The Lexus GS 450h, first introduced in April 2006 as a 2007 model, remains the only hybrid-powered performance luxury sport sedan in its segment. Based on the new-generation GS platform and featuring Lexus Hybrid Drive technology, the GS 450h offers V8-like performance with greater fuel efficiency.
"While others talk about plans to introduce hybrid-powered luxury models, Lexus has become a leader in this category," said Jim Farley, Lexus group vice president and general manager. "With three hybrid models – each with its own distinct application of Lexus Hybrid Drive – the brand is offering this in-demand technology in some of today’s most aspirational luxury vehicles."
For 2008, the unique GS 450h shares the front style refreshing of the GS 350 and GS 460 models, including revised front fascias with a new front bumper and lower intake design and a new chrome grille surround. All GS models gain side view mirror turn signals, and the GS 450h adds a hybrid-exclusive exterior color, Black Opal Mica, and also gains additional blue hybrid highlights.
The 2008 GS instrument panel has been revised, and a new brushed-aluminum shift-plate surround and wood-trim door switch plates accentuate the interior elegance. New interior choices include light gray leather trim and dark gray wood trim. A VDIM cutoff switch has also been added to allow the driver to disengage the stability system when appropriate.
With its advanced technology, high performance and indulgent luxury, the rear-wheel-drive 2008 GS 450h is the premium model in the GS series. In addition to the GS 450h, Lexus also offers the RX 400h luxury utility vehicle and the new-for-2008 LS 600h L flagship hybrid luxury sedan. In addition to boosting performance and fuel efficiency while lowering emissions, Lexus Hybrid Drive technology also further elevates the brand’s renowned smooth, quiet operation.
The GS 450h’s unique version of the Lexus Hybrid Drive powertrain combines a powerful 3.5-liter V6 engine with a compact, permanent magnet electric motor – all driving the rear wheels. The hybrid powertrain collectively produces 340 horsepower and can effortlessly accelerate the GS 450h from zero-to-60 mph in just 5.2 seconds.
Just as impressive as the GS 450h’s acceleration from a stop is how quickly and powerfully torque is delivered during mid-range acceleration. The hybrid system’s electric-drive motor delivers maximum torque immediately upon demand. This unique power-delivery characteristic is most noticeable, and most useful, during 30-to-50 mph passing and in traffic-merging maneuvers.
The GS 45h returns nearly 30-percent better fuel efficiency than some V8 models, with EPA-estimated fuel economy of 22 mpg city/25 mpg highway/23 mpg combined. The GS 450h is certified as a Super-Low Emissions Vehicle (SULEV).
Responsive Handling and Advanced Dynamics
The GS 450h matches its powerful acceleration with responsive handling while maintaining the ultra-comfortable ride that is synonymous with the Lexus brand. Double-wishbone front and multilink rear suspension systems endow the GS 450h with engaging handling performance. Like the V8-powered GS 460 model, the GS 450h is equipped as standard with Adaptive Variable Suspension (AVS), a driver-selectable shock absorber damping system. The standard 18 x 8-inch aluminum alloy wheels have a finish that is unique to the GS 450h and are equipped with 245/40R18 Z-rated summer performance tires; all-season run-flat tires are available.
An optional Active Power Stabilizer system helps to further reduce body sway during cornering. The system uses an Electronic Control Unit (ECU) to calculate the force needed to counter excess body sway, which is then applied to the stabilizer bars by front and rear electric-powered actuators.
The GS 450h also showcases the brand’s highest level of dynamic handling technology: the advanced Vehicle Dynamics Integrated Management (VDIM) system that goes beyond the capability of other stability and traction-control systems. VDIM is designed to anticipate the onset of a vehicle slide while cornering and then help to automatically correct the situation with a combination of braking, throttle and steering control in a way that is essentially transparent to the driver.
VDIM integrates Electric Power Steering (EPS), Variable Gear Ratio Steering (VGRS), Antilock Braking System (ABS), Electronic Brake-force Distribution (EBD), Brake Assist (BA), Vehicle Stability Control (VSC), Electronically Controlled Brakes (ECB), and Traction Control (TRAC).
"Full Hybrid" Powertrain
A "full hybrid," the GS 450h is capable of operating in gas-only or electric-only modes, or a combination of the two. One of a new generation of Lexus engines, the gasoline V6 uses a dual fuel-injection system that combines the benefits of direct injection with those of port injection, and an Electronic Throttle Control System with intelligence (ETCS-i). Dual Variable Valve Timing with intelligence (VVT-i) operates on the intake and exhaust valves to further enhance power and torque across a broad engine speed range.
The GS 450h hybrid powertrain uses two motor-generators, MG1 and MG2 (the drive motor). Each performs specific functions and can operate as both a motor and a generator, although MG1 is used as a starter motor and provides no motive force. The engine-driven generator (MG1) can charge the battery pack or provide additional power to MG2 as needed.
A 288-volt DC Nickel Metal Hydride (Ni-MH) battery pack is installed behind the rear seat area. The battery’s power is directed through a "boost converter" that can efficiently raise voltage to a maximum 650V DC. An inverter changes this to AC, providing its elevated power to the 147-kW electric motor, which turns as high as 14,400 rpm. The trunk also contains a 12-volt auxiliary battery that powers various vehicle systems, including audio and navigation.
Unique Hybrid Transmission
Power from the gas engine and electric drive motor (MG2) is distributed to the rear drive wheels via a planetary gear-type Electronically controlled Continuously Variable Transmission (ECVT). This special transmission, which eliminates specific gear ratios, features a two-speed torque-multiplication device that allows drivers to select from among three driving modes: power, normal and snow. "Normal" provides the smoothest operation and is ideal for city or suburban driving; "power" sharpens accelerator pedal response and "snow" mode softens accelerator pedal response making it easier to travel on slippery road surfaces.
The ECVT consists of a motor generator, motive power-dividing mechanism, two-stage motor-reduction device, electrically powered oil pump and hydraulic control system. The two-stage torque-multiplication device varies the gear ratio in two stages by controlling a planetary gear and two wet brakes, similar to the way a conventional automatic transmission operates.
This configuration allows the electric drive motor to operate in high or low ranges, with seamless transitions between the two. MG2 can therefore contribute power not just for acceleration, but at higher cruising speeds as well.
The driver will not feel the GS 450h’s transmission doing its work but will be keenly aware of its benefits in the powerful and uncannily smooth acceleration and passing performance. Sin ce the GS 450h is driven solely by its electric motors when starting, traveling slowly, and during low-load driving, the noise level is about half that of a conventional gasoline engine, enhancing the luxury experience.
Optimized Fuel Consumption
The GS 450h’s power-steering pump and air-conditioning compressor are electrically powered rather than engine-driven to reduce parasitic losses to the engine and thereby improve fuel consumption. This is necessary because the gas engine often shuts down – a fuel-saving benefit of the hybrid system – especially when the vehicle is stopped or driven slowly through traffic. Ultraviolet and infrared ray-reducing tinted glass on all windows helps to reduce demand on the air conditioner.
A regenerative braking system further boosts system efficiency. When the vehicle is coasting or the brakes are applied, the electric motors function as generators, capturing kinetic energy that would normally be lost as heat through the brakes and transforming it into useable electricity to recharge the batteries.
Advanced Safety Systems
All Lexus GS models implement a wide array of advanced safety systems. The Supplemental Restraint System (SRS) includes variable-force front airbags for both the driver and front passenger. Sensors determine the severity of an impact and in turn the airbag deployment force, helping to provide an appropriate level of occupant restraint. The GS features standard seat-mounted side airbags for the front seats, knee airbags for the driver and front passenger, and front and rear side-curtain airbags.
The optional Pre-Collision System (PCS) can help the driver to avoid an accident. A millimeter-wave radar sensor helps detect obstacles in front of the car, while vehicle speed, steering-angle and yaw-rate inputs help to determine whether a collision is unavoidable.
In such a situation, PCS switches the AVS to sport mode for optimal chassis response, preemptively retracts front seat belts, and pre-initializes Brake Assist so that increased braking will be applied the instant the driver depresses the pedal. The active-braking feature will automatically apply the brakes up to a deceleration rate of 0.3 G’s if the driver fails to react to system warnings.
Striking Lexus Design
The current generation GS sedans introduced the brand’s L-finesse design language. A 112.2-inch wheelbase, long hood, pulled-back cabin and short rear deck create a confident, powerful stance for the GS. A low 0.27 coefficient of drag (Cd) helps to maximize highway fuel efficiency and minimize wind noise.
Subtle visual differences distinguish the GS 450h from other GS models. These include a blue hybrid designation on the side rocker moldings, aluminum-and-blue enameled rear model designation, special 18-inch light-alloy wheels, a Lexis Hybrid Drive engine cover, blue front and rear "L" logos, a blue tint to the headlamps and tail lamps and a power meter that replaces the tachometer.
In designing the GS 450h, Lexus raised its own high standards for minimizing noise and vibration. Instead of attempting to mask noise, the engineers completely redesigned fans and motors, significantly reducing cabin-noise intrusion. Fluid-filled front-engine mounts, additional sound-absorbing asphalt sheets behind the instrument panel, and a new sound-absorbing windshield further enhance the quiet ride that redefines the term "Lexus-like."
Indulgent Luxury That’s Easy to Appreciate
Ultra-premium wood, polished-metal accents and leather trim endow the GS interior with a lavish yet high-precision feel. Touch points convey quality, and controls respond fluidly. The three-pod analog instrument cluster features an Electro Chromatic Display and variable-transparency glass for high visibility in a variety of light conditions.
Lexus designers strive to keep controls simple and intuitive, avoiding needless complexity. The SmartAccess keyless entry and push-to-start ignition allow the driver to keep the access fob in a pocket or purse. Audio and climate-control systems are easy to understand and operate, and the GS locates controls that are used less frequently behind a dash panel on the left side of the steering wheel.
The interior presents an indulgent environment with regency leather-trimmed seats in Ash, Cashmere or Black leather matched with wood trim in Dark Gray Bird’s-eye Maple, Brown Bird’s-eye Maple or Walnut, respectively.
The cabin is further enhanced with a wood and leather-trimmed three-spoke steering wheel – featuring audio and multi-information display controls – and a coordinating wood and leather-trim shift knob. The 10-way power-adjustable front driver and passenger seats are heated and ventilated, and there are height-adjustable headrests for all five seating positions.
As the top model in the GS line, the GS 450h features the highest level of standard luxury equipment and includes features that are optional on other GS models: power rear sunshade; heated and ventilated front seats; rear-seat side airbags; rain-sensing wipers; rear back-up camera; headlamp washers, and the Adaptive Front-lighting System (AFS), which helps illuminate a curve as the driver steers into it.
A power-tilt and telescopic steering wheel helps ensure a comfortable driving position. The standard dual-zone climate-control system filters the air, and a standard rear power sunshade adds to passenger comfort on warm days. The GS 450h includes the convenience of a power trunk closer, rain-sensing windshield wipers and Intuitive Park Assist (IPA), which uses ultrasonic sensors to detect the presence of objects close by and warn the driver of their proximity.
A Feast for the Ears
Lexus long ago established an elevated standard for mobile audio performance, and the next-generation GS models uphold this tenet with a standard system that features an AM/FM/cassette stereo and a six-disc, in-dash CD changer. The system plays through 10 premium speakers, and an Automatic Sound Levelizer (ASL) maintains consistent sound levels at varying vehicle speeds.
All styles of music come to life in the ultra-quiet Lexus GS interior with the optional 7.1-channel Mark Levinson® Premium Sound system. Featuring a total of 330 watts playing through 14 speakers, the system allows users to play both CDs and DVDs. DVD movies can be viewed on the color seven-inch touch screen when the parking brake is engaged.
Lexus Navigation System
The optional Lexus Navigation System includes voice-recognition that allows the driver to enter a destination by voice command. The display screen features a high-resolution 800 x 480 pixel display in 32,000 colors. On-screen details are crisp and clean, and maps and roads feature 3-D shadow effects.
The DVD-map database contains more than five million points of interest. The database for Chicago, Detroit, Los Angeles, and New York includes a building footprint display feature that can show graphic representations of buildings and structures to help the driver identify surroundings. System functions include multiple route calculations, route preview, simplified highway junction graphics, and a dual-map screen mode. Bluetooth® wireless technology allows the transfer of personal phone books to the navigation system, from which the driver can make hands-free phone calls via its touch-screen control panel.
All new Lexus vehicles come with a 48-month/50,000-mile basic limited warranty with roadside assistance for 48-months/unlimited miles. Powertrain and restraint system coverage is provided for 72 months/70,000 miles. Corrosion perforation protection is covered for 72 months, regardless of mileage. The hybrid-related components, including the HV battery, battery control module, hybrid control module and inverter with converter, are covered for eight years/100,000 miles.