petrol in a deisel engine

[ANN BEST]

My partner put �10 of unleaded into my diesel Vectra, realised then filled it up with diesel.  Didn't tell me until I complained about if not starting!!  Have been driving it.  What should I do now??

[ianess]

�10 would barely be a quarter tankfull so you may have just got away with it.  Keep the car filled to the brim [with diesel!] and the petrol will become more and more dilute.  Be cheerful.......it might never happen......if it does then get a new partner!

[Skids]

The whole system needs purging to get rid of all the unleaded.  Unfortunately, as its been driven with the unleaded fuel in it, you may have caused a lot of damage to the engine.  It needs to be taken to a garage, without driving it, for them to check it.  Tell your partner that if they put the wrong fuel in the car it should NEVER be topped up with the right fuel, and certainly NEVER be driven without having the tank drained and the right fuel put in.

[KebabMeister]

I gave this answer to a similar question:

Diesel engines have a higher compression ratio than petrol engines.  Compression ratio on a petrol engine is around 10:1 or just below.  Diesel are 20:1 and below.  

What does this mean?   Petrol is more refined than diesel which means because of the higher compression ratio it will detonate before diesel does.  In a petrol engine this is described as pre-detonation or 'pinking'.  It basically means that it is exploding.

Now, the engine will run but it might damage your engine in the long term.  You should really have tried to drain the tank and fill it with neat diesel.  If you continue to run your car avoid too many short cold journeys since the diesel injection pump is advanced to increase power (and increase timing/detonation).

[The Tiggster]

I did this too a few years ago, but put in slightly more than �10.00 worth. The car conked out about 2 miles from the garage & that's when the horrible sinking feeling came over me about what I had done.

Car was towed away & the engine drained. It cost me �40.00 to get it drained but the car was 100% after it.

Long & short of it - get it drained ASAP!

[memyselfandi]

fill the car up with diesel it shouldnt affect the engine in fact it will actually clean out the engine it happened me before and the mechanic drained only a small bit out and filled the car up with diesel i didnt start the car so i may have just been lucky! i know if i had put diesel into a petrol car it would have ruined the engine if it was started and all the fuel would have had to been removed

[KebabMeister]

Putting diesel into a petrol car won't ruin it; it simply won't run because the fuel isn't refined enough.

[THFCUK]

i put petrol into my dads diesel, and i told him out right, when he phoned up the garage they infromed him that at every 50 miles top it up with diesel and that it will be ok

[KebabMeister]

It's whatever you feel comfortable with.  Petrol in a diesal can damage your car, that's a 'can'.  When I was a mechanic there were always people filling their car up with the wrong fuel by mistake.  Diesel engines are designed to take a bit more punishment, especially in the compression/detonation area.  If it's a turbo diesel then it's actually better because it has a lower compression ratio and retarded injection timing.  If it's a normally aspirated engine and you thrash it then you may start melting things.

[teen]

My partner put �5 of petrol in the empty tank of my diesel ford encore.  He drove home 1/4 mile and we checked this website and others.  We decided to risk driving back to the garage revving high.  Got there ok and filled up with diesel.  The car actually seems to be running better now as if the petrol had cleaned it?  Risky decision though.  I would not have risked it with any more petrol or if I had the knowledge and tools to empty the tank.