Rob Midgley Avgas - What is it? deHavilland Moth Club. Fuels. Avgas - What is it? Mogas/UL how does they differ? Vapour Lock awareness. Match the oil with the fuel. Future trends. . Avgas - What is it ?. Narrow Fraction Distillate of crude oil. T.E.L. (0.56 g/l)
Avgas - What is it?
deHavilland Moth Club
Avgas 100LL contains 0.56g/l of TEL. BS4040 Mogas contained 0.075g/l.
Oil companies want to remove Lead. High cost, poor availability and separate refining required.
UL Grades would allow use of catalytic converters to reduce CO, NOx and SOx.
Avgas volume < 0.5% of Mogas volume.
Vapour forms in fuel lines, restricts the flow of fuel and causes fuel starvation.
Mogas/UL are wider fractions of distilled crude. Therefore it has a higher proportion of light distillate, which can form a vapour at:
a) higher pressures (i.e. lower pressure altitude)
b) lower temperatures
This is now permitted in UK for some Private Cat CofA but not Public Transport CofA aircraft.