--- title: Commonside: Petrol in a Diesel Car, Explained canonical: https://www.petrolinadieselcar.co.uk/petrol-in-diesel/commonside-nottinghamshire-ng17-2/ location: Commonside county: Nottinghamshire latitude: 53.126550 longitude: -1.305680 service: Petrol in a Diesel Car updated: 2026-10-24 --- # Petrol in a Diesel Car in Commonside: How Worried Should You Be? Not started? Then less anxious than you probably feel. Petrol sitting in a diesel tank does nothing to the engine till something draws it through your fuel system — your ignition priming your pump, your starter, or the drive itself. So the honest answer to the first query everyone around Commonside asks, "have I ruined it?", is usually no. Keep it that way: leave your engine off and call Petrol in Diesel. What petrol actually does to a diesel, how to gauge how far it's travelled, and how to stop it from happening a second time: that is the remainder of this page. ## Petrol in a diesel: what does it do to the motor? On its way through a motor, diesel does two jobs. It combusts, and before it combusts it lubricates. Extremely fine tolerances are built into your injectors and your high-pressure pump, and just your diesel flowing through keeps their surfaces from grinding together. Of those two jobs, petrol manages the first poorly and the second not at all. It is runnier than diesel and takes away the protection the system hinges on, so a pump running on a petrol mixture is a pump wearing itself. And petrol is made to resist igniting under compression, which is the reverse of what a diesel needs from its fuel. That is where the clattering comes from. Put those together and the shape of the problem is clear. The damage is done by circulation, not by contact. Where the petrol is only inside the tank, it is a fault of fuel, nothing more. Whatever a worn pump sheds goes on, borne by your fuel, into the injectors further along, which is why a pump that has worked on the petrol is where a mechanical issue starts. ## Four situations our engineers see in Commonside: how serious is petrol in a diesel? Filled up, and never started: no case is better. Being at a forecourt is what makes this the case: elsewhere, your car has been driven there to begin with. With that petrol held in your tank alone, it's emptied and purged right where it stands, and nothing more is needed. A moment's running, or just your ignition on. Petrol has left that tank and got to the filter and the fuel lines, since the system has been bled. Usually little more than clearing, flushing and sorting your filter, and so still easy. A few miles driven, and your pump has spent every one of them working on diluted fuel. The work is your tank, the lines, your filter and clean fuel through the entire circuit, and how hard your car was driven matters as much as how far. Driving the kids to Huthwaite All Saints Church of England Infant and Nursery School is one kind of trip. Any distance on the M1, under a mile from Commonside, means the motor working hard throughout, and a run to Nottingham, under 15 miles away, makes a very different task too. Driven on till it protested — rattling, smoke, a lumpy idle, a soft throttle. That's your engine telling you its fuel has stopped acting like diesel. Stop where you are — on the verge on Little Lane, at the kerb, down a side road — and don't move it. Long-term damage is very uncommon if a car is stopped soon, and the drain and flush that still go first sort it out. ## What Commonside drivers get told about petrol in a diesel — and the myths in it "Top it up the rest of the way with diesel and it will be fine" — a myth. It won't. A bigger tank of the same mix is all you get, since topping up takes out nothing. A diesel fuel system doesn't accept petrol by percentage in the way that advice presumes. Not so: a current diesel copes with a bit of petrol. Rather, the opposite. More precise components and higher pressure are the way a current diesel runs its fuel, and that makes the protection count more, not less. Myth: "If it starts and drives, there is no damage done." This is the one that catches people. The motorist of a petrol motor fed diesel normally stops, since it will not run, and the damage stops with them. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually will; meanwhile your pump grinds. Running isn't the same as fine. Not so: a two-stroke additive makes it safe to drive home. It was an old workaround, supposed for another fault. That petrol is still in the tank afterwards, and what it has diluted isn't put back. Myth: "Drain that tank yourself and you are sorted." After your engine has been run, some of the petrol is no longer inside that tank: it is in your filter and the fuel lines, and it goes straight back through the pump on the next start. Besides, petrol cleared into a can by the road is truly dangerous. ## Why petrol in a diesel happens so easily It is seldom carelessness, and nobody does it on purpose. One way only, because 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 vehicle. That's how the forecourt makes it straightforward. When routine and your car stop matching, it happens. Hire cars, courtesy cars, and cars that are new to you. Two vehicles on one driveway, one petrol, one diesel. The pumps in a different order on a well-known forecourt. A hurried fill on the way to Kirkby in Ashfield with a train to catch. Years of petrol vehicles behind you, a diesel Skoda Octavia in front of you at the forecourt for its first tank — that is when. Your hand does what it has always done when you add rain, a phone call or a back seat full of children. ## Avoiding petrol in a diesel next time you fill up around Commonside - 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. - Many cars state the fuel type inside your filler flap or on the cap, so check there on your first fill in a vehicle you do not know. - Label your key. In a home with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of intending to remember. - Say it before you lift it. On your first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the pump. It sounds silly and it works. - Mistakes like this are easy to make while your mind is on something else, and so the phone goes away. - Some diesels have a filler designed to block a petrol nozzle, and devices you can add exist for cars without one. Such an inhibitor helps up to a point — as a safety net, not a reason to stop checking the pump. - Stop as soon as you notice. Less petrol inside your tank makes a weaker mix. It doesn't change what to do next, which is still not to fire it up. ## Petrol already in a diesel around Commonside? Start here The order of things is brief, then. Leave it unstarted, with your ignition switched off as well. Yet on the forecourt, at Gulf or anywhere else? Ask the attendants to help you push the vehicle away from the petrol pump. Next, 0333 366 0103. We'll ask what got in, roughly how much, and if it's been run. Say so if it was AdBlue rather than petrol: it is a different problem, with its own page for Commonside, because AdBlue brings corrosion and deposits instead of lost protection. ## What makes one Commonside petrol in a diesel task cost more than the next There is no honest single price for this, since the four situations above are four different jobs. Which of them you are in is mostly what moves the cost. The proportion matters next, meaning how much of that tank is petrol, and then the location of your car and whether reaching it is safe for a van. Three questions come first, before quoting, rather than after — what went in, how much, has it run — and this is the reason. A range becomes a straight figure once the replies are in. ## About Commonside and its setting Commonside is a suburban area located on the riverside in Nottinghamshire, with a mix of semi-detached housing and a population of around 3929 residents. Commonside sits at an elevation of 164 metres, approximately 13.4 miles from Nottingham and 122.4 miles from London. Commonside is close to nearby places such as Huthwaite, Hilcote, and Fulwood, and is part of the wider East Midlands region. ## Across Nottinghamshire and around Commonside: fuel drain cover Petrol in diesel jobs around Commonside — part of the NG postcode area — go to vans that likewise cover the spots about it, Huthwaite, Hilcote and Fulwood included. The car doesn't need to come to us: our technicians drain on a forecourt, in a supermarket car park, in a lay-by or on your own drive. ## At the pump around Commonside, right now? Then, you couldn't be in a better place. Keep the car turned off, and ring.