6 Common Urban Myths about Misfueling:
We hear it all when dealing with thousands of angry and/or upset drivers who have put the incorrect fuel in their cars. Some of the ideas going around are quite alarming in that they are completely false and often confuse people and lead them down the wrong road.
So we decided to list de-bunk some of the most common false ideas about misfueling. Here is our list of Misfuelling Urban Myths:
Myth: A little bit of petrol is good for a diesel engine – it cleans out the fuel system and is done in cold climates to stop the diesel from freezing.
Truth: Any amount of petrol in a diesel system will reduce lubrication. Yes – it will clean the engine, however this dislodged gunk can clog the fuel lines, filter and injectors.
Cold-weather countries used to use a small amount of petrol in diesel a long time ago. This was way before modern diesel engines with high pressure pumps and common rail systems. Nowadays the diesel is specially engineered with numerous additives to ensure it doesn't freeze – but still manages to correctly lubricate the fuel system.
Myth: Wrong fuel? No problem – simply keep topping it up and don't run it too hard or rev too much.
Truth: The vast majority of people who try this do break down soon afterwards. Those few who manage to "get away" with it have simply solved the present, obvious problem. However they have also reduced the lifespan of the high-pressure pump, the lift pump, and the injectors. This means that they will need to be replaced sooner rather than later. It is for this reason that companies like Mercedes often refuse to guarantee any fuel system components that have been in contact with contaminated fuel, and quote thousands to replace everything.
Myth: It's worse to put diesel into a petrol car than petrol into a diesel.
Truth: Both cases are bad and both will cost a lot of money to fix if not noticed and resolved in a timely fashion. However, to be honest, both are easily and cheaply fixed if done so immediately. In reality though they are not even really comparable as they are completely different problems. Oranges and apples!
Myth: I should be ok to just drive it home and get it sorted there.
Truth: You might get home, but you risk damaging the vehicle in getting there. Additionally you have an even greater risk in breaking down on the way home. It is better to wait for a fuel drain at a warm petrol station than broken down in the middle of a dark, cold country road.
Myth: I can probably do the fuel drain myself.
Truth: Unless you are a trained contaminated fuel specialist you probably, unfortunately, can't. Even fully trained car mechanics often call us for help as fuel draining is a highly specialised service. There is also the small matter of what to do with the contaminated fuel once it has been removed.
Myth: I can re-use the drained fuel.
Truth: There will still be between 5 and 15 litres of fuel in an empty vehicle when the fuel warning light is on. Let's say you put 60 litres of petrol in a diesel car. When drained that 60 litres of petrol will now be mixed with 5-15 litres of diesel. Put that in a petrol car and you will soon see problems with the petrol car.