On Jul 2, 6:31*am, Evan Ludeman wrote:
On Jul 2, 1:19*am, Jim wrote:

Glad the gov is on the job on this one /sarc.

It’s only a problem for the high compression engines. Lycoming approved 93 octane unleaded auto fuel for the 0-360 a few years ago

http://www.avweb.com/avwebflash/news...AutoGasApprova...

Jim D

Right. *But this isn't a *technical* problem, is it.

Actually, it's a very technical problem - something government
committees aren't good at dealing with. 'Octane' is just one of a
large number of variables which effect how spark ignition fuels
perform. Serious AVGAS research ended as the jet age began and a lot
of scientific data seems to have been lost in last half century.

It's worth keeping in mind that present day engines were designed for
100LL - not the other way around. Since engine design was driven by
fuel availability, it's unlikely "drop-in" fuels will perform as well
as 100LL in engines not designed to use them. It may even turn out
new engines are required. In that case, IMHO, lightweight diesels
burning Jet A would be a better choice. Jet A is likely to be around
a long time.