Help, I’ve put the wrong fuel in my car!

Filling your tank with the wrong type of fuel is easily done – especially now a new fuel, E10, is available at pumps. If you make this mistake, here are four things you need to know…

WHAT HAPPENS WHEN YOU PUT PETROL IN A DIESEL CAR (OR VICE VERSA)?

Diesel is both a fuel and a lubricant that keeps the fuel pump and other components running smoothly. Unfortunately, when petrol and diesel are mixed, the opposite is true and this is likely to result in substantial damage to your car if you start the engine. You probably wouldn’t be able to start a petrol car if you filled it with diesel, which will, at least, limit the damage. Driving a diesel car filled with petrol is likely to result in serious damage to the pump and fuel lines.

WHAT IS E10?

E10 is a biofuel made up of 90% regular unleaded and 10% ethanol, hence its name E10. It was introduced in the UK in September 2021 to reduce carbon emissions from cars. Most petrol cars are compatible with E10 petrol (diesels aren’t) but older cars, in particular, may not be. Visit gov.uk/check-vehicle-e10petrol for more information.

WHAT IF I USE E10 BUT MY CAR IS NOT COMPATIBLE?

If your petrol car isn’t compatible with E10 and you mistakenly use it, there’s no need to panic. Your car will still run, just ensure you fill it with E5 (normal) the next time — if you were to use E10 regularly it may damage your car’s engine.

ARE YOU INSURED IF YOU PUT THE WRONG FUEL IN YOUR CAR?

Generally, insurance policies do not cover misfuelling, although some may cover the costs as part of accidental damage (check your policy for details).

IF YOU DO PUT THE WRONG FUEL IN YOUR CAR...

DON’T switch on the engine or put the key in the ignition.

DO leave the car where it is, if you can, inform the fuel station and call your breakdown cover provider (if you have one). They should be able to drain, flush and refuel your car.

DO pull over as soon as it’s safe to do so if you realise you’ve put the wrong fuel in after you’ve started driving.