--- title: Explained: Petrol in a Diesel Car Leith canonical: https://www.petrolinadieselcar.co.uk/petrol-in-diesel/leith-city-of-edinburgh/ location: Leith county: City of Edinburgh latitude: 55.975460 longitude: -3.180060 service: Petrol in a Diesel Car updated: 2026-10-11 --- # Leith: Petrol in a Diesel Car? How Worried to Be Far less than you probably are, if it hasn't been started. Petrol resting in a diesel tank does nothing to your motor until something pulls it through the fuel system — the ignition priming the pump, the starter, or the drive itself. So the honest answer to the first question everyone around Leith asks, "have I wrecked it?", is generally no. To keep it that way, call Petrol in Diesel then leave your motor switched off. Keep reading for three things: the effect petrol has inside a diesel motor, the clues of how far it has got, and ways to make sure you never repeat it. ## The engine and petrol in a diesel: what happens Two jobs fall to diesel on its journey round a motor. It burns, and before it combusts it lubricates. The high-pressure fuel pump and your injectors are built to very fine tolerances, and your diesel passing through them is what stops those surfaces from grinding against one another. Poorly at the first, not at all at the second: that's petrol. Being less viscous than diesel, petrol strips out the lubrication a fuel system needs, so a pump running on that mixture to wear itself. It's also made to resist igniting under compression — the reverse of what a diesel needs — which is why you get the rattling. The shape of the trouble is clear once you put those together. The damage is done by movement, not by contact. Where that petrol is only in that tank, it is a fault of fuel, nothing more. Whatever a worn pump sheds travels on, borne by the fuel, into your injectors downstream, which is why a pump that has worked on the petrol is where a mechanical issue starts. ## Petrol in a diesel in Leith: how serious is it? Four situations Fuelled, and not started: no case is better. That petrol is inside the tank and only your tank, and the task is a drain and a flush where your car sits. This is the one scenario that can only really take place on a forecourt, because anywhere else the car has been driven to get there. Your ignition turned on, or a brief start. The system has been bled, so petrol has left your tank and reached the fuel filter and the lines. Drain, flush, deal with the filter: still normally simple. Driven a few miles. Now your pump has spent these miles running on diluted fuel. Miles is only half of it; how hard it was driven matters just as much. Either way this work includes your tank, your lines, the filter and fresh fuel through the entire circuit. Driving the kids to the local primary school is one kind of trip. A run as far as Edinburgh, under 3 miles away, is a very different task. So is any miles on the M8, under 10 miles from Leith, where your engine has been running hard the whole time. Driven till it complained. Knocking, an uneven idle, smoke, a throttle that has gone soft. What you are hearing is your engine reporting fuel that no longer behaves like diesel. Leave it where it has stopped: a lay-by, a side street, the verge on Great Junction Street. A car pulled over early very seldom has lasting damage, since the fuel drain and the flush, which still go first, deal with it. ## Leith people and that petrol in a diesel myths they hear Myth: topping up to full with diesel makes it fine. It does not. Nothing is removed by topping up — you're left with a fuller tank, still the same mixture. That guidance assumes a diesel fuel system tolerates petrol by percentage. It does not. Myth: "A newer diesel can cope with a bit of petrol." If anything, the reverse. A current diesel runs its fuel through smaller parts at higher pressure, which makes the lubrication count more, not less. This is the one that catches motorists. Myth: "If it starts and drives, there is no harm done." The driver of a petrol motor fed diesel usually stops, because it will not run, and the harm stops there. A diesel fed petrol normally starts, idles and drives away as if nothing has happened, whilst the pump wears. A running engine does not mean fine. An outdated workaround for a different fault is behind this one. Myth: "Add some two-stroke oil and drive the car home." What petrol has thinned remains weakened, and the petrol stays in your tank regardless. "Drain it yourself and you're sorted" — a myth, since after it's been running some petrol sits in the fuel filter and lines, waiting to go straight back through the pump at your next start. It is also truly risky to drain petrol into a can by the kerbside. ## How petrol ends up: petrol in a diesel Carelessness is rarely the cause, and no one means to do it. The petrol nozzle is the smaller of the two and slides into a diesel filler with almost no resistance; a diesel nozzle mostly won't go into a petrol car at all. The forecourt makes it easy, and the slip runs one way. It happens when routine and your car stop matching. Hire cars, courtesy cars, and cars that are new to you. A household with one petrol and one diesel on the driveway. A forecourt you know, only with its pumps laid out differently. A train to catch, and a hurried fill en route to Edinburgh Waverley. A new-to-you diesel Volkswagen Tiguan, its first fuelling, and a motorist used to petrol: exactly when it occurs. Add rain, a phone call or a back seat full of children, and the hand does what it has always done. ## How to avoid petrol in a diesel at your next fill-up in Leith - Green for unleaded and black for diesel is normal in the UK — but not on each forecourt. Go by the label on the petrol pump, not the colour. - In a motor you do not know, look inside the flap over your filler or at the cap before your first fill: plenty of motors state the fuel type there. - Good intentions count for less than a sticker or a fob in a vivid colour on your diesel's key when a house has one of each. So mark it. - Before the nozzle comes off the pump the first time you fill a hired or new motor, say "diesel" out loud. Daft, yes, yet it works. - Mistakes like this are simple to make whilst your mind is on something else, and so the phone goes away. - Add-on devices exist for cars without one, and some diesels are built with a filler that won't take a petrol nozzle. Useful — but a safety net at best, never a reason to stop checking the label. - Less petrol means a thinner mixture, so stop as soon as you realise — while remembering that the next stage is unchanged. It is still not to fire it up. ## Already put petrol in a diesel around Leith? Short and simple, then, is the order of things. Do not switch your ignition on, and don't start it. The staff on the forecourt — whether at BP itself or wherever you filled up — will usually help roll it clear of the petrol pump if you ask. What got in, about how much, and if 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 separate issue — Leith has a page just for it. ## Why one petrol in a diesel task around Leith costs more than another A fair single price does not exist here: four situations, four separate jobs. Mostly, the cost shifts with which one you are in. After that it is the ratio — how much petrol got in against how much your tank takes — and then where the car is and whether a van can reach it safely. What went in, how much, and whether it has run — three queries we ask before quoting, not after, for precisely that reason. A range turns into a straight figure once the replies are in. ## About Leith, for a moment Leith is a coastal locality in the City of Edinburgh, situated on the Firth of Forth at an elevation of around 17 metres. Leith lies approximately 1.6 miles north of Edinburgh's city centre, with nearby areas including Hamilton Wynd, South Leith, and Bonnington. Leith is predominantly composed of flat housing, reflecting its urban character. Leith is home to around 8627 residents, according to approximate population figures. ## Leith and City of Edinburgh: where our fuel drain cover reaches Hamilton Wynd, South Leith and Bonnington are among the places near Leith that the same teams work, answering petrol in diesel call-outs across Leith's EH postcode area. No need to bring your vehicle to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all spots we drain. ## At the pump in Leith, still? Then, you could not be in a better position. Keep the car turned off, then ring.