I dont really believe any of it matters. remember back in the day when they had a special blend for break in? I hardly think that if you run the same temps with 20% or 40% that the engine is going to know the differance. also how does it matter if you break in an engine at 180-190 degrees and run it at 260 after break in? how can it make a differance what nitro content you use? sorry if this is confusing im on an im at the same time.