Mazda has added its i-stop stop-start technology to the new 3 range.
The system automatically switches the engine off when the car’s speed drops below 2mph or the driver engages neutral for more than a few seconds.
The engine then restarts when the driver depresses the clutch. Initially, the system will be available on the two 2.0-litre Sport models.
An i-stop equipped Mazda 3 offers fuel economy improvements of 19 per cent and CO2 emissions drop to below 160g/km compared to a standard 2.0-litre Mazda petrol engine.
Mazda sources have said that the technology should feature on all new petrol models by 2011. Diesel engines will be slower in getting the technology, but it should feature some time after 2011.