What Happens If You Put the Wrong Fuel in Your Car?

Putting the wrong fuel in your car is more common than most drivers think. Whether it’s petrol in a diesel vehicle or diesel in a petrol engine, using the wrong fuel can cause serious mechanical problems if the vehicle is started or driven. The good news is that quick action can often prevent major damage and expensive repairs.

In this guide, we explain what happens when the wrong fuel is added to your vehicle, the signs to look for, and what you should do immediately to protect your engine.

Petrol in a Diesel Car

Putting petrol into a diesel vehicle is one of the most serious fuel contamination issues. Diesel fuel acts as a lubricant for important engine components, while petrol reduces lubrication and can damage the fuel pump, injectors and engine system.

If the engine is started, contaminated fuel can circulate throughout the vehicle and cause expensive mechanical damage. In severe cases, the entire fuel system may require repairs or replacement.

Diesel in a Petrol Car

Diesel in a petrol car is generally less damaging than petrol in a diesel engine, but it can still create major performance problems. Diesel fuel is thicker than petrol and can affect ignition, fuel flow and combustion.

Common symptoms include difficulty starting the car, engine misfires, excessive smoke and rough performance. If the vehicle is driven, additional repairs may be required.

Signs You Put the Wrong Fuel in Your Car

• The engine won’t start
• Rough idling
• Excessive exhaust smoke
• Knocking noises
• Warning lights
• Loss of power
• Engine cutting out

What To Do Immediately

If you realise you’ve put the wrong fuel in your vehicle, do not start the engine. Starting the car allows contaminated fuel to circulate through the fuel system and increases the risk of expensive damage.

Instead:

• Stop fueling immediately
• Avoid turning the ignition on
• Move the vehicle safely if possible
• Call a professional wrong fuel rescue service

Professional Wrong Fuel Rescue in Sydney

Austech Mobile Mechanics provides fast mobile wrong fuel rescue services across Sydney. Our technicians can drain contaminated fuel, flush the system and help get your vehicle back on the road safely.

We service locations across Sydney, including Parramatta, North Sydney, Chatswood, Ryde, Blacktown, Liverpool and surrounding suburbs.