We test the all-electric Audi R8 that's capable of 0-62mph in 4.2sec, with an optimum range of 124 miles and charging time of less than one hour
What is it?
A lot has changed since we last tested Audi’s all-electric sports car. Back in 2010 it was a four-wheel-drive, four-motor prototype that was destined for 1000-car per year production. It was set to receive distinct styling, its own spaceframe, a unique interior, a 1600kg kerb weight and due to be sold at “above R8” prices.
Now, come 2013, it’s a two-motor, rear-wheel-drive, 1780kg coupe that’s based on the recently facelifted R8. Unfortunately, while the Audi R8 e-tron has developed rapidly, battery technology hasn’t. Long gone are the plans for mass production as a result; instead Audi has built 10 cars to a production standard, each valued at over £850,000, to demonstrate the technology and continue trials.
Opting for a rear-drive layout, instead of the quattro system found in normal R8s, may seem a somewhat counterintuitive move. Audi says, however, that the e-tron's rear-drive layout offers adequate traction, negating the need for four-wheel drive, and a more engaging driving experience. There would also be considerable packaging, weight and technical challenges to overcome using a quattro configuration.
The R8’s high-performance electric motors draw current from a 48.6kWh lithium-ion battery, the bulk of which sits behind the driver. Combined, the motors deliver 375.5bhp and 604.8lb ft. This allows the R8 e-tron to dispatch the 0-62mph sprint in 4.2sec and reach a limited top speed of 124.27mph. Derestricted it could reach over 155mph, at the cost of efficiency.
It’s not just the powertrain that’s different. The e-tron makes extensive use of carbonfibre, in order to bring its weight down to reasonable levels, and there are myriad cosmetic and technical changes. The braking system has undergone major revisions, while the motors allow for regenerative braking and an advanced form of torque vectoring.
What is it like?
One thing’s for sure: this is not a dull car. Press the start button and a bassy synthetic thrum fills the cabin. Select ‘D’ with the stubby gear lever, release the electronic handbrake and the R8 glides away.
Inside, it's much like a conventional R8, barring instrumentation that shows power usage, levels and distribution. Snug bucket seats, which adjust only fore and aft, replace the standard items. The e-tron's steering wheel adjusts for rise and reach, however, so finding a comfortable driving position isn't too difficult.
What's most notable is the absence of a rear-view mirror. The tall battery pack obscures your view, so Audi have blanked off the rear glass and installed a 6.8-inch AMOLED display and rear-view camera. It feels slightly unnatural at first, but you quickly acclimatise to it.
Squeeze the e-tron's throttle and, instantaneously, the electric motors spool and propel it forwards at a seemingly relentless rate. The throttle has a natural-feeling and linear response, impressive for an electric vehicle, while the braking system delivers barely perceptible transitions between regenerative and physical braking; there’s a phenomenal amount of stopping power on offer and engine braking can be simulated using the adjustable regeneration controls via the wheel-mounted paddles.
There’s a satisfying amount of feedback from the steering, assisted by being able to more easily hear what the tyres are doing, and the R8 corners in a flat fashion. Remarkably, it conceals its bulk well - 577kg of which is the battery - and never feels unwieldy or liable to break away unexpectedly. The ride quality is firm, predictably, but comfortable.
Audi’s torque vectoring system makes itself apparent in tighter, faster corners. As you perceive the car’s front end to be reaching the limit of adhesion, you’ll find that the nose tucks in hard and continues to travel in the desired direction. It’s a peculiar sensation but one that’s particularly gratifying, as you can feel the rear wheels being individually braked and accelerated to help maintain the desired line.
Because the artificially generated sound rises in pitch and volume with the road speed, and because the throttle operates in an intuitive fashion, it's easy to judge your control inputs. Making swift progress in the R8 e-tron feels delightfully natural as a result, and you very quickly forget that it's lacking an internal combustion engine.
As you’d expect, there’s plenty of grip and traction on offer but, with adjustable drive modes and stability control, the e-tron is more than happy to step its tail sideways. It’s thoroughly good fun yet it feels safe, controllable and quick – all while making its own unique noise. As with many high-performance Audis, it’s also effortlessly capable of flattering your own driving.
Equally satisfying is the depth of engineering in the R8 e-tron. Take, for example, the flaps in the apertures of the wheels. At speeds over 31mph they are forced closed by centrifugal force, reducing the e-tron’s coefficient of drag by 0.02Cd. Drop below that speed and they open again, allowing more air to flow over the carbon-ceramic disc brakes.
The true benefit to the Audi R8 e-tron's acceleration and range capabilities is marginal at best, but it demonstrates the lengths that Audi is willing to go to in order to eke every ounce of performance and efficiency out of a car.
Should I buy one?
Despite having a claimed optimum range of 133.59 miles, and an acceptable charging time of less than one hour from a dedicated point,Audi is not happy with the limitations enforced by currently available battery technology.
It’s an understandable concern. Driven at speed, Audi’s engineers say that the R8 e-tron will deplete its battery in approximately 30 miles. Regardless of how good the car might be, it’s a stumbling point that would put off many a customer – and it’s one of the primary reasons Audi won’t be selling the R8 e-tron any time soon.
So, regardless of how much you might want one, you won't be able to lay your hands on one. Nevertheless, it's a phenomenal piece of engineering, finished to an incredible standard, which shows what's possible using electric power.
If you’re in the market for an electric car with supercar-threatening performance, however, you could consider the Mercedes-Benz SLS ED. It costs approximately £302,000 plus taxes in left-hand drive markets and it’s claimed to sprint from 0-62mph in 3.9sec, before reaching a limited top speed of 155mph. Its range, however, is a similarly optimistic 155 miles.
Price £850,000 (est.); 0-62mph 4.2sec; Top speed 124.27mph (electronically limited); Economy N/A; CO2 0g/km (local); Kerbweight1780kg; Engine type Twin independent electric motors;Installation Rear, transverse Power 375.5bhp; Torque 604.8lb;Gearbox single-speed per-motor planetary
souce:autocar.co.uk
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