Vehicle Overview
The CLS line receives a light restyling for 2009 in a model that's otherwise mostly unchanged. Including the CLS550 and CLS63 AMG, the CLS-Class competes with the likes of the Audi A8, BMW 650 and Jaguar XK.

Dubbed a four-door coupe, the CLS-Class features a high belt line and short side windows. A distinctive body crease rises from the front wheel arch, extends across the side and continues through the contoured rear light cluster into the back bumper. The face-lift for 2009 includes a switch from a four-bar grille to a two-bar chrome design with gray mesh behind it. The side mirrors have been enlarged, and the turn-signal lights are now arrow shaped. New LED taillights are arrowhead shaped, and the new bumper sports trapezoidal dual tailpipes.

Projector-type headlights are standard, and bi-xenon headlights are optional. An automatic cornering light function with the bi-xenon units switches on the cornering lights during a turn, and the adaptive headlights pivot to follow the driver's steering movements.

The CLS seats up to four. The four-door layout permits easy entry and exit. Power front seats are standard and may be equipped with optional heating and ventilation. Massaging front seats are also optional. The instrument panel's central speedometer is flanked by a tachometer and clock. Completely black on the previous generation, the gauge faces are now white along their outer edges. Bar-graph displays show the fuel level and coolant temperature. The steering wheel is also new for 2009 — a slender, three-spoke design replacing a wheel with four short spokes and an overbearing center pad. The Comand interface — which controls the stereo, optional navigation and Bluetooth phone — has improved menus and controls.

Under the Hood
Beneath the hood of the CLS550 is a V-8 rated at 382 horsepower. The CLS63 AMG steps up to a 507-hp, 6.2-liter V-8. Built by hand at Mercedes' AMG division, the 6.2-liter shares no parts with the regular V-8. The transmission in both models is a seven-speed automatic with manual-shift provisions. The AMG Speedshift is calibrated for 35 percent faster shifts. Mercedes cites 0-60 mph times of 5.4 seconds for the CLS550 and 4.3 seconds for the CLS63 AMG. An optional performance package on the latter increases the 155-mph top speed to 186 mph.

The CLS63 also has firmer suspension tuning with three selectable comfort settings on the Airmatic air-spring suspension. It has larger brake discs than the CLS550, along with six-piston front and four-piston rear brake calipers. The CLS550's are four- and two-piston types, respectively. The CLS550's wheels are 18 inches in diameter, and the CLS63's are 19 inches.

Mercedes' Pre-Safe system is standard. It pre-tensions seat belts, moves the seats into a safer position and closes the sunroof if its forward-looking radar senses an impending collision. An electronic stability system, antilock brakes, front and rear side-impact airbags, and side curtain airbags are standard.