PSA Peugeot Citroën officially unveiled the group’s new Stop & Start system at a ceremony in Paris on Tuesday.

The Stop & Start system turns the engine off automatically and remains in standby mode, when the vehicle stops at traffic lights and traffic jams. The engine starts again instantly when the brake pedal is released, with the vehicle pulling away once the accelerator is pressed.

PSA claims the petrol-powered Citroën C3 1.4i 16V Stop & Start, which will be rolled out in early November, will be the first mass-produced car equipped with this innovative system.

However, Volkswagen has previously offered a similar system on low-volume Golf diesel models – the Mark One in the mid-1970s and the Mark 3 in the early 1990s.

The PSA system will be combined with the SensoDrive electronically controlled manual gearbox already available as an option on the Citroen C3. The new system will gradually be extended to other Citroën and Peugeot vehicles.

Citroen claims that repeated stopping and starting of the engine reduces fuel consumption and enhances driving pleasure rather than causing excessive petrol consumption.

It said the Stop & Start system reduces fuel consumption by 10% in city driving, by 6% in the standard EU combined cycle test, and by up to 15% in heavy traffic. CO2 emissions – used as the basis of vehicle taxation in some EU countries – are reduced by a similar proportion, the carmaker claims.

Citroen also said the Stop & Start system helps to improve the quality of life in cities, since drivers and the urban environment benefit from total silence during the many times the vehicles are stopped.

PSA Peugeot Citroën developed the Stop & Start system as part of its strategy of developing new technologies to combat the greenhouse effect by reducing fuel consumption and CO2 emissions while enhancing drivability.

Over 500,000 vehicles that emit less than 120 grams of CO2 per kilometre have already been sold by the group, with a target of 1.7 million by 2006.

“This performance results from the assertive policy deployed to further develop HDi diesel engines and introduce innovations such as electronically controlled gearboxes, PSA said in a statement.

“This latest development reinforces PSA Peugeot Citroën’s strategic focus on “useful technology for everyone,” delivering benefits for both customers and society as a whole. This pragmatic approach systematically produces quick-to-the-market, cost-effective solutions.”