Audi R8 e-tron

First drive
Ingolstadt, Germany

We liked
>> Brand new type of thrust
>> And lots of it
>> Silent gristle

Not so much
>> No steering feel
>> Seriously under-developed
>> Like a moving game

There's no sense, Audi believes, in limping in to the world's electric car future. Instead, via the R8 e-tron, it intends to get there with brakes ablaze, tyres melting and with four electric motors pumping out more torque than six HSV V8s.

Due to be on-sale (or, more specifically, on-lease) from mid-2012, the R8 e-tron is a fully-electric sportscar boasting four electric motors and sub-five second 0-100km/h sprinting. Audi limits the car to 200km/h, because the energy cost of going faster becomes stupendous. But it admits the electric R8 can pull far higher than that, depending on how it's geared.

For now, we are sampling the car in prototype form – and we don't have enough space to hit 150km/h, much less 200.

'Ours' is one of at least eight e-tron prototypes Audi has pounding the world's proving grounds and, according to insiders, it's the best and most advanced of them.

There's good and bad in it, immediately. Audi has lightened the car wherever it could, so there's a carbon-fibre, louvered panel sitting where the engine cover would normally be -- which means you can't see a thing behind you.

There is also a set of monster carbon-ceramic brakes, sitting inside unique wheels with a very cool yellow strip to designate electric power. They generate an astonishing 1250kW of stopping power, but they mean that the four motors are inboard, not the wheel hub-mounted systems people talk about as the full future.

The stripping continues inside, where the comfy R8 seats give way to carbon-fibre shells with thin strips of padding in them, while light-weight, artificial Alcantara replaces leather wherever possible.

Where you'd normally find a 5.2-litre V10 thumping out 560 horses, there's now a massive lithium-ion (LI) battery pack and a big computer brain. Carefully configured the e-tron retains the petrol car's 42:58 front-to-rear Quattro power ratio.

Packing 550kg of cells the battery pack theoretically stores 53kWh of energy (though, LI batteries being what they are, the usuable maximum is 42.4kWh).

At 1600kg all up it's not the heaviest fast electric car the world will see…

While there are still a few tricks up their sleeve before production that will take the maximum range out to 250km, Audi insiders admit that taking off in a fully charged R8 e-tron is like leaving home in a V10 R8 with 5.5 litres of fuel in the tank. That's because the four motors can combine for 230kW of power and an astonishing 4500Nm of torque.

Torque is instant and that's how it feels. People suggest that the acceleration is like riding a rubberband, but that's not quite right. Instead, it flips the whole idea of a linear power curve, punching hardest at lower speeds but still having reserves of gristle at higher revs.

It's utterly silent when you approach the R8 e-tron and it gets no louder when you nestle in to its tight, deep shell and switch it on. Unlike the R8 V10, there's no deep rumble, no menacing burble, no belligerent tremors.

Indeed, there's no hint of the tremendous potential of the four motors -- not even a fizz or crackle from the battery pack. Comforting? Perhaps, but a key part of the supercar phenomenon is threat, and most of that is audible. And the e-tron has nothing.

The dashboard changes its lighting to tell you it's all geared up to go, then you're free to massage the exact same throttle pedal you get with the Lamborghini-based R8. But, my goodness, when you stop massaging the pedal and start stomping it, the e-tron bursts into action.

It's all-wheel drive, with each of the electric motors taking care of one wheel and there's never a hint of wheelspin. It just grips and goes, because there's no potential, as with the petrol car, of building up revs. Here, you just step across and go, like you would with an automatic gearbox.

And then it explodes!

All four Pirellis scrabble at the ground as every scrap of 4500Nm of torque arrives instantly and makes every effort to snap the driveshafts clean in half.

You're instantly hurled even deeper into the seat shell and, where the petrol car bursts forward and then gets stronger with revs until you change gear and do it again, the electric car does something different. Instead, it punches you hard early, then holds you there and all you hear is the whining of the gear teeth as they mesh together. There's only one gear ratio, to slow down the spinning of the electric motors to drive the wheels at road speeds, and the car could, theoretically, be even quicker with a few of them. But that adds even more weight.

To be honest, it needs more forward thrust in the way that a lethal bullet needs a bigger caliber. It's plenty fast and, if its straight-line sprinting is slower than the V10 can manage, its rolling in-gear acceleration is mind-boggling. No waiting for the tacho to climb to fixed torque peaks or power curves. It just delivers everything it has, all the time.

And you hear a lot more of the other noises that the engine's exertions normally mask, too, like the sound of springs working or the tyres pounding or the gears cranking. None of them are intrusive, but they're actually a bit novel in a car this fast.

Alas the R8 e-tron is, in this guise at least, a seriously under-done machine. The steering is the biggest let-down -- some computer games have better steering feel and better response over bumps. You're always reacting to the car, not being a part of it and that's almost all down to its steering's inadequacy.

The brake pedal, too, feels odd, largely because you can use it to regenerate the battery by turning the electric motors back the other way (when they become generators) when you brake lightly. You can actually brake quite heavily around town with nothing but the electric motors, but then the electric brain switches to the conventional carbon-ceramic anchors at some point, and the change in feel is too pronounced. And squishy.

That said the e-tron is impressive around corners, because the four electric motors essentially mean that each wheel has its own differential so Audi can give it stupendously accurate torque vectoring -- adjusting the car's stance with minute tweaks of each wheel to hold the line you want in fast corners or to give you maximum drive out of slow ones. It's really like being the ball on the end of the string.

There are other issues Audi needs to sort out, too, such as a 27-minute range on full-throttle attacks and getting even more than the 400 volts it already uses.

"The higher the voltage (400), the better the efficiency and we would like to have even more," Audi's head of pre-development for vehicle concepts, Dr Michael Korte, admitted.

"Others use 260 to 270 volts for the battery system, but we're far higher than that."

It's also not so good at cruising speeds. Geared for attacking corners and mountain passes – it just has trouble getting to the mountain passes with enough juice to enjoy them.

"It does not make sense to do a steady speed with an electric car because every other engine is better and more efficient," Korte admitted.

"But we started with electric sportscars because there are not so price sensitive and we will go down into smaller cars later. Everything you have to learn about electric cars you can learn with this car."

One of the things they're learning is lithium-ion battery technology with partner, Sanyo, and there's a long way to go.

Lithium-ion, for all its reputation as the best contemporary commercial battery technology, is far short of petrol power, which has around 12,000 Watt-hours per kg of energy. LI by contrast has 200 -- even chocolate is 35 times better...