Jim Macklin wrote:
ECON 101

AvGas is available at X price
MoGas is available at 3/4X price
Cost to re-refine MoGas Y (why is a good choice of letter)
Cost to repair damaged engine (each) $20,000.

Cost to repair damaged fuel tanks, plumbing, pumps and
seals, unknown.

Cost of FAA violation of regulations, certificate
suspension, a lot
Cost of uninsured aircraft when your insurance is cancelled,
priceless.


Seeing large percentage of fleet GROUNDED when avgas goes away:

????????????

Avgas is on borrowed time.

Years ago, decades even, I remember the idea that aircraft were going
to have to operate on one of two fuels, automotive gasoline or Jet A.
And someone said that aircraft fuel systems needed to be built
impervious to alcohols, anilines, aromatics, or any other Bad Thing
thet might conceivably wind up in automotive gasoline.

The Rutanoids were running fuel on primary composite structure and I
said then, "You better make sure _no_ fuel can attack it". Oh no,
nothing but avgas was ever going in there. They wish they'd listened
now.

The diesels-primarily the (autoderivative!) Thielert/Centurion-are
sawing a hole in Lycoming's future, in case you hadn't noticed. Flight
schools over here and everyone in Europe is lining up for STC
conversions. Avgas will be no longer available in Europe in a short few
years and over here in a couple after that.

The Brazilians have had some success running some aircraft on straight
ethanol, and if one could get someone to build conformal pressure
tankage LP Gas might be possible-P&W radial powered helos have flown on
it. But otherwise, it's car gas, or convert to diesel or turbine.