Pyle: Petrol in a Diesel Car? How Worried to Be
Provided it has not been started, worry less than you likely are. Until the ignition primes your pump, the starter turns, or the vehicle is driven, petrol in a diesel tank simply waits there and does no harm. Which makes the honest reply to the first Pyle query — "have I ruined it?" — normally no. Keep it like that: leave the motor off and phone Petrol in Diesel. What petrol really does to a diesel, how to gauge how far it's travelled, and how to keep it from happening a second time: that's the rest of this page.
Inside the engine: what petrol in a diesel really does
Passing through a motor, diesel does two things at the same time. Oiling comes before burning; it does both. Very fine tolerances are built into your injectors and the high-pressure pump, and only your diesel flowing through keeps their surfaces from grinding together.
Petrol handles the first task badly and the second not at all. A pump working on a petrol mixture is wearing itself out, since petrol is runnier than diesel and strips out the lubrication your fuel system depends on. Petrol is also designed to resist igniting under compression — the reverse of what a diesel needs from its fuel — and that's where the rattling comes.
The shape of the trouble is plain when you put those together. It's circulation that does the damage, not contact. Petrol in the tank is a fuel fault. The beginning of a mechanical problem is a pump that has been running on that petrol — and whatever a worn pump sheds moves on with the fuel to your injectors downstream.
Four situations we see in Pyle: how bad is petrol in a diesel?
Fuelled, and never started: no case is better. That petrol is inside the tank and only that tank, and the job is a drain and a flush where the vehicle sits. This is the one scenario that can only really occur at a forecourt, since anywhere else the vehicle has been driven to get there.
Started for a second, or just your ignition on. With the fuel system primed, the lines and filter now contain petrol that has come from your tank. Drain, flush, see to your filter: still normally straightforward.
Driven a couple of miles. Now your pump has spent these miles labouring on weakened fuel. Tank, lines, filter, then fresh fuel put through the whole circuit: that is the work, and the way the vehicle was driven counts as much as the miles. The school run to the local primary school is one matter. Getting as far as Swansea, under 15 miles away, makes a very different job — as does any distance on the M4, under a mile from Pyle, with the engine labouring hard the whole time.
It protested, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone uneven. That's your engine telling you its fuel has stopped behaving like diesel. Whether it's the verge on Ffald Road, a lay-by or a side road, stop there and leave it. The drain and flush still go first, and they sort it out: when a vehicle is stopped quickly, permanent damage is very unusual.
Stories Pyle motorists hear about petrol in a diesel
"Top it up the rest of the way with diesel and it will be fine" — a myth. It will not. A fuller tank of the same mixture is all it gives, since topping up removes nothing. The idea behind the advice — that diesel fuel systems accept petrol by percentage — is wrong.
If anything, the reverse holds. Myth: "A current diesel can cope with a bit of petrol." Smaller parts and higher pressure are how a current diesel runs its fuel, and that makes the protection matter more, not less.
This is the one that fools drivers. Myth: "If it starts and drives, there is no harm done." The motorist of a petrol motor fed diesel normally has no choice but to stop, since it will not run, and the harm stops with them. Feed petrol to a diesel and it generally starts, ticks over and drives away like nothing has happened — all while its pump is wearing. Being able to run is not the same as being fine.
Not so: a two-stroke additive makes it safe to drive home. It is an old fix, meant for another issue. It does not put back what petrol has thinned, and the petrol is still in your tank afterwards.
The next start draws petrol back round your pump out of the lines and your filter, where some of that ends up after the engine has been run. That is why a DIY tank drain does not sort it — a myth. On top of that, petrol cleared into a can by the road is genuinely risky.
Why petrol in a diesel takes place so easily
It's 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 mostly won't go into a petrol motor at all. The forecourt makes it easy, and the slip runs one way.
The moment routine stops matching the vehicle is the moment it takes place. Hire cars, courtesy cars, and vehicles that are new to you. One petrol and one diesel on the drive of the same household. Your ordinary forecourt, its pumps now in a different order. Racing for a train at the nearest station and filling up en route. Precisely the moment it occurs: after years of driving petrol, a driver fills a diesel Skoda Octavia for the first time. Throw in rain, a phone call or a back seat full of children, and your hand repeats what it has always done.
Next time you fill up in Pyle: preventing petrol in a diesel
- Check the petrol pump, not the colour. In the UK unleaded handles are generally green and diesel black, but not on each forecourt. The label is what counts.
- In a motor you don't know, look inside the flap over your filler or at the cap before the first fill: plenty of vehicles state the fuel type there.
- Mark the key. In a home with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of intending to remember.
- It sounds daft and it does the trick: on the first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the pump.
- Put your phone away. This is an easy mistake to make while you're thinking about something else.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler designed to block a petrol nozzle, and aftermarket devices exist for the remainder. Treat it as a backstop, then keep reading the petrol pump.
- The moment you realise, stop: less petrol inside your tank means a thinner mixture. What to do next doesn't change, though — still do not start the car.
Pyle: already put petrol in a diesel?
Short and simple, then, is the order of things. Don't start the car, and do not turn your ignition on. The attendants on the forecourt — whether at Asda itself or wherever you filled up — will normally help push it clear of the petrol pump if you ask. 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's a different problem — corrosion and deposits and not lost protection — and it has its own page for Pyle.
Why one petrol in a diesel job in Pyle costs more than another
There is no fair single price for this, since the four scenarios above are four different jobs. Which of them you're in is mostly what shifts your cost. Next it is the ratio — how much petrol got in against how much your tank holds — and then where your car is and whether a van can reach it safely.
That's why we ask three queries before quoting rather than after: what was put in, how much, and whether it has run. The answers turn a range into a straight figure.
About Pyle and where it is
Pyle is a coastal village in Bridgend, situated near the sandy beaches of the Bristol Channel at an elevation of 37 metres. Pyle lies approximately 12 miles west of Swansea and is surrounded by nearby places such as North Cornelly, Kenfig Hill, and Coedhirwaun. Pyle has a population of around 2791 people and predominantly consists of semi-detached housing. Pyle is located about 153 miles west of London, making it a relatively distant but still accessible community.
Fuel drain cover across Bridgend, Pyle included
Pyle waits in the CF postcode area, and the teams that answer petrol in diesel jobs there work the spots near it as well — North Cornelly, Kenfig Hill and Coedhirwaun among them. You need not move your car to us. Forecourts, supermarket car parks, lay-bys and your own drive are all locations where we work.
In Pyle and still at the petrol pump?
Then, you couldn't be in a better place. Ring, and keep it turned off.