--- title: Worried? Petrol in a Diesel Car Highwoods canonical: https://www.petrolinadieselcar.co.uk/petrol-in-diesel/highwoods-south-yorkshire/ location: Highwoods county: South Yorkshire latitude: 53.499490 longitude: -1.302940 service: Petrol in a Diesel Car updated: 2026-10-14 --- # Highwoods: Petrol in a Diesel Car? How Worried to Be Likely less than you are now — as long as no one has started the vehicle. Petrol resting in a diesel tank does nothing to your engine till something pulls it through your fuel system — your ignition priming the pump, your starter, or driving itself. So the honest answer to the first question anyone around Highwoods asks, "have I wrecked it?", is normally no. To keep the vehicle that way, phone Petrol in Diesel and leave your engine alone. The rest of this page explains what petrol actually does to a diesel, how to judge how far it has got, and how to make sure it doesn't happen to you again. ## The motor and petrol in a diesel: what goes on Passing through an engine, diesel is doing two jobs at once. Before it combusts, it lubricates — and then it combusts. Extremely fine tolerances go into your injectors and the high-pressure pump, and only your diesel flowing through keeps their surfaces from grinding together. Of those two jobs, petrol manages the first badly and the second not at all. A pump working on a petrol blend is wearing itself out, since petrol is thinner than diesel and takes away the protection the fuel system relies on. Petrol is also designed to resist igniting under compression — the reverse of what a diesel wants from its fuel — and that's where any knocking comes. Taken together, they make clear what shape the problem has. The harm is done by movement, not by contact. Where that petrol is only inside that tank, it is an issue of fuel, nothing more. The beginning of a mechanical one is a pump that has been working on that petrol — and whatever a worn pump sheds moves on with the fuel to the fuel injectors downstream. ## Four scenarios our engineers see in Highwoods: how bad is petrol in a diesel? Filled up, and never started: nothing beats it. Only your tank has petrol in it, and so the job is clearing the tank and purging the fuel system where your car sits. This scenario can only really happen at a forecourt: anywhere else, your car got there by being driven. Started for a moment, or just the ignition on. Your system has been bled, and so petrol has left your tank and got to your filter and the fuel lines. Drain, flush, see to the fuel filter: still usually simple. Some miles driven, and your pump has spent each of them labouring on weakened fuel. Tank, lines, filter, then clean fuel put through the entire circuit: that's the work, and the way the vehicle was driven counts as much as the distance. Short trips, such as the school run to Highwoods Academy, are one thing. Any distance on the M18, under 5 miles from Highwoods, means the engine has worked hard throughout, and a run to Doncaster, under 10 miles away, makes a very different job as well. Driven on till it protested — rattling, smoke, a lumpy idle, a dead throttle. 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 quiet street, the verge on Old Farm Court. The fuel drain and flush still come first, and they deal with it: if a vehicle is stopped soon, long-term damage is very rare. ## Myths Highwoods people hear about petrol in a diesel Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. Topping up removes nothing; it gives you a fuller tank of the same mixture. The idea behind the advice — that diesel fuel systems accept petrol by percentage — is wrong. Myth: a current diesel copes with a bit of petrol. If anything, the opposite. More precise parts and higher pressure are how a modern diesel runs its fuel, and that makes the lubrication matter more, not less. Myth: "If it starts and drives, there is no harm done." This is the one that catches people. Feed diesel to a petrol motor and it usually won't run, and so the driver stops — and the damage stops with them. While your pump wears, a diesel fed petrol normally starts, idles and drives away as if nothing has happened. Being able to run isn't proof of being fine. Myth: a two-stroke additive makes it safe to drive home. It is an old fix, meant for another fault. What petrol has diluted stays thinned, and the petrol remains in the tank anyway. Once your engine has been run, part of the petrol sits in your filter and the lines, not the tank — and your next start sends it right back through your pump. So the myth "drain the tank yourself and you are sorted" doesn't stand up. Also, a can of petrol filled by the roadside is genuinely dangerous. ## How does petrol in a diesel occur? No one does it on purpose, and it is rarely carelessness. One way only, since of the nozzles: the narrower petrol one slides inside a diesel filler with almost no resistance, while the diesel one mostly won't fit a petrol motor. That's how the forecourt makes it easy. The moment routine stops matching the vehicle is the moment it happens. Any vehicle that's new to you — a hire car, on loan as a courtesy car, or brand new. Households running one of each, petrol and diesel. Your normal forecourt, its pumps suddenly in a different order. A train to catch, and a rushed fill en route to Mexborough. A new-to-you diesel Volkswagen Golf, its first fuelling, and a motorist used to petrol: precisely when it happens. Throw in a back seat full of children, a phone call or rain, and the hand wins. ## How to avoid petrol in a diesel on your next fill-up around Highwoods - Not every forecourt in the UK follows green for unleaded and black for diesel, even if most usually do. Read the petrol pump's label; the colour is just a hint. - Many cars state the fuel inside the filler flap or on the cap, so check there on the first fill in any motor you don't know. - A coloured fob or a sticker on the diesel's key does more than any amount of meaning to remember, in a household with one of each. - Say it before you lift it. On your first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the petrol pump. It seems daft and it works. - Tuck your phone away. This is an easy mistake to make whilst you're thinking about something else. - Some diesels have a filler designed to reject 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 reading the petrol pump. - Noticing it mid-fill? Stop there and then. A thinner mixture results from less petrol inside that tank, yet the next stage remains the same: don't crank it. ## Already put petrol in a diesel around Highwoods? The order of things is short, then. Leave it unstarted, with your ignition switched off as well. Ask the staff to help you push it clear of the petrol pump if you're still at the forecourt, whether that is JET or anywhere else. Then call 0333 366 0103 and tell us what got in, roughly how much, and if it has run. AdBlue, not petrol? Then say so. Corrosion and deposits, not lost lubrication, make it a different issue — Highwoods has a page all for it. ## What makes one Highwoods petrol in a diesel task cost more than the next An honest single quote doesn't exist here: four situations, four separate jobs. Which of them you're in is mostly what shifts the cost. The ratio counts next, meaning how much of that tank is petrol, and then the position of the car and whether reaching it is safe for a van. Ahead of any quote, not after, come three queries: the fuel that went in, its amount, and if it has run. That's why. A range turns into a straight figure when the replies are in. ## About Highwoods and its setting Highwoods is a suburban area in South Yorkshire, situated approximately 7 miles from Doncaster and 146 miles from London, with a population of around 3648 residents. Highwoods is characterised by its predominantly terraced housing stock and lies at an elevation of 48 metres above sea level. Highwoods is located near several other local places, including Mexborough, Bow Broom, and Swinton Bridge, and is part of the wider Doncaster urban area. ## Highwoods and South Yorkshire: where our fuel drain cover reaches Our teams answering petrol in diesel call-outs in Highwoods, in the S postcode area, also work the spots around it, Mexborough, Bow Broom and Swinton Bridge included. The car does not need to move to us: we drain on a forecourt, in a supermarket car park, in a lay-by or on your own driveway. ## At the pump in Highwoods, still? Nothing beats it: that is where you are. Switched off it remains; then phone.