Minus its former SL600 model, the 2011 Mercedes-Benz SL range still spans a big part of a very narrow performance niche. There's a V-8 in the least-expensive SL550, and true to its badge, it's a 5.5-liter engine that pumps out 382 horsepower through a paddle-shifted seven-speed automatic. The drivetrain's found across most of the Mercedes lineup, and it's a tart performer, with a promised 0-60 mph time of under six seconds and a top speed of 155 mph. Only in the rarified world of pro athletes and the very well-heeled, would the SL550's performance be found wanting.
In the two AMG versions of the hardtop convertible, you'll find two very different powertrains. The SL63 AMG thunders along courtesy a 6.2-liter V-8--the AMG division's first home-brewed engine--and it howls with 518 hp, teamed to an automated-manual seven-speed transmission. AMG says this one's up for a 0-60 mph rocket ride of less than 4.8 seconds.
At the very pinnacle of the SL universe is the MVP bauble, the Timberlake ride: the 604-hp, twin-turbo, 6.0-liter V-12 SL65 AMG. This hoary piece shovels that power and 738 pound-feet of torque out through a five-speed automatic; two fewer beefier gears means it can handle the monster acceleration and can help the SL65 AMG post 4.2-second runs to 60 mph.
There's a distinct difference between the SL550 and the AMG SLs, though all now have the Direct Steer system that quickens the car's response as the steering wheel moves farther off-center. The AMG SLs have much tauter tuning and faster steering, and even they have an absorbent, comfortable ride. Credit for that achievement goes to Active Body Control (ABC), a suspension setup that lets drivers choose comfort, normal, and sport driving modes. It's not needlessly complex with separate selections for steering and throttle, as are some other driver-configurable systems like Audi's Drive Select.