The sixth generation of the Mercedes-Benz SL550 roadster is being launched in 2012, 60 years after the first SL model debuted, with an all-new aluminum unit body, with torsional rigidity that's 20 percent stiffer than the previous-generation steel body. The SL550 coupe (pictured above) is powered by a new 429 horsepower 4.6-liter V8 engine with direct fuel injection, twin turbochargers and multi-spark ignition mated to a 7 speed automatic transmission. The engine has 20 percent smaller displacement but generates more horsepower and torque than the previous generation. A pair of paddles strategically positioned behind the upper steering-wheel spokes allows you to manually upshift and downshift the 7-speed automatic transmission with just a flick of your fingers. MSRP is $106,405 (including $905 transportation charge).
The new SL550 engine comes with an ECO stop-start system. Whenever the car stops with the brake pedal depressed, the engine is automatically turned off to save fuel. As soon as the driver touches the accelerator pedal, the engine computer selects the piston that is in the best position for first ignition, and the direct fuel injection and multi-spark systems work with a starter motor to seamlessly re-start the engine.
At the push of a button, the roof is opened or closed in less than 20 seconds. During this transformation, an intelligent tilting mechanism ensures that the roof and rear window "spoon" and retract into the top section of the trunk to preserve a good deal of useful trunk space.