--- title: Worried? Petrol in a Diesel Car Green Lane canonical: https://www.petrolinadieselcar.co.uk/petrol-in-diesel/green-lane-warwickshire/ location: Green Lane county: Warwickshire latitude: 52.279330 longitude: -1.904310 service: Petrol in a Diesel Car updated: 2026-10-09 --- # Green Lane: Petrol in a Diesel Car? How Worried to Be Unstarted? Then less anxious than you probably are. Everyone around Green Lane starts with "have I wrecked it?", and the fair answer is generally no: petrol left inside the tank of any diesel remains harmless till priming, cranking or driving pulls it into the system. To leave the vehicle that way, call Petrol in Diesel and leave the engine alone. Keep reading for three things: the effect petrol has inside a diesel engine, the clues of how far it has spread, and the way to make sure you never do it again. ## Your engine and petrol in a diesel: what goes on Two tasks fall to diesel on its journey through a motor. Before it burns, it protects — and then it combusts. Made to very fine gaps, the injectors and the pump depend on your diesel moving through them to stop their surfaces wearing against one another. Petrol handles the first job poorly and the second not at all. A pump working on a petrol blend is wearing itself out, because petrol is runnier than diesel and strips out the lubrication your fuel system depends on. Petrol is also made to resist igniting under compression — the opposite of what a diesel wants from its fuel — and that is where any knocking starts. The shape of the trouble is plain when you put those together. Not contact but circulation is what does the harm. All a tank with petrol in it amounts to is a fuel problem. After the pump has been labouring on that petrol, a mechanical problem has started: whatever is shed by a pump that's wearing down is carried onward to the fuel injectors with your fuel. ## How bad is petrol in a diesel? Four situations our technicians see around Green Lane Fuelled but never started — the best it gets. 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 that tank alone, it's cleared and purged right where it stands, and nothing more is needed. Started for a moment, or just the ignition on. Once primed, your system has drawn petrol out of that tank as far as the fuel filter and your lines. Normally nothing more than emptying, purging and sorting your filter, and so still straightforward. Driven a couple of miles. Now the pump has spent these miles running on diluted fuel. The work is that tank, the fuel lines, the filter and clean fuel through the whole circuit, and how hard the car was driven matters as much as how far. Driving the kids to Studley Infants' School is one kind of trip. Any distance on the M42, under 10 miles from Green Lane, means your engine has worked hard throughout, and a run to Birmingham, under 15 miles away, is a very different job as well. Knocking, a ragged idle, smoke, a throttle gone soft: driven till it complained. That's your engine telling you its fuel no longer is acting like diesel. Pull up wherever you are — the verge on Green Lane, a lay-by, a side street — then leave the car where it is. A car pulled over quickly very rarely has lasting damage, as the fuel drain and the flush, which still come first, take care of it. ## What Green Lane motorists get told about petrol in a diesel — and the myths in it It will not be fine. The myth: "Fill it the rest of the way with diesel and it will be." A fuller tank of the same mixture is all you get, since topping up takes out nothing. A diesel fuel system does not accept petrol by percentage in the way that guidance presumes. Myth: "A modern diesel can cope with a bit of petrol." If anything, the reverse. A modern diesel runs its fuel through smaller components at higher pressure, which makes the lubrication count more, not less. This is the one that fools motorists. Myth: "If it starts and drives, there's no harm done." 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 generally starts, ticks over and drives away as though nothing has happened, whilst your pump wears. Fine and running aren't the same thing. "A drop of two-stroke oil and drive it home" — a myth, taken from a fix from years ago, for a distinct issue. None of what petrol weakened gets put back by it — and later, the tank still holds the petrol. "Drain it yourself and you're sorted" — a myth, since after it's been running some petrol lies in the fuel filter and lines, ready to go right back through the pump at your next start. Also, a can of petrol filled by the kerbside is truly dangerous. ## Petrol in a diesel: how does it occur? Nobody does it on purpose, and it's seldom carelessness. The petrol nozzle is the narrower of the two and slides into a diesel filler with almost no resistance; a diesel nozzle generally will not go into a petrol motor at all. The forecourt makes it simple, and the slip runs one way. Habit and your car falling out of step is when it occurs. Courtesy car, hire car, or a vehicle that's new. A household with one petrol and one diesel on the driveway. The pumps in a different order on a familiar forecourt. A train to catch, and a rushed fill on the way to Redditch. A new-to-you diesel BMW 3 Series, its first fuelling, and a motorist used to petrol: exactly when it occurs. Throw in rain, a phone call or a back seat full of children, and the hand does what it has always done. ## Next time you fill up in Green Lane: avoiding petrol in a diesel - Green for unleaded and black for diesel is usual in the UK — yet not on each forecourt. Go by the label on the petrol pump, not the colour. - The first fill in a new car is the time to check the filler flap — inside it, or on the cap, many cars state which fuel to use. - One of each in the house? Mark the key to your diesel — a bright fob, a sticker — because intending to remember isn't enough. - "Diesel", out loud, before you lift the nozzle — each time a new or hired car needs its first tank. It seems silly. It works. - Whilst you are thinking about something else, this is an easy mistake to make — so put the phone away. - A misfuel inhibitor helps, up to a point. Some diesels come with a filler built to reject a petrol nozzle, and add-on devices are available for motors without one. They are a safety net, not a reason to stop checking the petrol pump. - The moment you realise, stop: less petrol inside your tank makes a thinner mixture. What to do next doesn't change, though — still do not fire it up. ## Green Lane: already put petrol in a diesel? In that case, there is only a short order of things. Starting it is out, and so is switching on your ignition. Ask the staff to help you roll it clear of the petrol pump if you are still at the forecourt, whether that's BP or anywhere else. Call 0333 366 0103 next, with three answers — the fuel, the rough volume, and if it's run. If it was AdBlue instead of petrol, say so. That is a different issue — corrosion and deposits rather than lost lubrication — and it has its own page for Green Lane. ## Why one petrol in a diesel task in Green Lane costs more than another Four separate tasks lie behind the four situations above — which is why there's no honest single price. 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 that tank takes, then the place your car is in and whether our van can reach it safely. Ahead of any quote, not after, we ask three questions: the fuel that went in, its amount, and whether it has run. That's why. Their answers are what turn a range into one firm number. ## About Green Lane Green Lane is a small hamlet in Warwickshire, situated on the riverside at an elevation of 72 metres, with semi-detached housing being the predominant type of accommodation. Green Lane lies near the cities of Birmingham and the towns of Studley and Redditch, and is close to the villages of Woodrow and Washford. Green Lane is located in the West Midlands region, approximately 92.6 miles northwest of London. Green Lane has a population of around 500 people, living in a quiet riverside setting. ## Across Warwickshire and in Green Lane: fuel drain cover Woodrow, Studley and Washford are among the places near Green Lane that the same vans work, answering petrol in diesel calls across Green Lane's B postcode area. A forecourt, a supermarket car park, a lay-by or your own drive are all locations we work, and the vehicle doesn't need to come to us. ## At the petrol pump in Green Lane, still? No position is better: that is where you now are. Ring, and leave it turned off.