Originally Posted by jabroni racing

thats a contridiction to the previous post you just agreed to.. the previous post said "Not that I switch back and forth with nitro content, but I always thought if you switch from 20 to 30, your engine will run faster, harder, therefore requiring a richer needle setting"

I was always told leaner for lower nitro (20%) and richer for higher nitro
(30%) cause more nitro and more power = more heat..