Naturally-aspirated M152 unit produces 310 kW (416 bhp / 422 PS) and 540 Nm (398 lb-ft) of torque and has been just introduced in the new 2012 SLK 55 AMG.

Mercedes-Benz has produced this video introduction for the new AMG naturally-aspirated 5.5 liter V8 engine.

The unenhanced-breathing M152 engine comes with 310 kW (416 bhp / 422 PS) and 540 Nm (398 lb-ft) of torque and will be first seen in the newly launched 2012 SLK 55 AMG.

The M152 comes with a new feature called AMG Cylinder Management - a cylinder shut-off system that can reduce the V8 to a four-cylinder while still delivering a healthy 230 Nm (170 lb-ft) of torque. That provides for a 30 percent improvement in fuel-economy over the engine it replaces and good for a rating of 8.5 liters/100 km in the new SLK 55 AMG. 

The engine is based on the M157 unit - a 5.5 liter twin-turbo V8 introduced last year - with both units sharing the same displacement (bore/stroke).