--- title: Worried? Petrol in a Diesel Car Feniton canonical: https://www.petrolinadieselcar.co.uk/petrol-in-diesel/feniton-devon/ location: Feniton county: Devon latitude: 50.787220 longitude: -3.282570 service: Petrol in a Diesel Car updated: 2026-10-11 --- # Should You Worry? Petrol in a Diesel Car in Feniton Probably less than you already are — provided no one has started it. "Have I wrecked it?" is the first thing anyone around Feniton asks, and the truthful answer is normally no, because petrol resting in a diesel tank harms nothing till it is drawn through the system — by ignition priming, by your starter, or by being driven. To keep the car that way, call Petrol in Diesel and leave the motor switched off. Further down, this page sets out what petrol really does inside a diesel, how far it may have gone, and how to stop it happening to you a second time. ## Inside the engine: what petrol in a diesel does Passing through an engine, diesel does two things at the same time. It combusts, and before it combusts it protects. Made to extremely fine tolerances, the fuel injectors and your pump rely on the diesel flowing through them to keep their surfaces from wearing against one another. Badly at the first, not at all at the second: that is petrol. The knocking comes from petrol being made not to ignite when compressed, which is precisely the reverse of what a diesel needs. On top of that it is runnier than diesel, it strips away the lubrication your system depends on, and any pump running on that mixture is wearing itself. Combined, those make the shape of the issue plain. Not contact but circulation is what does the harm. Petrol in the tank is a fuel fault. Whatever a worn pump sheds travels on, carried by your fuel, into the fuel injectors further along, which is why a pump that has been working on the petrol is where a mechanical fault begins. ## Feniton, petrol in a diesel: four cases, from mild to major The best case there is: filled up, not once started. At a forecourt, and genuinely only there, that petrol is still confined to the tank — because anywhere else your car was driven to get to it. The task is draining and flushing on the spot. A brief spell of running, or merely your ignition on. Once primed, the system has pulled petrol out of your tank up to the fuel filter and your lines. That is usually still a simple task — a drain, a flush, and the fuel filter dealt with. A few miles driven, and the pump has spent every one of them labouring on thinned fuel. The work is the tank, your lines, your filter and fresh fuel through the whole system, and how hard the car was driven matters as much as how far. On the school run to Feniton Church of England Primary School, the miles is small. Any mileage on the M5, under 10 miles from Feniton, means the engine working hard throughout, and a run to Exeter, under 15 miles away, is a very different task as well. Driven until it protested. Clattering, a ragged idle, smoke, a throttle that has gone soft. What you are hearing is your engine reporting fuel that no longer acts like diesel. Whether it's the verge on Station Road, a lay-by or a side street, stop where you are and leave it. The drain and flush still come first, and they deal with it: if a vehicle is pulled over early, lasting damage is very unusual. ## What Feniton motorists get told about petrol in a diesel — and the myths in it Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. Nothing comes out when you top up — the tank just carries more of the same mixture. Percentage is not how a diesel fuel system tolerates petrol, however much that advice assumes. "Newer diesels can handle a little petrol" — a myth, and closer to the reverse. Lubrication counts more on current diesels, not less, because their fuel runs through more precise parts at higher pressure. Myth: "If it starts and drives, there's no harm done." This is the one that fools drivers. Diesel in a petrol motor generally means a motor that won't run: the driver stops, and so does the harm. A diesel fed petrol usually starts, idles and drives away as though nothing has happened, while your pump wears. Being able to run is not the same as being fine. Myth: "Add some two-stroke oil and drive the car home." It is an outdated fix for a different problem. It doesn't put back what petrol has weakened, and that petrol is still inside the tank later. The next start sends petrol back round your pump out of your lines and the filter, where some of that sits once your engine has run. That is why draining your tank yourself does not leave you sorted — a myth. Clearing petrol into a can by the kerbside is also genuinely dangerous. ## How does petrol in a diesel happen? Carelessness is rarely the cause, and nobody means to do it. A diesel nozzle generally will not go into a petrol vehicle, yet the slimmer petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one mistake easy, and just in that direction. It takes place when routine and the vehicle stop matching. A new motor, a hire car or a courtesy car. Two vehicles on one driveway, one petrol, one diesel. Your usual forecourt, its pumps now in a different order. A train to catch, and a hurried fill on the way to the nearest station. Years of petrol motors behind you, a diesel Volkswagen Golf in front of you on the forecourt for its first tank — that's when. Throw in rain, a phone call or a back seat full of children, and the hand repeats what it has always done. ## Feniton people: how to prevent petrol in a diesel next time - Not every forecourt in the UK keeps to green for unleaded and black for diesel, though most usually do. Read the petrol pump's label; the colour is only a hint. - Inspect your filler flap. Plenty of cars state the fuel type inside the flap or on the cap. Look at it on the first fill in a car you do not know. - Good intentions count for less than a sticker or a fob in a bright colour on the diesel's key if a house has one of each. So mark it. - Say it before you lift it. On your first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the pump. It sounds silly and it works. - Mistakes like this are straightforward to make while your mind is on something else, so the phone goes away. - A misfuel inhibitor helps, up to a point. Some diesels come with a filler built to block a petrol nozzle, and add-on devices exist for vehicles without one. They are a safety net, not a reason to stop reading the petrol pump. - Noticing it halfway? Stop at once. A thinner mixture results from less petrol in the tank, yet the next stage remains the same: don't fire it up. ## Already put petrol in a diesel in Feniton? In that case, there's only a short order of things. Never fire it up, and do not switch the ignition on. Ask the staff to help you roll it clear of the petrol pump if you are still on the forecourt, whether that's Esso or somewhere else. What went in, roughly how much, and if it's run: tell us those when you call 0333 366 0103. Say so if it was AdBlue rather than petrol: it is a different fault, with its own page for Feniton, because AdBlue brings corrosion and deposits instead of lost lubrication. ## Why one petrol in a diesel task around Feniton costs more than another The four situations above are four separate jobs, so no single price for this would be honest. The scenario itself does most of the work of moving the cost. The proportion counts next, meaning how much of the tank is petrol, and then the position of the vehicle and whether getting to it is safe for a technician. Ahead of any quote, not after, we ask three questions: your fuel that got in, its amount, and if it's run. That is why. Given those replies, you get a straight figure instead of a range. ## About Feniton Feniton is a village in east Devon, situated inland at an elevation of around 84 metres, approximately 11.8 miles from Exeter. Feniton lies near the villages of Talewater, Colestocks, and Higher Cheriton, and is characterized by its semi-detached housing stock. Feniton has a population of around 1725 residents, and is located about 145.5 miles west of London. ## Across Devon and in Feniton: fuel drain cover The teams answering petrol in diesel jobs in Feniton, in the EX postcode area, also work the places around it, Talewater, Colestocks and Higher Cheriton among them. The vehicle does not need to move to us: our technicians drain on a forecourt, in a supermarket car park, in a lay-by or on your own drive. ## Still at the pump around Feniton? Nothing beats it: that is where you are. Keep it off. Phone.