Mogas
We operate 4 different ACs with mogas, a C182, a T craft, homebuilt with Rotax (4 cycle) and Lycoming. In all case, mogas improved, fuel consumption, oil consumption increased plug life, and generally improved performance.
In the case of the C182, it's oil guzzling O470 Conti's consumption dropped to 12/13 gph on fuel and, oil dropped 1 qt/hr, and performnace is closest to factory specs. The engine has 1300 hrs. Plug life had increased, and the JPI anylizer is stable with mogas, while eratic with AV gas, in addition to using more fuel for cooling, odd when considering that the higher octane should burn cooler.
Lead does not lubricate as is a popular myth in aviation, in fact it does damage to any engine. Before unleaded gas, the auto industry average engine lige was less than 50K miles, as opposed to double with unleaded. With modern FADECs, 200,000 in autos is becoming more and more common.
In the case of the Rotax, AV gas makes the little engine unruly and runs inconstantly. Rotax recommends replacing oil freqhently if using AV gas. Spark plugs load easily as well and consumption rises.
Crop dusters and banner towers have been using it for years. One banner tower on our fiels dreads towing banners from a busy airport due to "wandering" eyes. On less populated fields, they use mogas. Reasons, better fuel economy, better plug life. and performance.
The T Craft was OH ed nearly 25 years ago, and running mogas from the first day after OH. Oil consumption for the little Conti is very low, plug life (and just signed off it's annual) look as if they were fairly new.
FWIW