Should You Worry? Petrol in a Diesel Car in Red Bull
Far less than you probably are, if it has not been started. Everyone around Red Bull starts with "have I wrecked it?", and the honest answer is normally no: petrol resting in the tank of any diesel remains harmless till priming, cranking or driving draws it into the fuel system. Keep it that way: leave the engine off then call Petrol in Diesel. Read on for three things: the effect petrol has inside a diesel engine, the clues of how far it has got, and ways to make sure you don't do it again.
Inside the motor: what petrol in a diesel does
Passing through a motor, diesel is doing two jobs at once. Oiling comes before burning; it does both. Your high-pressure pump and your injectors are made to extremely fine clearances, and your diesel passing through them is what keeps those surfaces from wearing against one another.
Petrol handles the first task badly and the second not at all. It's runnier than diesel and strips away the protection the system depends 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 reverse of what a diesel needs from its fuel. That is where the knocking comes from.
Seen together, they show the shape the trouble takes. Contact doesn't do the damage — circulation does. Petrol in a tank is a fuel fault. After the pump has been labouring on that petrol, a mechanical issue has begun: whatever is shed by a pump that's grinding travels downstream to the injectors with your fuel.
How serious is petrol in a diesel? Four situations our technicians see around Red Bull
Fuelled but never started — the best it gets. Just the tank has petrol in it, and so the job is emptying that tank and cleaning your system where your car sits. This situation can only truly occur at a forecourt: anywhere else, the car got there by being driven.
The ignition turned on, or a short start. With the fuel system primed, your lines and filter now contain petrol that has come from that tank. That's usually still a simple job — a drain, a flush, and your filter dealt with.
Those few miles driven meant the pump labouring on fuel weakened by petrol the whole way. How hard your car was driven matters as much as how far, and this work takes in that tank, the lines, your filter and fresh fuel through the entire system. Driving the kids to The Reginald Mitchell Primary School is one kind of trip. Any miles on the M6, under 5 miles from Red Bull, means the motor working hard throughout, and a run to Stoke-on-Trent, under 10 miles away, makes a very different task too.
Knocking, a lumpy idle, smoke, a throttle gone soft: driven till it complained. That's your engine telling you its fuel has stopped behaving like diesel. Leave it where it has stopped: a lay-by, a quiet street, the verge on Congleton Road North. A vehicle stopped quickly very seldom has long-term damage, as the fuel drain and the flush, which still go first, sort it out.
Red Bull people and the petrol in a diesel stories they hear
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It will not. Nothing is removed by topping up — you are left with a bigger tank, still the same mixture. The assumption behind that advice — that diesel fuel systems tolerate petrol by percentage — is wrong.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the reverse. Smaller parts and higher pressure are how a modern diesel runs its fuel, and that makes the protection matter more, not less.
This is the one that catches motorists. Myth: "If it starts and drives, there is no damage done." Feed diesel to a petrol engine and it generally won't run, and so the motorist stops — and the harm stops with them. Feed petrol to a diesel and it generally fires up, idles and pulls away as if nothing has happened — all while its pump wears. Fine and running aren't the same at all.
An old workaround for a different problem lies behind this one. Myth: "Add some two-stroke oil and drive it home." It does not put back what petrol has diluted, and that petrol is still inside that tank afterwards.
Once your engine has been run, part of the petrol sits in the filter and the fuel lines, not the tank — and your next start pulls it right back through your pump. So the myth "drain that tank yourself and you are sorted" doesn't hold. On top of that, petrol cleared into a can by the road is genuinely risky.
How does petrol in a diesel happen?
On purpose? Never. Through carelessness? Rarely, if ever. The forecourt makes it easy: the petrol nozzle is the narrower of the two, and it slips into a diesel filler with almost no resistance, whilst a diesel nozzle mostly won't go into a petrol car at all. So the slip runs one way.
It takes place when habit and the car stop matching. A new vehicle, a hire car or a courtesy car. One petrol and one diesel on the driveway of the same household. Your usual forecourt, its pumps now in a different order. A rushed fill en route to Kidsgrove with a train to catch. Years of petrol motors behind you, a diesel Renault Clio in front of you on the forecourt for its first tank — that is when. Add rain, a phone call or a back seat full of kids, and the hand does what it has always done.
Red Bull drivers: how to prevent petrol in a diesel next time
- The label is what counts, 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.
- Many cars state the fuel type inside your filler flap or on the cap, and so check it on the first fill in any motor you do not know.
- A coloured fob or a sticker on the diesel's key achieves more than any amount of meaning to remember, in a home with one of each.
- It sounds 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.
- Tuck your phone away. This is an easy mistake to make while you are thinking about something else.
- Add-on devices are available for motors without one, and some diesels come with a filler that won't take a petrol nozzle. Useful — but a backstop only, never a reason to stop checking the label.
- Stop the moment you realise. Less petrol in your tank makes a thinner mix. It does not change what to do next, which is still not to start the vehicle.
Petrol already in a diesel in Red Bull? Start here
The order of things is short, then. Leave it unstarted, with your ignition switched off too. Ask the staff to help you push it away from the pump if you are still at the forecourt, whether that's Tesco or somewhere else. Then phone 0333 366 0103 and tell us what was put in, roughly how much, and if it has run.
If it was AdBlue and not petrol, say so. That is a separate issue — corrosion and deposits and not lost protection — and it has its own page for Red Bull.
Why one petrol in a diesel task in Red Bull costs more than another
An honest single quote doesn't exist here: four situations, four separate jobs. Mostly, the cost moves with which one you're in. Where your car is matters too, and whether a van can safely get to it, after the share of petrol to what that tank takes.
Three queries come first, before any quote, instead of after — what was put in, how much, has it run — and that is the reason. Those replies change a range into a straight figure.
About Red Bull and its setting
Red Bull is a suburban area in Cheshire, situated on the riverside with a mix of detached housing and open spaces. Red Bull has a relatively small population of around 741 residents and is located near other local places such as Hardings Wood and Butt Lane. Red Bull sits at an elevation of 121 metres, close to the city of Stoke-on-Trent, which is about 6 miles away. Red Bull is also within commuting distance of larger cities, with London being approximately 142 miles to the south.
Red Bull and Cheshire: where our fuel drain cover runs
Hardings Wood, Butt Lane and Woodshutts are among the spots near Red Bull that the same teams work, answering petrol in diesel call-outs across Red Bull's ST postcode area. A forecourt, a supermarket car park, a lay-by or your own driveway are all locations we work, and the car does not need to move to us.
In Red Bull and still at the petrol pump?
Then you are in the best spot there can be. Keep it off. Ring.