We’ve all been there. You’re stood at the fuel pump thinking about your day ahead. That impending deadline at work. The kid’s homework. Or what’s for dinner that evening. And before you know it, you’ve filled your diesel car with petrol. Or your petrol car with diesel. Ouch! It could be a costly error, but with some simple advice from Delphi we can help you minimize any damage and get you on your way again……and if you only remember one point from this, DO NOT start the ignition.

What to do if you put gas in a diesel tank:

Unfortunately petrol nozzles can easily fit into most diesel tanks so it’s an easy mistake to make. It can also be an expensive mistake to make, as putting petrol in a diesel car can cause significantly more damage than the other way round – diesel in a petrol car. That’s because diesel actually helps to lubricate the fuel pump. Petrol, however, works in reverse reducing the lubrication and creating friction between the key system components. This is bad news for you and your engine!

With today’s Common Rail diesel engines injecting fuel at pressures up to 2,000 bar, and injector tolerances being measured in microns, even a small amount of petrol can cause major damage to the pump and injectors. Worst still, because of the high pressures and flows involved this can easily and quickly spread to the rest of the engine, causing yet more damage. The result?  It could mean a new pump, filter, injectors, pipes, rails and even potentially a whole new engine. With a possible repair bill running into the thousands.

What to do if you put diesel in a gas tank:

On a positive note, it’s unlikely that you’ll put diesel in a petrol car as the diesel nozzle is normally bigger than the petrol tank filler. And even if you do, the impact will be a lot less. Typically you’d be looking at a clogged fuel system and spark plugs, and whilst the car won’t start because of it, it is easily repairable.

So now you know the consequences let’s take a look and what to do if you have a fueling mishap – there are three simple steps:

1. NEVER turn the ignition as this will pump fuel through the system – remove your keys from the ignition just to be sure. If you’ve already started the car, chances are damage has already been done but stop as soon as possible.
2. Put the car in neutral and get help to push the car to a safe place.
3. Call your local garage/recovery services for immediate assistance. They’ll be able to drain the fuel and assess any damage.