BMW i8 review (2013 prototype)

BMW i8 review (2013 prototype)

BMW's fascinating i8 plug-in hybrid car isn't like any other sports car you've ever driven.

What: BMW i8
Where: Miramar, France
Date: August 2013
Price: from £100,000 (est.)
Available: Spring 2014

BMW i8: first impressions

The BMW i8’s roots can be traced back to the Vision EfficientDynamics concept car of 2009. That car was built to demonstrate BMW’s future technologies but the response proved so positive that they decided to build a production version. A small team of crack engineers has developed the car in roughly half the time it normally takes BMW to build a new model.

The i8 is a plug-in hybrid sports car and will sit alongside the i3 family hatchback in BMW’s new ‘i' range of technologically advanced alternatives. It features two electric motors and a small, turbocharged petrol engine. The final production versions will be unveiled at next month’s Frankfurt show but while our pre-production test cars wore disguise, it was clear that the Vision’s futuristic styling remains largely intact.

Although the i8 is a rival to Porsche 911 in terms of size, price and performance, BMW expects it to appeal to a different type of customer. This is a car for those who want to present themselves as a style-setting eco-warrior.

BMW i8

 

BMW i8: performance 

The i8 has an engine, two motors, two fuel sources and two gearboxes, which must all join hands and pull together. BMW’s engineers admit that getting all this to work in harmony was the biggest challenge they faced.

To create the petrol engine, the engineers chopped their 3.0-litre, six cylinder engine in half to create a 1.5-litre, three cylinder. This is effectively the engine that will be used in the next generation Mini Cooper, although it remains to be seen whether the Mini will have a turbo capable of delivering 228bhp. It’s mated to a six-speed automatic gearbox with steering-wheel-mounted paddle-shifters for added entertainment.

The electric motor in the front is shared with the i3 but retuned to deliver 129-bhp to the front wheels. Unusually for an electric car its power is delivered through a two-speed gearbox to help the car reach its 155mph top speed. There’s a second motor in the rear and both are fed from a battery pack mounted between the driver and passenger. This is relatively small – a maximum of 5kWh – and can be recharged in a couple of hours using a conventional plug.

The i8 is good for 0-62mph in ‘under 4.5 seconds’

Add all this together and you have a combined output of 357bhp and 420 lb ft of torque. By comparison, a Porsche 911 Carrera S develops 395bhp and 324 lb ft.

BMW claims the i8 is good for 0-62mph in ‘under 4.5 seconds’ in Sport mode. This may be a function of the traction of four-wheel drive because the i8 never feels that quick - think Cayman rather than 911. It’s still not what you’d call slow, though, and the motors do a good job of supplementing the engine and offsetting any turbo lag.

The production cars are still about six months away and BMW’s engineers admit they’re still tweaking the various systems. At present the intervention of the petrol engine feels a little too abrupt and the engine note, which blends real and artificial tones, lacks the sophistication you’d expect of a £100k sports car.

BMW

 

BMW i8: ride and handling

Clever use of exotic materials – the body is aluminium and the cockpit is constructed from carbon fibre – has helped BMW keep the mass of the i8 down to ‘under 1,490kg’, which is the weight Porsche quotes for a 911 Carrera S. Given that the electric motors and batteries weigh some 200kg, this is an impressive achievement, and it makes a big difference to the ride and handling.

In electric mode the i8 makes serene progress

In electric mode the i8 makes serene progress. The ride is quiet and supple, which make this an effective town car. Sports mode stiffens up the damping and adds weight to the steering but while it definitely feels more aggressive, it’s still far from uncomfortable.

The steering has been kept deliberately light and while it feels too artificial at the straight ahead, it does offer decent feedback through the turns. It contributes to an agile car that changes direction with alacrity. Ultimately it isn’t quite as responsive or engaging as a 911 and the nose pushes wide (understeer) surprisingly early in low to medium speed corners, but this is still an entertaining car to drive.

BMW’s engineers admitted that they’re still making detail changes to the set-up so we’ll reserve final verdict until we drive production versions early next year.

BMW

 

BMW i8: interior

After the eccentricities of the exterior, the i8’s interior feels disappointingly conservative. It’s familiar BMW fare with attention focusing on a centrally mounted screen controlled by the latest iDrive system. There’s a conventional gearstick and steering wheel and just about everything you touch is trimmed in leather.

Those of a slender girth might find the seats lacking in support. BMW admits that their ‘one size fits all’ philosophy meant catering to ‘larger’ markets (think America). Officially, there’s also room for two in the rear, but there’s even less room than you’ll find in a 911, so it's best used as luggage space to supplement the modest boot.

BMW

 

BMW i8: economy 

This is the i8’s trump card. Although the official figures are yet to be announced, BMW claims it should achieve a European average of 113mpg. BMW also reckons that it will emit less than 59g/km of carbon dioxide compared with 224g/km for a 911 Carrera S. Even if you leave it in Sport mode and drive like an idiot, it should still use half the fuel of a 911. It is also exempt from London’s congestion charge.

A fascinating car boasting technology that really works

The i8 combines a carbon fibre passenger compartment with aluminium subframes front and rear. This extremely stiff structure should provide excellent crash protection to complement the airbags and electronic stability systems. The only real black mark against its safety credentials is a thick A-pillar (windscreen surround), which can obscure vision in some corners, although this is in itself a function of a need to accommodate an airbag.