As usual for the Porsche 911, the 991 generation is an evolutionary design step. Two basic principles were strictly respected: the roof line is less arched and tapers down into the rear and the front wings are higher than the lid.
Compared to the outgoing 997, the 991 is slightly larger, with the wheelbase increased by 100 mm (3.9 in) to 2,450 millimetres (96.5 in), and 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 to 1,380 kg (3,040 lb) for the manual Carrera, rising to 1,605 kg (3,538 lb) for the four wheel drive Turbo model with PDK (Porsche Doppelkupplung). PDK is available as an option for all 911 Carrera models as 7-speed transmission, featuring manual and automatic modes. Gears 1 to 6 have a sports ratio and top speed is reached in 6th gear. 7th gear has a long ratio and helps to reduce fuel consumption by keeping engine revs low. PDK is essentially two gearboxes in one and thus requires two clutches. For all 991 models PDK is produced by ZF Friedrichshafen. The auto start/stop function is standard in the 911 Carrera models.
Base models, introduced in September 2011 at the Frankfurt Motor Show. The Carrera is equipped with a 3.4 litre boxer engine with direct fuel injection, 350 PS (257 kW; 345 bhp) at 7,400 rpm and 390 N·m (288 lb·ft) at 5,600 rpm. The Carrera S has a 3.8 litre engine with 400 PS (294 kW; 395 bhp) at 7,400 rpm and 440 N·m (325 lb·ft) at 5,600 rpm.
The convertible model of the 991 was announced in both Carrera and Carrera S versions, at the LA Motor Show in November 2011.
In September 2012 at the Paris Motor Show, all-wheel-drive variants - the Carrera 4 and 4S, were added to the line-up.
Introduced in November 2014 at the LA Motor Show, the 991 Carrera GTS sits between the Carrera S and GT3. Base options included with purchase: 430 PS (316 kW; 424 bhp) PowerKit, Sport Chrono Package, Sport Exhaust System, Dynamic Engine Mounts, 10mm lowered suspension, Porsche Torque Vectoring (PTM) system, LED daytime running lights with Porsche Dynamic Lighting System (PDLS), Sport Design Front Spoiler, Sport Design Rear Mirrors, GTS badging, and 20" Centerlock wheels. When optioned with PDK, 0-60 mph is achieved consistently at 3.8 seconds with the help of Launch Control.
At the Detroit Motor Show in January 2014, Porsche introduced the Targa 4 and Targa 4S models. These new derivatives come equipped with an all-new roof technology with the original targa design, now with an all-electric cabriolet roof along with the B-pillar and the glass 'dome' at the rear.
On January 12, 2015, Porsche announced the 911 Targa GTS at the North American International Auto Show in Detroit. Similar in appearance to the existing Targa 4 and 4S models, the GTS added the 430 PS (316 kW; 424 bhp) engine plus several otherwise optional features.
With the introduction at the Geneva Motor Show, in March 2013, of the latest GT3 model came the announcement of active rear steering. It is claimed by Porsche to provide higher lateral dynamics than previously available. Car speed inputs determine whether the rears steer in the same or opposite direction of the front wheels. It is the first GT3 offered only with automatic transmission.
At the start of 2014, deliveries of the GT3 were halted following two fires. A subsequent recall to replace the engines of all 785 cars was announced in March 2014 before manufacturing of the GT3 would restart.
Porsche launched the RS version of the 991 GT3 at the Geneva Motor Show in 2015. Compared to the 991 GT3, the front fenders are now equipped with louvers above the wheels and the rear fenders now include 911 Turbo-like intakes, rather than an intake below the rear wing. The roof is made from magnesium. The interior includes full bucket seats (based on the carbon seats of the 918 Spyder), carbon-fibre inserts, lightweight door handles and the Club Sport Package as standard (a bolted-on roll cage behind the front seats, preparation for a battery master switch, and a six-point safety harness for the driver and fire extinguisher with mounting bracket).
The 3.8-litre unit found in the 991 GT3 is replaced with a 4.0-litre unit with 500 horsepower and 339 lb·ft (460 N·m) of torque. The transmission is PDK only. The drivetrain delivers 0 to 100 km/h (62 mph) in 3.3 seconds (0.6 seconds quicker than the 997 GT3 RS 4.0) and 0-200 km/h (0-124 mph) in 10.9 seconds. The 991 GT3 RS also comes with functions such as declutching by "paddle neutral" — comparable to pressing the clutch with a conventional manual gearbox – and Pit Speed limiter button. As with the 991 GT3, there is rear-axle steering and Porsche Torque Vectoring Plus with fully variable rear axle differential lock.
Revealed at the 2016 Geneva Motor Show on March 1, the 911 R shares most of its underpinnings with the GT3 RS, but removes the roll cage, rear wing, and associated bodywork for a weight savings of 50 kg. The R comes only with a 6-speed manual transmission, and has a top speed of 323 km/h (201 mph) due to a lower drag coefficient compared to the GT3 RS. It also offers additional options for a lighter flywheel and removal of the air conditioning and audio systems. Production will be limited to 991 examples, as a 2016 model.
Introduced in May 2013, the 991 Turbo has a twin-turbocharged 3.8 litre engine generating 520 PS (382 kW; 513 bhp) and 620 N·m (457 lb·ft) of torque. The S version has 560 PS (412 kW; 552 bhp) and 700 N·m (516 lb·ft) of torque, but the torque is pushed to 750 N·m (553 lb·ft) with overboost. Both vehicles have all-wheel drive and a seven-speed dual clutch sequential transmission. The Turbo S can reach 100 km/h (62 mph) in 3.1 seconds as claimed by Porsche but has achieved 2.6 seconds by many car magazine tests. New technologies featuring adaptive aerodynamics and rear wheel steer are new on these cars.
Turbo Cabriolet and Turbo S Cabriolet versions were added to the range at the 2013 Frankfurt Motor Show.
(SC) = Sport Chrono (PK) = Powerkit
Following an introduction at the 2015 Frankfurt Motor Show, the 991 was revised for the 2016 model year. The updated Porsche 911 (referred to as 991.2 internally at Porsche) introduced new styling and options, along with all new, smaller 3.0-litre twin-turbocharged flat-six engines across the range. This was the first time standard Carrera models had adopted turbocharged engines rather than naturally aspirated ones, which was criticised for lacking engine noise and feeling that previous non-turbo variations had.
Initially available models include coupé and cabriolet versions of Carrera and Carrera S, with Carrera 4, Carrera 4S, Targa 4 and Targa 4S coming a few weeks later.
In December 2015, Turbo and Turbo S versions were launched. In 2017, GTS versions were launched. Later on in the year at the 2017 Geneva Motor Show, the facelifted GT3 was revealed, sporting a larger 4.0-litre flat-six engine, aerodynamic upgrades, a revised look and an optional 6-speed manual gearbox, something which was absent on the 991.1-generation GT3.
The Porsche 991 was titled World Performance Car 2012 shortly after famed Porsche designer Ferdinand Alexander Porsche died. The GT3 was awarded the title of World Performance Car Of The Year in 2014.