From £13,420
The e-tron best lives up to the company's 'Vorsprung Durch Technik' mission statement

Our Verdict

The A1 is a stylish, high quality and competent supermini, if a little expensive, it has the cabin quality and powertrain refinement that we’ve come to expect from an Audi.

8 November 2010

What is it?

The A1 e-tron is a prototype version of the new A1 hatchback and can probably be awarded the title of the first true 'range extender' electric car.

It is powered primarily by an electric motor driving the front wheels, powered by a small battery pack. However, when the battery is exhausted, a tiny Wankel engine (mounted under the boot floor) kicks in and drives a generator, which, in turn, powers the electric motor. Like nearly all electric cars, the A1 has a single speed transmission.

The combination of a (three-hour) full battery charge from the household mains, and the petrol in the car’s three-gallon tank, gives a claimed 148mpg (1.9l/100km) on the upcoming EU electric vehicle test cycle.

The motor is good for 60bhp and 111lb ft of torque on a continuous basis, but is capable of 101bhp and 177lb ft for short bursts.

In place of the usual ICE transmission, the A1 e-tron's nose not only gets the electric motor, but also houses a DC/DC inverter, the motor’s electronic control system, a battery charger, a standard 12v battery and a high voltage air conditioning compressor.

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

Join the debate

Comments
23

10 November 2010

Sounds fascinating. I hope this range extender tech works out. Can you compare it (size, weight, refinement, cost) to the Lotus range extender module? i.e. Has anyone actually driven a car with that fitted yet?

Something I am not entirely clear about is how these range extenders perform once you are well past the 31 mile (in this case) limit. Can a 20hp generator really provide enough energy for you to drive an approx 1.5 tonne car as normal? If so, how?

10 November 2010

The technology and engineering here looks superb. I'd be interested to see what Audi's reasons are for not bringing this to market, in small cars, sooner as HH suggests it seems virtually production ready.


10 November 2010

Like Tom says, once the battery is exhausted, a 20hp or 12Kw engine/generator will only provide 20hp to a 60hp motor assuming no other losses in the system. And not even taking into account other electrical systems like air-con or headlights.

10 November 2010

This has to be the most exciting small car (Morgan 3 wheeler aside) since the original A2! Surely they have to build it?

10 November 2010

Really interesting and exciting concept, but would the market accept it?

For one thing, this car would be really really expensive, probably in the £30-50,000 range at today's prices, and still with a question mark the longevity of the battery. Plus, this car would have a sustained top speed (once the battery charge is depleted) of around 60mph, much less on an incline, or against a headwind. Thirdly, I would guess that the efficiency would be poor on long journeys since Wankel engines are inherently thirsty in addition to the battery charging/discharging losses - and the car would not be lightweight.

If the car is predominantly used for short runs with the battery charged from mains electricity, then I'm sure that decent performance with exceptional efficiency is possible.

10 November 2010

To answer Tom's question...

Once the battery is flat, you are limited by the power of the range extender engine. I would guess that the sustainable top speed for the A1 with a 20bhp generator would be in the region of 50 to 60mph. There will be a speed at which it requires 20bhp simply to overcome drag and rolling resistance, and it's going to be lower than the quoted 80mph top speed.

I quote some figures for the experimental Limo Green range-extended electric car, powered by the Lotus range-extender engine, in a blog post I wrote recently: http://www.greenmotor.co.uk/2010/11/on-road-in-jaguars-limo-green.html

The Limo Green Jaguar XJ has a 47bhp generator and can sustain an 80mph cruise indefinitely. But it can only sustain its 112mph top speed for three minutes at most before dropping back down to 80mph.

10 November 2010

Like Tom says, once the battery is exhausted, a 20hp or 12Kw engine/generator will only provide 20hp to a 60hp motor assuming no other losses in the system. And not even taking into account other electrical systems like air-con or headlights.

>>

Quick calculation based on the 1.4 TFSI which has 121bhp to do 126mph. Assuming the e-tron runs lower friction tyres and has a slightly lower CD due to very little need for radiators.

20bhp will get you to 62mph (I've been generous and assumed that 20bhp is the output of the generator)

20kW (if we assume journalistic error) will get you to 72mph

I can only assume that the way this system is meant to work is that the motor cuts in many times before the battery runs out and essentially serves to boost battery range.

At 70mph the car would need around 3kW more power than the range extended could provide, the 12kWh battery could provide this for ~4 hours which would result in a 280 mile motorway range on one charge. The range extender would also provide a certain level of limp home mode at 20bhp/60mph.

For a smalll car I could see this working quite well as it would reduce the need to carry a range extender capable of powering the car for extended cruising at motorway speeds. For large cars such as the Jag XJ hybrid the power requirements to travel at speed are actually no bigger than for a small car but they have more space to hide the range extender in.

10 November 2010

The figure of 148mpg and CO2 of 45g/km only apply to the test and not real life. You have to add the CO2 produced by generating the electricity to charge the battery before you left home however much coal, oil or gas was used. And as others have pointed out according to the article after 31 miles you have only 20hp available, similar to a Citroen 2CV but with over twice the weight. Although the Wankel engine is lightweight, compact and vibration free fuel efficiency is not very good nor is longevity.

10 November 2010

[quote Maxycat]The figure of 148mpg and CO2 of 45g/km only apply to the test and not real life. You have to add the CO2 produced by generating the electricity to charge the battery before you left home however much coal, oil or gas was used[/quote]

If you do that, then to make comparisons fair with conventional cars, you should also add the CO2 produced by manufacturing petrol/diesel to their emissions figures.

Which given the electricity required just to refine a gallon of diesel would charge the e-tron's battery four times over would make conventional cars look staggeringly bad compared to the A1 e-tron.

The A1 e-tron looks a very interesting concept to me, and the idea of using a cheaper half sized battery to provide short journey range and a tiny range extender to permit longer journeys very sensible. Between the plug-in Prius, the Volt, this car and the Leaf, we have the full range of hybrid/EV possibilities covered so it'll be fascinating to see which works well in the real world. I guess Audi are reluctant to introduce it in a small car because as is continually proven: people are reluctant to pay seriously premium money for a small car, and tricky to see this car costing much less than Leaf.

10 November 2010

[quote MrTrilby]

If you do that, then to make comparisons fair with conventional cars, you should also add the CO2 produced by manufacturing petrol/diesel to their emissions figures.

Which given the electricity required just to refine a gallon of diesel would charge the e-tron's battery four times over would make conventional cars look staggeringly bad compared to the A1 e-tron.

[/quote] Yes adding the energy to produce all fuels would make sense as long as you add the energy cost in transporting the fuel to make electricity as well and the energy used in its generation and distribution. Whilst electric motors are efficient making electricity is not. In an internal combustion engine you burn a fuel directly with electricity you first burn fuel then transmit and change the electricity many times before using it. For example burning gas to make electricity is cleaner than coal at the power station but when gas comes out of the ground it often contains so much CO2 that it will not burn. This CO2 plus other gasses have to be separated at an energy cost. CO2 waste gasses were and still are released into the atmosphere, have you noticed all the recent adverts by the big oil companies how they are now starting to pump the CO2 underground. When an electric car is produced that can do over 600 miles on a single charge and is comparable in price to a liquid fuelled car and has similar performance plus the electricity is as cheap as petrol or diesel to produce the there may be a future for electric cars.

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