On Tue, 15 Aug 2006 13:56:11 -0500, James Robinson
wrote:
LNG has about 73,000 BTU/US Gal., while ethanol has about 80,000. Gasoline
ranges between 110,000 and 125,000.

Of course you also get to factor in the difference in weight per
gallon...

Keep in mind that the LNG is also accompanied by a very heavy tank, which
has payload implications.

LPG has lighter tanks, but still heavy compared to the ones we have
now for gasoline... Now, on the other hand, I can see the Grumman AA1
series aircraft fuel tanks possibly being converted to LPG in that
they use the tubular spar for a fuel tank... One could perhaps argue
that under pressure the spar might even be stronger... Still, that's a
20g fuel tank... Range will be decreased, but cargo capacity will go
up a few pounds from the reduced weight of the fuel... I suspect that
most aircraft would not be able to have their fuel tanks so easily
modified...