Why Can’t You Put Petrol In A Diesel Car?

We’ve probably all been there at some point, accidentally putting petrol in a diesel car, or vice versa, only for our cars to come to an abrupt and spluttering halt just a mile or two down the road. In fact, on average someone puts the wrong fuel in their car every one minute and 45 seconds in the UK, so it’s nothing to be too embarrassed about!

If you call Wrong Fuel then it’ll be nothing more than a slight inconvenience as we come to you to drain the incorrect fuel from your car, fill you up again and then send you on your way.

But why is it our cars stop working and potentially become damaged if we accidentally mis-fuel? Let’s look at the science behind this common gaffe.

Petrol In A Diesel Car

Put simply, the way that fuel is burned differs between diesel and petrol engines, meaning that putting the wrong fuel in your car won’t spark it and allow it to burn for you to drive your car.

Diesel engines use compression-ignition technology to burn fuel (the fuel is compressed until it burns). Petrol isn’t able to work effectively in a diesel engine because it burns irregularly when subjected to compression, hence the coughing and spluttering of your vehicle!

Diesel In A Petrol Car

Filling up your petrol motor with diesel will probably see you grinding to a halt sooner than the other way around. This is because diesel is much heavier and less volatile than the correct fuel, so may not even ignite. Without the heavy duty pumps of a diesel engine, the fuel won’t reach the point where it can be burned, thus not running your car.

Furthermore, petrol engines are designed to draw in air and fuel before igniting this mixture with a spark. Because diesel is burnt via compression technology and not a spark, it doesn’t burn and means you’re left unable to drive your vehicle.

Thankfully, if you do find yourself in the predicament where you’ve filled up with the wrong fuel, we’re able to get to you and put you back on the road in next to no time. All you need to do is call a member of our team on 0800 634 9827 and we’ll see what we can do! We’re also over on Facebook and Twitter so you can keep up to date with our news.