Documentation for testing with unleaded/mogas?

[skirting_virga]

My 8A specifies 100LL in the POH and on the tank fillers, but I would like to start experimenting with a mogas mix (initially 25%, then 50% and possibly up to 75% eventually) for cruise. Cost is a secondary consideration - my goal is to reduce the potential lead deposits in the cylinders, plugs, and oil. UL94 is not readily available locally, but non-ethanol gasoline is. I operate at high density altitude and don't anticipate any trouble with knock, although it is comforting to think that even a small proportion of 100LL confers a significant vapor pressure and antiknock benefit.


What do I have to do to "legally" change the plane to allow the use of other fuels? Does this require an engine logbook entry?

 

[Sam Buchanan]

My 8A specifies 100LL in the POH and on the tank fillers, but I would like to start experimenting with a mogas mix (initially 25%, then 50% and possibly up to 75% eventually) for cruise. Cost is a secondary consideration - my goal is to reduce the potential lead deposits in the cylinders, plugs, and oil. UL94 is not readily available locally, but non-ethanol gasoline is. I operate at high density altitude and don't anticipate any trouble with knock, although it is comforting to think that even a small proportion of 100LL confers a significant vapor pressure and antiknock benefit.


What do I have to do to "legally" change the plane to allow the use of other fuels? Does this require an engine logbook entry?

You are not under any regulatory restrictions that prevent you from using any fuel you wish. Many RVs have been flown with auto fuel for the past few decades. There are operational considerations in regard to various seasonal blends of auto gas and specific engine configurations but these don't fall under any FARs.

Also, your POH does not carry any regulatory weight since a POH is not required for aircraft with an experimental airworthiness certificate and not part of the airworthiness process.

 

[Amadeus]

What do I have to do to "legally" change the plane to allow the use of other fuels?

Having 100LL labeled at tank filler location will be a problem if you intend to use full-service fueling. Most mogas/Swift94 are self-serve pumps but some locations, KJOT Joliet, IL for example, mogas is full-service only.

 

[skirting_virga]

You are not under any regulatory restrictions that prevent you from using any fuel you wish.

Also, your POH does not carry any regulatory weight since a POH is not required for aircraft with an experimental airworthiness certificate and not part of the airworthiness process.

Also, your POH does not carry any regulatory weight since a POH is not required for aircraft with an experimental airworthiness certificate and not part of the airworthiness process.

This is the information I was looking for, thank you.