This is the facelifted SL55 AMG. No, really it is. You can tell by the er, well... Okay, so the styling changes Mercedes-Benz made to its supercharged 5.4-liter V8-powered roadster are relatively minor: slightly reprofiled front bumper, three-slat grille in place of the earlier four-slat unit, redesigned tail-lamp lenses and new 18-inch wheels. Stand it next to the former model and we guarantee you will have a hard time telling the difference.
It's underneath where all the interesting stuff lurks. For starters, the SL55 AMG's three-valve-per-cylinder engine is reworked to deliver an added 17 hp, taking peak power up to 510 hp at 6100 rpm. Torque, always an SL55 AMG strength, also increases, topping out at 531 lb-ft between 2600 and 4000 rpm. Not exactly lacking in firepower, then. Changes to the engine include a larger throttle valve on the inlet manifold for improved breathing, changes to the management system to alter the operation of the fuel-injection system to make it cylinder selective, and there is a new supercharger unit that is claimed to be more efficient at higher operating speeds. The engine is mated to Mercedes' five-speed automatic.
Mercedes claims 0.2 second is shaved from the 0-to-62 time of 4.5 seconds with top speed limited to 155 mph, although North American customers can pay extra to have the top end extended to 186 mph.
This SL55 AMG is a more compelling car to drive hard over challenging roads than its predecessor. The car's overall character remains pretty much the same, but with greater control and added directness built into the chassis you find your confidence levels growing. Changes to the active body control system help rein in body movements faster and provide a more progressive action.
The steering ratio is also sharpened with new mapping and a revised hydraulic pump combined with a reworked damper for the steering rack. Along with more compliant bushings on the four-link front suspension, this improves on-center steering feel and provides sharper turn-in response. The former model's electrohydraulic brakes are replaced by a fully hydraulic system.