The current direct injection 3.8-litre flat-six engine from the Carrera S remains, with power increasing to 400 PS (294 kW; 395 hp). The Carrera engine is a 3.4-litre, producing 350 PS (257 kW; 345 hp). The car features an optional stop/start system and also electro-mechanical power steering. The car also features a new seven-speed manual gearbox, a first for a production car, along with an improved seven-speed PDK dual clutch transmission.
Compared to the outgoing 997, the 991 wheelbase has increased by 100 mm (3.9 in) to 2,450 millimetres (96.5 in), with the overall length up by 70 mm (2.8 in) to 4,490 millimetres (176.8 in). A new transaxle was developed so that the rear wheels could be moved 76 millimetres (3 in) backward in relation to the position of the engine, which significantly improves the weight distribution and cornering performance of the new 911. Due to the use of high-strength steels, aluminium and some composites the weight has been reduced by 45 kg (99.2 lb) to 1,395 kilograms (3,075 lb) for the manual Carrera S and 1,420 kilograms (3,120 lb) for the Carrera S equipped with the Porsche Doppelkupplung. Porsche also makes the Cayman and the Boxter.
Images of the 991 were widely published on the internet on 18 August 2011, prior to the car's official debut. The photos revealed Porsche had taken an evolutionary design step, in keeping with the previous generation 997 and 996.
The Porsche 991 was titled World Performance Car 2012 shortly after famed Porsche designer Ferdinand Alexander Porsche died.
It competes with such super cars like the McLaren MP4-12C, the Ferrari 458 Italia and California and, perhaps its biggest rival(both, on the street and the nurburgring lap record tables), the Nissan GTR.
Porche also made another legendary car, the Carrera GT, which was named the supercar of the decade 2000-2010.