---
title: Wrong fuel glossary | Misfuel Doctor
url: https://mis-fueldoctor.co.uk/glossary/
focus: wrong fuel glossary
phone: 01295 380724
updated: 2026-10-03
---
# Wrong fuel glossary
**Short answer**
The words that come up when you have put the wrong fuel in — from misfuelling itself to the parts of the fuel system it can damage — defined in plain English. If you have just put the wrong fuel in, skip the reading: leave the engine off and call 01295 380724.

[Call 01295 380724 — 24/7, nationwide](tel:+441295380724)

## Wrong fuel glossary, A to Z
MisfuellingPutting the wrong fuel, or a fluid that is not fuel, into a vehicle's tank. The common cases are petrol in a diesel and diesel in a petrol.

Fuel drainPumping the contaminated contents out of the tank, flushing the fuel lines and refilling with the right fuel, usually where the vehicle is parked.

Fuel flushRunning clean fuel through the lines, and sometimes the filter, after a drain to clear what is left behind.

Petrol in a dieselThe most common misfuel. Petrol thins the diesel and strips the lubrication the high-pressure pump depends on.

Diesel in a petrolLess common, because a diesel nozzle is wider than a petrol filler. Diesel does not ignite properly on a spark, so the engine misfires or will not start.

AdBlueA solution of 32.5% urea in de-ionised water, injected into a diesel's exhaust to cut nitrogen oxides. Its generic name is diesel exhaust fluid (DEF).

SCR (selective catalytic reduction)The exhaust system that uses AdBlue to turn nitrogen oxides into nitrogen and water. Fuel in the AdBlue tank can damage its pump and injector.

E10Petrol containing up to 10% renewable ethanol, the standard grade at pumps in Great Britain since September 2021.

E5Petrol containing up to 5% ethanol, sold as the super grade and kept for older vehicles that are not compatible with E10.

Red dieselGas oil marked with dye and charged at a lower rate of duty for permitted uses such as agriculture. Using it in a road vehicle is an offence.

High-pressure fuel pumpThe pump that feeds a modern diesel's injectors at very high pressure. It is lubricated by the diesel passing through it, which is why petrol damages it.

InjectorThe valve that sprays fuel into the engine. Damaged injectors are the expensive end of a misfuel.

Lift pumpThe in-tank pump that moves fuel towards the engine. On many cars it runs as soon as the ignition is switched on, which is why even turning the key matters.

Limp modeA protective mode in which the engine management limits power after detecting a fault; contaminated fuel is a common trigger.

Call-out feeThe charge for a technician to attend. Here it is £89 to £199 in the UK; the drain itself is priced separately at £199 to £1,999, and both are quoted on the phone before anyone travels.

Background: [Misfuelling on Wikipedia](https://en.wikipedia.org/wiki/Misfuelling).

Sister data: [Wrong Fuel Drain publishes the fuel-drain coverage dataset](https://wrongfueldrain.com/datasets/) (catalogue: [DCAT](https://wrongfueldrain.com/catalog.jsonld)). Each dataset lives on one site only.

### Open data and facts
[UK wrong-fuel searches by the fuel mix-up they name](/datasets/wrong-fuel-search-demand/)[The 50 questions UK drivers search most after misfuelling](/datasets/wrong-fuel-search-questions/)[Misfuel call-out price structure, UK and Ireland](/datasets/misfuel-callout-prices/)[How many UK drivers put the wrong fuel in each year?](/facts/wrong-fuel-each-year-uk/)[What share of wrong-fuel searches are about petrol in a diesel?](/facts/petrol-in-diesel-share-of-wrong-fuel-searches/)[How much is the misfuel call-out fee?](/facts/misfuel-callout-fee-uk/)[Glossary](/glossary/)[Open data licence](/licence/)