The system normally sends 70 percent of available power to the rear wheels to provide the traditional performance advantages of a rear-drive car, but 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.


Ultra-Advanced Dynamic Handling Control

The Lexus GS combines the best-proven design chassis systems with new dynamic handling technology. The double-wishbone front suspension and multilink rear suspension systems feature with geometry optimized to virtually eliminate unwanted wheel-angle changes during suspension movement. The result is a natural, confident feel that's also spirited.

An Adaptive Variable Suspension (AVS) system, standard on and exclusive to the GS 430, provides four settings, including "sport," for tighter, more precise control. AVS can automatically select appropriate suspension damping for driving conditions. New for 2007, the GS 430 offers the advanced Active Stabilizer system that reduces body sway and enhances vehicle control during cornering. This new system uses electric actuators, rather than slower hydraulic units commonly found in similar systems.

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 Active Stabilizer system responds within 20 milliseconds, compared to 100 milliseconds for a competitor. The Lexus system consumes no power under normal operating conditions, whereas the competitor's system consumes over 240 watts.

Lexus GS 430 provides the performance enhancements and advanced vehicle control of the Lexus Vehicle Dynamics Integrated Management (VDIM) system. VDIM integrates and manages a host of handling technologies more quickly than previous dynamic handling technologies could. 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 in a way that is essentially transparent to the driver.

VDIM integration helps to provide precise management for the Electronically Controlled Brakes (ECB), Variable Gear Ratio Steering (VGRS), Electric Power Steering (EPS), Vehicle Stability Control (VSC), Anti-lock Braking System (ABS), Brake Assist (BA), Electronic Brake-force Distribution (EBD), and engine torque (via the electronically controlled throttle). New for 2007, the GS also allows the driver to disengage the stability and traction control via the Trac Off switch.


Electric Power Steering

Electric Power Steering (EPS) in the GS 430 provides precise electric power assist using a DC motor built into the steering gear housing, rather than hydraulic assist. Eliminating the hydraulic steering pump reduces engine drag, and the simplified steering system is lighter and more compact, as well.

Also in Lexus GS 430, Variable Gear Ratio Steering (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 stability. 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 in lane changes and other transitional maneuvers.

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