Fuel dyes are dyes added to fuels, as in some countries it is required by law to dye a low-tax fuel to deter its use in applications intended for higher-taxed ones. Untaxed fuels are referred to as "dyed", while taxed ones are called "clear" or "white".
Plastic jerrycan containing 'red' diesel.
Fuel pumps in Ireland, with green gas oil and red kerosene, and notices that it is an offence to use marked fuels in a motor vehicle.
Petrol station in England, with 'red diesel' available for a lower price, but only for "off road use", i.e. agricultural machinery and similar.
Diesel (black) and dyed fuel oil (MPÖ; red) dispensers at a St1 petrol station in Tornio, Finland.
Avgas is an aviation fuel used in aircraft with spark-ignited internal combustion engines. Avgas is distinguished from conventional gasoline (petrol) used in motor vehicles, which is termed mogas in an aviation context. Unlike motor gasoline, which has been formulated without lead since the 1970s to allow the use of catalytic converters for pollution reduction, the most commonly used grades of avgas still contain tetraethyl lead, a toxic lead containing additive used to increase octane rating and prevent engine knocking. There are ongoing efforts to reduce or eliminate the use of lead in aviation gasoline.
An American Aviation AA-1 Yankee being refueled with 100LL avgas
Taking a fuel sample from an under-wing drain using a GATS Jar fuel sampler. The blue dye indicates that this fuel is 100LL.
An EAA Cessna 150 used for American STC certification of auto fuel
Purdue University Cessna 150M Swift Fuel demonstrator
