Audi is developing super-clean versions of the Q7 sport utility (pictured) and A8 limousine as part of an ambitious challenge for top-flight petrol-electric registrations across global markets, Fleet News can reveal.

The twin-power duo is tasked with widening the high-end motoring appeal of e-tron, the plug-in hybrid system that provides up to 31 miles of zero-emission driving in its initial application, the A3 Sportback, the most popular product from the premium brand market leader in Britain.

Linked with a 1.4-litre turbocharged TFSI engine, the electric motor boosts output to 201bhp to provide acceleration to 62mph in 7.6 seconds, a 137mph top speed with 37g/km emissions and economy of 176mpg on the official ECE test cycle.

In an interview as the German firm launched the e-tron A3, product marketing chief Christian Hartmann said the company had been researching hybrid mobility since the early 1990s, when it showed the Duo electric concept based on the Audi 100 saloon.

“Our engineers have spent a lot of time working in this area over the last two decades and we are convinced that we have reached the perfect compromise with this sytem, which eliminates anxiety over range limitation by allowing the car to travel up to 584 miles," he said.

“We believe the potential of e-tron is enormous and we hope our future models will win us leading alternative fuel positions in markets like the UK, China and the US. I can't say when they will arrive, but development is already at an advanced stage.

“Research is showing there is considerable appetite for our system. The bigger the car, the more sense it makes to use a drivetrain that delivers no-compromise driving performance but also provides zero-emission travel, which is growing in significance as access to inner city areas becomes more restricted.”