AMG Develops New V8 for SLK AMG That Blends Power and Efficiency

AMG is known for its powerful V8s and V12s in Mercedes' highest performance models, which usually comes at a detriment to efficiency and emissions. Now AMG has developed a new V8 that improves fuel consumption by 30% and increases power. 

The new 5.5 liter V8 makes 422hp, 62hp more than the previous SLK55 AMG, and fuel consumption has dropped 3.5 liters down to 8.5l/100km. The new engine does this through a combination of direct injection and cylinder deactivation. Mechanically, it is basically identical to the 5.5l V8 biturbo used in the E63 AMG and CL63 AMG, but the turbos have been removed. In their place, the engine gets a new intake, cylinder heads and valve train to allow for the cylinder deactivation. 

The cylinder deactivation works by cutting off four of the cylinders under partial load meaning that under most conditions the engine is actually a four cylinder. It takes just 30 milliseconds for the engine to go from running on four cylinders to running on eight. Drivers can even select a mode called Controlled Efficiency that forces the engine to stay in four-cylinder mode below 3600rpm. 

To further improve fuel economy the engine also uses start/stop technology. 

The new V8 will debut in the third generation SLK AMG in September at Frankfurt Motor Show in Germany.