What Happens if You Put Diesel in a Petrol Engine

What Happens if You Put Diesel in a Petrol Engine

Although it is unlikely to happen, given that the sizes of the fuel caps differ, it is still possible to put diesel in a car that takes petrol in older cars. It is most likely to happen to you when renting a car or driving a vehicle that takes different fuel to your own car. To find out what happens and what you should do, keep reading this OneHowTo article on what happens if you put diesel in a car that takes petrol.

Steps to follow:

If you put diesel in a petrol engine, you may be able to start it and drive it around briefly before it starts emitting white smoke and misfiring before breaking down. If you insist on starting the engine, you might actually exacerbate the problem because the fuel is not able to generate sparks and start the engine.


If you fill your petrol car with diesel, you have no option but to empty the whole tank, clean the circuit and the filter. To do this, you can take your car to a garage or you may be better to call a specialized company who will come to you and empty the fuel from your cars engine - but be warned this can be expensive!


If you realize your mistake quickly after beginning to fill up your tank, or if you avoid starting your engine after putting diesel in a car that takes petrol, you might get away with cleaning the tubes down which the diesel was filled only. But if the oil reaches the catalyst, it could be damaged and need to be changed.


As noted at the beginning, it is difficult to accidentally fill a car that takes petrol with diesel because the nozzle is too wide to fit, especially in newer cars. However, it is still possible, so be careful when you are filling up a car you don't ordinarily drive or you have just changed from a diesel to a petrol.

If you want to read similar articles to What Happens if You Put Diesel in a Petrol Engine, we recommend you visit our Cars category.