Two Dales: Petrol in a Diesel Car? How Worried to Be
Probably less than you already are — as long as nobody has started it. Everyone around Two Dales starts with "have I wrecked it?", and the fair answer is normally no: petrol resting inside the tank of any diesel stays harmless until priming, cranking or driving pulls it into the system. To leave the car like that, call Petrol in Diesel and leave the motor switched off. What petrol actually does to a diesel, how to judge how far it's travelled, and how to keep it from happening again: that is the remainder of this page.
Inside the motor: what petrol in a diesel really does
Passing through an engine, diesel does two things at once. It lubricates first, and only then does it burn. Built to very fine tolerances, the fuel injectors and the pump depend on your diesel moving through them to keep their surfaces from wearing against one another.
Badly at the first, not at all at the second: that is petrol. The rattling comes from petrol being designed not to ignite when compressed, which is precisely the reverse 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 such a mix is wearing itself.
Put these together and the shape of the problem is plain. It's circulation that causes the damage, not contact. All a tank with petrol in it amounts to is a fuel fault. The beginning of a mechanical one is a pump that has been running on that petrol — and whatever a worn pump sheds moves on with the fuel to the injectors downstream.
Petrol in a diesel around Two Dales: how bad is it? Four cases
Fuelled, and never started: nothing beats it. At a forecourt, and truly only there, the petrol is still limited to the tank — since everywhere else the car was driven to reach it. The task is emptying and flushing on the spot.
The ignition switched on, or a short start. Your system has been primed, and so petrol has left your tank and got to the fuel filter and the fuel lines. Normally nothing more than clearing, rinsing and sorting the filter, so still straightforward.
The pump has spent a few miles on diluted fuel — that's what driving the vehicle does. How hard your car was driven matters as much as how far, and the work covers that tank, the fuel lines, the fuel filter and fresh fuel through the entire system. Driving the children to Darley Dale Primary School is one kind of trip. Very different a second time: a trip to Sheffield, under 25 miles away, or some mileage on the M1, under 15 miles from Two Dales, where the motor kept working hard.
Knocking, an uneven idle, smoke, a throttle gone soft: driven until it complained. The fuel is not behaving like diesel any more, and the engine is telling you. Leave it wherever it stops: a lay-by, a side street, the verge on Wheatley Road. The fuel drain and flush-through still go first, and they take care of it: if a car is stopped soon, permanent damage is very uncommon.
Two Dales people and that petrol in a diesel myths they 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. Percentage is not how a diesel fuel system copes with petrol, however much that guidance assumes.
If anything, the reverse is true. Myth: "A newer diesel can cope with a bit of petrol." More precise parts and higher pressure are how a modern diesel runs its fuel, and that makes the lubrication matter more, not less.
The myth that catches drivers off guard: if it starts and drives, it must be unharmed. Feed diesel to a petrol motor and it generally will not run, so the driver stops — and the harm stops with them. A diesel fed petrol generally starts, idles and drives away as if nothing has happened, whilst your pump grinds. Fine and running are not the same thing.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a distinct problem. That petrol is still in your tank afterwards, and whatever it has thinned isn't put back.
The next start draws petrol back round your pump out of the lines and the fuel filter, where some of that sits once the motor has been run. That's why draining your tank yourself does not leave you sorted — a myth. Emptying petrol into a can by the kerbside is also genuinely dangerous.
Why petrol in a diesel occurs at all
On purpose? Never. Through carelessness? Seldom, if ever. One way only, since of the nozzles: the smaller petrol one slips inside a diesel filler with almost no resistance, whereas the diesel one generally won't fit a petrol car. That is how the forecourt makes it simple.
The moment habit stops matching the vehicle is the moment it takes place. Courtesy car, hire car, or a vehicle that's brand new. Two cars on one driveway, one petrol, one diesel. A forecourt you know, but with its pumps arranged differently. Rushing for a train at Matlock and filling up en route. A new-to-you diesel Renault Clio, its first fuelling, and a driver used to petrol: precisely when it occurs. Add a back seat full of kids, a phone call or rain, and habit takes over.
How to prevent petrol in a diesel on your next fill-up in Two Dales
- Not every forecourt in the UK follows green for unleaded and black for diesel, though most usually do. Check the petrol pump's label; the colour is just a clue.
- Many cars state the fuel type inside your filler flap or on the cap, so check there on the first fill in a vehicle you do not know.
- Good intentions do less than a sticker or a fob in a bright colour on your diesel's key when a household has one of each. So label it.
- "Diesel", out loud, before you lift the nozzle — each time a new or hired car gets its first tank. It seems daft. It does the trick.
- Tuck your phone away. This is an easy mistake to make while you're thinking about something else.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler built to refuse a petrol nozzle, and add-on devices are available for vehicles without one. They are a safety net, not a reason to stop checking the pump.
- The moment you realise, stop: less petrol in the tank means a weaker blend. What to do next doesn't change, though — still don't crank it.
Already put petrol in a diesel around Two Dales?
In that case, there is just a short order of things. Leave it unstarted, with your ignition off too. The staff at the forecourt — whether at Texaco itself or wherever you filled up — will usually help roll it away from the pump if you ask. Then call 0333 366 0103 and tell us what got in, about how much, and whether it has run.
If it was AdBlue rather than petrol, say so. That is a separate issue — corrosion and deposits and not lost protection — and it has its own page for Two Dales.
What makes one Two Dales petrol in a diesel task cost more than the next
The four situations above are four different jobs, so no single quote for this would be honest. What moves the cost is chiefly which of them you're in. The proportion counts next, meaning how much of the tank is petrol, followed by the location of your car and whether getting to it is safe for a technician.
Three queries come first, before quoting, rather than after — what was put in, how much, has it run — and that is the reason. A range becomes a straight figure when those replies are in.
About Two Dales itself
Two Dales is a suburban area situated on the edge of a lake in Derbyshire, with a mix of detached housing and scenic views. Two Dales sits at an elevation of around 120 metres, near the communities of Darley Dale and Upper Hackney. Two Dales is located approximately 15.8 miles from Sheffield and 129.8 miles from London, making it a relatively accessible lakeside location. Two Dales has a population of around 805 residents, living in predominantly detached homes.
Fuel drain cover around Two Dales and across Derbyshire
Petrol in diesel call-outs around Two Dales — part of the DE postcode area — go to vans that likewise cover the places around it, Darley Dale, Darley Hillside and Upper Hackney included. You need not bring the vehicle to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all spots where we work.
Two Dales: still at the pump?
In that case, you couldn't be in a better place. Switched off it remains; then ring.