Originally Posted by
Pilot DAR
Operate your aircraft in accordance with the Mogas STC. If there are limits, follow them. I would be suprised to hear that there are still altitude or temperature limitations associated with vapour lock, but I don't know all the wording of the STC's. In the very early days a few approvals did have altitude and temperature limits, but I believe these are long gone. We did a lot of testing to confirm that (for many Cessnas anyway) such limits were not required.
I think you have to be carefull with generalizations. I have a MOGAS STC for my Grumman AA1B which I basically use as an emergency contingency if I get stuck at an airport with no AVGAS. The STC paperwork clearly states that MOGAS use above 24 deg C is prohibited. This is obviously very restrictive during the summer months. Maybe Cessna's are less restrictive due to their gravity feed systems but I would advise anyone flying a low wing , or non Cessna high wing aircraft on MOGAS to make sure there are no temperature restrictions.