--- title: Sidcot: Petrol in a Diesel Car, Explained canonical: https://www.petrolinadieselcar.co.uk/petrol-in-diesel/sidcot-somerset/ location: Sidcot county: Somerset latitude: 51.312490 longitude: -2.821000 service: Petrol in a Diesel Car updated: 2026-10-09 --- # Sidcot: Petrol in a Diesel Car? How Worried to Be Likely less than you are now — provided nobody has started it. Everyone in Sidcot starts with "have I wrecked it?", and the fair answer is generally no: petrol left in your tank of any diesel remains harmless until priming, cranking or driving draws it into the system. Keep it like that: leave the engine off then phone Petrol in Diesel. What petrol really does to a diesel, how to judge how far it has travelled, and how to keep it from happening again: that's the remainder of this page. ## Petrol in a diesel: what does it do to the engine? Diesel does two tasks on its way through an engine. It burns, and before it ignites it protects. The high-pressure fuel pump and the fuel injectors are built to very fine clearances, and the diesel passing through them is what stops those surfaces from grinding against one another. Badly at the first, not at all at the second: that's petrol. The clattering comes from petrol being made not to ignite when compressed, which is precisely the opposite of what a diesel needs. On top of that it is thinner than diesel, it strips away the lubrication your system hinges on, and any pump running on that mix is wearing itself. Put these together and the shape of the problem is plain. Contact does not do the harm — circulation does. Any tank with petrol in it is a fuel fault. Whatever a worn pump sheds travels on, carried by the fuel, into the injectors further along, which is why a pump that has been working on that petrol is where a mechanical problem starts. ## Petrol in a diesel around Sidcot: how bad is it? Four cases Filled up, and not started: no case is better. That petrol is inside that tank and only the tank, and the job is a drain and a flush where the vehicle sits. This is the one situation that can only truly happen at a forecourt, because anywhere else your car has been driven to get there. A moment's running, or merely your ignition on. The system has been bled, and so petrol has left the tank and got to the filter and the lines. Still normally simple: drain, flush, and your filter sorted. Some miles driven, and your pump has spent each of them running on weakened fuel. Distance is only half of it; how hard it was driven counts just as much. Either way the work runs to the tank, the fuel lines, the filter and clean fuel through the entire circuit. The school run to Winscombe Primary School is one matter. A run as far as Wells, under 15 miles away, is a very different job. So is any distance on the M5, under 3 miles from Sidcot, where the motor has been running hard the whole time. It protested, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone uneven. The fuel is not behaving like diesel any more, and the motor is saying so. Whether it is the verge on Fountain Lane, a lay-by or a side road, stop where you are and leave it. Lasting damage is very rare when a vehicle is stopped quickly, and the fuel drain and flush-through that still come first take care of it. ## Sidcot people and the petrol in a diesel stories they hear Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. Topping up takes out nothing; it gives you a bigger tank of the same mix. A diesel fuel system doesn't tolerate petrol by percentage in the way that advice assumes. "Current diesels can handle a little petrol" — a myth, and nearer the reverse. At higher pressure, through finer parts: that's how a current diesel handles its fuel, so the protection counts more, not less. This is the one that fools drivers. Myth: "If it starts and drives, there's no harm done." Diesel in a petrol motor generally means a motor that won't run: the motorist stops, and so does the harm. A diesel fed petrol usually starts, ticks over and drives away as if nothing has happened, whilst the pump grinds. Being able to run is not proof of being fine. "A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a separate issue. That petrol is still inside that tank after that, and what it has thinned is not put back. "Drain it yourself and you are sorted" — a myth, because after it has been running some petrol sits in the fuel filter and lines, waiting to go right back through the pump on the next start. And, a can of petrol drained at the roadside is genuinely hazardous. ## Why petrol in a diesel takes place so easily Carelessness is seldom the cause, and no one means to do it. A diesel nozzle generally won't go into a petrol car, yet the narrower petrol nozzle goes into the filler of a diesel almost without resistance — so forecourts make this one mistake straightforward, and only in that direction. Routine and your car getting out of step is when it happens. Hire cars, courtesy cars, and motors that are new to you. A household with one petrol and one diesel on the drive. Your ordinary forecourt, its pumps now in a different order. Filling up in a hurry en route to Worle, with a train to catch. Years of petrol motors behind you, a diesel Renault Megane in front of you on the forecourt for its first tank — that's when. Throw in a back seat full of children, a phone call or rain, and habit wins. ## Preventing petrol in a diesel next time you fill up in Sidcot - The label is what matters, and so check the petrol pump instead of the colour: in the UK unleaded handles are normally green and diesel black, yet not on each forecourt. - Many motors state the fuel type inside the filler flap or on the cap, and so check there on your first fill in a motor you don't know. - One of each in the household? Mark your key to the diesel — a coloured fob, a sticker — because intending to remember isn't enough. - Say it before you lift it. On the 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 does the trick. - Whilst you are thinking about something else, this is an easy mistake to make — so tuck the phone away. - Add-on devices exist for cars without one, and some diesels come with a filler that will not accept a petrol nozzle. Useful — but a safety net at best, never a reason to stop checking the label. - Noticing it halfway? Stop there and then. A thinner mix results from less petrol in the tank, yet the next stage remains the same: don't fire it up. ## Petrol already in a diesel around Sidcot? Begin here Then the order of things is short. Don't switch your ignition on, and do not crank it. Still on the forecourt, at Texaco or anywhere else? Ask the staff to help you roll the vehicle away from the petrol pump. What went in, about how much, and whether it's run: tell us that when you ring 0333 366 0103. Corrosion and deposits form the issue with AdBlue, whereas petrol brings lost lubrication. So if it was AdBlue, say so — and read its own Sidcot page. ## One petrol in a diesel task in Sidcot costs more than another. Why? There's no honest single quote for this, since the four situations above are four different tasks. The situation itself does most of the work of moving your cost. Two things follow that: the petrol that was put in as a proportion of what your tank takes, then the spot the vehicle is in and whether a van can get to it safely. What got in, how much, and if it's run — three queries we ask before pricing, not after, for exactly that reason. A range becomes a straight figure once those replies are in. ## About Sidcot and where it is Sidcot is a suburban area in inland Somerset, situated approximately 10 miles from the city of Wells and 117 miles west of London. Sidcot has a relatively low elevation of 81 metres and is surrounded by nearby places such as Woodborough, Winterhead, and Winscombe. Sidcot is characterised by its predominantly detached housing stock, reflecting its residential nature. Sidcot remains a small but distinct community within the wider region. ## Across Somerset and in Sidcot: fuel drain cover Woodborough, Winterhead and Winscombe are among the spots near Sidcot that the same vans work, answering petrol in diesel calls across Sidcot's BS postcode area. A forecourt, a supermarket car park, a lay-by or your own drive are all places our engineers drain, and your car does not need to move to us. ## At the pump in Sidcot, right now? The best spot there is, then — that is where you are. Keep the car switched off, then ring.