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What do you do if you have accidentally put petrol in diesel car?

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2012-08-22 11:51:49
2012-08-22 11:51:49 says: If the tank was mostly filled with diesel, and the gasoline is a smaller proportion so that the engine still runs, the best remedy appears to be to buy a container of injector lubricant additive and cetane boost additive, and "overdose" it to protect the injection pump. Fill the tank completely with diesel to dilute the gasoline as much as possible, and keep driving. In the interest of protecting the engine, it would be prudent to avoid high engine speeds or high engine loads until the gasoline is sufficiently diluted.

If the tank has more gasoline than diesel fuel in it, the engine won't run on that mixture. It will be necessary to drain the tank and re-fill it with diesel. If the car was driven to the point of stalling, it will also be necessary to drain the injection pump housing and replace the fuel filter, and re-prime both of these with diesel fuel.

It depends...

Diesel is a lubricant, and the high pressure pumps used in most common rail diesel injection (CDI) engines - especially from Europe - rely on this for lubrication. Simply turning the ignition on could wash enough gasoline / petrol into the pump to destroy it - starting the engine could result in pieces of metal from the damaged pump reaching / blocking the injectors. Expect thousands of dollars in repair bills to replace the entire fuel / injection system.


If you've filled up with petrol / gasoline - DON'T turn on the ignition, DON'T start the engine - call your breakdown company and they'll arrange to have your tank drained. Inconvenient, but MUCH cheaper.

If you review the warning stories about putting petrol in diesel tanks, you will notice just a handful of reports distributed over many more websites. Everyone seems to have forgotten than petrol & diesel are products of the same distillation, but Diesel being about 10% denser than petrol. Take out the factors from supplier fuel additives which may or may not lubricate your diesel fuel pump. Engine oil or similar can be added to petrol to make diesel so with a full tank of 48 litres of petrol I needed to add 5 litres engine oil but opted for 8 litres as I didn't know the exact density of SAE10-30 engine oil. I had a HDI 2.0 common rail diesel engine with a full tank of petrol that ran like the fuel pump had died, clanking like a bat out of hell but after adding the engine oil it ran as normal & the garage couldn't even agree that I had put petrol in as there was nothing wrong.

I've read that petrol can dissolve the hardened metal of a a diesel fuel pump (Telegraph October 2011 - A Costly Mistake) but I don't think petrol can dissolve any metal and if it could diesel would likely too.

This is all conspiracy hogwash backed up by a dumbing down education system that wants to sell you old technology, because a lack of new technology is a backwash of a dumbing down education system.

If you put diesel in your petrol car well that's harder to resolve, because there isn't an easily accessible supply of kerosene...

How did I put petrol in my diesel car? Shell have recentyl re-branded their V Power Petrol & Diesel with the same red/black colours and were selling petrol in a black hose labelled just "V Power" next to a "V Power Petrol" hose. I would have to presume that Shell are now in the drain vehicle fuel business.

Related Questions

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Have it drained out and change filters

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If you put petrol in a diesel vehicle do not start the engine. Petrol will do serious damage to a diesel engine. You must drain all the petrol out and flush the fuel lines.

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if petrol is about 10% or less fill with diesel and carry on. otherwise remove as much as possible and fill with diesel.

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Yes, petrol/gasoline will severely damage a diesel engine.

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