What to do if you use the wrong fuel
In 2023, more than 1200 motorists called RAA Road Service needing help after they put the wrong type of fuel in their vehicle.
A quick search online found several videos of people misfuelling their vehicles. In one social media video, a person tells their partner that even though their car runs on diesel, they can still use cheaper unleaded.
He argues diesel is optional and the car will still run on unleaded petrol.
Cut to the next scene and the couple are standing on the side of the road as their car is hauled onto a tow truck.
So, what should you do if you accidentally fill your petrol tank with the wrong fuel?
I’ve put petrol in a diesel car
As soon as you turn the ignition on after putting petrol in a diesel car, you might be causing thousands of dollars of damage to your vehicle.
Unfortunately, it’s easier to make the mistake of misfuelling a diesel car because the petrol nozzle will fit into the filler on most modern diesel engines.
Petrol is a solvent and it can quickly damage a car’s fuel system. If you do put petrol into a diesel car, it can damage the vehicle’s fuel delivery and injection.
On top of that, the higher compression ratios in the combustion chambers of a diesel engine mean pre-ignition may occur, which can also damage the engine.
Misfuelling mishaps
The number of motorists who called RAA in 2023 after putting the wrong fuel in their vehicle.
I’ve put diesel in a petrol car
You’re less likely to put diesel in a petrol car as the diesel nozzle is too large for the filler. But that hasn’t stopped some motorists from making the mistake.
If you do manage to put diesel in your petrol vehicle and start the engine, you might find the car isn’t running smoothly.
You might also see white smoke coming from the exhaust, particularly if there’s more than half a tank of diesel in the car.
What should I do if I use the wrong fuel?
The best outcome is that you realise you’ve used the wrong fuel before driving away from the petrol station.
If you do realise you’ve misfuelled your car, don’t be tempted to start the engine and move the vehicle. Instead, get some help to push it into a parking bay.
You can then have it towed to a workshop where the tank will be drained and refilled with the correct fuel.
If you drive off without realising you’ve used the wrong fuel, the engine might run for a short time, but soon the car will stop or make loud rattling noises. You’ll need to get your car towed to a mechanic where the damaged fuel system will have to be repaired.
Do you need car advice?
RAA members can call our free Car Advice service for answers to their car questions.
Or call 8202 4689