The e-HDi 90 Airdream manual engine is capable of up to 78.5 mpg and CO2 emissions of as little as 91g/km. It has a reversible starter-alternator that works in tandem with an e-booster to provide a seamless Stop & Start function. Going further than other similar systems, the e-HDi's Stop & Start puts the engine into idle mode while decelerating before coming to a complete standstill. This reduces consumption by 15% in urban driving.