Petrol in a Diesel Car in Highfield: How Worried Should You Be?
Far less than you likely are, provided it hasn't been started. Everyone in Highfield starts with "have I wrecked it?", and the fair answer is usually no: petrol left in the tank of any diesel remains harmless till priming, cranking or driving draws it into the system. To leave the vehicle that way, ring Petrol in Diesel then leave the motor switched off. The remainder of this page covers what petrol actually does to a diesel, how to tell how far it has got, and how to make sure it doesn't happen to you again.
Petrol in a diesel: what does it do to the engine?
On its way through a motor, diesel does two tasks. It combusts, and before it burns it protects. What stops the surfaces inside the high-pressure pump and the fuel injectors from wearing down against each other is your diesel flowing through them — they are designed to extremely fine tolerances.
Of those two jobs, petrol manages the first poorly and the second never. A pump running on a petrol blend is wearing itself out, because petrol is runnier than diesel and takes away the protection the fuel system depends on. Petrol is also designed to resist igniting under compression — the opposite of what a diesel needs from its fuel — and that is where any knocking comes.
Together, those make the shape of the problem plain. Contact does not do the damage — movement does. All a tank with petrol in it amounts to is a fuel problem. The start of a mechanical problem is a pump that has been running on that petrol — and whatever a worn pump sheds moves on with your fuel to the fuel injectors beyond it.
How bad is petrol in a diesel? Four situations our technicians see around Highfield
The best case there can be: filled up, never started. At a forecourt, and truly only there, the petrol is still limited to your tank — since everywhere else the car was driven to reach it. The task is draining and purging on the spot.
The ignition turned on, or a brief start. Your system has been bled, and so petrol has left that tank and reached the filter and your lines. Drain, flush, see to the filter: still normally simple.
Some miles driven, and your pump has spent every one of them working on weakened fuel. How hard the car was driven counts as much as how far, and the work takes in your tank, the fuel lines, your filter and fresh fuel through the whole system. Short trips, such as the school run to Brookside Primary School, are one matter. Driving as far as Oxford, under 15 miles away, makes a very different job — as does any mileage on the M40, under 3 miles from Highfield, with your engine labouring hard the whole time.
Driven till it complained. Knocking, a lumpy idle, smoke, a throttle that has gone soft. What you are hearing is the motor reporting fuel that no longer acts like diesel. Stop wherever you are — the verge on Graham Road, a lay-by, a side street — then leave the vehicle there. A car stopped quickly very seldom has long-term damage, because the drain and the flush, which still go first, sort it out.
Petrol in a diesel stories Highfield motorists hear
"Top it up the rest of the way with diesel and it will be fine" — a myth. It won't. Nothing comes out when you top up — that tank just holds more of the same blend. The assumption behind the advice — that diesel fuel systems accept petrol by percentage — is wrong.
If anything, the reverse is true. Myth: "A newer diesel can cope with a bit of petrol." At higher pressure, through more precise components: that's how a current diesel moves its fuel, so the lubrication counts more, not less.
"It starts, it drives, and so there is no harm" — the myth that trips up most motorists than any other. The driver of a petrol motor fed diesel normally has no choice but to stop, because it will not run, and the harm stops there. Feed petrol to a diesel and it generally fires up, idles and drives away like nothing happened — all the while its pump is wearing. A running engine doesn't mean fine.
Myth: a two-stroke additive makes it safe to drive home. It is an old workaround, meant for another problem. That petrol is still in that tank afterwards, and whatever it has weakened is not put back.
The next start draws petrol back round your pump from the lines and your filter, where some of it ends up after the motor has been run. That's why draining your tank yourself does not sort it — a myth. And, a can of petrol drained at the kerbside is truly risky.
How does petrol in a diesel take place?
A careless moment is rarely the cause, and no one means to do it. A diesel nozzle mostly won't go into a petrol car, but the narrower petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one error straightforward, and only in one direction.
When routine and your car stop matching, it happens. Courtesy car, hire car, or a car that is brand new. A household with one petrol and one diesel on the driveway. The pumps in a different order on a well-known forecourt. A train to catch, and a hurried fill on the way to Bicester North. Years of petrol cars behind you, a diesel Renault Megane in front of you on the forecourt for its first tank — that is when. Your hand does what it has always done when you add rain, a phone call or a back seat full of kids.
Highfield drivers: how to avoid petrol in a diesel next time
- The label is what counts, so read the petrol pump instead of the colour: in the UK unleaded handles are usually green and diesel black, but not on each forecourt.
- In a car you don't know, look inside the flap over the filler or at the cap before your first fill: plenty of cars state the fuel there.
- Good intentions do less than a sticker or a fob in a bright colour on the diesel's key if a house has one of each. So label it.
- "Diesel", out loud, before you lift the nozzle — every time a new or hired car gets its first tank. It seems silly. It works.
- Thinking about something else is when this becomes an easy mistake to make, and so tuck your phone away then keep your mind on the petrol pump.
- Some diesels have a filler designed to refuse a petrol nozzle, and devices you can add exist for vehicles without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop reading the petrol pump.
- As soon as you realise, stop: less petrol in the tank makes a weaker blend. What to do next does not change, though — still do not start it.
Highfield: already put petrol in a diesel?
The order of things is brief, then. Don't switch the ignition on, and don't crank it. Ask the staff to help you roll it away from the pump if you are still at the forecourt, whether that's EG On the Move or somewhere else. Next, 0333 366 0103. We'll ask what got in, about how much, and if it's been run.
Corrosion and deposits form the issue with AdBlue, where petrol means lost lubrication. So if it was AdBlue, say so — and read its own Highfield page.
Why one petrol in a diesel task in Highfield costs more than another
Four different tasks lie behind the four situations above — which is why there's no fair single price. The scenario itself does most of the work of moving the cost. Two things come after that: the petrol that got in as a proportion of what that tank holds, then the spot your car is in and whether a van can reach it safely.
Before any quote, not after, we ask three questions: your fuel that was put in, its quantity, and if it's run. That's why. Those answers are what change a range into one firm number.
About Highfield and where it is
Highfield is a suburban area in Oxfordshire, situated inland at an elevation of 79 metres, approximately 11 miles from Oxford and 52 miles from London. Highfield is characterized by its predominantly semi-detached housing stock, with nearby areas including Bure Park, Greenwood, and Woodfield. Highfield has a population of around 6656 residents, making it a moderately sized community in the region.
Highfield and Oxfordshire: where our fuel drain cover runs
Bure Park, Greenwood and Woodfield are among the locations around Highfield that the same vans work, answering petrol in diesel jobs across Highfield's OX postcode area. A forecourt, a supermarket car park, a lay-by or your own drive are all spots we drain, and your car does not need to move to us.
At the pump in Highfield, right now?
Then you're in the best spot there is. Keep the vehicle turned off, then ring.