Should You Worry? Petrol in a Diesel Car in Pinkie
Far less than you likely are, provided it hasn't been started. Until the ignition primes the pump, your starter turns, or your car is driven, petrol in a diesel tank just waits there and does no harm. Which means the honest reply to the first Pinkie question — "have I ruined it?" — usually no. Keep it like that: leave your motor off and phone Petrol in Diesel. The rest of this page sets out what petrol really 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 the motor: what petrol in a diesel does
Two jobs fall to diesel on its route through a motor. It protects first, and only then does it burn. Extremely fine clearances are built into the injectors and the high-pressure fuel pump, and just your diesel flowing through stops those surfaces grinding together.
The second job petrol doesn't do at all, and the first it does badly. The clattering comes from petrol being made not to ignite when compressed, which is exactly the opposite of what a diesel needs. On top of that it is runnier than diesel, it strips away the protection the fuel system depends on, and any pump working on such a mix is wearing itself.
The shape of the problem is plain when you put those together. Not contact but movement is what does the harm. Where that petrol is only in your tank, it's a fault of fuel, nothing more. After the pump has been working on that petrol, a mechanical issue has begun: anything shed by a pump that's grinding travels onward to the injectors with the fuel.
Pinkie, petrol in a diesel: four situations, from mild to serious
Filled up, and not started: no case is better. That petrol is inside that tank and just that tank, and the job is a drain and a flush where your car stands. This is the one scenario that can only truly happen on a forecourt, as anywhere else your car has been driven to get there.
Started for a moment, or only the ignition on. With the system primed, your lines and filter already contain petrol that came from the tank. Still normally easy: drain, flush, and the filter dealt with.
Driven a few miles. Now your pump has spent these miles working on diluted fuel. Mileage is only half of it; how hard it was driven matters just as much. Either way the work runs to the tank, the fuel lines, your filter and clean fuel through the whole system. A school run to the local primary school is one matter. A run as far as Edinburgh, under 10 miles away, is a very different job. So is any miles on the M8, under 15 miles from Pinkie, where the motor has been labouring hard the whole time.
It complained, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone ragged. What you are hearing is your motor signalling fuel that no longer runs like diesel. Leave it where it has stopped: a lay-by, a quiet street, the verge on Edenhall Road. What goes first is still the drain and flush, and that takes care of it, with lasting damage very uncommon if a vehicle is stopped quickly.
Petrol in a diesel myths Pinkie drivers hear
It will not be fine. The myth: "Fill it the rest of the way with diesel and it will be." A fuller tank of the same mix is all it gives, since topping up removes nothing. The assumption behind that guidance — that diesel fuel systems accept petrol by percentage — is wrong.
Not so: a newer diesel copes with a bit of petrol. If anything, the reverse. Smaller parts and higher pressure are the way a newer diesel runs its fuel, and that makes the protection matter more, not less.
"It starts, it drives, and so no harm done" — the myth that catches more drivers than any other. A petrol motor fed diesel normally won't run, so the driver stops and the harm stops with them. Feed petrol to a diesel and it normally starts, idles and drives away as if nothing has happened — all while its pump wears. A running engine doesn't mean fine.
An outdated fix for a different fault is behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." It does not put back what petrol has diluted, and the petrol is still inside that tank later.
The next start draws petrol back round the pump from your lines and your filter, where some of that sits after your engine has run. That's why draining the tank yourself doesn't leave you sorted — a myth. On top of that, petrol emptied into a can by the road is truly risky.
Why petrol in a diesel takes place at all
Nobody does it on purpose, and it's seldom carelessness. One way only, since of the nozzles: the slimmer petrol one slips inside a diesel filler with almost no resistance, while the diesel one mostly won't fit a petrol car. That's how the forecourt makes it simple.
Routine and your car falling out of step is how it happens. A car that is new to you — a hire car, on loan as a courtesy car, or just bought. One petrol and one diesel on the driveway of the same household. A well-known forecourt with the pumps in a different order. Fuelling up in a rush on the way to Wallyford, with a train to catch. Precisely the moment it happens: after years of driving petrol, someone fills a diesel Volkswagen Golf for the first time. Your hand does what it has always done when you add rain, a phone call or a back seat full of children.
How to prevent petrol in a diesel on your next fill-up in Pinkie
- Not every forecourt in the UK follows green for unleaded and black for diesel, though most generally do. Read the petrol pump's label; the colour is only a clue.
- Check the filler flap. Many cars state the fuel inside the flap or on the cap. Look at it on your first fill in any car you don't know.
- Label the key. In a household with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of meaning to remember.
- "Diesel", aloud, before you pick up the nozzle — every time a new or hired car gets its first tank. It seems silly. It does the trick.
- Whilst you are thinking about something else, this is an easy mistake to make — so put the phone away.
- Add-on devices exist for motors without one, and some diesels come with a filler that won't accept a petrol nozzle. Useful — but a backstop only, never a reason to stop checking the label.
- Stop as soon as you notice. Less petrol in the tank makes a weaker blend. It doesn't change what to do next, which is still not to fire it up.
Already put petrol in a diesel around Pinkie?
The order of things is brief, then. Leave it unstarted, with the ignition off as well. Yet at the forecourt, at Tesco or anywhere else? Ask the attendants to help you push it away from the pump. What got in, about how much, and if it's run: tell us those when you ring 0333 366 0103.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost lubrication, make it a different issue — Pinkie has a page just for it.
Pinkie petrol in a diesel tasks: why one costs more than another
The four situations above are four separate jobs, so no single price for this would be fair. Chiefly, the cost shifts with which situation you are in. Next it is the share — how much petrol went in against how much the tank holds — and then where the car is and whether a technician can reach it safely.
Three queries come first, before quoting, instead of after — what went in, how much, has it run — and this is the reason. The replies change a range into a straight figure.
About Pinkie, for a moment
Pinkie is a coastal suburban area in East Lothian, situated near the city of Edinburgh and close to the Firth of Forth. Pinkie has a relatively low elevation of around 6 metres, and its location near the coast has influenced its development. Pinkie is characterized by its predominantly terraced housing and is part of the larger urban area surrounding Edinburgh, with nearby places including Lewisvale and Musselburgh.
Across East Lothian and around Pinkie: fuel drain cover
Pinkie waits in the EH postcode area, and our teams that answer petrol in diesel calls there work the spots near it as well — Lewisvale, Musselburgh and Levenhall among them. A forecourt, a supermarket car park, a lay-by or your own driveway are all places our technicians drain, and the vehicle doesn't need to come to us.
Still at the petrol pump around Pinkie?
In that case, you could not be in a better spot. Keep it switched off, and ring.