Petrol in a Diesel Car in Moorlands: How Worried Should You Be?
Provided it hasn't been started, you can worry less than you probably are. Until the ignition primes the pump, your starter cranks, or your car is driven, petrol in a diesel tank just rests there and does nothing. Which makes the truthful reply to that first Moorlands query — "have I ruined it?" — normally no. Keep it that way: leave the motor off and phone Petrol in Diesel. What petrol actually does to a diesel, how to judge how far it's travelled, and how to keep it from happening a second time: that is the remainder of this page.
The motor and petrol in a diesel: what goes on
Diesel does two tasks on its way through an engine. Oiling comes before burning; it does both. Your high-pressure pump and the injectors are made to extremely fine gaps, and the diesel passing through them is what stops those surfaces from grinding against each other.
Badly at the first, not at all at the second: that is petrol. A pump working on a petrol blend is wearing itself out, because petrol is thinner than diesel and takes away the protection 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 is where the clattering starts.
Together, those make the shape of the trouble plain. Not contact but movement is what does the harm. All a tank with petrol in it amounts to is a fuel issue. The start of a mechanical problem is a pump that has been running on that petrol — and whatever a worn pump sheds travels on with the fuel to the fuel injectors downstream.
Moorlands, petrol in a diesel: four situations, from mild to major
Fuelled but not once started — as good as it gets. At a forecourt, and really only there, that petrol is still confined to the tank — since anywhere else your car was driven to get to it. The job is emptying and rinsing on the spot.
A brief spell of running, or merely your ignition on. With the fuel system primed, your lines and filter now contain petrol that came from your tank. Normally little more than clearing, flushing and seeing to your filter, and so still easy.
A couple of miles driven, and the pump has spent every one of them working on weakened fuel. The work is the tank, the lines, your filter and fresh fuel through the whole circuit, and how hard your car was driven matters as much as how far. On the school run to Moorlands Junior School, the miles is small. Very different once more: a run to Bath, under 3 miles away, or some distance on the M4, under 10 miles from Moorlands, where your engine kept running hard.
Driven on till it complained — clattering, smoke, an uneven idle, a soft throttle. The motor is telling you the fuel is no longer acting like diesel. Leave it wherever it has stopped: a lay-by, a quiet street, the verge on Englishcombe Way. The drain and flush-through still go first, and they deal with it: if a car is stopped quickly, lasting damage is very rare.
What Moorlands people get told about petrol in a diesel — and the stories in it
"Top it up the rest of the way with diesel and it will be fine" — a myth. It won't. Topping up takes out nothing; it gives you a fuller tank of the same mix. Percentage is not how a diesel fuel system copes with petrol, however much that advice presumes.
If anything, the opposite holds. Myth: "A modern diesel can cope with a bit of petrol." Finer parts and higher pressure are the way a modern diesel runs its fuel, and that makes the protection matter more, not less.
"It starts, it drives, so there is no harm" — the myth that trips up more drivers than any other. A petrol motor fed diesel generally will not run, and so the driver stops and the damage stops with them. A diesel fed petrol normally starts, idles and drives away as though nothing has happened, whilst the pump grinds. A running engine doesn't mean fine.
Myth: "Add some two-stroke oil and drive it home." It is an outdated fix for a distinct problem. It does not put back what petrol has weakened, and the petrol is still in your tank later.
Once your engine has been run, part of that petrol is in your filter and your lines, not that tank — and the next start sends it right back through the pump. So the myth "drain the tank yourself and you're sorted" doesn't stand up. On top of that, petrol emptied into a can by the road is genuinely risky.
How does petrol in a diesel happen?
On purpose? Never. Through carelessness? Rarely, if ever. The forecourt makes it easy: the petrol nozzle is the smaller of the two, and it slips into a diesel filler with almost no resistance, while a diesel nozzle generally will not go into a petrol car at all. So the mistake runs one way.
Habit and the car getting out of step is how it happens. Hire cars, courtesy cars, and motors that are new to you. Two vehicles on one driveway, one petrol, one diesel. A forecourt you know, only with its pumps laid out differently. Rushing for a train at Oldfield Park and fuelling up en route. A new-to-you diesel Volkswagen Passat, its first fuelling, and a driver used to petrol: exactly when it takes place. Your hand does what it has always done when you add rain, a phone call or a back seat full of kids.
Preventing petrol in a diesel next time you fill up in Moorlands
- The label is what matters, so check the pump rather than the colour: in the UK unleaded handles are normally green and diesel black, yet not on each forecourt.
- In a vehicle you do not know, look inside the flap over your filler or at the cap before your first fill: plenty of motors print the fuel type there.
- Label your key. In a house with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of meaning to remember.
- It sounds daft and it does the trick: on your first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the pump.
- Thinking about something else is when this becomes an easy mistake to make, and so tuck your phone away and keep your mind on the petrol pump.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler built to refuse a petrol nozzle, and aftermarket devices exist for the rest. Count it as a backstop, then keep checking the petrol pump.
- Less petrol means a thinner mixture, and so stop as soon as you realise — though remembering that the next stage is unchanged. It is still not to fire it up.
Moorlands: already put petrol in a diesel?
Short and simple, then, is the order of things. Leave it unstarted, with your ignition off too. If you're still at the forecourt — Esso or anywhere else — ask the staff to help you roll the car away from the pump. Next, 0333 366 0103. We'll ask what went in, roughly how much, and if it has been run.
Corrosion and deposits are the trouble with AdBlue, where petrol means lost protection. So if it was AdBlue, say so — and see its own Moorlands page.
Why one petrol in a diesel task around Moorlands costs more than another
Four separate jobs sit behind the four scenarios above — which is why there's no honest single price. The scenario itself does most of the work of moving the cost. Next it is the proportion — how much petrol went in against how much the tank takes — and then where the car is and whether a van can reach it safely.
Ahead of any quote, not after, come three queries: the fuel that got in, its amount, and whether it has run. That is why. A range becomes a straight figure once those replies are in.
About Moorlands, briefly
Moorlands is a suburban area situated on the riverside in Somerset, with an elevation of around 85 metres. Moorlands lies close to the city of Bath, approximately 1.2 miles away, and is near other local areas such as Bloomfield and Bear Flat. Moorlands has a population of around 4670 people and predominantly consists of semi-detached housing. Moorlands is located within the South West region of England, about 97.2 miles from London.
Fuel drain cover across Somerset, Moorlands included
Petrol in diesel calls in Moorlands — part of the BA postcode area — go to teams that also cover the places around it, Bloomfield, Bear Flat and The Oval included. The vehicle does not need to move to us: we drain at a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
Moorlands: still at the pump?
Then, you couldn't be in a better position. Keep it off. Call.