Bulbery: Petrol in a Diesel Car? How Worried to Be
Probably less than you are now — provided no one has started the car. Everyone in Bulbery begins with "have I wrecked it?", and the honest answer is usually no: petrol resting in that tank of any diesel stays harmless till priming, cranking or driving draws it into your fuel system. Keep it that way: leave the motor off then ring Petrol in Diesel. The rest of this page covers what petrol actually does to a diesel, how to judge how far it has got, and how to make sure it does not happen to you again.
What petrol in a diesel does to your engine
Passing through a motor, diesel does two jobs at once. It lubricates to begin with, and only then does it burn. Built to very fine gaps, the injectors and the pump rely on your diesel flowing through them to keep their surfaces from wearing against one another.
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, so a pump running on that mixture wearing itself. It is also made to resist igniting under compression — the reverse of what a diesel needs — which is why you get the rattling.
The shape of the issue is plain once you put those together. Not contact but movement is what does the harm. A tank with petrol in it is a fuel fault. A pump that has been running on that petrol is the beginning of a mechanical one, and whatever a worn pump sheds travels on with your fuel to the injectors further on.
Four situations our technicians see around Bulbery: how serious is petrol in a diesel?
Filled but never started — as good as it gets. On a forecourt, and really only there, that petrol is still limited to your tank — since anywhere else the car was driven to reach it. The job is emptying and cleaning on the spot.
A moment's running, or merely the ignition on. Once primed, your system has pulled petrol from that tank up to the fuel filter and the lines. Drain, flush, deal with the filter: still usually straightforward.
Your pump now spent a few miles on thinned fuel — that is what driving it does. The work is that tank, the fuel lines, your filter and clean fuel through the entire circuit, and how hard the car was driven counts as much as how far. On the school run to Abbotts Ann Church of England Primary School, the mileage is short. A run as far as Winchester, under 15 miles away, is a very different task. So is any miles on the M3, under 15 miles from Bulbery, where your engine has been working hard throughout.
It protested, and only then stopped: smoke, knocking, a throttle gone soft, an idle gone uneven. What you are hearing is your motor signalling fuel that no longer behaves like diesel. Whether it's the verge on Timothy's Field, a lay-by or a side street, stop where you are and leave it. The fuel drain and flush-through still come first, and they take care of it: if a vehicle is stopped early, long-term damage is very uncommon.
What Bulbery motorists get told about petrol in a diesel — and the myths in it
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It will not. Nothing is removed by topping up — you are left with a fuller tank, still the same mix. Percentage isn't how a diesel fuel system tolerates petrol, whatever that guidance presumes.
If anything, the reverse is true. Myth: "A current diesel can cope with a bit of petrol." A modern diesel runs its fuel through smaller components at higher pressure, which makes the lubrication matter more, not less.
One myth that catches drivers off guard: if it starts and drives, it must be unharmed. The motorist of a petrol engine fed diesel normally has no choice but to stop, since it will not run, and the harm stops there. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually will; meanwhile your pump grinds. Being able to run isn't proof of being fine.
Myth: "Add some two-stroke oil and drive the car home." It is an outdated workaround for a different issue. What petrol has thinned stays diluted, and that petrol stays in that tank anyway.
The next start draws petrol back round the pump out of the fuel lines and the fuel filter, where some of that sits once your engine has run. That's why a DIY tank drain doesn't leave you sorted — a myth. Emptying petrol into a can at the roadside is also genuinely dangerous.
How petrol ends up: petrol in a diesel
No one does it on purpose, and it is seldom carelessness. The petrol nozzle is the smaller of the two and slides into a diesel filler with almost no resistance; a diesel nozzle mostly will not go into a petrol motor at all. The forecourt makes it simple, and the slip runs one way.
It happens when routine and the car stop matching. Any vehicle that's new to you — a hire car, on loan as a courtesy car, or brand new. Households running one of each, petrol and diesel. A familiar forecourt with the pumps in a different order. A rushed fill on the way to Andover with a train to catch. The first fill-up in a diesel Skoda Octavia after years of driving petrol is precisely the moment it takes place. Your hand does what it has always done once you add rain, a phone call or a back seat full of children.
Next time you fill up in Bulbery: preventing petrol in a diesel
- A green handle for unleaded and black for diesel is usual in the UK — yet not on every forecourt. Go by the label on the petrol pump, not the colour.
- The first fill in a strange motor is the time to check your filler flap — on it, or on the cap, plenty of motors state which fuel they take.
- One of each in the household? Mark the key to the diesel — a coloured fob, a sticker — because meaning to remember is not enough.
- "Diesel", aloud, before you lift the nozzle — every time a new or hired car gets its first tank. It seems daft. It does the trick.
- Whilst you are thinking about something else, this is an easy mistake to make — so put your phone away.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler built to block a petrol nozzle, and add-on devices exist for vehicles without one. They are a backstop, not a reason to stop checking the petrol pump.
- Stop the moment you notice. Less petrol inside your tank means a thinner blend. It doesn't change what to do next, which is still not to start the car.
Petrol already in a diesel in Bulbery? Begin here
Then, there is just a short order of things. Starting it is out, and so is switching on your ignition. Ask the attendants to help you push it clear of the pump if you're still at the forecourt, whether that is Shell or anywhere else. Next, 0333 366 0103. We will ask what was put in, roughly how much, and if it's been run.
If it was AdBlue instead of petrol, say so. That's a separate issue — corrosion and deposits and not lost lubrication — and it has its own page for Bulbery.
One petrol in a diesel task around Bulbery costs more than another. Why?
An honest single quote doesn't exist here: four scenarios, four separate jobs. What moves the cost is chiefly which of them you're in. The share counts next, meaning how much of that tank is petrol, and then the location of your car and whether reaching it is safe for a van.
Three questions come first, before any quote, rather than after — what was put in, how much, has it run — and this is the reason. Those answers are what change a range into one firm number.
About Bulbery, briefly
Bulbery is a suburban area situated on the riverside in Hampshire, with an elevation of around 80 metres. Bulbery lies near the cities of Winchester and Southampton, and is surrounded by smaller villages such as Abbotts Ann and Little Ann. Bulbery has a population of approximately 929 residents, who mostly live in detached houses. Bulbery is located about 64.5 miles from London, making it a relatively rural suburb in the South East region.
Across Hampshire and in Bulbery: fuel drain cover
Our vans answering petrol in diesel jobs around Bulbery, in the SP postcode area, equally work the places around it, Abbotts Ann, Little Ann and Red Rice among them. No need to move the vehicle to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all places where we work.
Bulbery: still at the petrol pump?
The best position there is, then — that's where you are. Switched off it stays; then call.