BMW's second plug-in hybrid model is the i8 supercar. It combines futuristic technology and styling with electric performance in every sense of the word. See what What Car? readers made of the car.

This is what the BMW i8 sounds like. If you had any doubts about its acoustic qualities, these should be put to rest once you’ve seen the video linked below. It lets you hear what the three-pot engine thrashed from the outside when pushed moderately hard on the Nürburgring… until it stutters to a halt on the side of the track due to an unknown malfunction.

The description of the TuriClips video reads that, “after about 15 minutes he drove off really slowly. I think it wasn't a major problem because I later saw him driving around the village of Nürburg again.”

Apparently, the most likely culprit responsible for the testing hiccup were the car’s brakes, though this was not confirmed – it’s the YouTube uploader’s speculation based on what he saw at the scene.

BMW needs to iron out these niggles before the cars start reaching customers (obviously), because a recall for the much-anticipated and highly acclaimed i8, presented as the world’s first desirable purpose-built hybrid sports car would be a big slap in the face for whomever handles their image and planning side of the business.

Remarkably complete as a sporting prospect, but only up to a point. Advanced, extravagant, fluent, fast, frugal – but lacking clarity of purpose

What is it like?

It should be like a Porsche 918 Spyder for a fifth of the outlay. It’s certainly got some promising ingredients.

The 1.5-litre three-cylinder Mini Cooper engine cradled between the i8’s back wheels has a higher specific output than any production combustion engine that BMW currently makes, feeding 228bhp and 236lb ft to the rear wheels of the car via a 6-speed ZF automatic transmission. Between the front wheels there’s a 128bhp, 184lb ft ‘hybrid synchronous’ electric motor, driving those front wheels through a two-speed automatic transmission.

And here’s the clever bit. That electric motor and transmission, the 7.1kWh lithium ion battery mounted where the car’s transmission tunnel might otherwise be and the high-voltage power management system add almost exactly 200kg to the i8. Relative to an aluminium or steel equivalent, says BMW, the carbonfibre-reinforced plastic monocoque saves exactly 200kg. So the car weighs in at 1540kg with fluids onboard: which is less than a current Porsche 911 Turbo, never mind the 918.

The i8’s two-speed gearbox, meanwhile, allows the electric motor to operate at peak torque as the combustion engine passes its torque peak in the lower intermediate gears. And that means, as well as 357bhp, you really do get 420lb ft of mid-range thrust from this car at times. And it feels like it.

Early impressions of the i8 are of nothing less than a fully-fledged supercar. The body looks ridiculously low, wide and ground-hugging. The styling’s got smack-in-the-chops impact to rival a Lamborghini, and scissor doors for belt-and-braces extravagant effect.

You have to fold yourself into the cabin between a low roofline and a high, wide, expensive-looking sill. And once you have, the interior’s got no less of a sense of occasion to it, with a generously sculptural, driver-focused dashboard, colourful LCD instruments, low-slung and deep-dished sports seats; there's also an abundance of little features and touches that lift the ambience way above BMW’s usual conservative norm.

So it talks the talk, the i8 - loud and clear. Walking the walk of something as pure as a Porsche 911 was always going to be the harder bit. On handling precision and that final sliver of driver engagement, the BMW falls short of brilliance. But it’s good, and almost there. Certainly good enough to consider the car an amazing success in its own hyper-specialised niche.

Right up until you go looking for that critical last fraction of driver appeal, in fact, the i8 does almost everything right. Starting off with ‘Comfort’ mode selected on its adaptive dampers and near-silent drive turning its front wheels, the i8 is comfortable and super-civilised around town. It’s a bit choppy-riding occasionally, but not often.

Its steering is light but there's a modicum of well-judged feedback, and performance is entirely decent in electric mode. Electric-only range is a bit low, in reality about 15 miles. But the BMW seldom operates like a range-extended EV unless you explicitly instruct it to anyway, its combustion engine regularly chiming in through most drive modes even when the battery is relatively well-charged.

Knock the gear selector into ‘Sport’ mode and the engine begins to run almost continually. Gun the accelerator away from a standstill and the powertrain feels like a big V6: instant and heavy-hitting on pedal response, but with a loud, gruff, synthesized soundtrack broadcast to you over the audio speakers.

Yet the harder it revs and the faster you go, the smaller that imaginary V6 seems. Work it really hard beyond 5000rpm and the i8’s performance level feels a touch thin and strained.

The car’s handling stands up more stoutly to inspection – but not indefinitely. Body control is excellent; steering response equally immediate. Lateral grip levels could be higher, particularly at the front wheels, which begin to scrabble and scream under load if you harry them.

Drive intelligently though, using weight transfer to give the steering authority on turn-in, and the i8 responds for the most part like any good mid-engined machine should: with some balance and alacrity, but exceptional in neither.

The rear axle is always glued to its line, giving dependable stability. It declines any attempt to adjust your arc through a corner with a bit of throttle-steering. That's a typical facet of a car that just doesn’t respond well to being driven hard, and one that approaches its adhesive limits a bit early for our tastes.

The i8 can be enjoyed vividly enough as you approach that point, of course. But not ultimately as vividly as a £100,000 sports car really ought.

Should I buy one?

If you genuinely don’t mind compromising on sporting clarity of purpose for lower emissions, enhanced economy and of-the-moment desirability, sure. But if that’s you, the sports car market would seem to be a strange place to go shopping for your next car anyway.

The BMW i8 doesn’t quite feel as exciting as it does fast; it’s secure and fluent, but not the last word in fun. Accounting for its novelty value, brimming supercar attitude and its low-emissions sense of environmental responsibility, it’ll be more than sporting enough to satisfy people who couldn’t otherwise have justified a sports car.

But it’s not quite convincing enough to hit the heights that true enthusiasts will expect of it. There is all the intriguing complexity in the world to contemplate here, but sadly not quite enough depth.

Verdict on plug-in BMW i8, a car set to bring about a performance car revolution

Verdict

The BMW i8 is the first of its breed and spectacularly good. Forget million-pound flights of fancy such as the McLaren P1 and Porsche 918. BMW’s crammed a level of tech into a car in 2014 that should still be relevant in 2024. The i8 is more of a precision tool than a tyre-smoking M model, and while a 911 may be sharper in bends, there’s no better definition of a sports car for the modern world.

BMW's future-proof hybrid sports car is finally here, and we've driven it. But what's it actually like?

So it actually work as a sports car?

For the most part, like a charm. In sports mode, using the paddle shifters, it disguises its hybridness entirely. It'll leap ahead with lag that's barely perceptible. Honestly it does an amazing impression of a 340bhp big six, rather than a 231bhp little triple. In sport mode some of the engine's natural frequencies are amplified through the hi-fi, and it's a strong, gutteral sound. The real pity is it doesn't rev beyond 6500, and for some reason its shifts up by itself on the red-line, even if you're in manual mode.

Even when the battery is pretty much depleted, by the way, you still get all the power of petrol plus electric. Remember, you never drive any car flat-out all the time, and so in the i8 (and any other hybrid), when all the engine's power isn't needed, spare is syphoned off to charge the battery just enough that for the next squirt of acceleration you can have the full petrol-plus-electric beans.

Is it 911 fast? Doesn't feel quite at that level. You don't get the high-rev drama or violence. But it's ruddy quick, be in no doubt. I believe the 4.4sec 0-62mph claim, because traction's so good.

But I'm worried about cornering, what with the mashup of different power sources for different axles.

Ah yes. Well, go into most corners and your doubts will be vaporised. It's wonderful. There's barely any roll, the steering is terrific, and there' a wonderful agility - it'll take left-right-left flicks like a lizard. In longer bends you can come on and off the throttle and tuck the nose in a little, or edge the tail out very slightly under power. It feels consistent and confident. Lovely.

Very long, slow, second-gear corners can trip it up though. If you go in too fast or under brake, and get understeer, the i8 seems to get a little confused and won't let you have full power for an annoying interlude. But if you get your entry speed right, then get early on the power, it feels just fine. I think there might still be a front-rear calibration issue in second gear, too. But what do I know - this is such a brainy car you never really know how it's doing what it's doing.

Er, calibration? Explanation please.

The engineers say the hardest job on the i8 wasn't the new materials or the weight or body. It wasn't even the power units per se. It was getting them to work together, getting everything smooth and maintaining the right variable torque split in corners. Imagine, you change throttle position. The petrol engine reacts, but with a bit of a delay as turbos do. So the electric front motor, and the auxiliary rear motor, have to be controlled to match that transient state, while maintaining the target front-rear torque split to keep the cornering dynamics right. Whatever of the six gears the petrol engine is in. However much grip each wheel has. Mind boggling.

Best not to think too hard. Just to let it get on with it, and enjoy the results, which except in that one tight-bend understeer situation, are fine. Anyway, the engineers say they're still working on a stickier front tyre compound, which should help too.

Ah yes, tyres. Aren't they a bit skinny?

Yes, they're narrow to save weight and drag. But they're tall, so the contact patch is longer than in a normal sports car, so overall there's enough tread on the road. That's with the optional tyres as on the photo car. The engineers admit the standard tyres don't give as much lateral g.

So does it cling on like a 911?

Not quite, but close. I found the limit easy to reach. But then that wasn't because it's a low limit, more that the car is confident and friendly and generally transparent as it gets there. And given the complexity that's remarkable.

How's the chassis itself?

Brilliant actually. The fundamentals are present: a very low C of G, all significant mass inside the wheelbase, and 53 percent on the rear, plus a palpably stiff body. You sit low, so you feel little rock or pitch. The steering is spot-on in ratio and progression, and gives you a good feel for the tyres' effort. Springing is beautifully judged, supple enough to be acceptable in grumpy urban running, but firm enough for the dampers to stick their teeth into when you're pressing on. In twisty and bumpy sections taken fast, there's no float to speak of and the dampers check body motions with terrific resolve, and yet they don't make things harsh when you're wafting. They're adaptive, but feel very natural. There's also remarkably little tyre roar, thanks probably to their narrowness, which adds to the refinement and matters a lot in electric running when there's no engine noise to drown the tyres out.

Electric mode you say?

You can select whether to use up the mains charge straight away, or save it for when you get to a town. As a pure EV the i8 is pretty good, though not as fast as an i3 as the motor is less powerful. But it's smooth and capable, probably as accelerative as a base-model supermini, and can do 75mph in all-electric mode. Going gently, 15 miles is easily possible on the battery. If you want more acceleration or speed, just kick-down the throttle and the engine cuts in to lend a (strong) hand. Only the brakes give it away: the mixing between regen and friction gives a grabby pedal at low speed. Again, the i3 is much better at this.

Will it do hybrid?

Yup, that's the normal 'comfort' mode. The engine cuts in and out, but it's not too obtrusive because it doesn't have the amplification that it has in sport mode. That said, there can be occasional pauses if the system thinks you don't want much power and you suddenly do, and it has to clear its throat, start the engine and change gear.

Sport mode is what it says: for quick driving. The engine always runs so it's always tensed and ready, and the car uses the electric system for regen so as to be sure the battery gets enough charge to ensure the full electric-augmented 362bhp is always under your toe.

I still don't believe the official economy numbers. Fess up, what did you actually get?

Er, about 24mpg on a fairly long day. But some context. There was some town running to begin with, and I did that at pretty much infinity mpg, because it was all electric. Then it was up into the mountains, where it fell to 19mpg. I really think other sports cars this quick would have been sub-20 for the town bit and low-teens for the mountains, given it was so heavy on second gear hairpins. My route took in barely any A-road cruising and just five or so miles of motorway. At steady speeds, the i8's small engine and its low drag would definitely help economy.

I can well believe it would go 30-50 per cent further on a gallon than rivals if you never plugged it in. If you always plugged it in and just did short commutes you'd never use any fuel at all. Somewhere between those usage extremes lies the 135mpg of the official test.

OK so it's economical in everyday running. Is it useable?

Pretty much. The rear seats are strictly for kiddies, but the front is habitable and comfortable. There's a bit of a boot under the rear hatch, but you'd end up using the rear seats for bags on a weekend away for two. The doors are a bit of an issue: sure they add theatre, but what with the high sills it makes getting in and especially getting out into a bit of a ballet. I wouldn't like to do it in a skirt (even were I female). And they have no storage pockets, and there are no front cup-holders. Porsche wouldn't make those mistakes. But a Porsche is a well-engineered ordinary car: the i8 is from another planet, or another era, and that's it's appeal.

So was this re-invention of the car worthwhile?

Well, it costs £95k after the Government grant, and a 350bhp 911 Carrera 4 PDK is £80k if vastly more tax-heavy. Now, was it worth all this BMW brainpower and new tech to make a car slightly less sporty than the Porsche that uses rather less fuel? That's a very dull question. For a start the 911 is 50 years into its development; the i8 is a first stab. I suspect different tyres and a firmware flash will soon improve it. But more than that, the i8 is exploring the future. It bestows lightweight construction, hybrid expertise, and a quick-thinking highly creative engineering mentality onto the whole BMW group.

It's an enormously satisfying thing to drive, because if you're thinking about it you can use its different characteristics in different ways to suit the moment - in fact it's at its very best either wafting in pure-EV mode, or being thrashed in sport mode.

And it makes everyone point and smile.

International journalists are test driving the new BMW i8 in Los Angeles.