Lexus GS: talking performance and technology; Lexus is redescribing and redefining itself—or, said another way, it is launching vehicles that will be distinctively, visually "Lexus." The first articulation is with the GS sport sedan

Automotive Design & Production, April, 2005 by Gary S. Vasilash

The all-wheel-drive system includes front, center and rear differentials. The center diff includes a clutch, according to Watson, that's similar to that found in an automatic transmission with limited-slip capability. Wheel sensors detect spin. This information is then used to adjust hydraulic pressure on the clutch pack to transfer torque to the appropriate place. Torque is split 50-50 during starting, accelerating, or slipping; during general operation, the torque is split up to 30-70, front to rear. In addition to which, there is electronic traction control, which, upon detection of wheel slippage, applies the brake to the slipping wheel or wheels; torque is then transferred to the non-slipping wheel on the given axle.

TECH TOUR DE FORCE. Also elevating the level of technological capabilities is the Lexus Vehicle Dynamics Integrated Management (VDIM) system, which avails itself of the multitudinous systems within the vehicle that deploy sensors that determine what various aspects of the vehicle are doing. To wit:

*** Vehicle stability control (VSC)

*** Traction control (TRC)

*** Brake assist (BA)

*** Anti-lock brakes (ABS)

*** Electronic throttle control with intelligence (ETC-i)

*** Electric power steering (EPS)

*** Variable gear ratio steering (VGRS)

*** Electronically controlled brakes (ECB)

These systems provide information including steering angle, yaw rate, deceleration, brake pressure, brake pedal stroke, and wheel speed. These systems use this information to make the necessary adjustments to the systems that they are tasked to. But VDIM orchestrates and integrates this information (via software). Watson says, "Basically, VDIM constantly monitors all of the variables of the vehicle's intended motion and direction as compared to its actual motion and direction. In other words, VDIM monitors the 'balance' of the vehicle and can therefore anticipate such problems before they occur, rather than reacting after the loss of stability. This is truly a fully dynamic system that takes vehicle stability control to previously unheard of levels."

INSIDE THE GS. There are other tech aspects of the GS, from the "smart" key fob (leave it in your pocket and you can open locked doors and the trunk), which leads to a push-start button rather than having to turn a key. This system is setup so that the driver, with foot on the brake, pushes the button once, and the starter cranks until the engine starts. To shut off the vehicle, the button is pushed again.

The front seats are both 10-way power and heated (cooling is an option). The head rests automatically adjust up or down depending on the seat position.

The instrument cluster perhaps indicates the combination of performance and technology better than any other aspect of the vehicle (assuming that you're not driving it, of course). The faces of the primary gauges are machined aluminum. Because machined aluminum could potentially cause a reflection problem for the driver, the engineers have deployed an electrochromatic device (ECD) over the cluster. Essentially, this is a glass-based system that allows the driver to dial in the amount of diffusion that he or she is comfortable with. Once that is set, then there is automatic adjustment of the reflectivity based on the amount of ambient light (i.e., the amount of diffusion necessary on a sunny day is different than that on a cloudy day).