Chassis/Body/Suspension/Tires/Brakes

The Lexus GS combines proven chassis systems with advanced dynamic handling technology to provide both agile handling and the Lexus trademark smooth ride. The double-wishbone front suspension and multilink rear suspension virtually eliminate unwanted wheel-angle changes during suspension movement. The result is a natural, confident feel that's also spirited. A 34.1-ft. turning circle (35.4 ft. for GS 350 AWD) is comparable to that of smaller cars and helps make the GS highly maneuverable.

In all GS models, Brake Assist (BA), Electronic Brake-force Distribution (EBD) and the Anti-lock Braking System (ABS) help form a powerful safety front. EBD optimizes brake pressure at each wheel to help reduce body dive or sway during hard braking and cornering. BA is designed to determine if the driver is attempting emergency braking, and, if the driver has not stepped firmly enough on the brake pedal to activate the ABS, it will apply increased braking force until pedal pressure is released.

Aluminum-alloy 18-inch wheels are standard on the Lexus GS 460 and available for the rear-wheel-drive Lexus GS 350, which features standard 17-inch wheels. For maximum handling capability, the Lexus GS 350 comes standard with 225/50R17 W-rated summer tires. The all-season 17-inch run-flat tires that are standard on the Lexus GS 350 AWD model are available on the GS 350 RWD. The GS 460 is equipped with 245/40R18 Z-rated summer tires or available all-season run-flats.

The Lexus GS 350's available all-wheel-drive system helps to enhance handling in diverse driving conditions. A planetary-gear center differential and a wet-type multi-disc clutch control front-to-rear power distribution. The system normally sends 70 percent of available power to the rear wheels to provide the traditional performance advantages of a rear-drive car and will vary the torque-split ratio from 30:70 to 50:50 in response to driving conditions and driver input. The AWD system's electronic-control strategy takes inputs such as steering and throttle angle from driver activity combined with vehicle signals from wheel speed and yaw rate sensors.

An Adaptive Variable Suspension (AVS) system, standard on the Lexus GS 460 and available on the GS 350, provides two settings, normal and "sport" for tighter, more precise control. AVS can automatically select appropriate suspension damping for driving conditions. The Lexus GS 460 also offers the advanced Active Power Stabilizer system that helps reduce body sway and enhances vehicle control during cornering. An Electronic Control Unit (ECU) calculates the force needed to counter excess body sway, which is then applied to the stabilizer bars by the front and rear actuators. The GS 350 models are equipped with Vehicle Stability Control (VSC) with traction control. The system can be disengaged with the "TRAC Off" switch when the situation warrants doing so.

In the GS 460, the Lexus Vehicle Dynamics Integrated Management (VDIM) system integrates and manages a host of handling technologies, including VSC. Combining input from a variety of sensors, VDIM is designed to anticipate the onset of a vehicle skid or slide and then help correct the situation with a combination of braking, throttle, and steering control. VDIM integration helps to provide precise management for the Electronically Controlled Brakes (ECB), Variable Gear Ratio Steering (VGRS), Electric Power Steering (EPS), VSC, ABS, BA, EBD, and engine torque via the electronically controlled throttle.

EPS in the Lexus GS 460 provides precise electric power assist using a DC motor built into the steering gear housing. Also in the GS 460, VGRS can vary the steering from 2.7 turns lock-to-lock for low-speed maneuverability to a slower 3.2 turns lock-to-lock for highway-speed control. VGRS also provides differential steering control, which helps correct for a delay in steering response, something that occurs in all vehicles, to help enhance driving feel during lane changes and other transitional maneuvers.

The Lexus GS 460's ECB is a brake-by-wire system. ECB translates brake pedal pressure into electric signals that, via computer control, help provide precise and optimized braking. Electronic control provides quick brake response when needed, helping the Lexus GS 460's VDIM system to anticipate and help correct skids before they occur. The ECB system is backed by conventional hydraulic brake control in the unlikely event of electronic failure.

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