How Worried Should You Be? Petrol in a Diesel Car in Darite
Likely less than you are now — as long as nobody has started the car. Till your ignition primes your pump, your starter turns, or your car is driven, petrol in a diesel tank simply waits there and does no harm. Which means the truthful reply to the first Darite query — "have I ruined it?" — usually no. Keep it that way: leave the engine off and ring Petrol in Diesel. The remainder of this page sets out what petrol actually does to a diesel, how to tell how far it has got, and how to make sure it does not happen to you a second time.
Inside your engine: what petrol in a diesel really does
Passing through an engine, diesel does two things at the same time. It lubricates to begin with, and only then does it burn. Built to extremely fine gaps, the fuel injectors and your pump depend on the diesel moving through them to stop their surfaces wearing against one another.
Of these two tasks, petrol handles the first badly and the second not at all. Being less viscous than diesel, petrol strips out the protection a fuel system needs, leaving a pump running on the blend to wear itself. It is equally made to resist igniting under compression — the opposite of what a diesel needs — which is where you hear the clattering.
Combined, those make the shape of the problem plain. The damage is done by circulation, not by contact. All a tank with petrol in it amounts to is a fuel issue. Whatever a worn pump sheds travels on, borne by your fuel, into your injectors downstream, which is why a pump that has worked on that petrol is where a mechanical fault starts.
Four scenarios our engineers see around Darite: how bad is petrol in a diesel?
The best case there can be: filled up, never started. Being at a forecourt is what makes this possible: elsewhere, the vehicle has been driven there to begin with. With that petrol kept inside your tank alone, it is emptied and rinsed right where it stands, and nothing more is needed.
Your ignition turned on, or a brief start. The fuel system has been primed, and so petrol has left the tank and reached your filter and your lines. Usually nothing more than clearing, flushing and seeing to your filter, so still straightforward.
Those few miles on the road were the pump labouring on fuel diluted by petrol the whole way. Distance is only half of it; how hard it was driven matters equally. Either way this work includes your tank, the fuel lines, your filter and clean fuel through the whole system. A school run to Darite Primary Academy is one matter. Very different again: a trip to Plymouth, under 25 miles away, or some miles on the M5, under 50 miles from Darite, where your engine never stopped running hard.
Rattling, a ragged idle, smoke, a throttle gone soft: driven till it complained. The fuel isn't acting like diesel any more, and the engine is telling you. Stop on the spot — on the verge on Hendra Close, at the kerb, down a side road — and do not move it again. Long-term damage is very uncommon when a car is stopped early, and the fuel drain and flush that still come first take care of it.
Darite drivers and the petrol in a diesel stories they hear
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It won't. A bigger tank of the same mix is all it gives, because topping up takes out nothing. The assumption behind that guidance — that diesel fuel systems tolerate petrol by percentage — is wrong.
"Current diesels can handle a little petrol" — a myth, and closer to the reverse. Smaller components and higher pressure are the way a newer diesel runs its fuel, and that makes the protection matter more, not less.
The myth that catches drivers out: if it starts and drives, it must be unharmed. The motorist of a petrol motor fed diesel usually has no choice but to stop, because it will not run, and the damage stops there. Feed petrol to a diesel and it usually fires up, idles and drives away as if nothing has happened — all while its pump is wearing. Being able to run isn't proof of being fine.
"A drop of two-stroke oil and drive it home" — a myth, taken from a fix from years ago, for a different problem. What petrol has thinned remains weakened, and the petrol remains in that tank anyway.
If the motor has been run, part of that petrol sits in the filter and the fuel lines, not the tank — and your next start pulls it straight back through the pump. So the myth "drain that tank yourself and you're sorted" does not hold. Emptying petrol into a can at the kerbside is also really hazardous.
Petrol in a diesel: how does it take place?
On purpose? Never. Through carelessness? Rarely, if ever. The forecourt makes it easy: the petrol nozzle is the narrower of the two, and it slides into a diesel filler with almost no resistance, whilst a diesel nozzle generally will not go into a petrol vehicle at all. So the error runs one way.
When routine and the car stop matching, it occurs. A motor that is new to you — a hire car, on loan as a courtesy car, or just bought. Households running one of each, petrol and diesel. A well-known forecourt with the pumps in a different order. A train to catch, and a rushed fill on the way to Liskeard. Years of petrol cars behind you, a diesel Volkswagen Golf in front of you at the forecourt for its first tank — that is when. The hand repeats what it has always done once you add rain, a phone call or a back seat full of children.
Darite drivers: how to avoid petrol in a diesel next time
- Green for unleaded and black for diesel is normal in the UK — but not on every forecourt. Go by the label on the pump, not the colour.
- Plenty of vehicles state the fuel inside the filler flap or on the cap, and so check there on your first fill in a vehicle you do not know.
- A coloured fob or a sticker on the diesel's key does more than any amount of meaning to remember, for a household with one of each.
- "Diesel", out loud, before you lift the nozzle — each time a new or hired car needs its first tank. It sounds silly. It does the trick.
- While you're thinking about something else, this is an easy mistake to make — so tuck your phone away.
- Add-on devices are available for cars without one, and some diesels come with a filler that will not take a petrol nozzle. Useful — but a safety net only, never a reason to stop checking the label.
- Spotting it halfway? Stop there and then. A weaker mix results from less petrol in the tank, but your next step stays the same: don't fire it up.
Already put petrol in a diesel in Darite?
Then, there is just a short order of things. Don't turn the ignition on, and don't fire it up. Ask the attendants to help you push it clear of the pump if you are still at the forecourt, whether that's BP or somewhere else. What was put in, about how much, and whether it has run: tell us those when you ring 0333 366 0103.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost protection, make it a different fault — Darite has a page just for it.
One petrol in a diesel task in Darite costs more than another. Why?
There is no honest single quote for this, since the four situations above are four separate jobs. Chiefly, your cost moves with which situation you're in. Beyond that it's the ratio — how much petrol went in against how much your tank takes — and after that where the vehicle is and whether our van can get to it safely.
Three queries come first, before quoting, instead of after — what was put in, how much, has it run — and that is the reason. Those replies are what turn a range into one firm number.
About Darite itself
Darite is a village in Cornwall, situated on the banks of a river at an elevation of 221 metres. Darite has a population of around 642 people, with a predominance of detached housing. Darite is located near several other small settlements, including Crows Nest, Higher Tremarcoombe, and Tremar Coombe. Darite is approximately 16.5 miles from Plymouth and 200.8 miles from London.
Across Cornwall and around Darite: fuel drain cover
Darite rests in the PL postcode area, and the teams that answer petrol in diesel calls there work the spots near it as well — Crows Nest, Higher Tremarcoombe and Tremar Coombe among them. You need not bring your car to us. Forecourts, supermarket car parks, lay-bys and your own drive are all places we drain.
In Darite and still at the pump?
The best place there is, then — that's where you are. Keep it off. Phone.