If you put the wrong fuel in your car, draining, cleaning and accidental damage can be costly. Car insurance and breakdown cover may help you get it sorted out.
Misfuelling means putting the wrong fuel in your car.
It's a surprisingly common error, but fortunately some car insurance policies will help you pay to put this costly mistake right.
Misfuelling cover means that your insurance policy will pay out for draining and cleaning the fuel tank at the filling station, or after being towed to a garage.
It can reimburse some, or all, of the cost of the contaminated fuel wasted by the incident.
Misfuelling cover isn’t often found as a standard feature of car insurance – out of 363 comprehensive car insurance policies on Defaqto, only 8% cover misfuelling as standard.
Only 4% of the policies could provide misfuelling cover as an optional extra, so you might not be able to add it to your cover, even if you want to.
Misfuelling cover will normally only pay for the draining and cleaning of your tank at the point of misfuelling.
If you’ve driven away and caused further engine problems, you’ll need to check whether you’re covered under the accidental damage section of your policy.
Of the 363 policies we checked on Defaqto, all offered accidental damage cover but 51% contained a misfuelling exclusion clause.
Some insurers refuse to pay anything at all for misfuelling under accidental damage while others cover the cost of repairing damage caused but wouldn’t pay to have your fuel tank drained and cleaned.
You’ll need to check your policy documents carefully, including the accidental damage section, to find out exactly what is and isn’t included.
If you realise you’ve filled up with the wrong fuel, the golden rule is not to drive your car anywhere.
Don’t even start the engine – remove the keys from the ignition and let the service station attendant know what’s happened.
Matt Oliver, our motoring expert says, “If you haven’t started the engine, draining and cleaning the tank of the wrong fuel should help fix the problem without damaging your car.
“But driving your car any distance, is considered intentional damage. It’s important to stop in your tracks and call for assistance.
“If you have cover under your car insurance policy or breakdown cover, call the helpline and follow its instructions.
“Failing to do so might invalidate your cover.
“If you don’t have cover, the service station attendant might be able to give you a number to call for a local assistance company - it’s unlikely to be the first time they’ve encountered this problem.”
If you’ve filled up with the wrong fuel, don’t start the engine - it could damage your car even more
Confusing petrol for diesel can damage your car’s fuel system.
When the petrol reacts with the diesel in the tank, it can cause the metal parts to rub together, damaging the pump. Even a small amount can cause things to go wrong.
If you start your car, the mixture can make its way through the rest of your car and damage other parts.
Your fuel system could need repairs or replacement, depending on how bad the damage is.
This isn’t as bad as putting petrol in a diesel car, but it can still do some damage.
The engine could start smoking if you start the car, or it could cut out altogether.
Put an ‘unleaded’ or ‘diesel’ sticker near or inside the petrol cap as a reminder to you (or anyone who borrows your car) which fuel the car takes.
Petrol nozzles, triggers and hoses are usually green, and diesel nozzles, triggers and hoses are usually black, but that’s not always the case.
Read the labels before fuelling, and if the colours are muddled - a black hose with a green handle, for instance - don’t take the risk, ask the person running the petrol station.
The diesel nozzle is larger than the neck of a petrol tank - it's more difficult to mis-fuel a petrol tank.
However, a petrol nozzle easily fits in a diesel filler. If the nozzle feels extra loose, take a second to check the fuel type before pulling the petrol trigger.
If the petrol and diesel hoses are the same colour, or are tangled, make sure you’ve picked up the right nozzle by tracing the hose back to the correct pump.
Last checked 3 June 2021