Should You Worry? Petrol in a Diesel Car in Mitcheldean
Provided it hasn't been started, worry far less than you probably are. Everyone around Mitcheldean begins with "have I wrecked it?", and the fair answer is usually no: petrol resting inside that tank of any diesel stays harmless till priming, cranking or driving pulls it into your fuel system. Keep it like that: leave your engine off then phone Petrol in Diesel. The rest of this page explains what petrol really does to a diesel, how to judge how far it has got, and how to make sure it doesn't happen to you again.
Inside your engine: what petrol in a diesel does
On its way through an engine, diesel has two jobs. It burns, and before it burns it lubricates. Extremely fine gaps go into the fuel injectors and the high-pressure pump, and just your diesel running through stops their surfaces grinding together.
The second job petrol doesn't do at all, and the first it does poorly. A pump working on a petrol mixture is wearing itself out, since petrol is runnier than diesel and strips out the lubrication the fuel system relies on. Petrol is also made to resist igniting under compression — the opposite of what a diesel needs from its fuel — and that is where any rattling starts.
Put these together and the shape of the issue is plain. It's movement that does the damage, not contact. Any tank with petrol in it is a fuel issue. Once your pump has been working on that petrol, a mechanical fault has started: anything shed by a pump that's grinding travels onward to your injectors with your fuel.
Mitcheldean, petrol in a diesel: four situations, from mild to significant
Filled up, and never started: no case is better. Just the tank has petrol in it, so the task is emptying the tank and flushing the system where the vehicle stands. This scenario can only truly occur at a forecourt: anywhere else, the vehicle got there by being driven.
A moment's running, or just your ignition on. Once primed, the fuel system has pulled petrol from that tank up to your filter and the fuel lines. Usually nothing more than clearing, cleaning and sorting your filter, and so still simple.
Those few miles on the road meant the pump working on fuel thinned by petrol the whole way. Mileage is only half of it; how hard it was driven counts equally. Either way this work includes that tank, the lines, the filter and clean fuel through the whole circuit. On the school run to Mitcheldean Endowed Primary School, the miles is short. Very different once more: a run to Gloucester, under 15 miles away, or any miles on the M50, under 5 miles from Mitcheldean, where the engine kept running hard.
Clattering, a ragged idle, smoke, a throttle gone soft: driven till it complained. The fuel is not acting like diesel any more, and your motor is saying so. Pull up where you are — on the verge on High Street, at the kerb, down a side road — and don't move it again. What comes first is still the fuel drain and flush, and that deals with it, with lasting damage very rare if a vehicle is pulled over quickly.
Mitcheldean motorists and that petrol in a diesel stories they hear
It will not be fine. The myth: "Fill it the rest of the way with diesel and it will be." Nothing comes out when you top up — your tank simply holds more of the same mixture. A diesel fuel system does not tolerate petrol by percentage in the way that guidance presumes.
Myth: a current diesel copes with a bit of petrol. Rather, the opposite. Lubrication matters more on current diesels, not less, because their fuel passes through finer parts at higher pressure.
This is the one that catches motorists. Myth: "If it starts and drives, there's no damage done." Diesel in a petrol motor usually leaves a motor that will not run: the driver stops, and so does the harm. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually does; meanwhile the pump grinds. Fine and running are not the same thing.
An outdated fix for a separate problem lies behind this one. Myth: "Add some two-stroke oil and drive it home." That petrol is still inside that tank after that, and whatever it has diluted is not put back.
Myth: "Drain the tank yourself and you are sorted." After your engine has run, some of the petrol is no longer in the tank: it's in your filter and your lines, and it goes straight back through your pump at your next start. On top of that, petrol cleared into a can by the road is genuinely risky.
How petrol ends up: petrol in a diesel
It's seldom carelessness, and nobody does it on purpose. One way only, because of the nozzles: the narrower petrol one slips inside a diesel filler with almost no resistance, whereas the diesel one generally will not fit a petrol vehicle. That is how the forecourt makes it simple.
When routine and your car stop matching, it occurs. Courtesy car, hire car, or a vehicle that's new. Households running one of each, petrol and diesel. A forecourt you know, only with its pumps arranged differently. A train to catch, and a hurried fill on the way to Lydney. A new-to-you diesel Volkswagen Golf, its first fuelling, and a driver used to petrol: precisely when it takes place. Add rain, a phone call or a back seat full of kids, and your hand does what it has always done.
Next time you fill up in Mitcheldean: avoiding petrol in a diesel
- A green handle for unleaded and black for diesel is usual in the UK — yet not on every forecourt. Trust the label on the petrol pump, not the colour.
- Many vehicles state the fuel type inside the filler flap or on the cap, and so check it on the first fill in a motor you do not know.
- Good intentions count for less than a sticker or a fob in a bright colour on the diesel's key if a home has one of each. So mark it.
- Say it before you lift it. On the 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 works.
- Thinking about something else is when this becomes an easy mistake to make, and so put the phone away then keep your mind on the petrol pump.
- Some diesels have a filler built to block a petrol nozzle, and devices you can add exist for cars without one. Such an inhibitor helps up to a point — as a safety net, not a reason to stop checking the pump.
- Less petrol makes a weaker mixture, and so stop as soon as you notice — while remembering that your next step is unchanged. It is still not to start it.
Mitcheldean: already put petrol in a diesel?
In that case, there is only a short order of things. Leave it unstarted, with your ignition switched off as well. Still at the forecourt, at Gulf or anywhere else? Ask the attendants to help you push the vehicle clear of the pump. Then call 0333 366 0103 and tell us what got in, roughly how much, and if it's run.
If it was AdBlue and not petrol, say so. That is a separate fault — corrosion and deposits and not lost protection — and it has its own page for Mitcheldean.
Mitcheldean petrol in a diesel tasks: why one costs more than another
Four different tasks lie behind the four scenarios above — which is why there is no fair single price. The situation itself does most of the work of moving the cost. Two things come after that: the petrol that was put in as a share of what that tank holds, then the place the vehicle is in and whether a technician can reach it safely.
That's why our engineers ask three queries before quoting instead of after: what got in, how much, and whether it's run. The replies change a range into a straight figure.
About Mitcheldean
Mitcheldean is a small town in Gloucestershire, situated inland at an elevation of around 153 metres, approximately 10 miles west of Gloucester. Mitcheldean lies near several nearby villages, including Brimps Hill, Abenhall, and Plump Hill, and is characterized by its predominantly semi-detached housing stock. Mitcheldean is home to around 2773 residents and is located about 104 miles west of London.
Mitcheldean and Gloucestershire: where our fuel drain cover reaches
Brimps Hill, Abenhall and Plump Hill are among the locations around Mitcheldean that the same teams work, answering petrol in diesel call-outs across Mitcheldean's GL postcode area. Our technicians drain where the vehicle is — your own drive, a lay-by, a supermarket car park, a forecourt — so it does not have to come to us.
Still at the petrol pump around Mitcheldean?
The best place there is, then — that is where you are. Turned off it stays; then phone.