What he's saying is that the weight measures the viscosity of the fluid. He's not saying that viscosity correlates with any automotive fluids.


As for after-run oil, I've never used a drop of the stuff in six years of running nitro and I've never had an engine gum up or rust. As long as you run it out of fuel at the end of your session you'll be fine. If you need to do this with a partial tank just pinch the fuel line going to the carb.