Riddings: Petrol in a Diesel Car? How Worried to Be
If it hasn't been started, you can worry less than you probably are. Everyone in Riddings begins with "have I ruined it?", and the honest answer is generally no: petrol left in your tank of any diesel stays harmless until priming, cranking or driving draws it into the fuel system. To leave it like that, ring Petrol in Diesel and leave your motor alone. Further down, you will find what petrol really does inside a diesel, how far it may have got, and how to stop it happening to you a second time.
What petrol in a diesel does to the motor
Diesel does two jobs on its way through a motor. It ignites, and before it burns it protects. Extremely fine gaps are built into the fuel injectors and your high-pressure pump, and just the diesel running through keeps those surfaces from grinding together.
Petrol handles the first job poorly and the second not at all. It is thinner than diesel and removes the protection your 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 reverse of what a diesel needs from its fuel. That's where the clattering comes from.
Combined, those make the shape of the trouble plain. Contact does not do the harm — circulation does. All a tank with petrol in it amounts to is a fuel issue. Whatever a worn pump sheds travels on, borne by the fuel, into the fuel injectors further along, which is why a pump that has worked on that petrol is where a mechanical fault starts.
How bad is petrol in a diesel? Four scenarios we see in Riddings
The best case there is: filled up, never started. That petrol is in that tank and just your tank, and the job is a drain and a flush where the car stands. This is the one situation that can only really take place at a forecourt, as anywhere else the car has been driven to get there.
Your ignition turned on, or a brief start. The system has been bled, and so petrol has left that tank and reached the fuel filter and the fuel lines. Still usually easy: drain, flush, and the fuel filter dealt with.
Your pump now spent a couple of miles on diluted fuel — that's what driving the car does. Miles is only half of it; how hard it was driven matters equally. Either way this work runs to the tank, the fuel lines, the filter and clean fuel through the entire circuit. Short trips, like the school run to Riddings Junior School, are one matter. A run as far as Derby, under 15 miles away, is a very different job. So is any distance on the M1, under 3 miles from Riddings, where the motor has been working hard the whole time.
Driven on until it protested — clattering, smoke, an uneven idle, a soft throttle. What you are hearing is the motor signalling fuel that no longer behaves like diesel. Leave it where it has stopped: a lay-by, a side street, the verge on George Street. A car stopped early very seldom has permanent damage, as the fuel drain and the flush, which still come first, take care of it.
Stories Riddings motorists hear about petrol in a diesel
False: topping up to full with diesel makes it fine. It doesn't. A fuller tank of the same mixture is all it gives, since topping up takes out nothing. The idea behind the guidance — that diesel fuel systems tolerate petrol by percentage — is wrong.
Myth: "A modern diesel can cope with a bit of petrol." If anything, the reverse. Protection counts more on current diesels, not less, because their fuel runs through more precise parts at higher pressure.
Myth: "If it starts and drives, there is no damage done." This is the one that fools drivers. 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 will; meanwhile your pump grinds. A running engine doesn't mean fine.
Myth: "Add some two-stroke oil and drive the car home." It is an old fix for a different problem. What petrol has thinned remains weakened, and the petrol remains inside the tank anyway.
Myth: "Drain that tank yourself and you are sorted." Once the motor has run, some of the petrol is no longer inside your tank: it is in the filter and the fuel lines, and it goes straight back through the pump at your next start. Draining petrol into a can by the roadside is also truly dangerous.
How does petrol in a diesel happen?
A careless moment is rarely the cause, and nobody means to do it. A diesel nozzle mostly won't fit a petrol motor, yet the narrower petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one error simple, and only in one direction.
When habit and the vehicle stop matching, it happens. A new motor, a hire car or a courtesy car. A household with one petrol and one diesel on the drive. A well-known forecourt with the pumps in a different order. Fuelling up in a rush en route to Alfreton, with a train to catch. Years of petrol vehicles behind you, a diesel Volkswagen Passat in front of you on the forecourt for its first tank — that is when. Your hand repeats what it has always done once you add rain, a phone call or a back seat full of kids.
How to avoid petrol in a diesel at your next fill-up around Riddings
- Not every forecourt in the UK follows green for unleaded and black for diesel, though most generally do. Check the pump's label; the colour is just a clue.
- Inspect your filler flap. Many motors state the fuel inside the flap or on the cap. Look at it on the first fill in any vehicle you do not know.
- Good intentions do less than a sticker or a fob in a bright colour on the diesel's key if a house has one of each. So mark it.
- Before the nozzle comes off the pump the first time you fill a hired or new motor, say "diesel" out loud. Daft, yes, but it does the trick.
- Thinking about something else is when this becomes an easy mistake to make, and so tuck your phone away then keep your mind on the pump.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler designed to block a petrol nozzle, and aftermarket devices are available for the remainder. Treat it as a safety net, and keep reading the petrol pump.
- Stop the moment you realise. Less petrol inside your tank means a weaker mix. It does not change what to do next, which is still not to fire it up.
Already put petrol in a diesel around Riddings?
Then, there's just a short order of things. Starting it is out, and so is turning on your ignition. The staff at the forecourt — whether at Esso itself or wherever you filled up — will normally help push it clear of the pump if you ask. Call 0333 366 0103 next, with three answers — your fuel, the rough volume, and if it's run.
Corrosion and deposits are the issue with AdBlue, where petrol brings lost protection. So if it was AdBlue, say so — and see its own Riddings page.
Why one petrol in a diesel job around Riddings costs more than another
The four scenarios above are four separate tasks, so no single quote for this would be honest. Chiefly, the cost shifts with which one you're in. Where the car is counts too, and whether our van can safely get to it, after the share of petrol to what that tank takes.
That is why our engineers ask three questions before pricing rather than after: what got in, how much, and if it has run. Given those answers, there is a straight figure rather than a range.
About Riddings, for a moment
Riddings is a village in Derbyshire, situated inland at an elevation of 143 metres, approximately 11 miles north of Derby. Riddings is characterized by its semi-detached housing stock and is located near other local places such as Leabrooks, Somercotes, and Codnor Park. Riddings has a population of around 2360 residents and is about 120 miles northwest of London.
Riddings and Derbyshire: where our fuel drain cover reaches
Our teams answering petrol in diesel jobs around Riddings, in the DE postcode area, also work the locations around it, Leabrooks, Somercotes and Codnor Park among them. A forecourt, a supermarket car park, a lay-by or your own drive are all spots we work, and the car doesn't need to move to us.
Riddings: still at the pump?
Nothing beats it: that is where you are. Keep the vehicle switched off, then ring.