I've never noticed a big difference in fuel consumption between 2&4 strokes. Except... with my Saitos, when I went to 20&30% Nitro, my run times went way up.But that was mainly when I was in 3-D flight. I like 2-strokes because they seem to spool up fast (wood)& they are happy with a lightly loaded prop- low pitch. I didnt have great luck with 4 & 5 pitch props on 4-strokes, I know other people use them but I think it wastes the low end torque of a 4-stroke and might be doing harm.