CITY centre fleets opting for diesel cars in a bid to become greener have been warned about the possible drawbacks of particulate filters.

Fleet management company Masterlease recommends fleets only opt for diesels with particulate filters if urban motoring forms a small part of driver’s journeys.

Peter Tatlock, managing director at Masterlease, said: ‘Diesel particulate filters work best at high temperatures to regenerate or burn off any harmful soot emissions, and they can only do this if they get regular exposure to the open road at a minimum of 50mph.

‘If urban driving is all that drivers do, the filter will clog up quickly and that will damage the optimum performance on the vehicle and affect emissions.’

Masterlease says the warning only affects diesel vehicles with particulate filters. Tatlock added: ‘If you are about to choose a new company car, think about your daily journey before making a decision. Fleet managers should also look at what type of journeys their drivers cover.’