Audi's battery-powered R8's enticing looks and performance aplenty hide a heart that is pure green, reports Peter Mckay.
Audi confesses it may have arrived a little late to the electro-mobility party; its mostly Japanese rivals were dancing and show-boating long before the German luxury brand even rang the doorbell.
Audi clearly wants to arrive with a flourish. While other brands roll out tiny plug-in city runabouts with modest performance credentials and geeky looks, Audi's sleek R8 supercar is leading the German brand's electric charge.
It's a heck of an eye-catcher in which to arrive at the electric vehicle (EV) soiree — a sleek supercar dubbed the R8 E-Tron that (almost silently) whooshes from standstill to 100km/h in a Porsche-like 4.8 seconds.
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With its prodigious acceleration — like a Scalectrix car jumping from rest — the R8 E-Tron quattro will target enthusiast drivers with a green bent when it goes into limited production in late 2012.
With looks to match its intent, the car has demonstrated that brands don't need to create cartoonish electric vehicles that appear to be the unfortunate outcome of a few moments of unseemly passion between a Smart car and a Tata Nano.
The R8 looks gorgeous and its aluminium spaceframe construction is suitably high-tech for a car of the future.
The R8 E-Tron is a full EV with a 550-kilogram battery pack mounted amidships and an asynchronous electric motor on each of the four wheels, making it a genuine all-wheel-drive vehicle. Power transmits to the wheels via a single-staged transmission and short input shafts.
It wasn't the cheapest car to develop but Audi sees it as a chance to integrate more expensive technology into a premium sports EV. It is also a golden opportunity to catch the eye of the world's media; hence Audi's exclusive invitation for Drive to get behind the wheel of this breakthrough supercar for a short road loop in Germany.
Our preview of Audi's electric future doesn't end with the R8. The brand has also developed a three-door E-Tron version of its city runabout, the A1. The R8 E-Tron may be the show-stopper but the A1 is the car most likely to generate serious production volumes. The final part of the jigsaw is a drive in Audi's first production petrol-electric hybrid, based on the Q5 soft-roader.
In the metal, our R8 E-Tron looks menacing and ready to excite. After wriggling into the racy Recaro seat, you twist the key and instead of the usual ferocious roar from a V8 or V10, there's ... nothing. Just a gauge in a surprisingly familiar cluster on the dash that advises you're "ready".
Moving the gear lever from P to D and pressing the accelerator unleashes a very swift change of scenery, accompanied by some growl from the fat, 19-inch tyres and a little resonance from within the car. "It's only a prototype," the man from Audi says.
There is no tachometer, of course, replaced by a dial representing the recuperation status of the energy supply and the output. You can select the level of recuperation by pressing switches on the steering wheel, influencing the energy recovery and braking power of the electric motors and so extending the range.
Audi's head of pre-development of vehicle concepts, Dr Michael Korte, says the R8 E-Tron is not an autobahn-storming machine designed for long runs on Europe's high-speed motorways. He compares it to a powerful sports motorcycle — a mix of fun and technology that is good for short bursts of stunning speed.
With a combined output of 230kW of power and about 680Nm of torque (Audi misleadingly claims 4500Nm but is calculating the output at the wheels rather than the motors), the R8's four engines can accelerate and decelerate individually with impressive exactness thanks to a clever management system.
Similar to the standard Audi R8, about 70 per cent of the power acts at the rear wheels in regular operation, with the remaining 30 per cent going to the front wheels. Should wheelspin occur, the software changes the balance in a fraction of a second.
The individual control of the four motors also allows so-called torque vectoring, the selective acceleration of individual wheels and, therefore, active distribution of torque. Any loss of traction in individual wheels, such as understeer and oversteer, is countered quickly using small power boosts and brake interventions.
Behind the cockpit are the large, fluid-cooled, rechargeable lithium-ion batteries and the electronics used to control the power flow. Impressively, engineers have managed a 42:58 front-to-rear weight distribution, matching the regular R8.
Audi insists the production R8 E-Tron will weigh no more than the V8-engined R8 supercar. In its final evolutionary stage for market, the R8 E-Tron's battery is expected to be good for a range of about 250 kilometres (although manufacturer claims of EV range are often optimistic).
While the R8 E-Tron may be the attention grabber, the E-Tron versions of Audi's small city runabout, the A1, and its compact soft-roader, the Q5, are also on hand for our test drive.
The A1 E-Tron is a three-door hatch that uses a tiny petrol engine to extend its range once its battery reserves are depleted. The range-extender comes in the form of a compact rotary engine used not as an alternative to the battery but, specifically, to put energy back into the battery when needed — such as on a longer-than-normal commute or a steep climb.
From the driver's seat, the three-door A1 E-Tron looks much like a regular A1 that goes on sale here next month. Except, that is, for unfamiliar gauges with terms such as "E-Tron ready" that give the all-clear to engage D on the gearbox selector and hit the accelerator for emission-free motoring using only the electric-drive system.
In this mode, the range is about 50 kilometres — good enough for most daily commutes. The Volkswagen Group, which owns Audi, says research shows that of the 60 per cent of Germans who travel to work by car, almost half travel less than 10 kilometres and a third travel less than 25 kilometres. Recharging every 50 kilometres means there would be no need to use any petrol.
Based on a suite of information the car collects (such as driving style, outside temperature, navigational data), it decides when to move to range-extender mode to replenish the battery that feeds an electric motor mounted transversely in the front. The driver may also press a button on the dash to trigger the range extender's vibration-free and quiet rotary engine.
The 254cc petrol engine is fed by a 12-litre fuel tank and powers a 15kW generator able to extend the A1 E-Tron's range by an extra 200 kilometres. True, it's consuming some petrol — a meagre 1.9 litres per 100 kilometres — but at the same time the battery is recharging and increasing the drive it supplies to the vehicle.
The lush torque of an electric motor is evident almost the instant you push the throttle and there's a feeling of almost limitless thrust, uninhibited by the need to change gears. The front wheels are fed a minimum 45kW of power and 150Nm of torque, with peak numbers as high as 75kW and 240Nm. The torque flows to the front axle via a single-stage transmission flanged to the electric motor. The almost-silent travel is eerie, with just a light whine and a little tyre noise discernible.
Claimed acceleration from rest to 100km/h is 10.2 seconds, with a top speed of more than 130km/h. That's not as impressive as a regular A1 but hardly a deal-breaker for most commuters. Obvious, too, is that there are few compromises with the A1's adaptation to the electric drivetrain. It still seats four, there is cabin cooling and heating, a premium sound system sits in the dash and the cargo area is its usual size. The T-shaped lithium-ion battery pack is hidden under the rear part of the centre tunnel and below the rear seats, giving excellent weight distribution.
Features such as full internet connectivity — with Google navigation and a wireless hot-spot — hint that it's a car more suited to contemporary city transport.
The A1 E-Tron also destroys another misconception — that EVs are heavier than regular cars because of the battery pack. The E-Tron version weighs about the same as the regular A1 as there is no heavy multi-stage transmission or four-cylinder engine and no big fuel tank.
A socket for the standard household plug fitting used to recharge the A1 is hidden behind the Audi badge on the grille. A flat battery requires less than three hours' charging time from a 240-volt grid — or 30 minutes for high-voltage fast charging.
On the move, the large electric motor driving the A1 E-Tron can convert deceleration energy into electric current , which is fed back to the electrical system by operating as a generator once the driver releases the accelerator. In city traffic, it can recover almost one-third of its energy.
The project leader for the A1 E-Tron, Dietrich Engelhart, is evangelical about his baby, using "when" rather than "if" to talk about a production version. "It is a mature concept with premium quality, the space, the ease of operation, convenience features such as a sound system," he says. "It's a true Audi."
While the ultimate goal is to provide pure electric propulsion, Audi is also developing more traditional hybrid vehicles for the short-term.
The company's first mass-market hybrid is set for German and US showrooms by the middle of next year, although right-hand-drive versions are unlikely.
The Q5 Hybrid Quattro — pitched as a sporty mid-size soft-roader with the power of a V6 and the fuel economy of a four-cylinder turbo diesel — offers the practicality of the Q5 range here.
A brief drive in Ingolstadt, Audi's hometown, adds weight to the claims. The direct-injection, turbo-charged petrol 2.0-litre four, and the associated electric motor sandwiched in between the engine and the gearbox, together have a system output of 180kW and 480Nm. That gives the vehicle excellent driveability, along with impressive acceleration of 7.1 seconds from 0-100km/h. Top speed is 222km/h. Fuel use on the official European cycle is a little less than 7.0L/100km.
There's some doubt that the compact hybrid soft-roader will make it to market as there are plenty of Audi engineers who still view diesel as a superior green technology. However, the US market has been slow to embrace diesel and Audi is keen to have a rival for the Lexus RX450h hybrid soft-roader.
The hybrid Q5 looks and feels normal inside, with no loss of cabin or luggage room. Press the start button and a "hybrid ready" sign tells the driver the Q5 is set to move. Slip the gear selection lever into D and you move off in pure electric mode. An EV button on the dash provides an extended drive mode. Press it and the petrol engine starts.
Audi first eased into hybrid development in 1989 with its "Duo" concept based on the 100 Avant. The Q5 is the result of three generations of development.
Changes from the Q5 range on sale here include modifying the engine internals and introducing the stop-start requirements of a hybrid (at rest, both power sources are deactivated). It gains an eight-speed automatic gearbox, electromechanical steering and larger brakes beneath 19-inch wheels.
The lithium-ion batteries, weighing just 38 kilograms, are stored where the spare wheel is normally housed. A redesigned instrument cluster now incorporates a "remaining battery charge" meter, which looks similar to a fuel gauge, and a larger dial that shows whether the car is using power from the engine or battery or is recovering energy under deceleration.
The powertrain of the hybrid Q5 can also be used in other Audis with longitudinally mounted engines — the new A8 and the as-yet unseen A6 are prime candidates.
For more on the Audi E-Tron concept cars, go to drive.com.au/audi
When silence is not golden
Premium car makers usually spend inordinate time and expense reducing noise and vibration, a painstaking process aimed at cocooning occupants in glorious silence.
Electric vehicles have no exhaust pipe and therefore emit no sounds of acceleration and gear changes.
Gliding through the streets, EVs are almost silent at speeds up to 25km/h. Beyond that, some tyre noise can be heard but it is not loud enough to warn pedestrians — particularly the vision-impaired — of approaching danger.
In the US and Japan, it is already law for silent cars to have a manufactured noise source and other countries are likely to follow.
Audi acousticians are hard at work developing unique artificial sounds for its E-Tron vehicles.
"It's not just a matter of safety," says the acoustics chief at Audi, Ralf Kunkel. "It is also a question of how the Audi of the future should sound."
That sound will not be of a combustion engine, nor of a jet aeroplane or anything in nature, such as the rustle of leaves.
Kunkel offers a clue: "The [EV] sound will be new and unusual. The Audi RSQ in the film I, Robot gives an indication."
SMH 22.11.10
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