I understand where you’re coming from, 2 stroke engines are not very efficient beasts, as you’re well aware, a lot of that nitro and fuel gets dumped straight out the exhaust port well before it has time to burn. Some engines / application benefit from high nitro content some don't. Those little engines under .1” definitely respond better to a medium dose 10-20%. Marine engines, well just keep adding head shims and bigger props and you can end up around 65% nitro [:-] High performance .21" buggy and car engines just love nitro between 20-30% That’s one of the main reason why I mix my own, so I can tailor it to my engines needs and application.