May 07 2014
BMW i8 in it's production form!
RMA Track Days talks about the BMW i8
What is it?
The BMW i8 could be the supercar of the future, a hybrid 2+2 coupe with price and performance figures to match a Porsche 911 or Audi R8 but CO2 emissions that equal a plug-in Prius.
We’ve never seen anything quite like this and given the technology on offer, its £99,895 price tag doesn’t seem like so much to ask to buy into it.
The i8 has a transverse mid-mounted 1.5-litre three-cylinder turbocharged engine that drives the rear wheels through a six-speed automatic gearbox. A small electric motor acts as a starter motor but can also fill in any torque gaps in the engine’s delivery. The front axle is driven separately by an electric motor and two-speed gearbox to create a car of incredible flexibility and complexity.
In eDrive mode the i8 is a zero-emission, front-wheel-drive machine with a useful 129bhp and 184lb ft, a top speed of 75mph and a range of 23 miles. In Comfort mode the i8 is a plug-in hybrid that’s quiet, refined, has a range of up to 310 miles and can be charged from zero to 80 per cent inside two hours. Select Sport mode by simply moving the gear selector from ‘D’ to ‘S’ and the i8 transforms again. Now the internal combustion engine and electric motor combine as effectively as possible to deliver maximum power, noise and excitement. So configured, the i8 generates 357bhp and 420lb ft. It also tightens its damping, reduces the electric power assistance for the steering and manages the car’s balance by manipulating drive to the front axle for ultimate agility and engagement. The numbers say the i8 combines 135mpg and 49g/km on the one hand or 0-62mph in 4.4sec and 155mph (limited) when driven like a sports car should be.
It’s only right and proper that the revolutionary powertrain is teamed with a structure that is an innovative mix of aluminium and carbonfibre. BMW calls it LifeDrive – the ‘Drive’ element of it being the aluminium chassis that carries the engine, electric motor and batteries, onto which the carbonfibre ‘Life’ passenger cell is bonded. This pegs the weight at 1485kg, and the battery unit, which runs along the traditional transmission tunnel route, helps to ensure the lowest c-of-g of any BMW past or present, at just 460mm (a gnat’s whisker higher than a Cayman’s). The i8 is light, stiff and exotically low.
What’s it like to drive?
Cruising at 55mph in near-silence in eDrive mode is fantastic, thanks to the airy cabin, the terrific view ahead, the tangible sense of chassis rigidity, the light, accurate steering and the easy and instant performance even without the petrol engine sparking into life. The real-world range seems to be more like 13 miles than 23, but you’ll enjoy every one of them and not just because you’re saving a few quid in fuel. Ask for too much acceleration and the three-cylinder engine starts almost imperceptibly. Now the i8 feels genuinely muscular, especially under part-throttle loads. The six-speed auto ’box (chosen for its weight) is maybe not quite as smooth as BMW’s new eight-speed, but such is the easy torque that you’ll hardly notice.
The switch to Sport mode is confirmed by the elegant digital instrument display glowing red and the 1.5-litre engine suddenly sounding like a 4-litre V6 – deep, heavy, but with a soft burr laid over the heavy metal, and a sound mostly generated by an audio speaker. In truth the i8 never feels as fast as something like an R8, but it’s fast enough to be exciting – somewhere between a Cayman S and a Carrera S. The six-speed ’box is quick, assured and takes downshifts nice and early, too. Better yet, the brakes – just like at low speeds – switch between regenerative braking and mechanical seamlessly. You can’t feel the difference at all, which is a nice confidence-booster.
Surprisingly the electric steering seems to have some genuine feedback, while body control is excellent and the impression of lightness continues even to the very limits of grip and over nasty, sudden undulations. But the i8 is somewhat hamstrung by chasing every last CO2 particle, because the narrow (but wider than standard) 215/45 R20 front tyres howl in protest when you really start to attack a road and then slowly but inexorably slip into understeer. In fact, understeer is the i8’s ultimate dynamic trait. Through quick corners there’s a delicious split-second where you turn and the rear seems to adopt the perfect slip angle, but as soon as you get back on the power it’s replaced by understeer.
This lack of adjustability is frustrating. I hadn’t expected a car with M3 levels of indulgence, but I had hoped for a really agile, super-accurate front end and a neutral-to-oversteering poise on corner exit. As it is, the i8 is a fascinating, hugely desirable and deeply impressive car, but it lacks the uplifting excitement of the best drivers’ cars.
How does it compare?
As drivers’ cars, the traditional and far less environmentally friendly 911 and R8 still rule. The best example of a future-generation supercar so far is the overweight, overpriced and largely ludicrous Mercedes SLS Electric Drive, which uses torque vectoring to provide a highly impressive driving experience. But that costs around £360,000. Perhaps the i8’s closest rival for driving enthusiast technophiles is the Tesla Model S.
Anything else I need to know?
People love this car and the complex multi-layered surfaces, kicked-up rear arches, floating roof line and butterfly doors are a sci-fi combination that looks astounding out on the public highway. Even though it seems to be inexplicably pushing a Porsche 991 out of its bottom (look again and you’ll see it forever more).
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