It"s the first volume-built...

It"s the first volume-built car to use the technology, which turns the engine off when the vehicle comes to a halt in traffic. The 1.4-litre unit automatically goes on "standby", re-starting only when the brake pedal is released and a gear is selected. Acceleration is then as normal.

As well as the potential for reduced noise and less pollution in areas around traffic lights and junctions, Citroen reckons owners will get a substantial cut in running costs. Engineers claim their testing has boosted fuel economy by six per cent in normal conditions, 10 per cent in city driving and 15 per cent in heavy traffic. The research has also shown a similar percentage reduction in CO2 emissions. The car goes on sale in November.