[Chrislong]

A by-product of the burnt fuel is water, so the higher the %age, the more water. So an engine running on 16% will not run cooler, and will not be as quick.

For your engine it is recommended to use 25%. I would choose Byron due to its lubricant properties, Optifuel is popular but it doesn't lubricate half as well, you will likely need after-run oil if you choose Optifuel to stop it rusting internally which I have heard of.

Personally I would choose 30%. I am relatively new to Nitro and was recommended 30% due to its performance, cooling, ease to tune and easy running. Life is not shortened (as long as tuned in properly). I have found keeping my engine running well easy.

If you revert back to factory settings for low end, high end and idle speed - start the engine on this and go from there. Use youtube to see and hear how an engine should be tuned and should sound - there is a particular rasp you need to hear. Too rich or too lean is bad for the engine, some people think just lean is bad, but rich is also damaging.

Have fun!