Should You Worry? Petrol in a Diesel Car in Raise
Far less than you likely are, if it has not been started. Petrol resting in a diesel tank does nothing to your engine until something pulls it through your fuel system — the ignition priming your pump, the starter, or driving itself. So the honest answer to the first query anyone in Raise asks, "have I ruined it?", is usually no. Leave the motor off then phone Petrol in Diesel — that keeps it like that. Further down, this page sets out what petrol really does inside a diesel, how far it might have got, and how to stop it happening to you a second time.
What petrol in a diesel does to the motor
On its way through an engine, diesel has two tasks. Oiling comes before burning; it does both. Extremely fine gaps are built into the injectors and your high-pressure pump, and only your diesel running through keeps their surfaces from grinding together.
The second task petrol doesn't do at all, and the first it does poorly. Being less viscous than diesel, petrol strips away the lubrication a fuel system needs, leaving a pump running on the blend to wear itself. It's equally made to resist igniting under compression — the reverse of what a diesel needs — which is where you get the clattering.
Combined, those leave the shape of the trouble clear. Not contact but movement is what does the harm. All a tank with petrol in it amounts to is a fuel issue. Once your pump has been running on that petrol, a mechanical issue has started: whatever is shed by a pump that's wearing travels downstream to your injectors with your fuel.
Four scenarios we see in Raise: how bad is petrol in a diesel?
Filled but not once started — as good as it gets. Being at a forecourt is what makes this the case: elsewhere, the car has been driven there to begin with. With the petrol held in the tank alone, it's drained and flushed on the spot, and nothing more is needed.
Ignition on, or started for a second. Petrol has left that tank and got to the filter and your lines, because the system has been bled. Drain, flush, deal with the filter: still usually simple.
Those few miles driven were your pump labouring on fuel thinned by petrol the whole way. The work is the tank, the lines, the filter and clean fuel through the whole circuit, and how hard the car was driven matters as much as how far. On the school run to Alston Primary School, the miles is short. Any distance on the M6, under 25 miles from Raise, means the engine has worked hard throughout, and a run to Carlisle, under 25 miles away, makes a very different job as well.
Driven till it complained. Knocking, an uneven idle, smoke, a throttle that has gone soft. The fuel is not behaving like diesel any more, and your motor is telling you. Leave it where it has stopped: a lay-by, a side street, the verge on Forest Drive. A vehicle pulled over early very seldom has long-term damage, since the fuel drain and the flush, which still go first, deal with it.
What Raise drivers 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 will not. A fuller tank of the same mix is all it gives, since topping up takes out nothing. A diesel fuel system doesn't tolerate petrol by percentage in the way that advice supposes.
"Modern diesels can handle a little petrol" — a myth, and nearer the reverse. Smaller parts and higher pressure are the way a modern diesel runs its fuel, and that makes the lubrication count more, not less.
Myth: "If it starts and drives, there is no damage done." This is the one that fools motorists. Feed diesel to a petrol engine and it generally won't run, so the motorist stops — and the damage stops with them. Whilst your pump wears, a diesel fed petrol normally starts, ticks over and drives away as if nothing has happened. Running isn't the same as fine.
An old workaround for a separate issue lies behind this one. Myth: "Add some two-stroke oil and drive the car home." That petrol is still in that tank after that, and what it has weakened isn't put back.
"Drain it yourself and you're sorted" — a myth, since after it's been running some petrol lies in the filter and lines, waiting to go right back through your pump at the next start. It's also truly risky to drain petrol into a can by the kerbside.
How it happens: petrol in a diesel
It is seldom carelessness, and nobody does it on purpose. The forecourt makes it simple: the petrol nozzle is the narrower 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 error runs one way.
Habit and the vehicle getting out of step is how it occurs. Courtesy car, hire car, or a motor that is new. Two vehicles on one driveway, one petrol, one diesel. A forecourt you know, only with its pumps laid out differently. A train to catch, and a rushed fill en route to Haltwhistle. A new-to-you diesel Renault Megane, its first fuelling, and a motorist used to petrol: precisely when it occurs. With rain, a call coming in, or children to deal with, the hand just does what it has always done.
Avoiding petrol in a diesel next time you fill up in Raise
- The label is what matters, and so check the petrol pump rather than the colour: in the UK unleaded handles are usually green and diesel black, but not on each forecourt.
- Plenty of vehicles state the fuel inside your filler flap or on the cap, and so check there on your first fill in any motor you do not know.
- Good intentions do less than a sticker or a fob in a vivid colour on the diesel's key when a home has one of each. So mark it.
- Before the nozzle leaves the pump the first time you fuel a hired or new vehicle, say "diesel" out loud. Daft, perhaps, yet it does the trick.
- Put the phone away. This is an easy mistake to make while you are thinking about something else.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler designed to reject a petrol nozzle, and add-on devices are available for the remainder. Treat it as a backstop, then keep checking the petrol pump.
- As soon as you notice, stop: less petrol inside that tank makes a weaker mixture. What to do next doesn't change, though — still do not start the vehicle.
Petrol already in a diesel around Raise? Begin here
In that case, there is only a short order of things. Leave it unstarted, with the ignition switched off as well. Still at the forecourt, at Quality Fuels or anywhere else? Ask the attendants to help you push it clear of the petrol pump. Next, 0333 366 0103. We will ask what got in, roughly how much, and if it's been run.
Corrosion and deposits are the issue with AdBlue, whereas petrol means lost lubrication. So if it was AdBlue, say so — and read its own Raise page.
What makes one Raise petrol in a diesel task cost more than the next
There's no honest single quote for this, since the four situations above are four separate tasks. Chiefly, your cost moves with which situation you are in. The share counts next, meaning how much of the tank is petrol, and then the position of your car and whether getting to it is safe for a technician.
What was put in, how much, and if it has run — three queries we ask before quoting, not after, for exactly that reason. The replies change a range into a straight figure.
About Raise
Raise is a locality situated on the riverside in Cumbria, with a elevation of 274 metres, and is located near the city of Carlisle, approximately 20 miles away. Raise has a population of around 1075 people and predominantly features terraced housing. Raise is close to other nearby places such as Alston, Bayles, and Blagill, and is about 247 miles northwest of London.
Fuel drain cover in Raise and across Cumbria
Alston, Bayles and Blagill are among the places near Raise that the same vans work, answering petrol in diesel jobs across Raise's CA postcode area. You need not bring the car to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all spots we drain.
At the pump in Raise, still?
Nothing beats it: that is where you are. Switched off it remains; then ring.