New power plant provides for more power and better fuel economy. The S 63 AMG gets 10.5 liters/100 km in the European cycle. The model goes on sale in September.

Mercedes-Benz AMG has announced the new 2011 S 63 AMG will come with the performance division's latest 5.5 liter biturbo V8 engine.

That power plant has an output of 537 bhp (400 kW / 544 PS) and 800 Nm (590 lb-ft) of torque. With the AMG Performance Package, that gets tuned up to 563 bhp (420 kW / 571 PS) and 900 Nm (664 lb-ft). The new S 63 AMG couples both those iterations to the 7-speed Speedshift MCT transmission.

Mercedes-Benz is living up to its promise of recent years to greatly improve fuel-economy on all its vehicles (and its AMG vehicles, in particular) without any compromise in performance. With the addition of a stop/start system, fuel-economy on the S 63 AMG comes in at 10.5 liters/100 km in the European cycle, and the engine represents a 25 percent increase in fuel-efficiency over the model's previous 6.3 liter V8 unit while boosting overall power as well.

The S 63 AMG hits the 100 km/h mark in just 4.5 seconds - 4.4 with the performance package. Top speed is electronically limited to 250 km/h (155 mph) on the standard model but is bumped up to 300 km/h (186 mph) when buyers opt for the package.

Tech goodies include Active Lane Keeping and Blind Spot Assistance. The sport suspension has such features as Active Body Control for crosswind stabilization. Torque Vector braking keeps things tight in the corners as well and the Direct Steer system also helps with handling and response in the curves.

The car comes standard with 19-inch triple-spoke light-alloy AMG wheels in titanium gray.

On the inside is an AMG instrument panel with AMG V8 Biturbo logo on the screen. That logo also subtlely tags the outside of the vehicle too. There's also a sound-system by Bang & Olufsen and the Passion leather finish.

The S 63 AMG goes on sale in September.

Prices start at €143,752 (including 19% VAT in Germany) for the short wheelbase version, €151,368 for the stretched variant.

Gallery: 2011 Mercedes S63 AMG gets new 5.5 liter V8 biturbo engine - in detail