Thanks to their low running costs, miserly fuel bills, and refined, nippy performance, small diesel cars are soaring in popularity amongst UK car buyers, Citroen UK claims.

Sales for 2003 to the end of August were up by more than 25% compared to the same period last year and diesels now account for 10% of all small cars sold.

Europe's second largest car maker, PSA Peugeot Citroën, claims to be the UK's most successful small diesel car supplier, with Peugeot and Citroën having sold 18,709 models from their 206 and C3 ranges so far in 2003, up some 23% from 15,142 in 2002.

Key to this success has been the group's latest-generation 1.4 litre HDi diesel engine, developed as part of a partnership with Ford that will result in a comprehensive range of advanced power units from around 1.4 to three-litres in size.

The latest model using the 1.4 litre engine, the Citroën C2 launched in the UK on 19 September, emits a claimed 108g/km of CO2 - the lowest of any car with a conventional engine - and promises fuel economy of up to about 70 mpg.

Peugeot Citroën Automobiles UK chairman Tod Evans said: "We intend to focus on producing diesel engines which emit less than 120 g/km, and at year-end 2002, 190,000 vehicles fell into this category. Our plan is to increase that figure by a factor of 9, to 1.7 million vehicles with emissions of less than 120g/km by 2006. The vast majority of these vehicles will fit into the small car, supermini category."