Petrol in a Diesel Car in Tilley: How Worried Should You Be?
Likely less than you already are — as long as nobody has started it. Everyone around Tilley starts with "have I ruined it?", and the fair answer is usually no: petrol left in the tank of a diesel stays harmless until priming, cranking or driving draws it into your fuel system. To keep the car that way, ring Petrol in Diesel then leave the engine switched off. Below, this page sets out what petrol actually does inside a diesel, how far it may have gone, and how to stop it happening to you a second time.
Inside your engine: what petrol in a diesel really does
On its way through a motor, diesel does two jobs. It protects to begin with, and after that does it burn. What keeps the surfaces inside your high-pressure pump and the injectors from wearing against each other is the diesel flowing through them — they're made to very fine clearances.
The second task petrol doesn't do at all, and the first it does poorly. The clattering comes from petrol being designed not to ignite when compressed, which is precisely the reverse of what a diesel needs. On top of that it is runnier than diesel, it strips away the protection your system depends on, and any pump working on such a mixture is wearing itself.
The shape of the issue is plain once you put those together. Not contact but movement is what does the damage. All a tank with petrol in it amounts to is a fuel issue. A pump that has been running on that petrol is the start of a mechanical one, and whatever a worn pump sheds moves on with the fuel to the injectors downstream.
How serious is petrol in a diesel? Four scenarios our technicians see in Tilley
Filled but not once started — the best it gets. Being on a forecourt is what makes this possible: elsewhere, your car has been driven there to begin with. With that petrol held in your tank alone, it's emptied and flushed on the spot, and nothing more is needed.
Started for a moment, or just your ignition on. With the system primed, your lines and filter now hold petrol that has come from the tank. That's normally still a straightforward task — a drain, a flush, and your filter seen to.
Driven a couple of miles. Now the pump has spent these miles running on weakened fuel. How hard the car was driven counts as much as how far, and this work takes in that tank, the fuel lines, the filter and clean fuel through the entire circuit. Short trips, such as the school run to St Peter's CofE Primary School, are one matter. A run as far as Wrexham, under 25 miles away, is a very different job. So is any miles on the M54, under 15 miles from Tilley, where the engine has been working hard the whole time.
Driven on until it complained — clattering, smoke, a ragged idle, a soft throttle. The engine is telling you your fuel is no longer behaving like diesel. Stop wherever you are — the verge on Shrewsbury Road, a lay-by, a side street — then leave the vehicle where it is. What goes first is still the drain and flush-through, and that sorts it out, with permanent damage very rare when a vehicle is stopped soon.
Stories Tilley people hear about petrol in a diesel
Myth: topping up to full with diesel makes it fine. It doesn't. Nothing is removed by topping up — you are left with a bigger tank, still the same mix. The assumption behind the advice — that diesel fuel systems tolerate petrol by percentage — is wrong.
If anything, the reverse holds. Myth: "A newer diesel can cope with a bit of petrol." Lubrication counts more on current diesels, not less, since their fuel passes through more precise parts at higher pressure.
The myth that catches drivers off guard: if it starts and drives, it must be unharmed. Feed diesel to a petrol engine and it generally will not run, so the motorist stops — and the harm stops with them. Whilst your pump wears, a diesel fed petrol normally starts, idles and drives away as if nothing has happened. Running isn't the same as fine.
Not so: a two-stroke additive makes it safe to drive home. It is an old workaround, supposed for another issue. That petrol is still in that tank after that, and whatever it has thinned is not put back.
Myth: "Drain that tank yourself and you're sorted." Once your engine has been run, some of the petrol is no longer in that tank: it's in the filter and the fuel lines, and it goes right back through the pump at your next start. Besides, petrol cleared into a can by the road is truly risky.
How it happens: petrol in a diesel
Nobody does it on purpose, and it's rarely carelessness. The petrol nozzle is the smaller of the two and slips 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 easy, and the mistake runs one way.
Routine and the vehicle getting out of step is when it happens. Any motor that is new to you — hired, on loan as a courtesy car, or brand new. Households running one of each, petrol and diesel. Your usual forecourt, its pumps suddenly in a different order. Racing for a train outside Wem and fuelling up en route. Exactly the moment it occurs: after years of driving petrol, a driver fills a diesel Skoda Octavia for the first time. 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 around Tilley: avoiding petrol in a diesel
- The label is what matters, so read the pump instead of the colour: in the UK unleaded handles are usually green and diesel black, but not on each forecourt.
- Check the filler flap. Plenty of motors state the fuel type inside the flap or on the cap. Look at it on your first fill in a car you do not know.
- A coloured fob or a sticker on the diesel's key does more than any amount of meaning to remember, for a household with one of each.
- It seems daft and it works: on the first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the petrol pump.
- Mistakes like this are easy to make while your mind is on something else, so the phone goes away.
- Some diesels have a filler built to refuse a petrol nozzle, and devices you can add are available for vehicles without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop reading the pump.
- Less petrol means a weaker mixture, and so stop the moment you realise — while remembering that your next stage is unchanged. It's still not to fire it up.
Put petrol in a diesel around Tilley already?
Short and simple, then, is the order of things. Don't turn the ignition on, and do not fire it up. Ask the attendants to help you roll it away from the petrol pump if you're still at the forecourt, whether that is Valero or anywhere else. Next, 0333 366 0103. We'll ask what went in, roughly how much, and if it has been run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost lubrication, make it a separate problem — Tilley has a page just for it.
Why one petrol in a diesel task around Tilley costs more than another
The four scenarios above are four separate jobs, so no single quote for this would be fair. Which of them you are in is mostly what moves your cost. The proportion counts next, meaning how much of the tank is petrol, and then the location of the vehicle and whether reaching it is safe for our van.
Ahead of any quote, not after, come three queries: the fuel that got in, the amount, and if it's run. That is why. Those answers change a range into a straight figure.
About Tilley itself
Tilley is a small hamlet situated on the riverside in Shropshire, with an elevation of around 80 metres. Tilley lies near the villages of Tilley Green and Ruewood, and is close to the town of Wem. Tilley is characterized by its predominantly detached housing stock, and is located approximately 17 miles from the city of Wrexham. Tilley is a rural community in the West Midlands region, about 144 miles northwest of London.
Fuel drain cover across Shropshire, Tilley included
Petrol in diesel calls around Tilley — part of the SY postcode area — go to teams that also cover the locations about it, Tilley Green, Ruewood and Wem included. A forecourt, a supermarket car park, a lay-by or your own driveway are all places our technicians drain, and your car does not need to come to us.
At the petrol pump in Tilley, right now?
In that case, you could not be in a better place. Switched off it stays; then call.