Should You Worry? Petrol in a Diesel Car in Tankersley
Less than you likely are, provided it has not been started. Till your ignition primes your pump, your starter turns, or your vehicle is driven, petrol in a diesel tank simply sits there and does nothing. Which means the truthful reply to that first Tankersley question — "have I ruined it?" — usually no. Leave your motor off then ring Petrol in Diesel — that keeps it like that. The remainder of this page covers 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 again.
Inside the motor: what petrol in a diesel really does
Diesel does two tasks on its way through a motor. Before it combusts, it protects — and then it ignites. Very fine gaps go into the fuel injectors and the high-pressure fuel pump, and only your diesel flowing through keeps those surfaces from grinding together.
Badly at the first, not at all at the second: that is petrol. Being less viscous than diesel, petrol strips away the lubrication a fuel system needs, leaving a pump on the blend wearing itself. It's equally made to resist igniting under compression — the reverse of what a diesel needs — which is why you hear the clattering.
Taken together, they make clear what shape the issue takes. The damage is done by movement, not by contact. Where that petrol is only inside that tank, it is a fault of fuel, nothing more. After the pump has been working on that petrol, a mechanical fault has begun: whatever is shed by a pump that's wearing down travels downstream to the fuel injectors with the fuel.
Tankersley, petrol in a diesel: four cases, from mild to serious
The best case there can be: filled up, never started. Being on a forecourt is what makes this the case: elsewhere, the car has been driven there to begin with. With that petrol kept in your tank alone, it is emptied and cleaned right where it stands, and nothing more is needed.
Ignition on, or started for a moment. Once primed, the system has pulled petrol from your tank up to the fuel filter and the fuel lines. Still normally straightforward: drain, flush, and your filter dealt with.
Your pump has spent a couple of miles on thinned fuel — that's what driving it does. The work is the tank, the lines, your filter and clean fuel through the whole circuit, and how hard your car was driven counts as much as how far. Driving the children to Tankersley St Peter's CofE (Aided) Primary School is one kind of trip. A run as far as Sheffield, under 10 miles away, is a very different task. So is any mileage on the M1, under a mile from Tankersley, where the motor has been running hard throughout.
Driven till it protested. Clattering, a lumpy idle, smoke, a throttle that has gone soft. The motor is telling you your fuel is no longer acting like diesel. Whether it's the verge on Fenn Road, a lay-by or a side road, stop where you are then leave it. Permanent damage is very rare when a vehicle is stopped soon, and the drain and flush that still come first deal with it.
Petrol in a diesel stories Tankersley motorists hear
False: topping up to full with diesel makes it fine. It doesn't. Topping up removes nothing; it gives you a bigger tank of the same mix. That advice presumes a diesel fuel system tolerates petrol by percentage. It doesn't.
"Current diesels can handle a little petrol" — a myth, and nearer the opposite. At higher pressure, through more precise components: that is how a newer diesel handles its fuel, and so the lubrication counts for more, not less.
"It starts, it drives, and so there is no harm" — the myth that catches most motorists than any other. Any petrol motor fed diesel normally will not run, so the driver stops and the harm stops with them. A diesel fed petrol normally starts, idles and drives away as if nothing has happened, while the pump wears. Running does not mean fine.
An old fix for a distinct fault is behind this one. Myth: "Add some two-stroke oil and drive the car home." What petrol has thinned remains weakened, and that petrol stays inside that tank anyway.
The next start sends petrol back round the pump out of the lines and your filter, where some of that ends up after the motor has run. That is why draining the tank yourself does not leave you sorted — a myth. It is also truly risky to drain petrol into a can by the kerbside.
How does petrol in a diesel occur?
Carelessness is rarely the cause, and nobody means to do it. The forecourt makes it simple: the petrol nozzle is the slimmer of the two, and it slides into a diesel filler with almost no resistance, whilst a diesel nozzle mostly will not go into a petrol vehicle at all. So the mistake runs one way.
It happens when routine and the vehicle stop matching. Courtesy car, hire car, or a vehicle that's new. One petrol and one diesel on the driveway of the same household. A familiar forecourt with the pumps in a different order. A hurried fill en route to Elsecar with a train to catch. A new-to-you diesel Volkswagen Passat, its first fuelling, and a driver accustomed to petrol: exactly when it happens. With rain, a call coming in, or children to deal with, your hand just does what it has always done.
Preventing petrol in a diesel next time you fill up in Tankersley
- Read the petrol pump, not the colour. In the UK unleaded handles are usually green and diesel black, yet not on each forecourt. The label is what counts.
- The first fill in a new motor is the time to check the filler flap — inside it, or on the cap, many cars state the fuel they take.
- Good intentions count for less than a sticker or a fob in a vivid colour on your diesel's key if a household has one of each. So mark it.
- Before the nozzle leaves the pump the first time you fill a hired or new car, say "diesel" aloud. Silly, perhaps, yet it does the trick.
- Thinking about something else is when this becomes an easy mistake to make, so put the phone away then keep your mind on the petrol pump.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler designed to block a petrol nozzle, and aftermarket devices are available for the rest. Treat it as a safety net, then keep reading the petrol pump.
- Less petrol means a weaker blend, so stop as soon as you notice — while remembering that the next stage is unchanged. It's still not to start it.
Put petrol in a diesel around Tankersley already?
Then, there is only a short order of things. Starting it is out, and so is switching on the ignition. Still on the forecourt, at BP or anywhere else? Ask the attendants to help you roll the vehicle clear of the petrol pump. Call 0333 366 0103 next, with three facts — the fuel, the rough quantity, and if it's run.
Say so if it was AdBlue instead of petrol: it's a separate problem, with its own page for Tankersley, because AdBlue brings corrosion and deposits rather than lost lubrication.
Why one petrol in a diesel job around Tankersley costs more than another
Four different tasks lie behind the four scenarios above — which is why there's no fair single price. Chiefly, your cost moves with which one you're in. The ratio counts next, meaning how much of your tank is petrol, followed by the position of your car and whether getting to it is safe for a van.
Three queries come first, before any quote, rather than after — what was put in, how much, has it run — and that is the reason. A range becomes a straight figure once those answers are in.
About Tankersley and its setting
Tankersley is a small village in South Yorkshire, situated near the River Don and close to the towns of Barnsley and Sheffield. Tankersley sits at an elevation of 149 metres, with the village and surrounding areas like Upper Tankersley and Pilley forming a local community. Tankersley has a mix of housing, but detached homes are particularly prevalent in the area. Tankersley is located approximately 7.8 miles from Sheffield, making it a commuter base for the city.
Tankersley and South Yorkshire: where our fuel drain cover reaches
Upper Tankersley, Pilley and Birdwell are among the places near Tankersley that the same vans work, answering petrol in diesel call-outs across Tankersley's S postcode area. You need not move your car to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all spots where we work.
Tankersley: still at the petrol pump?
The best spot there is, then — that is where you are. Turned off it stays; then call.