--- title: Showell Green: Petrol in a Diesel Car, Explained canonical: https://www.petrolinadieselcar.co.uk/petrol-in-diesel/showell-green-west-midlands/ location: Showell Green county: West Midlands latitude: 52.448600 longitude: -1.868370 service: Petrol in a Diesel Car updated: 2026-10-10 --- # Petrol in a Diesel Car in Showell Green: How Worried Should You Be? Provided it has not been started, worry less than you probably are. Petrol sitting in a diesel tank does nothing to your engine until something pulls it through the system — the ignition priming your pump, your starter, or driving on its own. So the fair answer to the first question everyone around Showell Green asks, "have I ruined it?", is usually no. Leave the motor off and phone Petrol in Diesel — that is how you keep it like that. The rest of this page explains what petrol really does to a diesel, how to judge how far it has got, and how to make sure it doesn't happen to you a second time. ## What petrol in a diesel does to the motor Passing through a motor, diesel is doing two jobs at the same time. Lubricating comes before burning; it does both. Very fine gaps go into the fuel injectors and the high-pressure fuel pump, and only the diesel flowing through stops those surfaces grinding together. Poorly at the first, not at all at the second: that is petrol. A pump working on a petrol mixture is wearing itself out, because petrol is runnier than diesel and takes away the lubrication your fuel system relies on. Petrol is also designed to resist igniting under compression — the opposite of what a diesel wants from its fuel — and that's where any knocking starts. Combined, those make the shape of the problem clear. It's movement that does the harm, not contact. Petrol in the tank is a fuel problem. A pump that has been labouring on that petrol is the start of a mechanical one, and whatever a worn pump sheds moves on with your fuel to the fuel injectors downstream. ## How bad is petrol in a diesel? Four situations we see around Showell Green The best case there can be: filled up, never started. On a forecourt, and genuinely only there, the petrol is still confined to that tank — since anywhere else the car was driven to reach it. The task is emptying and purging on the spot. Ignition on, or started for a moment. With your system primed, your lines and filter already hold petrol that came from that tank. Drain, flush, see to the filter: still normally straightforward. A few miles driven, and your pump has spent every one of them running on diluted fuel. Miles is only half of that; how hard it was driven counts just as much. Either way the work runs to the tank, the lines, the filter and fresh fuel through the entire system. On the school run to St John's CofE Primary School, the mileage is small. Driving as far as Birmingham, under 3 miles away, makes a very different task — as does any distance on the Aston Expressway, under 5 miles from Showell Green, with your engine working hard all the way. Driven until it protested. Rattling, a ragged idle, smoke, a throttle that has gone soft. The motor is telling you the fuel is no longer behaving like diesel. Whether it is the verge on Park Road, a lay-by or a side road, stop there then leave it. What goes first is still the drain and flush, and that deals with it, with long-term damage very rare when a car is pulled over quickly. ## Showell Green drivers and that petrol in a diesel myths they hear False: topping up to full with diesel makes it fine. It doesn't. Topping up removes nothing; it gives you a fuller tank of the same mix. Percentage is not how a diesel fuel system copes with petrol, whatever that guidance assumes. "Modern diesels can handle a little petrol" — a myth, and nearer the opposite. A modern diesel sends its fuel through more precise parts at higher pressure, which makes the protection matter more, not less. "It starts, it drives, and so there is no harm" — the myth that trips up more drivers than any other. Diesel in a petrol motor usually means a motor that won't run: the motorist stops, and so does the damage. A diesel fed petrol normally starts, ticks over and drives away as though nothing has happened, while your pump grinds. Being able to run isn't the same as being fine. Myth: "Add some two-stroke oil and drive the car home." It's an outdated fix for a distinct issue. None of what petrol thinned is put back by it — and afterwards, that tank still holds that petrol. Myth: "Drain the tank yourself and you are sorted." Once the motor has run, some of that petrol is no longer inside the tank: it is in the fuel filter and your lines, and it goes right back through the pump at your next start. Draining petrol into a can at the kerbside is also genuinely risky. ## How petrol ends up: petrol in a diesel A careless moment is seldom the cause, and no one means to do it. One way only, because of the nozzles: the narrower petrol one slips inside a diesel filler with almost no resistance, whereas the diesel one mostly will not fit a petrol vehicle. That is how the forecourt makes it simple. The moment routine stops matching your car is the moment it occurs. A new motor, a hire car or a courtesy car. One petrol and one diesel on the driveway of the same household. The pumps in a different order on a well-known forecourt. Fuelling up in a rush en route to Moseley Village, with a train to catch. The first fill-up in a diesel Volkswagen Golf after years of driving petrol is exactly the moment it happens. Your hand repeats what it has always done when you add rain, a phone call or a back seat full of kids. ## Next time you fill up in Showell Green: avoiding petrol in a diesel - The label is what counts, so check the pump instead of the colour: in the UK unleaded handles are normally green and diesel black, but not on every forecourt. - The first fill in an unfamiliar car is the time to check the filler flap — on it, or on the cap, plenty of motors state which fuel to use. - One of each in the home? Label the key to your diesel — a coloured fob, a sticker — since intending to remember isn't enough. - Before the nozzle leaves the petrol pump the first time you fill a hired or new motor, say "diesel" out loud. Daft, perhaps, yet it does the trick. - Mistakes like this are simple to make while your mind is on something else, so your phone goes away. - Some diesels come with a filler designed to refuse a petrol nozzle, and devices you can add exist for motors without one. Such an inhibitor helps up to a point — as a safety net, not a reason to stop checking the petrol pump. - Stop the moment you notice. Less petrol inside that tank means a thinner mixture. It doesn't change what to do next, which is still not to start the car. ## Showell Green: already put petrol in a diesel? Short and simple, then, is the order of things. Leave it unstarted, with the ignition switched off too. The attendants at the forecourt — whether at Shell itself or wherever you filled up — will normally help push it clear of the petrol pump if you ask. Then call 0333 366 0103 and tell us what went in, roughly how much, and whether it has run. Say so if it was AdBlue rather than petrol: it is a separate problem, with its own page for Showell Green, because AdBlue brings corrosion and deposits instead of lost lubrication. ## One petrol in a diesel task in Showell Green costs more than another. Why? An honest single quote does not exist here: four situations, four separate tasks. Which of them you are in is mostly what moves your cost. Two things come after that: the petrol that was put in as a proportion of what that tank holds, then the place your car is in and whether our van can get to it safely. Three queries come first, before any quote, rather than after — what went in, how much, has it run — and this is the reason. A range becomes a straight figure once those replies are in. ## About Showell Green itself Showell Green is a suburban area in the West Midlands, situated approximately 2.6 miles southeast of Birmingham city centre. Showell Green sits at an elevation of around 135 metres, near the suburbs of Sparkhill and Wake Green. Showell Green is characterized by its predominantly terraced housing stock, reflecting the area's historical development as a residential neighbourhood. Showell Green is also close to the Greet area, forming part of the larger Birmingham urban landscape. ## Across West Midlands and in Showell Green: fuel drain cover Petrol in diesel calls in Showell Green — part of the B postcode area — go to teams that likewise cover the locations round it, Sparkhill, Wake Green and Greet included. Our engineers drain wherever your car is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it does not have to come to us. ## Still at the petrol pump around Showell Green? The best position there is, then — that is where you are. Leave it switched off, then ring.