Do it yourself
Frequently asked questions about cars and motorcycles
Car tutorial (Do it yourself) Motorcycle tutorial (Do it yourself) Frequently Asked Questions

What happens if we put petrol in diesel (or vice versa)?

Model: (Various brands) Various
Part: Checks and maintenance

Video tutorial

What happens if we mistakenly put the wrong fuel in our car's tank? If we put petrol in the diesel tank, it is a serious problem because petrol washes away the lubricating properties of diesel, causing the injectors to run 'dry', seizing within minutes.

Additionally, in the high-pressure environment of a diesel engine, petrol can cause pre-ignition, risking damaging the pistons and causing severe engine and injection system damage.

If you realise this, do not even insert the key, as the electric pump would activate, pushing the wrong fuel into the engine. Push the car to a safe place and call a mechanic to completely empty the tank.

If, however, we put diesel in a petrol car, it is a less serious case: the engine often won't start at all because diesel does not ignite with the spark from the plugs, or it starts poorly and emits blue smoke. It can foul and damage the plugs, lambda sensor, and catalytic converter.

If we put a small amount in a nearly empty tank, fill up with petrol immediately to dilute the diesel: the vehicle will run, albeit with some performance loss, until it has cleared the mixture. If we put a lot of diesel in, we need to call a mechanic to drain the tank.


Posted on 13 August 2026 by ScegliAuto


Related tutorials

How to Remove Petrol from a Diesel Car Fuel Tank
How to Remove Petrol from a Diesel Car Fuel Tank
(Various brands) Various In this video, see how to remove petrol that has been mistakenly added to the fuel tank of a diesel car. This is even worse if it is a Ford, which - …
How to Empty the Fuel Tank
How to Empty the Fuel Tank
(Various brands) Various Sometimes it may be necessary to empty the fuel tank, for example, in the case of incorrect refuelling (petrol instead of diesel or vice versa). If y…
What Happens If You Put Petrol Instead of Diesel
What Happens If You Put Petrol Instead of Diesel
(Various brands) Various In this case, the vehicle was a Ford Fusion, but the concept applies to any type of vehicle: this car was filled with petrol instead of diesel. The o…

Other guides you may be interested in

    Frequently Asked Questions

    • Vari - Does the Sym Symphony 200cc have any known faults or problems? Read answer
    • Vari - What problems does the Keeway K-Light 125 have? Read answer
    • Vari - What are the main problems with the Keeway Superlight 125? Read answer

How to Remove the Rear Seat of a Hyundai Tucson?

To remove the rear seat of a Hyundai Tucson, follow these steps. Start by moving the front seats to their most forward position to gain space. Next, locate the release lever on the underside of the rear seat, near the floor. Press this lever down while pulling the seat upwards to unlock it from the anchor pins. Once unlocked, tilt the seat upwards and forwards to remove it from its position. Repeat this process for both sides of the rear seat. Be careful of any electrical cables or components that may be connected to the seat during removal. Once the rear seat is removed, the disassembly is complete.

Watch the video!


by ScegliAuto

More videos