🚀 go-pugleaf

re:  comments on air temperature and humidity vs. fuel economy

Cold air is more dense than warm air, so a proper fuel/air
mixture requires more fuel per unit volume of air.

Humid air is less dense than dry air, so it would seem
reasonable that humid air would require less fuel per unit
volume of air for the proper mixture.

In aircraft operating at high altitudes ( in this case, greater
than about 5000 feet above sea level) the fuel/air mixture is
leaned to increase fuel economy.  (In the case of a non-supercharged
piston engined aircraft, the decrease in fuel burn rate can
be greater than 25%, if memory serves me correctly.)

I realize I'm over-simplifying things quite a bit,
and I'm probably ignoring several factors,
but my point is that air temperature and humidity will
affect fuel economy.

Jonathan E. Quist
ihnp4!laidbak!jeq