After creating a new segment in 1997, the Lexus RX went on to become the best-selling luxury SUV in the world. The improvements introduced to the 2006 model bring additional dynamism and refinement that will consolidate the dominant position of RX in the global SUV market.
Reflecting the Lexus ongoing commitment to the pursuit of perfection in automotive quality, performance, technology and refinement, the RX model range has consistently topped the J.D. Power and Associates rankings. Awards include the North American IQS (Initial Quality Study) category in 2001, 2003, 2004 and 2005, as well as the APEAL (Automotive, Performance, Execution, Layout) category in 1998, 2003, 2004 and 2005.
Originator of today’s luxury SUV as we know it, the permanent 4-wheel drive RX model range’s unrivalled reputation is founded on aerodynamically class-leading styling (with the lowest drag coefficient of any luxury SUV, 0.33). This comes allied to excellent dynamic performance - most notably in the fields of handling, ride comfort, NVH and braking, as well as a comprehensive range of advanced, technologically innovative features. Air suspension, Neural Network Control air conditioning, an electrically operated tailgate, 40:20:40 split/folding rear seats and Intelligent Adaptive Front Lighting System (I-AFS) are part of the offer. The RX range further benefits from the highest levels of active and passive safety, including a segment-first SRS Knee Airbag.
The 2006 Lexus RX 350 further refines driving pleasure through the class-leading performance of a new, state-of-theart, 3.5 litre V6 petrol powerplant. The 24 valve, 3456 cm3, aluminium block unit is the first engine in this segment to adopt Dual VVT-i (Variable Valve Timing-intelligent), an optimised, low pressure loss, variable intake and exhaust valve timing system. This is combined with roller rocker valve activation with HLA (Hydraulic Lash Adjuster) valve clearance adjustment, and an electrically activated ACIS (Acoustic Control Induction System), which varies air induction by automatically adjusting the intake pipe length according to engine rpm.
Achieving the optimum balance of high performance with low fuel consumption and emissions, the new, ultra-smooth Lexus V6 is the most powerful, yet the most economical ‘conventional’ 6-cylinder petrol engine in the premium SUV market segment. It generates 276 DIN hp/203 kW at 6,200 rpm and 342 Nm/252 lb.ft of torque at 4,700 rpm, giving the RX 350 a 0-100 km/h acceleration time of just 7.8 seconds – a 6-cylinder luxury SUV best - and an electronically governed top speed of 200 km/h. Conversely, the RX 350’s combined cycle fuel consumption figure improves by some 8% to a class-leading 11.2 l/100km.
The RX 350’s V6 powerplant is mated to a 5-speed, automatic transmission featuring a newly developed shift control logic, which promotes superior performance and excellent fuel economy.
Moving the gearshift lever into ‘S’ mode activates a manual, 5-speed, sequential-shift system, offering enhanced engine braking, precise control and greater driving involvement. The gear indicator in the driver’s instrument binnacle features an ‘S’ position, which displays each manually selected gear range.
The RX 350’s permanent 4-wheel drive now adopts a new centre differential featuring a viscous coupling. The limitedslip function inherent in this system not only promotes the smooth delivery of the 35% increase in output generated by the new 3.5 litre V6, but also, allied to re-tuned Vehicle Stability Control (VSC) and Traction Control systems, further enhances traction and stability under all driving conditions.
The steering of the new Lexus SUV has also been reconfigured to provide a more direct and responsive feel appropriate to the increased power of the new V6. Furthermore, additional low speed steering assistance now compliments the RX 350’s best-in-class 5.7 metre turning radius, further increasing the luxury SUV’s urban versatility.
In refining the RX 350, particular attention has been paid to noise and vibration reduction, ensuring that, though substantially more powerful than its predecessor, the new Lexus luxury SUV is significantly quieter at all engine speeds. A new bonnet insulator, dashboard silencer and improvements to the exhaust system significantly reduce the transmission of engine noise and vibration into the cabin.
Noise levels have been reduced through the addition of a more effective transmission tunnel insulator and a soundabsorbent intermediate transmission shaft seal.
Marked improvements in noise reduction have been achieved through the adoption of a new windscreen. This is equipped with an acoustic inner film boasting high noise damping characteristics, leading to a cabin noise reduction of up to 3 dB when driving. New front floor carpeting further reduces road noise intrusion.
The new RX 350’s Lexus Multimedia and Navigation System features a peerless Mark Levinson Premium Audio System with DVD video playback capability, the latest Lexus navigation technology incorporating Bluetooth phone connectivity, and the Lexus Parking Assist Monitor. All systems are operated via the Electro Multi Vision, a 7-inch VGA LCD touch screen, for the ultimate in intuitive functionality.
The new Mark Levinson system features a 7 channel, 210 Watt DSP amplifier and 11 speakers. It will play CD, DVD video and DVD audio discs as well as MP3 and WMA files. Via the Electro Multi Vision display screen the Mark Levinson® Premium Audio/Video system introduces Lexus owners to home theatre entertainment optimised for the playback of music, music videos and DVD films.
Employing a DVD disc to store map information of the entire Western Europe, the speed of calculation of the next generation Lexus Navigation System’s processor, has increased an impressive 65%. The new Lexus Navigation System is equipped with a 3-language voice command system that can control several navigation, audio, climate and phone functions. In addition, voice guidance is available in 10 languages. Last but not least, integrated Bluetooth® connectivity allows for hands-free phone use in the car.
The Lexus Parking Assist Monitor features a rear mounted video camera which automatically projects a full-colour rear view of the surrounding, whenever reverse gear is engaged. Screen generated guidelines indicate the prospective course of the vehicle based on the current steering angle.
3.5 LITRE V6 PETROL ENGINE
The Lexus RX 350 is powered by a new, highly innovative, aluminium-block petrol engine which is the most powerful, yet the most economical, 6-cylinder petrol unit in the Premium SUV market segment.
The 24 valve, 3456 cm3, chain-driven double overhead camshaft V6 combines Dual VVT-i (Variable Valve Timing-intelligent), roller rocker valve activation with HLA (Hydraulic Lash Adjuster) valve clearance adjustment, and an electrically activated, ACIS (Acoustic Control Induction System) variable air induction system to achieve the optimum balance of high performance with low fuel consumption and emissions.
The RX 350’s 3.5 litre V6 is the first engine in this market segment to adopt Dual VVT-i, an optimised, low pressure loss, variable intake and exhaust timing system. Able to control intake and exhaust camshafts through angles of up to 40 and 35 degrees respectively, Dual VVT-i allows a greater intake/exhaust valve overlap, benefiting both low-end and high-end torque as well as contributing to a significant reduction in exhaust emissions.
The chain-driven valve system features roller rocker arms, the marked reduction in friction between the camshaft and sliding components – some 15% at 2,000 rpm - enhancing fuel efficiency. In addition, the diameter of both intake and exhaust valves has been enlarged to improve efficiency, high load valve springs and a concave camshaft profile increase valve lift to boost output, whilst a ceramic check-ball Hydraulic Lash Adjuster ensures the system requires no valve clearance adjustment over the life of the vehicle.
Refining the intake air flow of this unit has been a priority for the engineers of the Lexus Development Centre, located in Japan. As a result, the new V6 achieves the world’s largest volume of intake air amongst 6-cylinder powerplants. Along with an enlarged valve diameter and wider cam action, the shape of the intake manifold and the cylinder head intake port diameter and length have been optimised to improve output and torque, and air cleaner and duct profiles revised to reduce intake pressure loss.
Another segment-first, a high-speed electrically activated Acoustic Control Induction System (ACIS) featuring the system actuator bonded to the resin-made surge tank through an advanced laser-welding process, varies air induction by automatically adjusting the intake pipe length according to engine rpm, optimising the fuel/air mixture to further boost torque across the full rev’ range.
In addition, centrifugal cast iron cylinder liners feature a ‘spiny’ outer wall liner to improve bonding with the cylinder block, increase radiation characteristics, reduce piston temperature and suppress cylinder bore deformation. And pentroof, slant squish combustion chambers combine with a shallow piston cavity and centrally located, high-ignition, long-reach iridium spark plugs for excellent combustion and anti-knocking performance.
Gas flow within the stainless steel exhaust system has been optimised to reduce pressure loss between the exhaust manifold and silencer, enhancing engine performance. The exhaust manifold features ultra-thin-plate ceramic catalytic converters to further improve performance, significantly reduce warm-up times and, hence, reduce emissions.
Moreover, the by-wire control logic of the new 3.5 litre V6’s throttle valve has been re-configured; the ECU eliciting a more prompt engine response to any given throttle pedal angle.
Within a remarkably compact design, extensive measures have been taken to reduce engine weight and minimise noise and vibration. The new V6 employs a die-cast aluminium cylinder block, lightweight pistons, a thin-wall aluminium cast intake manifold and a resin-made surge tank.
The overall engine assembly is made lighter and more compact through the installation of the water pump, oil filter and oil pump within the chain cover. And the optimisation of the high-tensile forged crankshaft’s balance weight combines with lightweight pistons, roller rocker valve activation with HLA, and urethane foam acoustic damping to both engine and chain covers to significantly reduce engine noise and vibration across the entire power band.
Representing power and torque increases of 35% and 21% respectively over the previous RX 300, the ultra-smooth Lexus V6 generates 203 kW/276 DIN hp at 6,200 rpm and 342 Nm/252 lb.ft of torque at 4,700 rpm. This rewards the new RX 350 with a 0-100 km/h acceleration time of just 7.8 seconds, which makes it the quickest amongst 6-cylinder luxury SUVs. Top speed has been electronically limited to 200 km/h.
Conversely, specific fuel consumption (g/kWh, grams per kilowatt-hour) has seen an average 4% improvement over that of the RX 300 across the entire rev’ range, whilst the RX 350’s combined cycle consumption figure improves by some 8% to an outstanding 11.2 l/100km, making it the most economical amongst conventional 6-cylinder petrol engines in the premium SUV segment.
5-SPEED AUTOMATIC TRANSMISSION
The RX 350’s 3.5 litre V6 powerplant is mated to a 5-speed, automatic transmission. A newly developed shift control logic promotes superior performance and excellent fuel economy.
Gear downshift - for example, from 4th to 2nd gear - has been significantly improved through a new control logic. By predicting the level of engine torque developed at any given moment through a reading of engine status, the transmission ECU can instigate a 4th to 2nd downshift simultaneously to the engine ECU’s adjustment of the by-wire throttle angle, obviating the requirement for a slower, two-stage operation. This new control logic reduces downshift times by some 0.2 seconds at 60 km/h, elicits an even smoother gearshift and greatly enhances throttle response.
A further new control logic, Shift Phase Controller, has also been adopted for situations involving, for instance, a rapid 2nd to 4th to 2nd gear change sequence such as might occur during an interrupted kick-down. Through simultaneous control of clutches and torque management, this logic promotes both significantly smoother gear changes and reduces shift times by about 0.8 seconds at 80 km/h, further improving the RX 350’s rapid response to throttle inputs.
Moving the transmission’s gearshift lever into ‘S’ mode activates a 5-speed sequential gearrange selection system – forward for up-shifts, backwards for down-shifts - offering enhanced engine braking, more precise control and, hence, greater driving involvement. The gear indicator in the driver’s instrument binnacle now features an ‘S’ position, which displays each manually selected gear range.
PERMANENT 4-WHEEL DRIVE
The RX 350’s, 50:50 front-rear torque split, full-time 4-wheel drive adopts a new centre differential featuring a viscous coupling. The limited-slip function inherent in this system not only promotes the smooth delivery of the increased torque generated by the new 3.5 litre V6, but also, allied to Vehicle Stability Control (VSC), further enhances traction and stability under all driving conditions.
When, for instance, wheelspin is detected at the front of the vehicle, the viscous coupling will lock, passing more torque to the rear in order to counteract the usual differential effect. The new centre differential greatly improves the RX 350 4-wheel drive system’s efficiency in responding to momentary traction loss, whilst the action of all three differentials is further complemented by the ability of Lexus’ proven Traction Control system to reduce individual wheel speed whenever traction loss is detected.
Vehicle Stability Control and Traction Control systems have also been retuned in order to better respond to the 21% torque increase brought by the new 3.5 litre V6 engine. In addition, communication between the engine ECU (Electronic Control Unit) and the Brake Control ECU is now done through a faster CAN (Controller Area Network) multiplex network, 100 times faster than the previous connection, which allows a better interaction between the Vehicle Stability Control and the new 3.5 litre V6 engine.
LEXUS MULTIMEDIA AND NAVIGATION SYSTEM
The new RX 350’s optional Lexus Multimedia and Navigation System features a peerless Mark Levinson Premium Audio System with integrated DVD video playback capability, the latest Lexus Navigation technology incorporating Bluetooth® phone connectivity, and the Lexus Parking Assist Monitor.
All three systems are operated via an Electro Multi Vision 7”, high-quality, VGA LCD centre console display screen. Reinforcing the intuitive functionality of all Lexus controls, the touch-sensitive, Electro Multi Vision screen is flanked by a comprehensive range of main menu buttons, allowing every single operational requirement to be rapidly effected within a maximum of just three steps. Each button opens a different function menu, which may then be adjusted entirely via the touch screen. The satellite navigation, audio and hands-free telephone systems also benefit from voice command, the system now recognising three languages: English, French and German.
Mark Levinson Premium Audio System
Maintaining the exemplary standards already established by Lexus in the field of in-car high fidelity, the RX 350 sound system features a magazine-less, 6-disc, in-dash DVD changer and steering wheel mounted audio control switches fitted as standard. The system is now prepared to play both WMA and MP3 music files.
Moreover, the Lexus Multimedia and Navigation System provides Lexus owners with the possibility of watching music videos and DVD films within the luxurious environment of the new RX 350 interior.
The unique link between Lexus and Mark Levinson - the world’s most exclusive maker of home audio systems - is based on the conviction that Lexus cars alone offer an appropriate level of acoustic integrity to allow occupants to experience and appreciate the subtle detail and nuance that separate the very best audio systems from those that are merely adequate.
The quality of the new Lexus RX 350 cabin makes a significant contribution to achieving the sound quality demanded of Mark Levinson audio systems. The interior of the car is exceptionally well isolated, with ultra-low levels of ambient noise. Several components have a high level of rigidity in order to avoid undesirable resonances.
The new Mark Levinson system features a 7 channel DSP amplifier employing an all digital signal path, with both Dolby Digital 2.1 and DTS (Digital Theatre Systems) 2.1 capabilities. It will produce a total RMS power output of 210 Watt, all channels driven, covering a frequency range of 20-20 kHz, with less than 0.1% Total harmonic Distortion (THD). Key to the new Mark Levinson system are no less than 11 loudspeakers, including front centre and coaxial rear centre speakers, each one custom engineered for the particular acoustic characteristics and location within the new RX 350 cabin. The sonic benefits of the 11 speaker system include lower distortion, higher resolution, natural dynamics through greater sound pressure levels and an extended frequency response for harmonic richness and musicality.
The system will play CD, DVD video and DVD audio discs, as well as MP3 and WMA files stored on an CD or DVD.
The Lexus Navigation System
Employing a DVD disc to store map information of the entire Western Europe, the next generation Lexus Navigation System display now features a VGA resolution (Video Graphics Array, 800x480 pixels). The new system now features a 32,000 colour range, as opposed to 256 of the outgoing system.
The appearance of navigation maps was deliberately aligned with the colour and graphics of printed maps in order to afford the user instant familiarity with the on-screen image. In addition, key POIs (points of interest) are now displayed in 3D.
The speed of calculation of the new system’s processor has increased an impressive 65%, whilst the graphic draw performance is also three times faster.
The new Lexus Navigation System is equipped with 3-language voice command (English, French and German) for several navigation, audio, climate control and phone functions. In addition, voice guidance is available in 10 languages. The system is one of the few on the market to combine the advantages of both touchscreen and voice command. A Search function that allows the user to search for the nearest Point of Interest using voice recognition has been incorporated, as well as a route tracing feature and detailed lane guidance in several main European cities (Berlin, Birmingham, Brussels, Cologne, Frankfurt, Glasgow, London, Manchester and Munich).
The new system also introduces a practical ETA (estimated time of arrival) feature, which foresees the exact time of arrival to the final destination. In addition, if required by the user, the navigation system can mark the route taken by the vehicle during the current journey.
Other functions are carried over from the previous system, such as RDS-TMC (Radio Data System – Traffic message Channel) which, in countries with the available infrastructure, provides dynamic route guidance capabilities. The system automatically monitors traffic information in conjunction with its route search programme, enabling alternative routes to be suggested if congestion or delays are detected ahead.
A Bluetooth phone, hands-free system is also integrated into the new Lexus Navigation System. It enables the user to make and receive hands-free cellular phone calls by operating the touch-sensitive 7” LCD screen, the steering pad switches or through vocal commands. Moreover, the system can store up to 1,000 contact numbers from a mobile phone.
Lexus Parking Assist Monitor
Abetted by the new luxury SUV’s class-leading turning circle of just 5.7 metres, the RX 350’s Multimedia and Navigation system further benefits from a Lexus Parking Assist Monitor. Lexus was the first manufacturer to offer this system in the premium SUV segment.
Operating through the vehicle’s high-quality, Electro Multi Vision centre console display screen, the system features a video camera mounted in the rear number plate surround that automatically projects a full colour rear view of the surroundings whenever reverse gear is engaged. Even greater manoeuvring accuracy is promoted by screengenerated guidelines which indicate the prospective path of the vehicle based on the current steering position.
In displaying the estimated path, vehicle width line and distance guidelines on the EMV screen, the Parking Assist Monitor represents a significant advance over conventional, sonar equipped systems.
ADDITIONAL LUXURY FEATURES
A key feature of the new Lexus RX 350 is the power operation of the rear tailgate, a feature still rare in the premium SUV segment. The tailgate will automatically open and close at the touch of a button, and may also be activated from a distance via the vehicle’s key fob. To ensure safe operation, movement of the tailgate is indicated by the sounding of a buzzer, whilst touch and motor sensors will stop the door when an obstruction to either closing or opening is detected. In this eventuality, the Power Back Door will immediately move in the opposite direction.
To further aid convenience, the tonneau-type luggage bay cover is automatically retracted as the tailgate opens. There are 12 Volt power outlets in the centre console and luggage compartments, whilst hidden underfloor storage compartments with click-release pop-up lids are also accessible in the luggage bay.
For more flexible, versatile load carrying, the three rear seat backs (which are adjustable forwards and backwards by 120 mm and may be reclined independently) can be folded down in a variety of combinations unique to the RX 350: 100%, 80%, 60%, 40 or 20%. With the central section of the 40:20:40 seating format lowered, long loads such as fishing rods or skis can extend through from the luggage compartment between the two outer rear passengers. Larger loads can be carried by laying one of the larger seat backs flat, allowing awkward shapes to be easily accommodated.
In addition, a sliding centre console box adapts the RX 350 cabin architecture to the needs of the front seat occupants. The adjustable console box may either slide forwards to give the feeling of a continuous sweep from the centre console, or backwards to allow a ‘walkthrough’ between the front seats.
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