---
title: Diesel in a Petrol Car? Mobile Fuel Drain
canonical: https://www.petrolinadieselcar.co.uk/diesel-in-petrol/
service: Diesel in a Petrol Car
updated: 2026-10-01
---

# Diesel in a Petrol Car: What to Do Now

If you have put diesel in a petrol car, leave the engine off and don't try to start it again.

The diesel is sitting in the tank, and draining it out is usually all the car needs. Petrol in Diesel drains diesel from petrol cars as well as petrol from diesels, and we do it where the car is.

## Diesel in a petrol car: the first few minutes

- Leave the key out of the ignition, including to move the car.

- Don't top up with petrol to try to dilute it, because the diesel is still in there afterwards.

- If you are blocking a pump, put the car in neutral and push it clear. The forecourt staff will usually give you a hand.

- Call 0333 366 0103 and tell us where you are, roughly how much diesel went in and whether the engine has run.

## Why it happens less often, and what diesel does in a petrol engine

A diesel pump nozzle is wider than the filler on most petrol cars, so this way round is harder to do by accident. It still happens, and when it does, the first steps are the same.

A petrol engine relies on a spark to light its fuel, and diesel does not ignite that way.

A petrol engine fed diesel usually just will not run, so the car tends to splutter, smoke and stop rather than carry on. That is the good news in all of this, because a car that has stopped has not been driven far on the wrong fuel, and the further it goes, the more of the fuel system the diesel reaches.

## If you have already driven it

Pull over as soon as it is safe and switch off.

We can still sort it out where you have stopped, so there is no need to restart it or arrange a tow.

When it is caught early, lasting damage is very rare.

## Fuel drain for diesel in a petrol car: what we do

We come to the car, on the forecourt, at the roadside or outside your home.

We drain the tank, flush the fuel lines and the filter so no diesel is left in the system, refill with clean petrol and start the engine to check it runs properly.

The whole job is done where the car is, so it never needs to go to a garage.

## What it costs

There is no fixed price on this page, because jobs differ.

What changes it most is whether the engine has been started or driven, and after that how much went in and where the car is.

Ring with those details and we can tell you what the job will involve.

## Diesel in petrol: questions

## How do I know if I put diesel in my petrol car?

The receipt will tell you what went in.

If the car struggled to start, smoked or cut out soon after you filled up, that is worth checking first.

## Will my car be all right?

It is very likely to be.

Lasting damage is rare when the car is stopped soon and the tank is drained and the system cleaned, and that is what we do where you are.

## Do I need to take it to a garage or a dealer?

No. We drain and flush the car wherever it is, so there is no need to move it.

## Is diesel in my petrol car covered by insurance?

Some policies include misfuelling cover and some don't, so it is worth checking yours. We come out either way.

## Is this the same service as petrol in a diesel?

It is the same kind of job the other way round, and we do both.

If it was petrol that went into a diesel, or AdBlue into the diesel tank, those have their own pages.