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AIBU?

Share your dilemmas and get honest opinions from other Mumsnetters.

Original poster

Petrol in diesel tank ..it's driving ok..aibu to still drive it?

55 replies

larazaded · 28/12/2018 12:47

This morning half asleep I put £5 worth of petrol in my diesel car..realised and started to put diesel in.
I've drove it since on motorway and it's fine.
Because it was a small amount will it be ok?

OP posts:
VickyEadie · 28/12/2018 12:49

I can't advise (Google?) but was thanking the designer and manufacturer of my petrol-only car two weeks ago when I stupidly attempted to put diesel in it and the talk just wouldn't let me get the nozzle in!

VickyEadie · 28/12/2018 12:49

*tank (obviously)

milkjetmum · 28/12/2018 12:50

I think it will be cheaper to get the fuel tank drained than to do a full engine clean...

ChristmasTwatteryDoesMyHeadIn · 28/12/2018 12:50

No, no, no. You need to get it drained and cleansed properly. It will work it’s way through the engine and fuck it up.

Petrol into diesel is worse than diesel into petrol because diesel engines are so highly strung.

(DP was a mechanic before his current job)

It’s a total PITA I’ve done it before.

Bigonesmallone3 · 28/12/2018 12:51

I know it's really bad one way round but not so bad the other way round!
Can't remember which tho 🤦‍♀️
How long was u on the motorway for and how much diesel did u put in after?

Passmethecrisps · 28/12/2018 12:51

Not as far as I know - You will ruin the engine.

My understanding is that a small amount of diesel in an unleaded tank can be resolved by adding unleaded but not the other way round.

Was there a lot of diesel in it anyway

ScienceIsTruth · 28/12/2018 12:51

Too late to ask now, you've already driven it.

I, personally, wouldn't have risked it, and I guess the answer to how much damage you've done partly depends on the size of your fuel tank, and the ratio of diesel to petrol (although I was told any amount of petrol in a diesel car is a bad thing).

Original poster
larazaded · 28/12/2018 12:51

I put £13 of diesel in after and about 6 miles up motorway ..I need to get back other way later tho.

OP posts:
Schmoobarb · 28/12/2018 12:52

I can't advise (Google?) but was thanking the designer and manufacturer of my petrol-only car two weeks ago when I stupidly attempted to put diesel in it and the talk just wouldn't let me get the nozzle in!

Due to the designs of fuel filler and petrol pump nozzles you can’t misfuel a petrol with diesel but you can the other way around

OP I am no expert but I think I read somewhere that as long as it’s only a small amount of petrol and you then dilute it with a lot of diesel it should be OK. I wouldn’t take my word for it though!

Lonecatwithkitten · 28/12/2018 12:52

My DP is an automotive engineer and told me if I ever put petrol in my diesel car I should not even turn on the engine otherwise it is a full engine strip.

SharpLily · 28/12/2018 12:53

Stop driving now! Get the tank drained and hope you haven't stressed the engine too much. Petrol running through a diesel engine is a bad thing and WILL damage it.

Passmethecrisps · 28/12/2018 12:53

If you call your insurance/recovery company they often have dedicated teams who will come and fix this. There will be a cost but cheaper than having a knackered car.

Idiot1 · 28/12/2018 12:55

Years ago I put 20£ petrol into my diesel car. The man at the garage put in a full bottle of engine oil and then topped it up with diesel, I then had to drive it round til it emptied. Worked out fine in the end

BollocksToBrexit · 28/12/2018 12:55

Was the tank close to empty when you put the petrol in? Is it an old car or newish one? DH is a chemistry prof. He said an old car would tolerate it better. He says to fill the tank with diesel to dilute the petrol and you should be ok. Apparently some truck drivers add a bit of petrol to their tanks as it stops the diesel freezing.

Grimbles · 28/12/2018 12:56

You can possibly get away with about 5% petrol but you really are risking your engine to drive it. Diesel fuel has a lubricant in it that helps the fuel pump run properly, petrol being pumped through can damage the pump and cause bits of metal to circulate through the engine causing more damage.

So it might be driving ok, but you are risking thousands of pounds of damage depending on the car.

Schmoobarb · 28/12/2018 12:57

Found this online

www.telegraph.co.uk/motoring/caradvice/honestjohn/10450126/What-happens-if-I-put-petrol-in-my-diesel-car.html

I think you should have put much more diesel in though to dilute it more. Unless the tank was already quite full.

HolgerLowCarbingLoser · 28/12/2018 12:57

You shouldn’t drive it, it will really fuck up your engine.

Any fuelling station will have the number for a company that will come out and drain your engine. Or call the AA (or your own breakdown cover). They will charge you extra as it’s not a breakdown, but they will know what to do.

You really can’t drive it until this is sorted.

namechangedtoday15 · 28/12/2018 12:58

I did this at a garage but realised as soon as I'd put the petrol in. Asked the garage what to do - they said ring AA. They said not to start the engine as you damage the engine as soon as the petrol goes through the engine. Had to have tank drained.

You're obviously beyond that now - I would phone your local dealer for whichever brand of car you have and ask their advice and / or AA. I would not drive it again without advice.

Thesnobbymiddleclassone · 28/12/2018 12:59

Get it drained! The moment a drop gets to the engine your engine will need doing and the cost of it all will rocket!

billysboy · 28/12/2018 13:01

try putting some engine oil in with it and as much diesel as you can should be fine

Mummylife2018 · 28/12/2018 13:03

Diesels like a bit of unleaded every now and again. Just fill tank to brim with diesel it will be fine

MPForFlydaleNorth · 28/12/2018 13:03

Call your breakdown cover provider for a mid fuel - dp put £20 of unleaded in our diesel car last year accidentally and luckily the car cut out 5 minutes away from the petrol station. We had to pay a £200 surcharge as it wasn't covered but they came and drained the tank and topped us up with a bit of diesel and advised we put a whole tank in and go for a long drive. We were advised to get the fuel filter replaced at the following service. Call them and ask for advice, better to be safe than sorry

MPForFlydaleNorth · 28/12/2018 13:04

Mis fuel not mid fuel obviously!

Mummylife2018 · 28/12/2018 13:05

My above advice came from an RAF Aircraft engineer and former mechanic

Oysterbabe · 28/12/2018 13:05

If you weren't going to drain it you should have at least filled the tank.

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