Audi A3 TCNG review

* Powered by natural gas * CO2 emissions as low as 27g/km * Range: 267 miles...

Audi A3 TCNG review

The Audi A3 TCNG is powered by natural gas and this Turbocharged Compressed Natural Gas (TCNG) prototype has a big part to play in Audi's eco-engineering of the future.

The majority of participating filling stations (virtually none in the UK) currently stock such gas in its most natural form derived from fossil fuels but Audi is building a factory that will produce it in synthetic form. Furthermore, it will power the process by using excess energy generated through green sources such as wind farms.

The factory will also be able to produce methane, which can then be fed back into the German gas grid. The single facility will produce enough gas to power 1500 cars for 15,000 miles a year.

Audi claims the CO2 saved in the production process completely offsets what is produced from the cars exhaust, in this case a prototype Audi A3 Sportback.

Whats it like to drive? The 1.4-litre engine in the A3 TCNG is so similar to the one in the standard petrol car that it has a back-up petrol tank to boost the overall range.

The driving experience is virtually the same, too; smooth to pull away and offering the same 0-62mph time of just shy of 10 seconds.

What it does lack, is the revving nature of a petrol engine. It also misses some urgency in the lower gears and doesn't respond rapidly to the throttle in higher ratios. However, heavily snow-covered Swedish roads meant we werent able to test that thoroughly.

The upside of this is an engine that's impressively quiet and refined, even at 60-70mph.

Fuel efficiency has yet to be confirmed, but Audi reckons the A3 TCNG will emit around 116g/km if it uses fossil fuel-produced natural gas, but the equivalent of just 27g/km if you take into account the e-gas the company will put back into the grid.

Although these figures are not final, they hint at respectable efficiency, with a gas-alone range of around 267 miles almost 15 miles for every kilo of gas it can carry.

Whats it like inside? As the development car is an existing A3 Sportback, the interior is unchanged from the car on sale to customers today. The one change is a slight reduction in boot capacity, because of the two gas canisters it has to carry.

As a result the luggage space drops by 50 litres to 320 litres.

Should I buy one? Our test car is not one that will make it to production, but a version of the next A3 will be powered by compressed natural gas, as will a future A4. We are not likely to see any of them in the UK, though, due to the virtually non-existent fuelling infrastructure.

What Car? says

Tom Webster