Fairview: Petrol in a Diesel Car? How Worried to Be
Not started? Then less worried than you probably are. "Have I ruined it?" is the first question anyone in Fairview asks, and the honest answer is normally no, since petrol resting in a diesel tank hurts nothing until it is dragged through the system — by ignition priming, by the starter, or by being driven. Petrol in Diesel is who to call, with your engine left off, and so it stays that way. The rest of this page explains 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 the engine
Diesel has two jobs on its way through an engine. Before it combusts, it protects — then it ignites. The high-pressure fuel pump and the injectors are designed to very fine tolerances, and the diesel passing through them is what stops those surfaces from wearing against one another.
Of these two jobs, petrol manages the first poorly and the second never. A pump working on a petrol blend is wearing itself out, since petrol is thinner than diesel and strips out the lubrication the fuel system relies on. Petrol is also designed to resist igniting under compression — the reverse of what a diesel needs from its fuel — and that is where any clattering starts.
The shape of the trouble is plain once you put those together. Contact does not do the damage — circulation does. All a tank with petrol in it amounts to is a fuel fault. A pump that has been working on that petrol is the start of a mechanical one, and whatever a worn pump sheds moves on with your fuel to your injectors further on.
Fairview, petrol in a diesel: four situations, from mild to major
Fuelled up, not once started. The best case there can be. Being at a forecourt is what makes this possible: elsewhere, your car has been driven there to begin with. With the petrol kept in the tank alone, it is emptied and flushed on the spot, and nothing more is needed.
A moment's running, or merely your ignition on. With the fuel system primed, the lines and filter now contain petrol that came from your tank. Drain, flush, see to the filter: still normally straightforward.
Those few miles driven were the pump labouring on fuel weakened by petrol throughout. Distance is only half of that; how hard it was driven counts equally. Either way this work runs to the tank, the fuel lines, the filter and fresh fuel through the entire circuit. Driving the children to Holy Trinity Church of England Primary School is one sort of trip. Getting as far as Gloucester, under 10 miles away, makes a very different job — as does any distance on the M5, under 5 miles from Fairview, with the engine labouring hard all the way.
It complained, and only then stopped: smoke, knocking, a throttle gone soft, an idle gone uneven. That is your motor telling you its fuel has stopped acting like diesel. Stop on the spot — on the verge on All Saints Villas Road, at the kerb, down a side road — and don't move it. What comes first is still the drain and flush, and that deals with it, with long-term damage very uncommon when a vehicle is pulled over quickly.
Fairview drivers and that petrol in a diesel stories they hear
It will not be fine. The myth: "Fill it the rest of the way with diesel and it will be." Nothing comes out when you top up — the tank just carries more of the same mixture. Percentage isn't how a diesel fuel system copes with petrol, whatever that advice assumes.
"Modern diesels can handle a little petrol" — a myth, and closer to the opposite. More precise parts and higher pressure are how a current diesel runs its fuel, and that makes the lubrication matter more, not less.
"It starts, it drives, and so no harm done" — the myth that trips up more drivers than any other. Feed diesel to a petrol motor and it normally will not run, so the driver stops — and the harm stops with them. Feed petrol to a diesel and it usually starts, idles and pulls away as if nothing has happened — all while its pump is wearing. Running isn't the same as fine.
Myth: "Add some two-stroke oil and drive the car home." It's an old fix for a separate fault. What petrol has diluted stays weakened, and the petrol stays in your tank anyway.
The next start sends petrol back round the pump from your lines and the filter, where some of it sits once your engine has run. That's why draining the tank yourself does not leave you sorted — a myth. Draining petrol into a can by the kerbside is also genuinely risky.
How petrol ends up: petrol in a diesel
It is seldom carelessness, and nobody does it on purpose. 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 vehicle at all. The forecourt makes it simple, and the error runs one way.
The moment habit stops matching your car is the moment it happens. A new vehicle, a hire car or a courtesy car. Households running one of each, petrol and diesel. Your usual forecourt, its pumps suddenly in a different order. A train to catch, and a hurried fill on the way to Cheltenham Spa. A new-to-you diesel Volkswagen Tiguan, its first fuelling, and a motorist accustomed to petrol: exactly when it takes place. Throw in a back seat full of children, a phone call or rain, and habit takes over.
Fairview motorists: how to avoid petrol in a diesel next time
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, even if most generally do. Read the petrol pump's label; the colour is just a clue.
- The first fill in a new car is the time to check the filler flap — on it, or on the cap, many motors state the fuel to use.
- Good intentions do less than a sticker or a fob in a bright colour on the diesel's key when a house has one of each. So label it.
- Before the nozzle leaves the petrol pump the first time you fill a hired or new car, say "diesel" out loud. Silly, perhaps, but it works.
- Whilst you are thinking about something else, this is an easy mistake to make — so tuck your phone away.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler built to reject a petrol nozzle, and add-on devices are available for the remainder. Treat it as a backstop, then keep reading the petrol pump.
- Noticing it mid-fill? Stop there and then. A weaker mixture follows from less petrol in your tank, yet the next stage stays the same: don't start it.
Already put petrol in a diesel around Fairview?
Then, there's only a short order of things. Do not fire it up, and do not switch the ignition on. Yet at the forecourt, at BP or anywhere else? Ask the staff to help you roll it clear of the pump. Then call 0333 366 0103 and tell us what was put in, about how much, and whether it's run.
Say so if it was AdBlue instead of petrol: it is a separate fault, with its own page for Fairview, since AdBlue brings corrosion and deposits instead of lost lubrication.
What makes one Fairview petrol in a diesel task cost more than the next
A fair single price does not exist here: four scenarios, four separate jobs. What shifts the cost is mostly which of them you're in. Where the vehicle is matters too, and whether a technician can safely get to it, after the ratio of petrol to what the tank takes.
Ahead of any quote, not after, we ask three queries: your fuel that went in, the amount, and whether it's run. That's why. A range becomes a straight figure when those answers are in.
About Fairview, briefly
Fairview is a suburban area in Gloucestershire, situated on the riverside at an elevation of 67 metres, with a mix of residential and local amenities. Fairview lies close to the city of Gloucester, approximately 8 miles away, and is also near other nearby places such as Whaddon and Cheltenham. Fairview has a population of around 10090 people, predominantly residing in flats. Fairview is located within the wider South West region, about 87 miles west of London.
Fairview and Gloucestershire: where our fuel drain cover runs
The teams answering petrol in diesel calls around Fairview, in the GL postcode area, equally work the spots around it, Whaddon, Cheltenham and Coltham Fields included. The car does not need to come to us: our engineers drain at a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
Fairview: still at the petrol pump?
No position is better: that is where you now are. Keep the car switched off, then ring.