AMG Action! Mercedes eyes new naturally aspirated V8

Mercedes-Benz has selected the twin turbocharged 5.5-liter V8 engine to power the recently unveiled S63 AMG, CL63 AMG and CLS63 AMG, with ratings between 525 hp and 577 hp.

But it's going to be a different story for the successor to the SLK55 AMG set to be revealed at next year's Frankfurt motor show. Sources within the Stuttgart headquarters suggest the new performance roadster is earmarked to receive a yet-to-be revealed naturally aspirated version of Mercedes-Benz's new 5.5-liter V8.

Tuned by AMG's powertrain department, it is claimed to deliver about 422 hp-- 62 hp more than the 5.4-liter V8 used by the outgoing SLK55 AMG. Among the developments featured on the new 90-degree engine is a cylinder cut-off mechanism conceived to lower consumption.

Meanwhile, insiders say AMG will retain the naturally aspirated 6.2-liter V8 in the facelifted C63 AMG set to hit North America in early 2011.

The AMG variant of the upcoming two-door CLK replacement, however, is likely to adopt the same naturally aspirated 5.5-liter V8 engine as the new SLK55 AMG.

Heading the new C-class coupe lineup, the C55 AMG coupe is set to spawn a hardcore Black Series model aimed at the recently unveiled, limited-production BMW M3 GTS.

By Greg Kable