The engine runs great on Mogas, I don't notice any difference from 100LL. I don't consider this engine a high compression, it is 8.5:1, which is the same as the newer O-200D.

I got an unofficial thumbs up from a person who worked at Continental for using Mogas in the IO-240.

FYI I just did a 3.5 hour X/C flight today and averaged 5.6 GPH counting only the flight time. If I count the taxi time too (chock to chock), it was 5.0 GPH.