The Porsche 991 uses a direct injection 3.8-liter flat-six engine from the Carrera S model, with power increasing to 400 PS (294 kW; 395 hp).
New for the first time on a 911 model are electronic parking brakes (button selectable) and 20 inch diameter wheels. The car also features a new seven-speed manual gearbox, a first for a production car, along with an improved seven-speed Porsche Doppelkupplung (PDK) dual clutch transmission.
BMW i8 uses a plug-in hybrid system consisting of a turbocharged three-cylinder BMW TwinPower Turbo petrol engine and BMW eDrive technology in the form of an electric drive system. The 1.5-liter combustion engine develops 170 kW/231 hp and drives the rear wheels of the BMW i8, while the 96 kW/131 hp electric drive sends its power to the front wheels and allows an all-electric range of up to 35 kilometers (22 miles) and a top speed of 120 km/h (75 mph).
Here is an excerpt from their review:
Going the distance
Our 21.5mpg fuel return suggests the 911 will go around 300 miles between fill-ups. Thanks to the i8’s efficient three-cylinder engine, it has a 50-mile longer range, despite the fact its tank takes only 42 litres of fuel. Plug into the mains for three hours or so and the BMW offers an extra 22 miles of all-electric range.
Company car tax
If you’re considering these models as a company car, the BMW i8 is a no-brainer. Emissions of 49g/km mean it has a Benefit-in-Kind rate of five per cent, so higher-rate earners pay £1,999 a year. That’s £9,688 less than those choosing the 911, which emits 202g/km and is taxed at 34 per cent.
1st place: Porsche 911
If you’re buying a sports car, then ultimate driving thrills will be at the top of your shopping list – and in this respect the 911 remains unrivalled. With its agile and adjustable handling, strong performance and scintillating soundtrack, the Porsche is one of the most engaging and involving cars money can buy. However, the hi-tech i8 shows that the 911 will have to evolve if it wants to stay on top in the future.