How Worried Should You Be? Petrol in a Diesel Car in Midhurst
Probably less than you are now — provided no one has started the vehicle. Everyone around Midhurst begins with "have I ruined it?", and the fair answer is generally no: petrol left in your tank of any diesel stays harmless until priming, cranking or driving draws it into the system. Leave the motor off and ring Petrol in Diesel — that is how you keep it like that. The rest of this page sets out what petrol actually does to a diesel, how to tell how far it has got, and how to make sure it does not happen to you a second time.
The motor and petrol in a diesel: what goes on
Diesel does two tasks on its way through a motor. It combusts, and before it ignites it protects. Your high-pressure pump and the injectors are made to extremely fine clearances, and the diesel passing through them is what keeps those surfaces from grinding against one another.
Of those two tasks, petrol handles the first badly and the second never. It's thinner than diesel and strips away the protection the fuel system depends on, so a pump running on a petrol blend is a pump wearing itself. And petrol is made to resist igniting under compression, which is the opposite of what a diesel needs from its fuel. That's where the knocking comes from.
Seen together, they make clear the shape the problem takes. Not contact but movement is what does the harm. Petrol in a tank is a fuel problem. The start of a mechanical one is a pump that has been labouring on that petrol — and whatever a worn pump sheds travels on with your fuel to the fuel injectors beyond it.
Four scenarios we see in Midhurst: how serious is petrol in a diesel?
Filled up, not once started. The best case there is. Only the tank has petrol in it, so the task is clearing that tank and purging your system where the car sits. This scenario can only truly happen on a forecourt: anywhere else, the vehicle got there by being driven.
Ignition on, or started for a second. Petrol has come out of your tank and got to the filter and the lines, because the system has been primed. Drain, flush, deal with the fuel filter: still usually straightforward.
Driven a couple of miles. Now the pump has spent those miles working on diluted fuel. The work is the tank, the fuel lines, the filter and clean fuel through the entire system, and how hard the vehicle was driven matters as much as how far. Short trips, like the school run to Midhurst CofE Primary School, are one thing. A run as far as Chichester, under 15 miles away, is a very different job. So is any miles on the Waterlooville Bypass, under 15 miles from Midhurst, where the engine has been running hard the whole time.
Clattering, a ragged idle, smoke, a throttle gone soft: driven till it complained. The engine is telling you the fuel is no longer behaving like diesel. Leave it wherever it has stopped: a lay-by, a quiet street, the verge on Rumbolds Hill. The drain and flush still come first, and they deal with it: if a car is stopped early, lasting damage is very unusual.
What Midhurst motorists get told about petrol in a diesel — and the myths in it
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It won't. Nothing is removed by topping up — you are left with a fuller tank, still the same mix. The idea behind that advice — that diesel fuel systems tolerate petrol by percentage — is wrong.
If anything, the opposite holds. Myth: "A newer diesel can cope with a bit of petrol." Finer components and higher pressure are the way 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 catches most motorists than any other. Diesel in a petrol motor usually means a motor that will not run: the driver stops, and so does the damage. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, as it usually does; meanwhile the pump wears. Fine and running are not the same at all.
Myth: "Add some two-stroke oil and drive the vehicle home." It is an outdated workaround for a distinct problem. It doesn't put back what petrol has thinned, and the petrol is still inside your tank afterwards.
"Drain it yourself and you're sorted" — a myth, since after it has been running some petrol lies in the fuel filter and lines, ready to go right back through your pump at your next start. Clearing petrol into a can by the roadside is also really dangerous.
How does petrol in a diesel occur?
No one does it on purpose, and it's seldom carelessness. A diesel nozzle mostly won't fit a petrol car, but the smaller petrol nozzle goes into the filler of a diesel almost without resistance — so forecourts make this one mistake straightforward, and only in one direction.
When habit and the vehicle stop matching, it takes place. A new motor, a hire car or a courtesy car. Two vehicles on one driveway, one petrol, one diesel. The pumps in a different order on a well-known forecourt. Racing for a train outside Liphook and filling up en route. A new-to-you diesel Volkswagen Golf, its first fuelling, and a motorist accustomed to petrol: precisely when it occurs. With rain, a call arriving, or a car full of children to deal with, the hand just does what it always has.
How to prevent petrol in a diesel on your next fill-up around Midhurst
- The label is what matters, and so read the petrol pump instead of the colour: in the UK unleaded handles are normally green and diesel black, but not on every forecourt.
- Inspect the filler flap. Plenty of vehicles state the fuel inside the flap or on the cap. Look at it on your first fill in a car you do not know.
- Label the key. In a household 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 seems silly and it works: on the first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the petrol pump.
- Put the phone away. This is an easy mistake to make while you're thinking about something else.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler built to refuse a petrol nozzle, and add-on devices are available for vehicles without one. They are a safety net, not a reason to stop checking the pump.
- Less petrol makes a weaker mix, so stop as soon as you notice — while remembering that your next stage is unchanged. It's still not to start the car.
Midhurst: already put petrol in a diesel?
The order of things is short, then. Leave it unstarted, with the ignition off as well. Ask the attendants to help you roll it clear of the petrol pump if you are still at the forecourt, whether that's Esso or anywhere else. What went in, about how much, and if it has run: tell us that when you ring 0333 366 0103.
Say so if it was AdBlue rather than petrol: it's a different problem, with its own page for Midhurst, because AdBlue brings corrosion and deposits rather than lost lubrication.
Midhurst petrol in a diesel tasks: why one costs more than another
Four separate tasks sit behind the four situations above — which is why there's no honest single quote. The situation itself does most of the work of moving the cost. Where the car is matters too, and whether a technician can safely reach it, after the ratio of petrol to what that tank holds.
Ahead of any quote, not after, we ask three questions: your fuel that was put in, the amount, and whether it's run. That is why. A range turns into a straight figure once the replies are in.
About Midhurst
Midhurst is a town situated in the western part of West Sussex, on the River Rother, with a mix of old and new buildings. Midhurst sits at an elevation of 32 metres, near the South Downs National Park, and is surrounded by villages such as West Lavington and Easebourne. Midhurst has a population of around 6554 people, predominantly living in detached houses, and is located near the A286 and A272 roads. Midhurst is also close to the nearby market city of Chichester, which is about 10 miles away.
Across West Sussex and around Midhurst: fuel drain cover
Petrol in diesel calls in Midhurst — part of the GU postcode area — go to teams that likewise cover the places around it, West Lavington, Easebourne and Cocking Causeway among them. You need not bring your car to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all spots where we work.
Midhurst: still at the pump?
Then you're in the best position there can be. Turned off it remains; then call.