Audi expects to cut the CO2 output of its range and improve fuel consumption by 20% by 2012 thanks in the main to the introduction of stop-start technology.

Audi has revealed the A3 1.4 TFSI with a manual gearbox will be the first car to feature the technology arriving before July. The A3 will be followed quickly by A4 and A5 models.

Audi claims the technology improves fuel efficiency by more than 5mpg.