I have seen many people new to RC with high oil content fuels lean their engines out to much trying to get them tuned properly trying to get good performance and crisp throttle response. Matter of fact I was one of them when I started in to RC I started with high oil content fuels. With lower oil content fuel in my opinion you are less likely to over lean the engine and will be able to tell it sooner if you do then with high oil content fuels. Just like my above post states. [ In addition the high oil content prevents lean bog when an engine is over-leaned thus allowing the engine to run at this lean setting without the customary telltale lean bog warning letting you know the engine is overheating.] No I am not arguing I am discussing and appreciate your opinion. No I am not and expert and have only been in the hobby for about 7 years but have been a motorcycle mechanic and machinist for over 35 years.
I do recommend being on the safe side no matter what ever he runs to have a temperature gun or something. Before someone says anything no I do not tune to any certain temperature but does help to let you know if you are to lean particularly being new to the hobby.
