1QwkSport,

300+ degrees F is pretty scary, at those temps castor is starting to polymerize.
Thank goodness for synthetics!

I didn't realize you are running cars, I am running much lower temps as I am running my engines in aircraft
although I don't know precisely how much lower. I have run 30% nitro in my YS four strokes and got
great performance but have switched to20% nitro 20% lubricant fuel so I can run the same fuel in both my
two stroke and four strokes. The drop in nitro for the four strokes had a very small effect.

Happy flying, Oscar