I recently read a article by a CEN Team driver. He recomended that hobbyists go to their local auto parts store (Pep boys, Autozone, etc) and buy a can of Marvel Mystery Oil (Its a fuel/oil additive that is supposed to be great for your full size cars engine). He says it works great and improves the temps/life and performance of your Nitro engine. JUST A DROP OR TWO PER TANK THOUGH!
Yeah, I have some, never tried it though. It is a great lubricant to use when you are rebuilding engines or anything like that. And im sure it would be great to cycle some through your nitro engine every once in a while.
I agree that oil additives help in reducing the operating temperature but I suggest you choose a Moly-Graphene based oil additive such as the Everglide. It is becoming a popular oil additive among truck drivers and race car enthusiasts as the nano-based formula is incredibly effective in reducing friction and in prolonging the engine and other parts. I have personally tried it and I won't ever go back to my previous oil additive. Its technology is pretty impressive!