Here’s What Happens When You Put The Wrong Fuel To Your Car (And What You Should Do)

I believe this is a question we’ve all wondered at a certain point: “what happens if i accidentally put petrol (diesel) in my diesel (petrol) engine car?”.

Well, because misfuels do happen (surprisingly, they are quite common), here’s what to expect and what you should do. Before we start, it’s important here to note that the best thing to do in both cases is to remove the keys from the ignition and do not, i repeat do not, attempt to start the car. But what if you do start the car? What will happen to the engine?

Let’s find out. (the article continues after the ad)

First of all, putting gas to a diesel car is not the same as putting diesel to a gas car. The consequences are much more severe in the first case. Here’s why. 

I accidentally put petrol in my diesel car

Because diesel is not only a fuel but it also acts as a lubricant to the fuel pump, putting petrol into your diesel tank is much dangerous and it will cause more damage. Petrol actually causes the reverse (it adds more friction in the diesel engine’s parts) so you understand that the more petrol that gets pumped through your diesel system, the more severe the damage will be. Depending on the amount of petrol, the damage on a common rail (HDi) diesel engine will vary from damaging the fuel pumps, pipes, filters, injectors, or even the entire engine.

I accidentally put diesel in my petrol car

If this is the case, the aftermath may not be as bad as you think it’ll be. Most chances are that your engine will survive. This is because diesel and petrol are ignited differently. Petrol is ignited by a spark that’s generated by the spark plugs while diesel needs to be compressed in order to ignite. Therefore, when you try to start the car, it simply won’t start as diesel will clog up the spark plugs. Still bad, but not as bad the opposite scenario.

So, what to do in case you messed up the pumps and put the wrong fuel to your car:

  • Do not attempt to start the car. Simply remove the keys from the ignition.
  • Get the car to a safe location: if you are in a petrol station, just put the car in neutral and get someone to push you to a safe spot.
  • Call your car insurance company. The roadside assistance will come, drain the wrong fuel so you can fill your tank with the right one.

If you like what you read, then you will definitely love this one: Never Get Fooled Again: How To Check The Manufacturing Date Of Car Tires 

Photo: Staff Sgt. Jason Colbert / U.S. Air Force
Sources: Wrong fuel advice | What Happens If You Put the Wrong Fuel in Your Car?

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