I know that additives like LiquiMoly MOS2 that actually do work and make a difference in engine performance parameters? Any other oil additives that actually stand out from the crowd for their abilities? Many claim better fuel economy, low friction, reduced oil consumption. But what additives have you (or someone you know) tried and those additives proved to be successful investings? I have tried MotorKote a long time ago and noticed absolutely no difference in performance or fuel economy.