BMW’s futuristic i8 hybrid shows James Fossdyke that eco-friendly doesn’t have to mean dull

Some things just don’t age. Frank Gehry’s Guggenheim Museum, for example, looks as though it was built last week, but it’s now more than 20 years old. And don’t get me started on Madonna. She’s 60, apparently, but she looks about 35 to me.

In the motoring world, meanwhile, the BMW i8 seems to have followed a similar ageing process. It’s hard to believe that this futuristic hybrid sports car is now more than four years old.

Most manufacturers will indulge in a little nip-and-tuck surgery when one of its models hits the four-year mark. Maybe a new set of lights and bumpers, or perhaps a flash new interior. Understandably, though, BMW hasn’t felt the need for that. So instead, Munich’s finest have simply given us a convertible version.

And it’s an incredible thing to behold. The i8 has always been cool, what with the two-tone bodywork that makes it look as though the chassis is bursting out of the shell, but cutting away the roof has somehow made it even more jaw-dropping.

The best bit (and probably the worst bit, but I’ll get onto that later) is the doors. They hinge from the sides of the windscreen, so they open up and out like some kind of Star Wars spaceship. No matter where you are if you open the doors to an i8 Roadster, you’ll feel the gaze of every passer by.

As you get in, you’ll slide back into luxuriously appointed and perfectly sculpted leather seats, while a digital instrument display and central media system greet you. Everything works and feels exactly as it should in a £125,000 drop-top sports car. Except for the starter button. Were this a Jaguar or a Mercedes, you’d push the button and wait for the inevitable cacophony of exploding petrol, but in the BMW your ears are assaulted with nothing but silence.

That’s because the i8 is a plug-in hybrid, which means you can plug it in, charge it up and get yourself 33 miles of silent, zero-emission, engine-free motoring. If you start getting bolshie with the accelerator or the batteries run flat, however, all is not lost. There’s a 1.5-litre, 228bhp petrol engine there to offer a helping hand.

As a result, this road-going spaceship managed to return 141.2mpg on the official economy test, and because it emitted carbon dioxide at a rate of just 46g per kilometre, it’s deemed green enough to scoot around London without incurring the Congestion Charge.

But don’t be fooled by the numbers - this is still a sports car. In total, its hybrid system produces 369bhp (141 from the electric motors, 228 from the engine), and because the electric motors have so much low-down grunt, that’s enough for a 0-62mph time of 4.6 seconds.

For those who love a stat, that makes this eco-friendly, Congestion Charge-dodging, planet-saving sports car just as fast as the Porsche 911 Carrera.

BMW, though, doesn’t pride itself solely on performance figures or eco credentials. The German brand claims to make ‘the ultimate driving machine’, and the i8 delivers.

As with so many of the great BMWs, you don’t really get into the driving seat so much as merge into the machine. The driving position, which is so often flawed in convertible sports cars, is brilliant, and the steering is like honey in your hands. It isn’t really an out-and-out sports car, but a brisk cruiser that car flows between bends with an impressively dismissive nonchalance.

But before you rush to your local dealership with cash in hand, there are one or two issues you need to be aware of.

Firstly, those stunning doors. Yes, their visual impact is epic, but because they open up and out, it’s astonishingly easy to bang your head on them as you get out. After a few bruises, you’ll have to devise your own strategy for alighting - I found rolling over the door sill was the best way of getting my 6ft 2in, 15st frame out of the driving seat. I’ll be honest; it wasn’t the smoothest exit, and the car’s aesthetic qualities ensured I had an amused audience.

Secondly, it doesn’t feel quite as fast as the performance figures suggest. Maybe it’s the engine note, which has more in common with a VW Golf GTI than a Ferrari 812, but it doesn’t have the drama you might get from, say, a BMW M3 that costs half as much.

You won’t get the claimed economy, either, unless you have impressive self-restraint, a short commute and a charging point in your garage. It’ll be more efficient than most sports cars, I grant you, but 140mpg is fanciful for most owners.

Other niggles include the fact that the roof switch is far too well hidden, while the boot space isn’t what you might call cavernous.

But despite all that, it’s hard not to have a soft spot for the i8. As a technical achievement, it’s outstanding. Little else has this much visual impact or this performance, let alone the environmental credentials.

Best of all, though, the i8 shows us that although the future of motoring is far from certain, the world's car manufacturers will make sure the roads are still graced with great design, great engineering and, perhaps most importantly, excitement.