Petrol in diesel – misfuel guide

25 January 2021 | Bruce Compton

Misfuelling with petrol in diesel is a more common mishap than you may have realised with 3/4 of 150000 reported cases a year being reported by the AA.    With diesel car sales on the increase over recent years, this figure seems likely to rise.

If you have been unfortunate enough to put petrol in diesel then this quick guide will cover what to expect and what to do.

petrol in diesel

Do not start your Engine!

If you realise that there is petrol in your diesel before starting your vehicle then your damage is limited to a fuel drain as the wrong fuel will be contained to just the fuel tank.

Call a professional fuel drain company such as Auto Fuel Fix who will attend your vehicle in situ and drain the contaminated fuel.  You will not be allowed to leave your car at the pump, so ask an attendant to help you push your vehicle to a safe and appropriate place.  This is unlikely to be the first time that the attendant has seen this happen, so don’t be embarrassed.

If you have started the engine after putting petrol in diesel:

Petrol in diesel can damage the seals and reduce the lubrication in the fuel pump causing a rub.  Starting the engine gives the wrong fuel time to travel along the fuel system and the longer that the car s started for, te more likely there will be residual damage.  So… if you have started the car before you notice that you have misfuelled, then turn off as soon as you realise. If you are driving, make sure you find a safe place to stop.

You are still able to phone a mobile fuel drain company to attend your vehicle and the tank can be drained on the spot, providing that you are in a safe place.   However, if you have driven the car with petrol in diesel then you should consider replacing the fuel filter, which can not be done on site.  Contact a reputable garage to have te vehicle cchecked over for any additional residual effects and to have the filter replaced at your earlest convenience.  The fuel drain company may well offer you a specalist additive on site which will help in removing the wrong fuel particles until you get there.

If you have driven the vehicle and pulled over on a major road, or have driven it for some time then you maay need to get the car recovered to a grage to have the tank drained.  This of course will take extra time and will cost you more. Unfortunately,  the longer that you have driven, the more likely it is that you will need to replace parts of the fuel system as the petrol will have a corrosive effect on certain components.

Older and higher mileage vehicles will likely encounter more problems.

For a more comprehensive guide to misfuelling and specifically petrol in diesel, tae a look at the complete guide to petrol in a diesel car from Autofuelfix.