In article ,
"Blueskies" wrote:

"Robert M. Gary" wrote in message
oups.com...
On Oct 29, 1:42 pm, Dallas wrote:
My C150M POH shows an approved fuel grade includes AVGAS 80.

Assuming you could find 80, how safe is it to run?

And, what are the modifications made to the fuel system to run MOGAS?

On a purely theoretical level, what would be the ramifications of fueling
up an unmodified Cessna 150 with 92 octane MOGAS?

--
Dallas

Depending on where you live MOGAS may not be approved. Only certain
blends of MOGAS are approved by the FAA and many communities restrict
those blends. .


Only if the airplane has the STC. If no STC, mogas is not approved...

There are two STCs involved:
1. Engine STC, verifying that the engine in question can safely run on
it.

2. The installation STC, which verifies that you will not get vapor lock.
In this case, a gravity-fed system has a major advantage.
For more than a one-off approval, you have to load the tank with 110F
fuel and climb to 10,000 feet to prove tha no vapor lock problems are
there. Sometimes an additional boost pump is required.