absorb frontal crash energy forward of the passenger cabin. ACE™ also helps maintain the structural integrity of the passenger cabin during a severe car-to-car offset frontal crash. ACE™ does this by distributing forces through multiple load paths during the crash, thus allowing more uniform energy absorption and less cabin intrusion.
If the MDX should collide head-on with a smaller and lighter vehicle, ACE™ helps provide good engagement of the small vehicle’s frame. This helps reduce the risk of intrusion while simultaneously helping to disperse the crash energy across a wider area at the front of the vehicle. The upper portions of the ACE™ front structure also improve cabin protection.
IIHS SIDE IMPACT CRASHWORTHINESS EVALUATION (SICE)
The 2009 MDX achieves a "GOOD" rating in the rigorous IIHS Side Impact Crashworthiness Evaluation (SICE) evaluation, which measures how well a vehicle withstands intrusion from a large SUV in a side collision. The MDX’s high-strength steel safety cage and the use of high-strength side door beams help make it resistant to intrusion.
ACTIVE FRONT HEAD RESTRAINTS
The 2009 MDX is fitted with active front head restraints designed to help reduce the likelihood of neck injuries in the event of a rear impact. The head restraint is mechanically linked to a lumbar plate located inside of the front seatback. In a rear impact, the passenger’s body pushes against the seatback, causing the head restraint to move forward in a carefully prescribed arc. This motion helps equalize the impact forces transmitted to the head, neck and spine as the occupant’s head moves backward during the collision. Effectively managing and dispersing this energy is critical to help reduce the likelihood of injuries.
PEDESTRIAN INJURY MITIGATION
Acura’s safety interests extend beyond care for vehicle occupants. The MDX hood area is specially designed to deform if contact is made with a pedestrian. Underneath the hood are energy-absorbing supports and hood hinges, the windshield-wiper pivots are a breakaway design and the front fender brackets are also designed to bend if a collision with a pedestrian should occur. Research shows that features such as these dramatically improve a pedestrian’s chance of survival if struck by a moving vehicle.
SEATBELT AUTOMATIC TENSIONING SYSTEM AND LOAD LIMITERS
Both of the MDX front seat belts have an automatic tensioning system with load limiters to help protect the driver and front passenger in a collision. Research has shown that seat belts that are snugly secured around the occupants provide better protection, so in the first few milliseconds of a collision the tensioners - powered by a pyrotechnic device - automatically tighten the front seat belts. Then if the deceleration forces rise above a predetermined threshold, the load limiter releases a small length of seatbelt webbing to reduce the pressure on the occupant in a controlled manner. This helps reduce the injuries that seatbelts can cause in a severe high-speed collision. In addition, the driver’s seatbelt has a dual-stage load limiter. This provides a higher initial load, then steps down to a lower load after a certain amount of belt spools out. It is specially designed to prevent too much forward driver movement, given the close proximity of the steering wheel.
DRIVER AND FRONT PASSENGER DUAL-STAGE, DUAL-THRESHOLD AIRBAG SUPPLEMENTAL RESTRAINT SYSTEM (SRS)
Dual-stage airbags are provided for the 2009 MDX driver and front passenger. These airbags are designed to maximize protection for the head and chest during a moderate to severe front collision. Each airbag inflator has two stages that can be deployed at different times instead of a traditional single inflation stage. Combining dual-stage and dual-threshold technology with technology that detects if the occupants are belted or unbelted, the airbags are deployed in a sequence based on crash severity.
Dual-Stage, Dual-Threshold Airbag Parameters
- Airbag deployment characteristics are finely controlled depending on the severity of a collision
- The dual-stage, dual-threshold strategy applies to front airbags only and does not affect operation of side airbags or side curtain airbags
The MDX airbag system uses a seat weight sensor to assess the weight of the front passenger. The front passenger airbag is shut off if the weight sensor indicates that a small child or a baby carrier is occupying the front seat. A seamless instrument panel cover fully conceals the passenger airbag. The driver’s seat has a seat position sensor. If the seat is in a more forward position, where the occupant will be close to the airbag, the airbag is fired with a longer delay to reduce the chance of any injury caused by the airbag itself. The driver-side airbag is located in a small steering wheel mounted housing.
DRIVER AND FRONT PASSENGER KNEE BOLSTERS
To help prevent injuries to the driver or front passenger’s legs in a frontal collision, the 2009 MDX has energy absorbing knee bolsters. They are designed to help dissipate collision forces if the driver or front passenger’s legs should contact the lower instrument panel during a frontal collision. In addition, the driver’s side has dual-density knee bolsters that are designed to provide additional protection to small-stature occupants who have to sit close to the steering wheel.
DRIVER AND FRONT PASSENGER SIDE AIRBAGS WITH FRONT PASSENGER OCCUPANT POSITION DETECTION SYSTEM (OPDS)
Side airbags mounted in the outboard area of each MDX front seatback are designed to provide upper torso protection in the event of a severe side impact. In addition, the front passenger’s seat is equipped with Occupant Position Detection System (OPDS), an innovative system designed to deactivate the side airbag if a small child (or small-stature adult) leans into the side airbag deployment path. When the passenger returns to an upright seating position, the side airbag reactivates so it can deploy to help protect the occupant in a side impact. This unique system utilizes sensors in the passenger seatback to determine the height and position of the occupant, and determine if it is safe to deploy the side airbag.
SIDE CURTAIN AIRBAGS
In a sufficient side impact or rollover, the MDX’s side curtain airbags deploy from roof-mounted modules to provide head protection for all three rows of seating. Side curtain airbags effectively cover the side window area from the front seats all the way to the third-row seat. Tests show that the g- forces acting upon an occupant’s head are far lower with side curtain airbags.
In the 2009 MDX the side curtain airbag system includes three satellite sensors and a main unit that work in concert to detect a crash within 5-7 milliseconds. Even though the latest MDX is projected to offer better rollover stability than the previous MDX, the system includes a rollover sensor and performs solidly with a 4-Star* rating in the NHTSA rollover category.
LOWER ANCHORS AND TETHERS FOR CHILDREN (LATCH)
The 2009 MDX includes a LATCH (Lower Anchors and Tethers for CHildren) child-seat mounting system for the second-row seating positions. LATCH features built-in lower anchors and ready-to-use tether attachment points that allow compatible child safety seats to be installed without using the vehicle’s seat belt system. Additionally, the LATCH system simplifies child-seat installation when using a LATCH-compatible child seat.
FUEL TANK SAFETY
The MDX’s 21-gallon fuel tank is positioned in front of the rear body-deformation zone to minimize the risk of damage in a collision. Locating the fuel tank in this protected area optimizes vehicle balance by moving the weight of the fuel tank farther forward. Thus, handling characteristics are minimally affected whether the fuel tank is full or near empty.