Should You Worry? Petrol in a Diesel Car in Newtown
Likely less than you are now — as long as nobody has started the vehicle. Petrol resting in a diesel tank does nothing to the motor till something pulls it through the fuel system — the ignition priming the pump, your starter, or driving itself. So the honest answer to the first query everyone around Newtown asks, "have I wrecked it?", is normally no. Keep it that way: leave your engine off then phone Petrol in Diesel. Further down, this page sets out what petrol actually does inside a diesel, how far it might have got, and how to stop it happening to you again.
Petrol in a diesel: what does it do to the engine?
Diesel does two tasks on its way through a motor. It lubricates to begin with, and after that does it burn. The high-pressure pump and the injectors are built to very fine tolerances, and your diesel passing through them is what keeps those surfaces from wearing against one another.
Poorly at the first, not at all at the second: that is petrol. It is runnier than diesel and takes away the lubrication the system depends on, and so a pump running on a petrol mixture is a pump wearing itself. And petrol is made to resist igniting under compression, which is the opposite of what a diesel needs from its fuel. That's where the knocking comes from.
The shape of the problem is clear once you put those together. Contact does not do the damage — movement does. Where the petrol is only in the tank, it's an issue of fuel, nothing more. The start of a mechanical problem is a pump that has been labouring on that petrol — and whatever a worn pump sheds moves on with the fuel to the injectors beyond it.
Four situations our engineers see around Newtown: how bad is petrol in a diesel?
Fuelled, and never started: no case is better. Being on a forecourt is what makes this possible: elsewhere, your car has been driven there to begin with. With the petrol kept in your tank alone, it's cleared and flushed right where it stands, and nothing more is needed.
A moment's running, or just your ignition on. Once primed, the system has drawn petrol out of that tank up to the filter and the lines. Normally little more than clearing, flushing and seeing to the fuel filter, and so still simple.
A few miles driven, and your pump has spent every one of them running on thinned fuel. Tank, lines, filter, then clean fuel put through the entire system: that's this work, and the way the vehicle was driven counts as much as the miles. A school run to Layston Church of England First School is one matter. Very different again: a trip to Cambridge, under 25 miles away, or any miles on the A1(M), under 10 miles from Newtown, where the engine kept running hard.
Driven on until it protested — clattering, smoke, a ragged idle, a dead throttle. What you are hearing is the engine signalling fuel that no longer acts like diesel. Leave it where it has stopped: a lay-by, a side street, the verge on Paddock Road. Lasting damage is very unusual when a vehicle is pulled over quickly, and the fuel drain and flush-through that still come first take care of it.
What Newtown motorists get told about petrol in a diesel — and the stories in it
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It won't. Nothing is removed when you top up — that tank simply holds more of the same blend. A diesel fuel system doesn't tolerate petrol by percentage in the way that guidance presumes.
Myth: "A modern diesel can cope with a bit of petrol." If anything, the opposite. A newer diesel runs its fuel through smaller components at higher pressure, which makes the lubrication matter more, not less.
One myth that catches people out: if it starts and drives, it must be unharmed. Diesel in a petrol motor normally means a motor that won't run: the motorist stops, and so does the harm. A diesel fed petrol generally starts, idles and drives away as if nothing has happened, whilst your pump wears. Running is not the same as fine.
Not so: a two-stroke additive lets you to drive home. It is an old fix, supposed for another fault. None of what petrol thinned is put back by it — and later, that tank still holds that petrol.
The next start draws petrol back round the pump out of your lines and the filter, where some of that ends up after the motor has been run. That's why draining the tank yourself does not sort it — a myth. It's also genuinely hazardous to drain petrol into a can by the kerbside.
How petrol ends up: petrol in a diesel
On purpose? Never. Through carelessness? Rarely, if ever. One way only, since of the nozzles: the slimmer petrol one slips inside a diesel filler with almost no resistance, while the diesel one mostly won't fit a petrol vehicle. That's how the forecourt makes it easy.
When habit and the car stop matching, it occurs. Courtesy car, hire car, or a motor that's new. Two motors on one driveway, one petrol, one diesel. Your normal forecourt, its pumps suddenly in a different order. A train to catch, and a hurried fill en route to Ashwell & Morden. A new-to-you diesel Volkswagen Golf, its first fuelling, and a motorist used to petrol: exactly when it occurs. Add a back seat full of kids, a phone call or rain, and habit takes over.
Next time you fill up around Newtown: preventing petrol in a diesel
- Green for unleaded and black for diesel is normal in the UK — yet not on every forecourt. Go by the label on the pump, not the colour.
- Check your filler flap. Many motors state the fuel inside the flap or on the cap. Look at it on your 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 meaning to remember, in a household with one of each.
- It sounds daft and it works: on the first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the petrol pump.
- Thinking about something else is when this becomes an easy mistake to make, so tuck 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 refuse a petrol nozzle, and add-on devices exist for the rest. Count it as a backstop, then keep reading the petrol pump.
- As soon as you notice, stop: less petrol inside your tank means a thinner blend. What to do next does not change, though — still do not start the vehicle.
Petrol already in a diesel in Newtown? Start here
Short and simple, then, is the order of things. Don't crank it, and do not turn your ignition on. If you are still at the forecourt — Esso or anywhere else — ask the attendants to help you roll the vehicle away from the pump. Next, 0333 366 0103. We'll ask what got in, roughly how much, and if it's been run.
If it was AdBlue rather than petrol, say so. That is a separate fault — corrosion and deposits rather than lost protection — and it has its own page for Newtown.
Newtown petrol in a diesel tasks: why one costs more than another
Four different jobs lie behind the four situations above — which is why there is no honest single quote. What shifts your cost is chiefly which of them you are in. Where the vehicle is matters too, and whether a van can safely reach it, after the ratio of petrol to what your tank takes.
Three questions come first, before quoting, rather than after — what got in, how much, has it run — and this is the reason. A range turns into a straight figure when the replies are in.
About Newtown, for a moment
Newtown is a suburban area in Hertfordshire, situated on the riverside at an elevation of 99 metres. Newtown lies approximately 30.9 miles from London and 18.6 miles from Cambridge, with nearby places including Buntingford, Aspenden, and Wyddial. Newtown has a population of around 4066 people, predominantly living in semi-detached housing. Newtown is characterized by its residential community and proximity to the surrounding countryside.
Fuel drain cover across Hertfordshire, Newtown included
The vans answering petrol in diesel jobs in Newtown, in the SG postcode area, equally work the locations around it, Buntingford, Aspenden and Wyddial among them. The car does not need to move to us: we drain at a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
At the pump around Newtown, right now?
The best spot there is, then — that is where you are. Leave it switched off, and ring.