--- title: Worried? Petrol in a Diesel Car West Looe canonical: https://www.petrolinadieselcar.co.uk/petrol-in-diesel/west-looe-cornwall/ location: West Looe county: Cornwall latitude: 50.350930 longitude: -4.463550 service: Petrol in a Diesel Car updated: 2026-10-11 --- # Should You Worry? Petrol in a Diesel Car in West Looe Provided it hasn't been started, you can worry less than you likely are. Till the ignition primes your pump, your starter turns, or the car is driven, petrol in a diesel tank just rests there and does no harm. Which means the honest reply to the first West Looe question — "have I wrecked it?" — normally no. Petrol in Diesel is who to ring, with the engine left off, and so it stays that way. The rest of this page covers what petrol really does to a diesel, how to tell how far it has got, and how to make sure it does not happen to you again. ## Your engine and petrol in a diesel: what happens On its way through a motor, diesel has two jobs. Oiling comes before burning; it does both. Extremely fine tolerances go into the fuel injectors and the high-pressure pump, and just the diesel running through keeps their surfaces from grinding together. Of these two jobs, petrol handles the first badly and the second not at all. The clattering comes from petrol being made not to ignite when compressed, which is exactly the reverse of what a diesel needs. On top of that it is runnier than diesel, it strips away the lubrication the system depends on, and any pump working on that mixture is wearing itself. Seen together, they show the shape the issue has. The harm is done by movement, not by contact. Any tank with petrol in it is a fuel problem. Once the pump has been working on that petrol, a mechanical issue has started: anything shed by a pump that is grinding is carried downstream to the injectors with your fuel. ## How bad is petrol in a diesel? Four situations our technicians see in West Looe The best case there is: filled up, not once started. On a forecourt, and genuinely only there, that petrol is still confined to your tank — because anywhere else your car was driven to get to it. The job is draining and purging on the spot. The ignition turned on, or a brief start. With your system primed, your lines and filter now hold petrol that came from your tank. That is usually still an easy job — a drain, a flush, and your filter seen to. Those few miles driven were the pump labouring on fuel weakened by petrol the whole way. The work is your tank, the fuel lines, your filter and fresh fuel through the entire system, and how hard your car was driven matters as much as how far. A school run to Looe Primary Academy is one thing. Driving as far as Plymouth, under 15 miles away, makes a very different job — as does any distance on the M5, under 50 miles from West Looe, with your engine working hard all the way. Driven until it complained. Clattering, a lumpy idle, smoke, a throttle that has gone soft. The motor is telling you the fuel is no longer acting like diesel. Leave it where it stops: a lay-by, a side street, the verge on Barn Meadow Park. What goes first is still the fuel drain and flush-through, and that takes care of it, with long-term damage very rare if a car is pulled over quickly. ## Myths West Looe people hear about petrol in a diesel Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. Topping up takes out nothing; it gives you a fuller tank of the same mixture. Percentage is not how a diesel fuel system copes with petrol, however much that advice supposes. Myth: "A newer diesel can cope with a bit of petrol." If anything, the opposite. Finer components and higher pressure are the way a newer diesel runs its fuel, and that makes the protection count more, not less. Myth: "If it starts and drives, there's no damage done." This is the one that fools people. Feed diesel to a petrol motor and it usually will not run, and so the driver stops — and the damage stops with them. A diesel fed petrol usually starts, idles and drives away as if nothing has happened, whilst the pump grinds. Fine and running aren't the same at all. An old fix for a separate problem lies behind this one. Myth: "Add some two-stroke oil and drive the car home." That petrol is still inside the tank afterwards, and what it has thinned is not put back. "Drain it yourself and you're sorted" — a myth, because after it has been running some petrol sits in your filter and lines, waiting to go right back through the pump at your next start. On top of that, petrol emptied into a can by the road is genuinely hazardous. ## How petrol ends up: petrol in a diesel It is rarely carelessness, and nobody does it on purpose. The forecourt makes it easy: the petrol nozzle is the narrower of the two, and it slides into a diesel filler with almost no resistance, while a diesel nozzle mostly will not go into a petrol motor at all. So the slip runs one way. Routine and the car falling out of step is when it happens. A new car, a hire car or a courtesy car. One petrol and one diesel on the drive of the same household. Your usual forecourt, its pumps now in a different order. A train to catch, and a hurried fill en route to Looe. Precisely the moment it happens: after years of driving petrol, a driver fills a diesel Renault Clio for the first time. With rain, a call coming in, or children to deal with, the hand just does what it always has. ## How to avoid petrol in a diesel at your next fill-up around West Looe - Check the petrol pump, not the colour. In the UK unleaded handles are normally green and diesel black, yet not on each forecourt. The label is what counts. - Inspect the filler flap. Many motors state the fuel type inside the flap or on the cap. Look at it on your first fill in any vehicle you don't know. - A coloured fob or a sticker on the diesel's key achieves more than any amount of intending to remember, in a house with one of each. - Before the nozzle leaves the pump the first time you fill a hired or new car, say "diesel" aloud. Daft, perhaps, but it works. - Thinking about something else is when this becomes an easy mistake to make, so tuck your phone away and keep your mind on the pump. - Some diesels have a filler built 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 pump. - Less petrol makes a thinner mixture, and so stop as soon as you notice — though remembering that the next step is unchanged. It is still not to start the car. ## Put petrol in a diesel in West Looe already? Then the order of things is brief. Starting it is out, and so is switching on the ignition. Ask the staff to help you roll it away from the pump if you are still on the forecourt, whether that is Texaco or somewhere else. What got in, about how much, and if it's run: tell us that when you phone 0333 366 0103. AdBlue, not petrol? Then say so. Corrosion and deposits, not lost protection, make it a separate problem — West Looe has a page all for it. ## What makes one West Looe petrol in a diesel job cost more than the next There is no honest single price for this, since the four situations above are four different jobs. What shifts the cost is mostly which of them you are in. The ratio matters next, meaning how much of your tank is petrol, followed by the position of the car and whether reaching it is safe for a technician. What was put in, how much, and whether it has run — three questions our engineers ask before quoting, not after, for exactly that reason. Those replies turn a range into a straight figure. ## About West Looe, for a moment West Looe is a suburban area situated on the south coast of Cornwall, near the town of Looe and overlooking the English Channel. West Looe sits at an elevation of around 77 metres, with detached housing being the predominant type of accommodation in the area. West Looe is located near several nearby places, including Looe, Portlooe, and East Looe, and is approximately 14 miles from the city of Plymouth. West Looe has a population of around 1673 residents. ## Fuel drain cover around West Looe and across Cornwall Petrol in diesel jobs in West Looe — part of the PL postcode area — go to teams that also cover the locations around it, Looe, Portlooe and East Looe included. A forecourt, a supermarket car park, a lay-by or your own driveway are all spots our technicians work, and the car does not need to move to us. ## At the pump around West Looe, still? No position is better: that is where you now are. Keep the vehicle turned off, and ring.