How can you tell if diesel has petrol in it?

In brief

A petrol smell, thinner and lighter-coloured fuel, and a lower flash point. A laboratory flash point test confirms it; even a few percent of petrol shows up. Call 07950 582635 or send an enquiry.

What petrol in diesel does

Petrol strips the lubrication diesel injection pumps depend on, so an engine run on contaminated fuel can wear its pump and injectors and send metal particles through the system. Petrol also lowers the flash point of the whole load, turning it into mixed fuel.

If you find petrol in diesel

Stop using the fuel, keep it in a closed container away from drains and ignition sources, and note roughly how much there is. Yes, as mixed fuel.

How City Fuel Services handles waste diesel

Send us the five details: business and postcode, roughly how much waste diesel there is, what it is and any contamination, how it is stored and reached, and whether you need one collection or regular ones. We assess it, confirm a rebate or a collection charge, and collect on a consignment note.

Terms used in this answer

Flash point: The lowest temperature at which a liquid gives off enough vapour to catch light. Petrol's is around minus 40 °C; diesel's is above 55 °C.
Diesel bug: Bacteria and fungi that grow where water meets diesel in a tank. They form slime and sludge that block filters.

Key facts
Problem	Petrol in Diesel
Recoverable?	Yes, as mixed fuel.
Fuel	Diesel
Also called	DERV (diesel engine road vehicle), road diesel, white diesel
Waste code	13 07 01* (fuel oil and diesel)