Petrol in a Diesel Car in Broadsea: How Worried Should You Be?
Far less than you likely are, provided it hasn't been started. Petrol resting in a diesel tank does nothing to your engine till something pulls it through the fuel system — your ignition priming your pump, your starter, or driving itself. So the truthful answer to the first query anyone in Broadsea asks, "have I ruined it?", is generally no. Keep it like that: leave your motor off and call Petrol in Diesel. What petrol really does to a diesel, how to judge how far it has travelled, and how to stop it from happening a second time: that is the remainder of this page.
Your engine and petrol in a diesel: what happens
Two tasks fall to diesel on its journey round a motor. It protects to begin with, and after that does it burn. The high-pressure fuel pump and the injectors are built to extremely fine gaps, and your diesel passing through them is what stops those surfaces from grinding against one another.
The second job petrol doesn't do at all, and the first it does badly. It is thinner than diesel and removes the lubrication the system rests on, so a pump running on a petrol mix 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.
Put those together and the shape of the problem is plain. It is movement that does the harm, not contact. Where the petrol is only inside that tank, it's a problem of fuel, nothing more. Once your pump has been labouring on that petrol, a mechanical issue has begun: whatever is shed by a pump that's wearing down is carried downstream to the fuel injectors with the fuel.
Four scenarios our engineers see around Broadsea: how bad is petrol in a diesel?
The best case there can be: filled up, not once started. Being on a forecourt is what makes this possible: elsewhere, the vehicle has been driven there to begin with. With that petrol held in your tank alone, it's drained and rinsed on the spot, and nothing more is needed.
A brief spell of running, or merely your ignition on. Once primed, the fuel system has pulled petrol from that tank up to the filter and the fuel lines. Usually little more than emptying, rinsing and sorting your filter, and so still straightforward.
The pump now worked a couple of miles on thinned fuel — that is what driving the vehicle does. Miles is only half of it; how hard it was driven matters just as much. Either way this work runs to that tank, the lines, the fuel filter and fresh fuel through the whole circuit. On the school run to the local primary school, the distance is short. Any mileage on the M90, over 50 miles from Broadsea, means your engine working hard throughout, and a run to Aberdeen, under 50 miles away, makes a very different task too.
Driven on till it complained — clattering, smoke, an uneven idle, a soft throttle. That's the motor telling you its fuel has stopped behaving like diesel. Leave it wherever it stops: a lay-by, a side street, the verge on Watermill Road. Lasting damage is very unusual when a car is stopped early, and the drain and flush-through that still go first sort it out.
What Broadsea motorists 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. Nothing is removed by topping up — you're left with a bigger tank, still the same mixture. The assumption behind that guidance — that diesel fuel systems tolerate petrol by percentage — is wrong.
"Modern diesels can handle a little petrol" — a myth, and closer to the reverse. A newer diesel sends its fuel through smaller parts at higher pressure, which makes the protection count more, not less.
This is the one that fools drivers. Myth: "If it starts and drives, there's no harm done." The driver of a petrol motor fed diesel normally stops, since it will not run, and the damage stops with them. 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 aren't the same at all.
Myth: "Add some two-stroke oil and drive the car home." It's an outdated fix for a distinct issue. That petrol is still inside your tank afterwards, and what it has diluted is not put back.
Myth: "Drain that tank yourself and you're sorted." Once the engine has been run, some of that petrol is no longer inside the tank: it is in the fuel filter and your lines, and it goes right back through your pump on your next start. And, a can of petrol filled by the roadside is truly dangerous.
Petrol in a diesel: how does it happen?
It is rarely carelessness, and nobody does it on purpose. The petrol nozzle is the slimmer of the two and slides into a diesel filler with almost no resistance; a diesel nozzle generally won't go into a petrol vehicle at all. The forecourt makes it simple, and the mistake runs one way.
It occurs when routine and your car stop matching. Hire cars, courtesy cars, and motors that are new to you. One petrol and one diesel on the driveway of the same household. A well-known forecourt with the pumps in a different order. Rushing for a train outside the nearest station and filling up en route. Exactly the moment it happens: after years of driving petrol, a driver fills a diesel Volkswagen Golf for the first time. Add a back seat full of kids, a phone call or rain, and the hand takes over.
Broadsea drivers: how to avoid petrol in a diesel next time
- Read the pump, not the colour. In the UK unleaded handles are usually green and diesel black, yet not on every forecourt. The label is what matters.
- Plenty of motors state the fuel inside your filler flap or on the cap, so check it on your first fill in a car you do not know.
- A coloured fob or a sticker on your diesel's key does more than any amount of intending to remember, in a household with one of each.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the pump. It seems daft and it does the trick.
- While you're thinking about something else, this is an easy mistake to make — so put the phone away.
- Some diesels have a filler built to block 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.
- Spotting it halfway? Stop at once. A weaker mixture results from less petrol in that tank, but the next step remains the same: don't crank it.
Already put petrol in a diesel in Broadsea?
Then the order of things is brief. Starting it is out, and so is turning on your ignition. Yet on the forecourt, at Shell or anywhere else? Ask the staff to help you push the vehicle away from the pump. What got in, roughly how much, and if it has run: tell us those when you ring 0333 366 0103.
If it was AdBlue instead of petrol, say so. That's a different issue — corrosion and deposits rather than lost protection — and it has its own page for Broadsea.
Why one petrol in a diesel task in Broadsea costs more than another
Four different jobs lie behind the four scenarios above — which is why there's no honest single price. What moves your cost is mostly which of them you're in. Two things come after that: the petrol that was put in as a proportion of what that tank takes, then the spot your car is in and whether our van can reach it safely.
That's why we ask three questions before costing rather than after: what was put in, how much, and whether it has run. With those replies, there is a straight figure instead of a range.
About Broadsea, for a moment
Broadsea is a coastal suburban area in Aberdeenshire, situated near the towns of Fraserburgh and Sandhaven. Broadsea lies at a low elevation of around 16 metres, with the North Sea to the east. Broadsea is characterized by its predominantly flat-type housing, which reflects the local architectural style. Broadsea is located approximately 37.7 miles from Aberdeen, the nearest city.
Broadsea and Aberdeenshire: where our fuel drain cover reaches
Fraserburgh, Pitblae and Sandhaven are among the places around Broadsea that the same teams work, answering petrol in diesel call-outs across Broadsea's AB postcode area. A forecourt, a supermarket car park, a lay-by or your own drive are all places our engineers work, and the car does not need to come to us.
At the petrol pump around Broadsea, still?
Nothing beats it: that is where you now are. Keep it off. Phone.