The SL suffix always has been a bit optimistic, even when applied to the original Mercedes-Benz SL roadster of 1957. Although the car was definitely sporty, it wasn't exactly light, tipping the scales at a relatively well-fed 2926 pounds. With each successive generation, Stuttgart's SL has turned into a Serious Leviathan. The latest and--literally--greatest iteration is the line's new flagship, the SL55 AMG. It weighs a sumoesque 4311 pounds--143 more than the already hefty SL500. Mercedes and its in-house tuner AMG have more than compensated for this portliness, however, with a sensational V-8 engine that answers all questions and quashes all doubts. Wedging a belt-driven, screw-type supercharger between the cylinder banks of AMG's all-aluminum, SOHC 5.5-liter V-8 adds 167 horses to the SL corral, for a total of 469. The result is a true thoroughbred, a serious rival for the Porsche 911 Turbo, the Aston Martin V12 Vanquish, and the Ferrari 360 Modena.
Visually, the AMG version of the fifth-generation SL is no improvement over the SL500. The various spoilers, the chiseled rocker covers, and the F1-inspired nose seem to neutralize the SL's stealthy appeal.... Read full article