Every couple of months we get a call from someone who has filled up with the wrong fuel.  It can be a disastrous mistake, so we will share some thoughts on how it can happen and what to do.

Not many people have confessed to putting diesel into a petrol vehicle at the bowser, although I hear that it has been done.  It takes quite a bit of effort being that the diesel fuel nozzle doesn't fit into the filler neck - the one labelled "unleaded fuel only".  While some people persist longer than others when encountering these obstacles, it is a fairly fool-proof setup.  Do take care if you are filling from a jerry can though, it can happen easily this way.

Pouring petrol into a diesel car happens much more commonly and can cause extensive damage.  Be aware if you are driving a vehicle that you are not familiar with such as a work vehicle or your friends car; this is when it tends to happen and makes it even more awkward to explain.

Irrespective of whether you put petrol in a diesel vehicle or vice versa, the best-case scenario is if you realise your mistake before you turn the key.  Put the car in neutral and find someone who feels sorry for you to help push the car away from the bowser to a safe parking spot.  Call your mechanic who will organise a tow truck and reassure yourself that while it is very inconvenient you have avoided any serious damage.

If you do drive away, you will soon receive a message from the engine that something is wrong.  You'll notice unusual sounds and the sooner you pull over and turn off the engine the better.  The longer you continue in denial the more likely the car will grind to a halt without your help (well, without any more of your help).

Remember, this is most likely to happen to a car that's not yours or if it is yours it's the brand new one that you've just collected from the dealer.  But not now that I've warned you.  Drive safe.