Filling up vehicles with the wrong type of fuel is surprisingly common – according to the RAC, 50,000 of their members alone ‘misfuelled’ in 2007.

The most common scenario is putting petrol into a diesel. This is relatively easy to do as the petrol nozzles on garage fuel pumps are slightly smaller than those for diesel – meaning that a petrol pump and easily be used to fill up a diesel. Doing the reverse isn’t so easy, as the nozzle will need to be forced in – which should be a warning sign that something’s wrong!

Helping out misfuelled drivers is getting to be big business – the AA has just doubled the size of its Fuel Assist fleet – a dedicated fleet of vans that provide a mobile fuel draining service for drivers who have filled up their vehicles with the wrong type of fuel.

In case you do ever do this, don’t start your engine once you realise your mistake. This will make pumping out the incorrect fuel easier and will reduce the chance of any damage to your engine. If you are already driving when you realise your mistake, stop as soon as possible and phone your hire company’s breakdown service for advice.

When you are driving a hire van, there’s an obvious increased risk of using the wrong fuel – especially if you normally drive a petrol car.

Remember that the vast majority of vans are diesel powered – certainly most rental vehicles are. Most rental companies label the filler caps of their vehicles with the required fuel type – check and ask if unsure.