It happens. We get distracted and think we are acting out of habit and suddenly we realize we’ve put the wrong type of fuel into our gas tank. You’re not alone. Or maybe you accidentally filled up with the wrong fuel because you didn’t know what type of fuel you were supposed to use – with so many options of fuel out these days how do we know which one is right for our car? And what will happen to your vehicle and how should you respond if you find yourself accidentally filling up with the wrong type of fuel? The answers to these questions will vary depending on what type of fuel your vehicle is supposed to take, what type of fuel you accidentally filled it with, and how much of the wrong fuel was used.

What Happens When You Put Petrol Gasoline Into A Diesel Engine?

Filling your diesel fueled engine with petrol gasoline is the most serious wrong fuel mistake you can make. If you fill your diesel fueled engine with regular petrol gasoline it is extremely important not to run your vehicle until the fuel system has been completely cleaned out because this can lead to serious damage occurring in your engine. Once you start a diesel engine that has been fueled with petrol gasoline it doesn’t take long for catastrophic failure of the injection pump, the injectors, and finally the entire engine to occur.

What Happens When You Put Diesel Into A Petrol Gasoline Engine?

Vehicles that have a gas engine are not able to combust diesel fuel. However, putting diesel fuel into a gasoline fueled engine typically is not as harmful as putting gasoline into a diesel fueled engine. If you only put in a couple gallons of diesel, then it may only make the car run a bit more poorly, but if you put too much diesel into a gasoline fueled engine then the vehicle may quickly stop working. Ignoring the problem could potentially cause the fuel pump, fuel lines, and fuel injectors to be ruined, and the fuel filter to get clogged up leading to other damage occurring.

What Happens When You Put A Higher-Octane Gasoline Into An Engine That Requires A Lower Octane Gasoline?

Octane numbers are those numbers you see distinguishing regular gasoline from premium gasoline. You might think that using a premium gasoline even if your vehicle doesn’t call for it will help your vehicle to run better, but the only real difference you will notice will be in the cost to fill up. Fortunately, if you accidentally fill up using premium gasoline instead of regular gasoline, you should not experience any damage to your vehicle either.

What Happens When You Put A Lower Octane Gasoline Into An Engine That Requires A Higher-Octane Gasoline?

Unfortunately, using regular gasoline in a vehicle that calls for the usage of premium gasoline is not the same as using premium gasoline in a vehicle that only needs regular gasoline. If your vehicle calls for premium gasoline and you do not use it, serious damage may occur. You will most likely notice a spark knock which will sound like a high-pitched pinging or rattling noise. The spark knock can cause long-term damage if it occurs too much. Your engine’s computers are able to adjust timing to help limit the amount of damage caused, so if this is only done accidentally one time you will probably notice reduced performance and lowered fuel economy but will not likely experience serious damage from the spark knock. Just make sure you switch back to premium fuel as soon as you can.

What To Do If You Do Fill Your Tank With The Wrong Fuel Type

It is obviously best to make sure you know what type of fuel your tank takes and pay close attention at the pump to make sure you are using the right type of fuel, but if you do find yourself accidently filling your tank with the wrong type of fuel here are the steps you should take:

If you are still fueling up when you notice your mistake:

  • Stop adding fuel immediately.
  • Don’t start your car or turn the key to “on”.
  • Disconnect the battery.
  • Push your car away from the fuel pump area.
  • Have the car towed to a repair facility.
  • Have your gas tank professionally drained and the fuel system flushed out.

If you begin driving before you notice your mistake:

  • Pull over and shut off the engine immediately.
  • Have the car towed to a repair facility.
  • Have your gas tank professionally drained, the fuel system flushed, and make any necessary repairs.

Will My Automobile Insurance Cover Damages?

Most automobile insurance coverages have a misfuelling exemption clause that will exempt the insurance company from being responsible for any claims resulting from adding the wrong type of fuel to your vehicle. You should check your current policy documents to see if your policy includes this misfuelling exemption clause. Even if your policy does not include this exemption clause, it is unlikely that your insurance company will pay for the cost of having your vehicle towed and professionally drained and flushed out.