Best in Class

Best in class:
Ford Fiesta 1.6 TDCi Econetic - 98 g/km
Seat Ibiza Ecomotive - 98 g/km
Best of the rest:
Polo Bluemotion - 99g/km
Mini Cooper D - 104g/km
Vauxhall Corsa 1.3 CDTI - 105g/km
Mazda 2 1.4 TD - 107g/km
Mini Cooper D Clubman - 107g/km
Skoda Fabia 1.4 TDI Greenline, 109g/km

Its a joint top place for the excellent Ford Fiesta Econetic and Seat Ibiza Ecomotive. The Ibiza has a 69bhp 1.4-litre TDI engine with just 98g/km CO2 - both a three and five-door version - whilst the Ford features a 1.6-litre TDCi unit offering 90bhp. Both are the lowest emission combustion-engined cars currently on sale in Britain - lower, even, than the Toyota Prius (104 g/km). And, like the Polo Bluemotion both are also road-tax exempt. The Mini Cooper D has recently had its emissions reduced to 104 g/km, a remarkable figure for a 110 bhp diesel, it's Clubman counterpart also does well with just 109g/km. Superminis are too cheap to be viably equipped with hybrid powertrains, but improved engine efficiency and weight-saving measures will see more of them breaking the 100g/km mark within two years. All the best cars in this class are diesel, incidentally.