Porsche has unveiled the top dog in its Gran Turismo line. The new Panamera Turbo S raises the four-door sports car bar with a 4.8 liter, V8 biturbo charged engine that delivers 550 hp (410 kW) , which is 50 hp (37 kW) more than the engine found in the Panamera Turbo. The Panamera Turbo S also ups the torque from 700 to 750 Nm, while an overboost function in "Sport" and "Sport Plus" mode sees the torque peak at 800 Nm. These improvements allow the car to go from a standing start to 100 km/h (62 mph) in 3.8 seconds, on its way to a top speed of 306 km/h (191 mph).

Porsche says that, despite the increase in performance, the fuel consumption of the Panamera Turbo S remains at the same level as the Panamera Turbo. Under the European NEDC system the vehicle covers 100 km (62 miles) on 11.5 liters (20.45 mpg U.S.), which falls to 11.3 liters per 100 km (20.81 mpg U.S.) when fitted with the 19-inch, all-season tires with optimized rolling resistance developed especially for the Panamera by Michelin.

Porsche attributes the increase in performance of the Panamera Turbo S over the Panamera Turbo to two key enhancements. Firstly, improved turbochargers with titanium-aluminum alloy that reduces the weight of the turbine and compressor wheel, and secondly, modified engine control. The company says these combine to provide the Turbo S with a lower moment of inertia and more agile engine responsiveness.

Agility extends beyond the engine too, with a Porsche Dynamic Chassis Control (PDCC) active roll stabilization system that curtails the vehicle's tendency to lean when cornering. Additionally, the Gran Turismo's Porsche Torque Vectoring Plus (PTV Plus) system applies a variable torque split to the rear wheels and combines with an electronically controlled rear differential lock to provide superior traction.

The Panamera Turbo S also comes with the Sport Chrono Package Turbo as standard, which tunes the suspension and power unit for sportier performance at the push of a button.

The exterior sees an increased rear axle track width, 20-inch Turbo II wheels and adaptive extending four-way spoiler. While inside there's a bi-color leather finish, which is offered in a new black/cream combo exclusive to the new Panamera Turbo S, with an also exclusive grey/cream combo to be available from autumn (Northern hemisphere).

Porsche will start deliveries of the new Panamera Turbo S in June, 2011, with the vehicle costing EUR167,076 (approx. US$236,116) in Germany.