Vehicle Overview
The Mercedes-Benz S-Class sedan gained two potent new engines for 2003. A supercharged 5.5-liter V-8 generates 493 horsepower in the S55 AMG; the twin-turbo V-12 in the S600 produces the same horsepower output. An available Pre-Safe system can recognize an impending impact before it occurs so it can adjust the seats to the safest position and activate the seat belt pretensioners.

New 4Matic all-wheel-drive versions of the S430 and S500 went on sale during 2003. For the 2005 model year, 4Matic is a no-charge option on those models. The full-time all-wheel-drive system has a front-to-rear 40/60 torque split, but the car varies torque distribution to individual wheels under slippery conditions.

A new seven-speed-automatic transmission went into rear-wheel-drive S430 and S500 sedans for 2004. A DVD-based navigation system and MP3 play capability became standard.

Mercedes-Benz describes the S-Class as a sedan with a coupelike profile that's highlighted by a low nose and taller tail. A laid-back grille and smooth underbody improve airflow, which keeps the sedan's coefficient of drag at a mere 0.27.

The S55 AMG features a sport suspension, racy aerodynamic body trim and 18-inch tires on Monoblock alloy wheels. Both the S600 and S55 AMG have Active Body Control that continuously adjusts suspension firmness to eliminate body roll during cornering, acceleration and braking.

Fitted with a three-place rear bench, the S-Class seats up to five occupants. A split rear bench with power adjustments is optional. The front seats have 14-way power adjustments. Full leather upholstery, a navigation system and a Bose audio system are standard. Befitting its price, the S600 gets four heated power seats and a higher level of wood and leather trim. Adaptive cruise control is optional.

Under the Hood
Mercedes-Benz offers three V-8s and a V-12. The S430 holds a 275-hp, 4.3-liter V-8, and the S500 gets a 302-hp, 5.0-liter V-8. The high-performance S55 AMG uses a 493-hp, supercharged 5.5-liter V-8. The S600 sedan carries a turbocharged 5.5-liter V-12 that delivers 493 hp and 590 pounds-feet of torque. A seven-speed-automatic transmission goes into rear-wheel-drive S430 and S500 sedans, while the S55 AMG, S600, and 4Matic-equipped S430 and S500 sedans use a five-speed automatic.

Side-impact airbags are installed in each door. Side curtain-type airbags deploy from the roofline to protect occupants' heads. An Electronic Stability Program stability system combines traction control with lateral skid-control technology.

Driving Impressions
Loaded with technology, the S-Class is a smooth and supremely capable cruiser that may initially be marred by a slight sense of detachment; but that sensation soon eases. Despite its bounty of alluring attributes, the steering seems just a little too light.

Even in the S500, performance is near stunning and automatic-transmission response qualifies as masterful. Although the ride is smooth, the S500 hits a few bumps rather hard. In fast curves, this big sedan stays remarkably upright.