Situated in the rear half of the transmission tunnel and under the rear seats is the car’s Sanyo Lithium-Ion battery pack. A relatively modest 12kWh (half the size of battery pack used by the Nissan Leaf) will take the A1 around 31 miles in most normal conditions, arguably enough range for the average European or US commute.
What makes the A1 e-tron really special is the 'Range Extender generator module'. This is based around a tiny, 245cc, single rotar, Wankel engine. It generates a maximum 20bhp, driving a generator, which provides electricity once the battery has been run down to its lowest charge.
The Wankel engine, generator, power electronics, induction and exhaust system have been combined into a module that weighs just 65kg and fits under the A1's boot floor, without compromising luggage space. There’s even room under the floor for the Bose Hi-Fi’s bass booster.
The Chevy Volt was trailed by GM as being a range extender but, in certain high-speed situations, the Volt's engine can be coupled directly to the car’s electric motor. The A1 e-tron, however, is a true range extender in that the engine is not connected in any way to the wheels.
This completely new drivetrain has not changed the A1 in any significant way. The only external differences are the Carbon Fibre Reinforced Plastic roof panel and wheels. Compared to the massively compromised Mini E, the A1 e-tron is in another league.
What's it like?
Genuinely exceptional. Even though our test drive was on a circuit, it's hard to believe that the e-tron is not showroom ready. In fact, much of development was completed in virtual reality and real-world trials with members of the public began in Paris this summer.
In pure electric mode it is swift and quiet and handles very tidily. Despite the extra weight of the range extender running gear, the A1 had enough verve to be interesting.
Under hard acceleration it is satisfyingly quick and impressively noiseless. After a few laps of the circuit (which was laid out to imitate town driving) and a few full-bore accelerative runs, I lamented to the engineer in the passenger seat that 'I hadn't got the Wankel engine to kick in'.
In fact, it had, four times. It was so quiet, so well insulated and so inherently smooth running I just hadn’t noticed. Audi claims that further refinement improvements are in the pipeline.
Using the stock automatic gear lever, the driver can select either 'D', 'R', 'N' or 'Range', the latter allowing the engine to cut in an out during normal driving to help preserve the battery.
Not all Range Extender systems will be this well integrated or refined, but this system has to be the way forward for production electric vehicles. Not only does it completely overcome 'range anxiety' but it's also much more cost-effective than a longer range, pure EV.
For example, the money saved by using a battery half the size of the one in the Nissan Leaf, is far more than than cost of adding the A1's range extender module.
Should I buy one?
If you could, I’d recommend it very highly. But you can't. And despite the A1 e-tron’s advanced state, it is still some way from being given the green light by Audi's board.
Insiders hint that the current strategy is to first introduce electric motivation on high-end Audi models. That would be a huge mistake. This A1 is far more sophisticated and production ready than the R8 e-tron, which is scheduled for small-scale production in 2012.
On this limited showing, I'd say it was also better than Chevy's Volt.
Of anything Audi has done in the last decade, it is probably this exceptional car which best lives up to the company's 'Vorsprung Durch Technik' mission statement. It really has to find its way into the showroom.
Audi A1 e-tron
Price: n/a; Top speed: 80 mph; 0-62mph: 10.2sec; Economy: 148mpg; CO2: 45 g/km; Engine: Transverse electric motor, rear-mounted Wankel generator; Power: 101bhp at 5000rpm; Torque: 177lb ft continuous; Gearbox: direct drive