How Worried Should You Be? Petrol in a Diesel Car in Ewshot
Provided it has not been started, worry far less than you likely are. "Have I ruined it?" is the first question everyone in Ewshot asks, and the honest answer is generally no, since petrol left in a diesel tank harms nothing until it's dragged through the fuel system — by ignition priming, by your starter, or by being driven. Petrol in Diesel is who to ring, with your motor kept off, and so it stays that way. What petrol actually does to a diesel, how to gauge how far it's gone, and how to keep it from happening a second time: that is the remainder of this page.
Petrol in a diesel: what does it do to the motor?
Diesel has two jobs on its way through an engine. Lubricating comes before burning; it does both. Very fine clearances are built into your injectors and the high-pressure fuel pump, and just the 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 out the protection a fuel system needs, leaving a pump running on the mixture to wear itself. It is also made to resist igniting under compression — the opposite of what a diesel needs — which is where you hear the knocking.
Together, those make the shape of the trouble plain. It is circulation that does the damage, not contact. All a tank with petrol in it amounts to is a fuel fault. The start of a mechanical problem is a pump that has been working on that petrol — and whatever a worn pump sheds travels on with your fuel to the injectors downstream.
Ewshot, petrol in a diesel: four cases, from mild to major
Filled but not once started — as good as it gets. On a forecourt, and really only there, the petrol is still confined to that tank — because everywhere else your car was driven to get to it. The job is emptying and purging on the spot.
A brief spell of running, or merely your ignition on. With the fuel system primed, the fuel lines and filter now hold petrol that has come from that tank. Normally nothing more than clearing, rinsing and seeing to the filter, so still easy.
Your pump has worked a few miles on weakened fuel — that's what driving it meant. The work is the tank, your lines, the fuel filter and fresh fuel through the whole system, and how hard your car was driven matters as much as how far. A school run to Folly Hill Infant Academy is one thing. Very different a second time: a trip to Winchester, under 25 miles away, or any distance on the M3, under 5 miles from Ewshot, where the motor never stopped labouring hard.
It complained, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone ragged. What you are hearing is your engine signalling fuel that no longer runs like diesel. Pull up wherever you are — the verge on Church Lane, a lay-by, a side street — and leave the car there. Long-term damage is very unusual when a vehicle is stopped quickly, and the fuel drain and flush-through that still go first deal with it.
Myths Ewshot drivers hear about petrol in a diesel
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. Topping up removes nothing; it gives you a fuller tank of the same mixture. A diesel fuel system doesn't tolerate petrol by percentage in the way that advice presumes.
"Newer diesels can handle a little petrol" — a myth, and closer to the opposite. At higher pressure, through smaller components: that is how a modern diesel moves its fuel, and so the lubrication counts for more, not less.
Myth: "If it starts and drives, there's no harm done." This is the one that fools drivers. Diesel in a petrol motor generally means a motor that won't run: the motorist stops, and so does the harm. Whilst the pump grinds, a diesel fed petrol normally starts, ticks over and drives away as if nothing has happened. Running isn't the same as fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a distinct issue. What petrol has diluted remains diluted, and that petrol stays in your tank anyway.
Myth: "Drain your tank yourself and you are sorted." Once the engine has been run, some of that petrol is no longer in your tank: it is in your filter and the fuel lines, and it goes straight back through your pump on the next start. On top of that, petrol cleared into a can by the road is truly risky.
How petrol ends up: petrol in a diesel
It's rarely carelessness, and nobody does it on purpose. The petrol nozzle is the slimmer of the two and slides into a diesel filler with almost no resistance; a diesel nozzle generally will not go into a petrol car at all. The forecourt makes it simple, and the error runs one way.
Habit and the vehicle falling out of step is when it occurs. Hire cars, courtesy cars, and motors that are new to you. Two motors on one driveway, one petrol, one diesel. A well-known forecourt with the pumps in a different order. A train to catch, and a rushed fill en route to Farnham. The first fill-up in a diesel Volkswagen Passat after years of driving petrol is exactly the moment it occurs. Add a back seat full of kids, a phone call or rain, and habit takes over.
Next time you fill up in Ewshot: avoiding petrol in a diesel
- Read the petrol pump, not the colour. In the UK unleaded handles are generally green and diesel black, but not on every forecourt. The label is what matters.
- In a motor you do not know, look inside the flap over the filler or at the cap before your first fill: plenty of motors print the fuel type there.
- Mark your key. In a household with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of intending to remember.
- "Diesel", out loud, before you lift the nozzle — each time a new or hired car needs its first tank. It seems silly. It does the trick.
- Mistakes like this are straightforward to make while your mind is on something else, and so your phone goes away.
- Add-on devices are available for vehicles without one, and some diesels come with a filler that won't accept a petrol nozzle. Helpful — but a safety net at best, never a reason to stop checking the label.
- As soon as you realise, stop: less petrol inside your tank means a weaker mixture. What to do next does not change, though — still don't start it.
Already put petrol in a diesel in Ewshot?
Then the order of things is short. Never start the car, and do not switch your ignition on. The staff on the forecourt — whether at Shell itself or wherever you filled up — will usually help roll it away from the pump if you ask. Then phone 0333 366 0103 and tell us what got in, roughly how much, and if it's run.
If it was AdBlue rather than petrol, say so. That is a different problem — corrosion and deposits rather than lost lubrication — and it has its own page for Ewshot.
Why one petrol in a diesel task around Ewshot costs more than another
Four separate jobs lie behind the four scenarios above — which is why there is no fair single quote. The situation itself does most of the work of moving your cost. The share matters 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 van.
Three questions come first, before any quote, instead of after — what got in, how much, has it run — and this is the reason. The answers turn a range into a straight figure.
About Ewshot, for a moment
Ewshot is a small village in Hampshire, situated inland at an elevation of 169 metres, with detached housing being the predominant type of accommodation. Ewshot lies near the villages of Warren Corner, Redlands, and Doras Green, and is approximately 24 miles from the city of Winchester. Ewshot is also within commuting distance of London, being around 35 miles from the capital. Ewshot has a population of around 654 residents.
Across Hampshire and around Ewshot: fuel drain cover
Ewshot sits in the GU postcode area, and the teams that answer petrol in diesel call-outs there work the locations around it as well — Warren Corner, Redlands and Doras Green among them. A forecourt, a supermarket car park, a lay-by or your own driveway are all locations we drain, and the vehicle does not need to come to us.
Ewshot: still at the petrol pump?
No position is better: that's where you are. Switched off it remains; then phone.