sports car

The Science of Misfuelling

One of the most feared mistakes for motorists is filling their car with the wrong fuel. Everyone knows that putting petrol in a diesel car or vice versa spells trouble for your engine, but do you understand the mechanics behind it? In this post, we’re going to look at the how, the why and the what to do if you’ve found yourself filling up with the wrong fuel. But first, which is worse?

sports car

It’s incredibly difficult to put diesel in petrol cars by mistake. First of all, the nozzles on diesel pumps are often considerably larger than the fuel cap of petrol cars, and there’s a reason for that. Despite this precaution, filling a petrol car with diesel is an awful lot less damaging than its counterpart.

Why? Mainly because diesel does not evaporate upon ignition. When you try to start your petrol car filled with diesel, the engine simply won’t fire up. It is, however, an easy fix, unlike the other way around. Simply draining the tank, cleaning the injectors and refilling with petrol is more than likely enough to rectify the issue for the most part. There are other steps you can take to be on the safe side, but they’re not always necessary.

On the flip side, filling a diesel engine with petrol can have significantly more damaging repercussions. Diesel engines – and its injectors, specifically – notoriously have a very low tolerance for petrol. The thinner consistency of petrol causes the diesel engine to burn out through friction. If you’ve come this far without realising your mistake, it’s too late to turn back. You’re looking at some pretty pricey repair procedures.

If you get lucky, you’ll notice your mistake before turning the ignition, as this is the spark that creates the most damage. Petrol, in particular, is highly volatile and combustible and forces the pistons to behave out of character. This can be incredibly detrimental to your car’s internal composition, and the reason a more radical overhaul may be required.

At this point, all you can do is call your breakdown cover service and insurance company and hope for the best. With any luck, the damage will be minimal and you can get away with a less complex repair job. Many insurance companies do offer cover for these instances, so it’s something worth looking out for when seeking a provider. And believe me, it’s worth the investment. You never know when you will make a fatal oversight that will cost a significant sum to fix.

If you were able to spot the mistake before firing up your engine, you might have saved yourself an awful lot of heartache. As mentioned above, a complicated replacement of parts likely won’t be necessary. It’s far cheaper just to drain and clean your engine than it is to replace it entirely, so count your blessings. Your breakdown cover may even carry out this service for you, making your mistake a mild inconvenience at worst. Look on the bright side – not everyone can be so lucky.