Have you put petrol in your diesel car? Don’t panic!
Diesel cars may have seen a surge in popularity over the past ten years or so but upwards of 25% of our cars still run on petrol. With such a large number of each type on the road it’s more important than ever to keep track of which cars run on which fuel. Making the wrong choice at the petrol pump could end up costing you a lot of money, so here’s some advice on how to avoid this surprisingly common mishap and what to do if it happens to you.
How does it happen?
If you’re in a new car (or one belonging to someone else) and you’re accustomed to driving a car with a petrol engine, it’s all too easy to absent-mindedly pull up at the station and, out of habit, start pumping petrol into your vehicle. Unfortunately, petrol nozzles are small enough to fit into the filler neck in diesel cars, so you might not notice you’ve made a mistake until it’s too late. Diesel nozzles, meanwhile, are actually too big to fit into the filler necks in petrol cars, so you’d need to be especially determined to make that error.
What damage can it do?
Petrol strips a diesel engine of the lubricant it needs to keep it ticking over, as well as damaging seals. It will almost certainly lead to the engine seizing, by which point the whole engine block and many vital components will likely be destroyed beyond repair.
What should I do if I notice right away?
If you notice at the pumps that you’ve put petrol in your diesel car DO NOT START THE CAR, DO NOT PUT YOUR KEYS IN THE IGNITION and, if the car is locked, DO NOT UNLOCK THE CAR. Turning the key in the ignition could prime the fuel pump and contaminate engine components. This can happen even if you started turning the key and stopped yourself at halfway. Some newer cars also prime the fuel pump when you unlock the doors. Before doing anything at all with your key, call a breakdown assistance service and wait for them to come and pump the unsuitable fuel out of your tank. You can then fill up with the correct fuel and be on your merry way.
If you were near empty and you only put in a small amount of the wrong fuel, it’s possible that you could completely fill the tank with the correct fuel and see no ill-effects. Some engines can cope with up to 10% contamination, so if you only added one litre of the wrong fuel and still have space for 50 litres of the correct fuel it might be worth the risk. But beware: even a small amount of contamination is enough to severely damage modern common-rail diesel (CRD) engines. You should always ask your mechanic and/or the manufacturer to get their advice before you think about starting your engine. If you’ve filled your tank with the wrong fuel, someone will have to come and drain it out.
What if I’ve already driven off?
If you’ve noticed your mistake after you’ve left the forecourt, you should find a safe place to pull over and contact a breakdown service or your mechanic immediately. They should be able to come and drain the engine. It may seem expensive but it’ll work out cheaper than replacing all the parts destroyed by driving with the wrong fuel.
How do I know if I’ve misfuelled?
There are a number of symptoms to look out for: the vehicle may be difficult to start - especially when the engine is warm, the engine may be very noisy, smoke may come from the exhaust, the engine may not stop once started, or there may be a loss of power.
How much will it cost?
A lot. If you haven’t started your car and a fuel drain will suffice, it could cost around €400. If you’ve driven with the incorrect fuel on board it’s likely that many parts of your car have been damaged. The cost of replacing them could run into the thousands.
How do I avoid making this mistake?
There are plenty of measures you can take to prevent such a costly error. Firstly, make sure everyone who drives the car, or may drive the car in the future, knows what type of engine it has. Labelling your tank with a ‘DIESEL’ or ‘PETROL’ sticker is a great way to remind yourself, and anyone else who may need to refuel the vehicle, of which fuel to use. And finally, stay tuned in! It’s easy to zone out while carrying out mundane, everyday tasks like stopping for petrol, but a mistake at the petrol pump could cause you a lot of grief in the long run.
We hope this article has been helpful. Check out our other posts for more handy information on road safety, your home and a whole lot more!
All the best,
The Team at GMIB.ie