--- title: Worried? Petrol in a Diesel Car Broadwater canonical: https://www.petrolinadieselcar.co.uk/petrol-in-diesel/broadwater-west-sussex/ location: Broadwater county: West Sussex latitude: 50.829350 longitude: -0.367100 service: Petrol in a Diesel Car updated: 2026-10-16 --- # How Worried Should You Be? Petrol in a Diesel Car in Broadwater Unstarted? Then less anxious than you probably feel. Until your ignition primes the pump, the starter turns, or your vehicle is driven, petrol in a diesel tank just waits there and does no harm. Which makes the truthful reply to the first Broadwater query — "have I wrecked it?" — normally no. To keep the car like that, ring Petrol in Diesel and leave your engine alone. The remainder 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. ## Petrol in a diesel: what does it do to your engine? Two tasks fall to diesel on its journey round a motor. It burns, and before it combusts it protects. Very fine gaps are built into the injectors and your high-pressure pump, and just the diesel flowing through keeps those surfaces from grinding together. Petrol does the first job poorly and the second not at all. It's runnier than diesel and removes the protection the fuel system hinges on, so a pump running on a petrol blend is a pump wearing itself. And petrol is made to resist igniting under compression, which is the opposite of what a diesel needs from its fuel. That is where the clattering comes from. Combined, those make the shape of the problem plain. It is movement that does the damage, not contact. All a tank with petrol in it amounts to is a fuel problem. The start of a mechanical one is a pump that has been working on that petrol — and whatever a worn pump sheds travels on with the fuel to the fuel injectors downstream. ## How serious is petrol in a diesel? Four situations our technicians see in Broadwater Fuelled up, not once started. The best case there can be. Only the tank has petrol in it, so the job is clearing the tank and flushing the fuel system where the car sits. This scenario can only truly happen on a forecourt: anywhere else, your car got there by being driven. The ignition switched on, or a short start. The system has been bled, so petrol has left that tank and reached the filter and your lines. Normally little more than emptying, cleaning and seeing to the filter, so still straightforward. Those few miles driven meant the pump working on fuel weakened by petrol the whole way. Tank, lines, filter, then clean fuel put through the entire circuit: that is this work, and the way the vehicle was driven counts as much as the mileage. Driving the kids to Downsbrook Primary School is one sort of trip. Driving as far as Brighton and Hove, under 10 miles away, makes a very different task — as does any mileage on the M23, under 25 miles from Broadwater, with the motor working hard the whole time. Driven until it protested. Clattering, a lumpy idle, smoke, a throttle that has gone soft. The fuel is not acting like diesel any more, and your engine is saying so. Leave it where it has stopped: a lay-by, a quiet street, the verge on Kingsland Road. Permanent damage is very uncommon if a car is stopped soon, and the fuel drain and flush that still go first sort it out. ## Myths Broadwater 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. A bigger tank of the same mixture is all it gives, because topping up removes nothing. The assumption behind the advice — that diesel fuel systems tolerate petrol by percentage — is wrong. Myth: a modern diesel copes with a bit of petrol. Rather, the opposite. Finer parts and higher pressure are the way a current diesel runs its fuel, and that makes the lubrication count more, not less. Myth: "If it starts and drives, there's no harm done." This is the one that catches drivers. Diesel in a petrol motor usually leaves a motor that will not run: the driver stops, and so does the damage. Feed petrol to a diesel and it normally fires up, ticks over and drives away as if nothing happened — all the while its pump is wearing. Being able to run isn't proof of being fine. "A drop of two-stroke oil and drive it home" — a myth, taken from a fix from years ago, for a separate problem. What petrol has weakened remains thinned, and that petrol remains in the tank regardless. "Drain it yourself and you're sorted" — a myth, because after it has been running some petrol lies in your filter and lines, ready to go straight back through your pump on your next start. It's also truly hazardous to drain petrol into a can by the kerbside. ## Why petrol in a diesel happens so easily It's rarely carelessness, and nobody does it on purpose. A diesel nozzle generally will not go into a petrol motor, yet the smaller petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one mistake simple, and only in one direction. The moment routine stops matching the car is the moment it happens. Courtesy car, hire car, or a vehicle that's new. One petrol and one diesel on the drive of the same household. A forecourt you know, but with its pumps arranged differently. Fuelling up in a hurry on the way to East Worthing, with a train to catch. A new-to-you diesel Renault Megane, its first fuelling, and a motorist used to petrol: precisely when it occurs. Add rain, a phone call or a back seat full of kids, and the hand does what it has always done. ## Next time you fill up around Broadwater: avoiding petrol in a diesel - Not every forecourt in the UK keeps to green for unleaded and black for diesel, even if most usually do. Check the petrol pump's label; the colour is just a clue. - Many cars state the fuel type inside the filler flap or on the cap, and so check it on your first fill in any car you do not know. - One of each in the household? Mark the key to your diesel — a coloured fob, a sticker — because meaning to remember isn't enough. - Say it before you lift it. On the first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the petrol pump. It seems daft and it works. - Mistakes like this are simple to make whilst your mind is on something else, so the phone goes away. - Add-on devices exist for vehicles without one, and some diesels are built with a filler that won't take a petrol nozzle. Helpful — but a backstop only, never a reason to stop checking the label. - Stop as soon as you realise. Less petrol inside the tank means a thinner blend. It doesn't change what to do next, which is still not to start it. ## Already put petrol in a diesel in Broadwater? Then the order of things is brief. Never start the vehicle, and don't switch your ignition on. Ask the staff to help you push it away from the pump if you're still at the forecourt, whether that is Shell or anywhere else. Call 0333 366 0103 next, with three facts — your fuel, the rough quantity, and whether it's run. If it was AdBlue instead of petrol, say so. That's a separate problem — corrosion and deposits and not lost protection — and it has its own page for Broadwater. ## Broadwater petrol in a diesel jobs: why one costs more than another The four scenarios above are four different jobs, so no single price for this would be honest. Which of them you are in is mostly what moves the cost. The share matters next, meaning how much of the tank is petrol, followed by the location of the vehicle and whether reaching it is safe for a technician. Before any quote, not after, we ask three questions: your fuel that got in, the volume, and if it's run. That's why. A range becomes a straight figure once the replies are in. ## About Broadwater and its setting Broadwater is a coastal suburban area in West Sussex, situated near the town of Worthing and approximately 9.8 miles from Brighton and Hove. Broadwater lies at a low elevation of around 6 metres, reflecting its proximity to the sea. Broadwater has a mix of housing types, but terraced housing is particularly prevalent in the area. Broadwater is also close to other nearby places, including Sompting Abbotts and East Worthing. ## Across West Sussex and around Broadwater: fuel drain cover Broadwater rests in the BN postcode area, and the vans that answer petrol in diesel calls there work the places around it as well — Sompting Abbotts, Worthing and East Worthing among them. No need to move your car to us. Forecourts, supermarket car parks, lay-bys and your own drive are all locations where we work. ## Still at the petrol pump in Broadwater? In that case, you couldn't be in a better place. Keep it off. Phone.