Mercedes SLK55 AMG Coming at Frankfurt With New 5.5L V8

The SLK-Klasse AMG for the Frankfurt Motor Show will be equipped with a new 5.5-liter V8 engine. The 5,461cc engine in the new Mercedes is a normally aspirated version of the twin-turbo 5.5-liter V8 that powers the new CLS63 AMG and E63 AMG models.

In order to pack the all aluminum 187kg V8 in the SLK the removal of the two turbos was necessary.The new 5.5 V8 has received an extra 60hp over the old V8 in the outgoing SLK55 AMG to 420 hp, while torque has risen from 509 Nm to 539 Nm (376lb-ft to 398lb-ft), acording to autocar.co.uk.

Also, the fuel economy and CO2 emissions have been improved by 30% in the new SLK55-AMG over the old model. The engine features an innovative F1-inspired AMG Cylinder Management shut-off system, that allows the engine to run on just four cylinders under partial loads to help economy. The SLK55 AMG will also feature a new sports exhaust system with two separate rear silencer flaps. These stay closed at low revs below 2000rpm, and progressively open as the driver applies more throttle for a louder exhaust note.

Alongside the SLK55 AMG at Frankfurt will be a diesel version of the new SLK, the first time an oil-burner has features in the roadster. The Mercedes SLK250 CDI will be powered by a 201hp four-cylinder turbodiesel that is already used in many of the staple Mercedes models. Both models are expected to enter showrooms by early 2012.