Hot weather and autogas?

Hi Troop..........

The weather forecast for Idaho today is staggering! 107° F in Boise, 108° in
Twin Falls and 110° in Mountain Home. Montana is similar with 108° forecast
in Helena.

Last year, on my way to OSH, I planned my fuel stops to take advantage of
autogas availability. I stopped at Pullman, WA and filled up. As we were
flying past Helena, Montana, the OAT showed 85° at 9500'. Fuel pressure went
to zero and the electric pump (ahead of the firewall) made no difference.
Within one minute the engine quit. Not rough. QUIT.

I'll spare you the details, but fortunately, as I was about to turn downwind
for a soybean field, it had cooled off enough to restart. Cautiously, we
climbed and made our way to Helena, 25 miles distant. Draining the autofuel
and filling up with 100 LL solved the problem.

Unless you are *absolutely* sure that your engine will not vapor lock in
extreme temperatures, do not run autogas. It is not worth the few bucks
difference. Don't worry about the 100 LL fouling a plug or two - your plane
will still fly.

I am not looking for an discussion or argument about autogas. I use it
regularly in moderate temps. I will not use it when the mercury rises to
these levels.

Keep 'em flying,
Rich S.