Lycoming O-540 on mogas
 

Anybody has experience operating Lycoming O-540 family engines on automotive gasoline?

Autofuel STC
 

See Petersen Aviation | Auto Fuel STC

Buy the STC, stick placards on aircraft, add a paragraph to the POH.

That was almost ten years ago, things may have changed.

@ MALEW As you don't put your Country of residence, (Why the hell are people so coy about that? I can understand not wanting to be tracked down, but really! ).......Your term "Automotive Gasoline" leads one to guess USA /Canada....or possibly Europe where English is a second language?



Anyway, In UK It is currently mandated in law that Road diesel shall contain ~6% bio-fuel . They daren't raise this, as, perversely, it's mainly the modern Commom rail systems and some high-pressure conventional pumps whichhave problems.

THE SAME RULING IS BEING APPLIED TO ROAD FUEL (PETROL /GASOLINE)
Leaded pump-petrol is now extinct. Unleaded , by and large contains a small percentage of Bio (Ethanol)
It eats certain rubbers, alloys (aluminium with zinc is common- Mazak) and brass...(Which again contains zinc)

A friend has had a great deal of trouble with his 1960's motorbikes, left over winter in a well insulated garage... the brass filter screen on the fuel taps ,was completely eaten away and the petrol was a greenish colour!

I URGE ANYONE, CONTEMPLATING BUYING FILLING-STATION FUEL, TO DO YOUR DUE DILIGENCE...CHECK THE SOURCE DISTRIBUTOR AND REFINERY WHERE THE FUEL COMES FROM.....some brands/grades DO contain Ethanol, some don't.

AIUI, Certain Rotax-powered machinery is certified as OK with a small Ethanol content, Some cases, the engine is OK but the airframe fuel system is NOT.

FAILURE TO CHECK COULD KILL YOU!!!!!

Much of my flying has been in Pawnees, Lycoming O-540's, 235 HP running auto gas. We had the STC of course. That engine loves auto gas. The glider clubs I was in loved the cheaper costs.
Bryan