Petrol in a Diesel Car in Locharbriggs: How Worried Should You Be?
Provided it has not been started, worry less than you probably are. "Have I wrecked it?" is the first thing everyone in Locharbriggs asks, and the honest answer is usually no, since petrol left in a diesel tank hurts nothing till it is dragged through the system — by ignition priming, by the starter, or by driving. Leave the motor off and ring Petrol in Diesel — that keeps it like that. The remainder of this page explains what petrol really does to a diesel, how to tell 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 does
Two jobs fall to diesel on its journey through a motor. Before it burns, it protects — and then it burns. Built to extremely fine tolerances, the fuel injectors and your pump depend on your diesel moving through them to stop their surfaces wearing against one another.
Petrol handles the first job badly and the second not at all. The rattling comes from petrol being made not to ignite when compressed, which is exactly the opposite of what a diesel needs. On top of that it is thinner than diesel, it strips out the lubrication the system hinges on, and any pump working on that mix is wearing itself.
Taken together, they show the shape the trouble takes. Not contact but circulation is what causes the damage. 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 begun: anything shed by a pump that's grinding travels onward to your injectors with your fuel.
Locharbriggs, petrol in a diesel: four cases, from mild to major
The best case there is: filled up, not once started. On a forecourt, and really only there, that petrol is still limited to the tank — since everywhere else the vehicle was driven to reach it. The job is emptying and cleaning on the spot.
Started for a second, or just your ignition on. Once primed, your system has drawn petrol out of the tank as far as the fuel filter and the fuel lines. Normally nothing more than draining, rinsing and sorting your filter, and so still simple.
Your pump now worked a couple of miles on diluted fuel — that's what driving the vehicle meant. How hard your car was driven counts as much as how far, and the work covers that tank, the lines, your filter and fresh fuel through the entire circuit. On the school run to the local primary school, the miles is short. Any miles on the A74(M), under 10 miles from Locharbriggs, means the motor working hard throughout, and a run to Carlisle, under 50 miles away, makes a very different task too.
Driven until it complained. Rattling, a lumpy idle, smoke, a throttle that has gone soft. What you are hearing is the motor reporting fuel that no longer acts like diesel. Pull up where you are — on the verge on Quarry Road, at the kerb, down a side road — and do not move it again. A vehicle pulled over early very rarely has long-term damage, because the fuel drain and the flush, which still come first, sort it out.
Myths Locharbriggs motorists hear about petrol in a diesel
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It won't. Nothing comes out when you top up — your tank simply carries more of the same blend. The assumption behind the advice — that diesel fuel systems accept petrol by percentage — is wrong.
"Newer diesels can handle a little petrol" — a myth, and closer to the opposite. At higher pressure, through more precise parts: that is how a newer diesel handles its fuel, and so the lubrication matters for more, not less.
This is the one that catches drivers. Myth: "If it starts and drives, there's no harm done." Feed diesel to a petrol motor and it usually won't run, and so the motorist stops — and the harm stops with them. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, as it usually does; meanwhile the pump wears. Fine and running are not the same at all.
Myth: "Add some two-stroke oil and drive it home." It is an outdated fix for a separate problem. What petrol has weakened stays weakened, and that petrol remains in that tank regardless.
The next start sends petrol back round the pump out of the lines and the filter, where some of it ends up after the engine has been run. That's why draining your tank yourself does not sort it — a myth. Also, a can of petrol drained by the kerbside is genuinely dangerous.
Why petrol in a diesel takes place at all
Carelessness is rarely the cause, and nobody means to do it. The petrol nozzle is the smaller 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 mistake runs one way.
Habit and the vehicle falling out of step is when it happens. Any motor that's new to you — a hire car, on loan as a courtesy car, or just bought. Two motors on one drive, one petrol, one diesel. The pumps in a different order on a familiar forecourt. A rushed fill en route to Dumfries with a train to catch. The first fill-up in a diesel Volkswagen Golf after years of driving petrol is exactly the moment it occurs. Your hand repeats what it has always done once you add rain, a phone call or a back seat full of children.
Locharbriggs motorists: how to prevent petrol in a diesel next time
- Green for unleaded and black for diesel is usual in the UK — but not on every forecourt. Trust the label on the pump, not the colour.
- Many motors state the fuel type inside your filler flap or on the cap, so check there on the first fill in any vehicle you do not 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.
- "Diesel", aloud, before you lift the nozzle — each time a new or hired car needs its first tank. It sounds daft. It works.
- Thinking about something else is when this becomes an easy mistake to make, and so tuck the phone away then keep your mind on the petrol pump.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler designed to block a petrol nozzle, and add-on devices are available for motors without one. They are a backstop, not a reason to stop reading the petrol pump.
- Stop as soon as you realise. Less petrol in the tank means a thinner mixture. It doesn't change what to do next, which is still not to fire it up.
Petrol already in a diesel in Locharbriggs? Begin here
Short and simple, then, is the order of things. Never crank it, and do not turn your ignition on. Still on the forecourt, at Esso or anywhere else? Ask the attendants to help you push the car away from the pump. Then call 0333 366 0103 and tell us what was put in, roughly how much, and if it has run.
If it was AdBlue and not petrol, say so. That is a different issue — corrosion and deposits instead of lost lubrication — and it has its own page for Locharbriggs.
Locharbriggs petrol in a diesel jobs: why one costs more than another
Four separate tasks sit behind the four scenarios above — which is why there's no fair single price. What moves your cost is mostly which of them you're in. The proportion matters next, meaning how much of the tank is petrol, followed by the position of the car and whether getting to it is safe for a van.
Ahead of any quote, not after, come three questions: your fuel that was put in, its quantity, and if it has run. That is why. Those answers are what turn a range into one firm number.
About Locharbriggs itself
Locharbriggs is a village situated on the banks of a river in Dumfries and Galloway, with a mix of terraced housing and other residential properties. Locharbriggs sits at a relatively low elevation of 27 metres, near the towns of Heathhall and Tinwald. Locharbriggs is located close to the English border, with the city of Carlisle just 29.6 miles away. Locharbriggs has a population of around 1506 people, making it a small but established community.
Fuel drain cover across Dumfries and Galloway, Locharbriggs included
Petrol in diesel call-outs around Locharbriggs — part of the DG postcode area — go to vans that likewise cover the locations about it, Heathhall, Tinwald and The Grove included. The vehicle doesn't need to come to us: we drain on a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
Still at the pump around Locharbriggs?
In that case, you could not be in a better spot. Keep it off. Phone.