--- title: Explained: Petrol in a Diesel Car Ashford canonical: https://www.petrolinadieselcar.co.uk/petrol-in-diesel/ashford-surrey/ location: Ashford county: Surrey latitude: 51.432870 longitude: -0.462060 service: Petrol in a Diesel Car updated: 2026-10-04 --- # Ashford: Petrol in a Diesel Car? How Worried to Be Probably less than you already are — provided nobody has started it. Petrol sitting in a diesel tank does nothing to your engine until something pulls it through the system — the ignition priming the pump, your starter, or the drive itself. So the honest answer to the first query everyone in Ashford asks, "have I ruined it?", is normally no. Keep it that way: leave the engine off then phone Petrol in Diesel. What petrol really does to a diesel, how to gauge how far it has travelled, and how to stop it from happening again: that is the rest of this page. ## Your engine and petrol in a diesel: what goes on On its way through a motor, diesel has two jobs. Lubricating comes before burning; it does both. Made to extremely fine tolerances, the fuel injectors and your pump rely on your diesel flowing through them to keep their surfaces from wearing against one another. Of these two tasks, petrol handles the first badly and the second not at all. The knocking comes from petrol being designed 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 out the protection your system depends on, and any pump working on such a blend is wearing itself. Combined, those make the shape of the issue clear. Contact does not do the harm — movement does. Any tank with petrol in it is a fuel fault. A pump that has been running on that petrol is the beginning of a mechanical one, and whatever a worn pump sheds travels on with the fuel to the injectors downstream. ## Ashford, petrol in a diesel: four situations, from mild to serious Fuelled up, never started. The best case there can be. On a forecourt, and truly only there, the petrol is still limited to your tank — because anywhere else the vehicle was driven to get to it. The task is draining and purging on the spot. Ignition on, or started for a moment. With the system primed, the fuel lines and filter now hold petrol that has come from the tank. Usually little more than draining, flushing and seeing to the fuel filter, and so still simple. Driven a couple of miles. Now your pump has spent those miles working on thinned fuel. Miles is only half of it; how hard it was driven matters equally. Either way this work includes your tank, your lines, the filter and clean fuel through the whole circuit. Short trips, such as the school run to St Michael Catholic Primary School & Nursery, are one thing. A run as far as Westminster, under 25 miles away, is a very different job. So is any miles on the M3, under 3 miles from Ashford, where the engine has been running hard throughout. Driven until it protested. Rattling, a lumpy idle, smoke, a throttle that has gone soft. That is your motor telling you its fuel no longer is acting like diesel. Leave it where it stops: a lay-by, a quiet street, the verge on Fordbridge Road. What goes first is still the fuel drain and flush, and that sorts it out, with lasting damage very rare when a car is stopped soon. ## What Ashford drivers get told about petrol in a diesel — and the stories in it False: topping up to full with diesel makes it fine. It does not. Topping up takes out nothing; it gives you a fuller tank of the same mixture. A diesel fuel system doesn't tolerate petrol by percentage in the way that advice supposes. If anything, the reverse holds. Myth: "A newer diesel can cope with a bit of petrol." More precise components and higher pressure are the way a modern diesel runs its fuel, and that makes the protection matter more, not less. Myth: "If it starts and drives, there is no damage done." This is the one that catches drivers. Any petrol engine fed diesel usually won't run, so the driver stops and the damage stops with them. While the pump wears, a diesel fed petrol normally starts, ticks over and drives away as though nothing has happened. Fine and running aren't the same at all. An old fix for a different fault lies behind this one. Myth: "Add some two-stroke oil and drive it home." That petrol is still inside your tank afterwards, and what it has weakened isn't put back. If the motor has run, part of the petrol sits in your filter and the lines, not the tank — and the next start pulls it straight back through the pump. So the myth "drain your tank yourself and you're sorted" does not hold. On top of that, petrol emptied into a can by the road is genuinely dangerous. ## How does petrol in a diesel occur? A careless moment is rarely the cause, and nobody means to do it. One way only, because of the nozzles: the slimmer petrol one slides inside a diesel filler with almost no resistance, while the diesel one mostly will not fit a petrol vehicle. That's how the forecourt makes it easy. It occurs when routine and the vehicle stop matching. Courtesy car, hire car, or a motor that is new. Two cars on one driveway, one petrol, one diesel. A forecourt you know, but with its pumps arranged differently. A hurried fill en route to Ashford Surrey with a train to catch. Precisely the moment it occurs: after years of driving petrol, a driver fills a diesel Renault Megane for the first time. With rain, a call arriving, or a car full of children to deal with, your hand just does what it has always done. ## How to avoid petrol in a diesel on your next fill-up around Ashford - Check the pump, not the colour. In the UK unleaded handles are usually green and diesel black, but not on every forecourt. The label is what counts. - Plenty of cars state the fuel type inside your filler flap or on the cap, and so check it on your first fill in a motor you do not know. - One of each in the house? Label your key to the diesel — a coloured fob, a sticker — since meaning to remember is not enough. - It sounds daft and it works: on the first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the pump. - Tuck your phone away. This is an easy mistake to make while you are thinking about something else. - Some diesels have a filler designed to block a petrol nozzle, and devices you can add are available for vehicles without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop checking the pump. - Less petrol means a weaker mixture, so stop as soon as you notice — while remembering that the next step is unchanged. It's still not to fire it up. ## Ashford: already put petrol in a diesel? Then, there's only a short order of things. Do not crank it, and do not switch your ignition on. Ask the staff to help you push it away from the petrol pump if you are still on the forecourt, whether that is Shell or somewhere else. Next, 0333 366 0103. We will ask what was put in, about how much, and if it has been run. Say so if it was AdBlue instead of petrol: it's a separate issue, with its own page for Ashford, because AdBlue brings corrosion and deposits rather than lost lubrication. ## Why one petrol in a diesel job in Ashford costs more than another The four situations above are four different jobs, so no single price for this would be honest. The situation itself does most of the work of moving the cost. After that it's the proportion — how much petrol was put in against how much the tank holds — and then where your car is and whether a technician can reach it safely. Three questions come first, before any quote, rather than after — what was put in, how much, has it run — and this is the reason. Those answers are what turn a range into one firm number. ## About Ashford and its setting Ashford is a town in north Surrey, situated approximately 15 miles southwest of central London. Ashford sits in a low-lying area near the River Thames, with nearby places including Chattern Hill, Littleton Common, and Ashford Common. Ashford has a population of around 24,136 people and is characterised by predominantly semi-detached housing. Ashford is connected to the surrounding area by a network of roads and railways. ## Fuel drain cover across Surrey, Ashford included Petrol in diesel calls in Ashford — part of the TW postcode area — go to teams that also cover the places about it, Chattern Hill, Littleton Common and Ashford Common among them. You need not move your car to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all locations where we work. ## Still at the petrol pump around Ashford? The best spot there is, then — that's where you are. Call, and keep it turned off.