BMW i8 vs. Porsche 911 – Which One Is A Better Car?

BMW i | August 5th, 2014 by 4
BMW i8 Vs Porsche 911 8 750x500

AutoExpress UK sets out to find out if the BMW i8 is a better car than the renowned Porsche 911.

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 Vs Porsche 911 8 750x496

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.

2nd place: BMW i8

In many respects, the i8 is a watershed moment in sports car history. By blending hi-tech engineering and supermini running costs with supercar pace and show car looks, BMW has redefined what’s possible for a performance car. Yet it lacks the driver engagement that makes you want to take it out just for the hell of it. Don’t underestimate the importance of the BMW, though. One day, all sports cars will be like t


Porsche 911 Carrera S PDK BMW i8
On-the-road price/total as tested £86,623/£109,306 £96,385/£105,840
Residual value (after 3yrs/30,000) £43,658/50.4% £52,337/54.3%
Depreciation £42,965 £44,048
Annual tax liability std/higher rate £5,843/£11,687 £999/£1,999
Annual fuel cost (12k/20k miles) £3,545/£5,909 £1,985/£3,308
Ins. group/quote/road tax band/cost 47/N/A/K/£285 50/N/A/A/£0
Cost of 1st/2nd/3rd service £480/£610/£480 £1,000 (5yrs/60k)
Length/wheelbase 4,491/2,450mm 4,689/2,800mm
Height/width 1,295/1,808mm 1,298/1,942mm
Engine Flat-six/3,800cc 3cyl/1,499cc/electric
Peak power 395/7,400 bhp/rpm^ 357/5,800 bhp/rpm
Peak torque 440/5,600 Nm/rpm^ 570/3,700 Nm/rpm
Transmission 7-spd auto/rwd 6-spd auto/4wd
Fuel tank capacity/spare wheel 64 litres/sealant 42 litres/sealant
Boot capacity 145 litres 154 litres
Kerbweight/payload 1,415/435kg 1,485/370kg
Turning circle/drag coefficient 11.1 metres/0.29Cd 12.3 metres/0.26Cd
Basic warranty (miles)/recovery 3yrs (unltd)/3yrs 3yrs (unltd)/3yrs
Service intervals/UK dealers 18,000 (2yrs)/36 Variable/153
Driver Power manufacturer/dealer pos. 6th/6th* 10th/24th*
Euro NCAP: Adult/child/ped./stars N/A N/A
0-60/30-70mph 3.7/3.2 secs 4.6/3.7 secs
30-50mph in 3rd/4th 3.0/4.1 secs 1.8/2.5 secs
50-70mph in 5th/6th/7th 4.8/6.6/11.0 secs 3.2/4.0 secs/N/A
Top speed/rpm at 70mph 187mph/1,800rpm 155mph/2,000rpm
Braking 70-0/60-0/30-0mph 43.1/31.9/8.2m 44.0/32.5/10.2m
Noise levels outside/idle/30/70mph 67/48/60/70dB N/A/N/A/64/73dB
Auto Express econ (mpg/mpl)/range 21.5/4.8/303 miles 38.4/8.5/355 miles
Govt urban/extra-urban/combined 23.3/42.2/32.5mpg N/A/N/A/134.5mpg
Govt urban/extra-urban/combined 5.1/9.3/7.2mpl N/A/N/A/29.6mpl
Actual/claimed CO2/tax bracket 304/202g/km/34% 170/49g/km/5%
Airbags/Isofix/park sensors/camera Six/yes/£396/£1,085 Six/yes/yes/yes
Adapt dampers/stability/cruise ctrl Yes/yes/£267 Yes/yes/yes
Climate ctrl/leather/heated seats Yes/yes/£320 Yes/yes/yes
Met paint/LED lights/keyless go £801/£1,926/£801 Yes/yes/£795
Sat-nav/USB/DAB radio/Bluetooth Yes/yes/yes/£446 Yes/yes/yes/yes