Introduced late in the 2003 model year, this CLK55 AMG is powered by the same 5.4-liter naturally aspirated V-8 that motivated its predecessor, tuned for 20 more horses (freer breathing brings the total to 362), with torque holding at 376 pound-feet. The reinforced five-speed automatic features AMG's Speedshift programming. Sport and comfort modes adapt shift points and firmness to differing driving styles, or press a button for manumatic mode, and the driver can control shifts via the lever or via buttons on the back of the steering wheel. In this mode it remains more manual than most Benzes, upshifting to prevent over-revving but never downshifting at wide-open throttle.