Hitchcocks Forum

A real stupid, senior moment last weekend. Arrived at the filling station and stuck the diesel filler into the petrol tank, and pulled the trigger. The gods must've been looking over me and I stopped almost instantly - only about 15 pence worth had registered. I then filled up with petrol and put in about £9.

Question is, does this matter and am I needlessly worrying? Does diesel sink or float in petrol? I'm a little concerned in that if it is heavier and the diesel sinks to the bottom, then the next time I start her up the carb might get just the cupful of diesel that I put into the tank and cause problems. If that's the case I'm happy to drain a half gallon or so to release the diesel. Then again, if the diesel floats it'll just get sloshed around the tank and mix into the petrol and just get burnt up in the process.

Can anyone put my mind at ease?

Your ok ogri, a little bit oily thats all, such a small amount probably won't even register..

Its putting petrol into diesel thats the demon one..

No problem at all. Might smoke a bit but won't do any damage. I once put about a gallon in a car tank - filled to the top with petrol and didn't notice a thing.

Don't worry, no harm done even if you'd put more in.
I did it big time wirh the Flash, went two miles home with a big cloud of white diesel smoke billowing out behind me.

Phew! Thanks men.

It's amazing what relatively simple engines WILL burn. I remember in my youth I HAD to go somewhere one Sunday and was out of petrol. Garages closed on Sundays in those days. I did have some paraffin however so I bunged that in with some two-stroke oil and the 9E ran quite well. It wouldn't have been 100% paraffin but pretty close, and the carb full of petrol warmed things up first. Fortunately there was petrol available at the end of the journey as I suspect it wouldn't have started from cold. Eeee, the things we got up to!

I once added about 3 gallons of petrol to my 2001 diesel Citroen Xsara, so just drowned it in diesel and drove normally, I swear to this day it was faster, never did it any harm.

You were lucky very lucky. Petrol shags injection pumps

Three gallons in a tank full? I think you must have been right on the edge of damaging the pumps. I once risked one gallon (or there abouts) but I wouldn't have gone much more.