BMW i8 12 Concept cars that became real

First drive: the BMW i8

How new? Remind me.

About as far from the usual BMW template as you can get. The i8 has a 1.5-litre turbo three-cylinder engine mounted transversely ahead of the rear wheels. Tiny but mighty, this little triple makes 231bhp and drives only the rear wheels. The front wheels have a 131bhp electric motor. Down the spine is a plug-in battery big enough to power the front wheels for about 15 all-electric miles in gentle town driving. It'll do that on two hours' charge. The battery and motor are technology borrowed from the i3 electric hatchback, although different outputs. After the battery is flat, or when you need more power, the petrol engine starts, giving you a 4WD hybrid.

The main tub is carbon-fibre - again the same sort of newly developed stuff they've used on the i3. The subframes aluminium, the exterior panels (and my how revolutionary they look) are thermoplastic, except the roof which is moulded out of recycled carbonfibre offcuts. Even the glass in the doors and rear is half the weight of the normal stuff. It's the hardened, thin 'gorilla glass' used on phone screens.

It had a silly name. It had butterfly doors. It had levels of aero-efficient body layering that'd put a Sara Lee cake to shame and a three-cylinder engine with a pair of electric motors. In a BMW!

But as astonishing as that original ‘Vision EfficientDynamics' concept was, it was accompanied with a general mood of: ‘Yeah, but it'll never look like that'. BMW itself even admitted the car only ‘previewed styling ideas'.

Fast forward a few years, and it seems that preview was actually a facsimile. Because the new BMW i8 is finally amongst us, and... the only thing changed the original 2009 concept car is the silly name.

OK, so a few other details have altered, but by and large, this slice of the future looks like - in the words of TG's Paul Horrell - an escaped concept car. Excellent, therefore.

But it's a rare thing for manufacturers to promise the future and actually deliver it. So the BMW i8 now slots into the esteemed annals of Production Cars That Look Pretty Much Identical To Their Concept Car Previews. A catchy title, you'll agree. Click through for some of the most iconic, and feel free to chime in below with your own suggestions.

What's the exact point of all this complication and novelty?

Efficiency. The aim is to make a car that'll operate all-electrically in the new era when some cities are banning or tolling combustion cars. And even in the hybrid and sports modes, even if you never plug it in, it'll go about 30-50 percent further on a gallon than other cars of similar performance: we're talking 0-100 in 4.4 sec. And because plug-in energy isn't counted in the European fuel cycle, it registers an official figure of 57.4kpl and 49g/km CO2.

Thanks to all that obsessive lightweighting, it's just 1465kg, even though it's got nearly 98kg of battery aboard, and another 100kg of power electronics and e-motors. There's a second motor, which acts as a starter/alternator for the petrol engine, and more interestingly develops a pulse of torque that covers the hole while the turbo spools up. Wringing all that power out of a 1.5-litre engine required a far bigger puffer than on the same engine in a Mini Cooper, and that'd normally lead to endless laaaaaaag.

Weight affects consumption when you're accelerating or climbing, but drag matters at steady speed. To eke out the energy, the tyres are low-resistance jobs, and have a narrow but tall shape to cut drag. The body is obsessively low-drag, with a Cd of 0.26 and a low frontal area.