The S 450 packs a new 3-valve-per-cylinder 4.6-liter V8, bumped up from its previous displacement of 4.3 liters. The S 500 is powered by a completely new engine, the 5.5-liter V-8 that has gone back to a 4-valve-per-cylinder design. The top-of-the-line S 600 is powered by an upgraded version of the 6.0-liter 3-valve V-12 twin-turbo engine currently used in the $350,000 Maybach sedans rated at 510 horsepower.

The S 450 and the S 500 models offer similar levels of standard equipment, though the S 500 comes standard with leather. The S 600 adds Parktronic front and rear parking radar system, and the newly updated Distronic radar-controlled cruise control. The V8s come with the seven-speed automatic, while the V12 is equipped with a heavy-duty five-speed automatic.

Options include active headlamps, Active Body Control (standard on S 600), bi-xenon headlamps, Brake Assist Plus, cornering lamps, Distronic Plus, dynamic multicontour seats, with or without massage, Keyless Go, Linguatronic voice activation, hard-drive navigation system, Panorama glass roof, Park Assist, a Reverse camera that displays on the COMAND screen, ventilated seats with fans, and a surround-sound audio system with surround at each seat. Whew!

The new S-Class safety package is unequalled in the class, with all the usual brake and airbag technology upgraded. The Brake Assist feature has been improved to Brake Assist Plus status, and is fully integrated with Parktronic and Distronic, respectively the radar-controlled parking and distance-controlling cruise control systems. The system now has two forward-facing radar systems, and can apply the brakes at any speed from zero up to about 125 mph and bring the car to a full stop without driver input. The company says the new system can reduce rear-end collisions in stop-and-go traffic by up to 75 percent. An added wrinkle to the revised PreSafe system that closes the sunroof, closes windows and repositions the seat in the event of an impending collision is that the air chambers in the backs of the multicountour bucket seats inflate to add support to the upper body in case of a rear-ender. The Electronic Stability Program, or ESP, which was introduced to the world on the S-Class two generations ago, is back as standard equipment, with two new features: trailer stabilization, and tire-pressure monitoring.

Another new offering is the optional Night View Assist. It uses infrared, not thermal imaging as the Cadillac's older systems. Using infrared headlamps, a tiny camera picks up and projects clear, sharp images of what's ahead of the car. The picture is displayed in the space normally occupied by the speedometer and tachometer, which change to bar graphs underneath the night vision display when it's activated. Unlike the thermal systems, the Mercedes system uses a sharper SIMOS display instead of a CCD, it does not depend on heat generated by engines or humans to create images, and can operate unaffected by temperature extremes. The system is a world first, and an exclusive S-Class option.

4Matic all-wheel drive is expected in the fourth quarter of 2006 for V8 models. A high-performance AMG model with a new 6.3-liter naturally aspirated V8 replacing the supercharged 5.5-liter V8 is expected to follow. And diesels may be available in 2007.