The LS 430 handles well for such a large, luxurious sedan. It responds predictably when driven to the limit of the tires in corners, though it doesn't encourage you to do so the way a BMW does. The softness of the suspension results in squirmy transient response when compared with say, the BMW 745i. But the LS 430 does generate lots of grip and offers the responsiveness afforded by rear-wheel drive and double-wishbone suspension front and rear. New monotube shock absorbers improve handling for 2004. The new shocks are larger and more technologically advanced, resulting in flatter cornering response and a smoother ride. The steering system has also been improved for 2004, providing more road feel, more feedback, more precision.

Two suspension options are available, a sport suspension and an air suspension. The Sport Package features a sport-tuned suspension and 18-inch wheels and tires. This setup improves handling feel while maintaining a smooth, comfortable ride. While Mercedes and other manufacturers offer sport suspension packages that result in a harsh, choppy ride, this isn't one of them. Even with the sport suspension, the LS 430 rides smoothly and softly. The optional air suspension allows the driver to switch between two shock-damping modes (and to raise the ride height for driving in deep snow). However, the car floats a little more on the air suspension, even in the Sport mode, making it feel bigger, more boatlike. For this reason, we prefer the sport suspension.

The Lexus V8 is smooth and quiet, and the new six-speed automatic shifts so smoothly it's almost seamless. The 4.3-liter V8 generates 290 horsepower and 320 pounds-feet of torque. Acceleration performance has been improved significantly over last year's model. Lexus says the 2004 LS 430 can accelerate from 0 to 60 mph in 5.9 seconds, a significant improvement over last year's 6.3-second performance. The performance improvement is almost entirely a result of the new six-speed automatic. First gear is lower, and second, third, and fourth gears are closer together, all of which makes for a quicker launch and quicker acceleration. Yet the LS 430 still earns an EPA-estimated 18/25 mpg City/Highway, a benefit of the transmission's long-legged fifth and sixth gears. The driver can manually control shifting, though we found it usually best to put it in Drive and let it does its job. Engine and transmission are designed to favor smoothness over performance, however, so they do not offer the crispness of a BMW powertrain, the other end of the spectrum. The engine's electronic throttle control (drive-by-wire) system helps smooth acceleration from a standing start by very slightly delaying throttle opening when the driver steps on the accelerator pedal, and the transmission favors smoothness over shifting speed. But overall, the Lexus V8 and six-speed automatic are a powerful team, delivering strong acceleration performance for quick passing and freeway merging.

The brakes are responsive and easy to modulate for smooth stopping power. Four-channel, four sensor ABS helps the driver maintain steering control during panic stops. Brake Assist is designed to determine if the driver is attempting emergency braking and, if the driver has not stepped hard enough on the brake pedal to activate the anti-lock brake system, it applies maximum braking pressure until pedal pressure is released. Vehicle Stability Control (VSC) is an excellent active safety feature that helps control side skids under demanding conditions by correcting loss of lateral traction during cornering. VSC integrates traction control to help limit rear wheel spin on slippery road surfaces.

The optional Dynamic Laser Cruise Control system is designed to maintain a set distance from the vehicle traveling in front.