A WARNING has been sounded over potential problems with new-generation diesel engines.

Leasing company Lex says drivers in urban areas are at risk of the engines’ Exhaust Particulate Filters (EPF) clogging up. Some of the firm’s drivers are having to visit a dealership every six weeks to have their filters unblocked. The problem occurs predominantly in traffic at low speed, it adds.

Lex says fleets can alleviate the potential problem by following manufacturer operating recommendations.

According to manufacturer guidelines, an EPF-equipped diesel engine is likely to clog up unless it is operated at 50mph for at least 20 minutes, or covers 50 miles at motorway speeds at least once every couple of weeks.

These driving conditions effectively burn off the soot particles that the EPF has been equipped to prevent from escaping into the atmosphere.

Drivers should look out for a warning light that notifies them that the EPF is blocked and that the car needs a run out at 50mph for a prolonged period.

Lex maintenance manager Jamie Wiseman said: ‘If a driver knows their car is going to spend most of its time in urban areas at low speed, then it’s worth avoiding a car with an EPF.’