Lloyds TSB autolease has seen the total cost of repairs on its fleet of 130,000 vehicles reach a quarter of a million pounds so far this year – up from £150,000 for the same period last year.
In one case, a driver who put petrol in his diesel-powered car found the total repair costs reaching almost £6,000.
The company has recorded 750 incidents in its fleet, an increase of 34% on last year, and bosses are now urging fleet managers to educate their employees about the problem.
Head of technical services George Reid said: ‘One in three new cars is diesel, so it’s no wonder that the problem is becoming much more widespread. It’s happening on average more than 400 times a day and it is now even excluded in many insurance policies.’
He added: ‘To reduce repair bills, fleet managers can take straightforward action in two areas.
‘Firstly, inform their drivers that if they do misfuel, starting the engine may add thousands to the repair bill. Even the smallest amount of petrol can cause a massive amount of damage to a diesel engine, since it requires the self-lubricating properties of oily diesel, which are lacking in petrol.
‘If started, it is likely that the fuel injection components and filters will all have to be replaced, and in many cases the engine itself.
‘If a driver does misfuel, they should roll the vehicle out of the way and call their breakdown service, who will follow the manufacturer guidelines to safely drain the fuel system.’
The company suggests that another step fleets can take is to ensure that refuelling flaps on diesel vehicles are clearly marked with diesel stickers.