Randay fuel makers have spent years and tons of money testing and perfecting fuels for todays nitros. Now by adding extra oil for protection you may unknownly damage the motor sooner than if you just used a good named pre-mix. If your motor is tuned correctly and not allowed to run to hot, it'll last a long,long time. Oil burns hotter than the methyl alcohol and nitromethane, now by adding more oil your combustion temp is going to go up accordingly. Which will make you have to richen more than should be needed, causing poor performance all around. In my years of playing with nitros of all sorts your asking for trouble by adding some "protection" to your fuel.....just don't do it