BMW i8 vs Porsche 911

BMW i8 vs Porsche 911
4 Aug, 2014 11:31am

Cutting-edge hybrid sports car, the BMW i8, meets a high-performance legend in the shape of the Porsche 911

BMW is out to rip up the sports car rulebook with its all-new i8. Featuring jaw-dropping looks and advanced construction, the hi-tech newcomer promises to blend scorching supercar performance with supermini running costs. And its figures certainly make remarkable reading. With 357bhp the i8 is capable of sprinting from 0-60mph in under five seconds, yet it claims nearly 135mpg at the pumps, and boasts emissions of just 49g/km.

Facing the bold new BMW is one of the oldest sports cars on the planet: the Porsche 911. However, while the legendary rear-engined machine has been around for 50 years, the latest seventh-generation model is one of the most complete performance cars ever.

BMW i8 review

Porsche 911 review

So, can the futuristic BMW topple the perfectly evolved Porsche?

Click on the links above to read each in-depth review, then read on for our verdict.


Interior space

There’s little to choose between our contenders when it comes to practicality. Both feature a similar 2+2 seating layout, although the BMW’s lower roofline means it has less headroom here, while each car’s boot will swallow a couple of bags for a weekend away.

Forward visibility is excellent in both models, but the Porsche is easier to park due to its larger rear windows. That’s no bad thing given parking sensors are £396 extra.

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.

Bmw i8 design secrets

The i8’s jaw-dropping beauty is clearly much more than skin deep. Lift off the car’s sculpted panels and you’ll discover a lightweight but strong carbon fibre-reinforced plastic structure, which is mounted to an aluminium chassis that carries the BMW’s engine, electric motor, lithium-ion batteries and suspension components. All in, the i8 weighs just 1,485kg, which is remarkable, given the amount of heavyweight items it’s carting around.

The innovation extends to the drivetrain, which features a highly tuned 228bhp version of the new 1.5-litre three-cylinder engine that recently debuted in the new MINI. The front axle is driven by an electric motor with its own two-speed gearbox.

Perhaps the BMW’s greatest party trick is its ability to make the most efficient use of the hybrid motor by linking up to the car’s sat-nav. Plot your destination into the route-finder and the i8 will attempt to calculate the best way to use battery and electric power.

For instance, if there are a number of towns on your journey, the car’s electronic brain will keep enough battery power stored to get you through the urban section in electric mode only.


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

BMW i8 UK action

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 this.


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