Europe's carmakers improved fuel efficiency last year at only half the pace needed to fulfil a promise to the European Commission to reduce emissions of carbon dioxide, new figures due shortly will show.

Provisional figures for CO2 emissions from new cars show the European industry produced an average efficiency of 160 grams per kilometre last year, down only 1.8 per cent on the previous year. To meet the target of 140 g/km by 2008 the carmakers need an annual rate of improvement of 3.3 per cent, suggesting they may have to accelerate the introduction of expensive new technologies to boost fuel efficiency.