Moly Disulfide (MoS2) is a naturally occurring mineral (molybdenite) that is extremely soft...can be as soft as talc. High performance engine builders have used lubricants made from MoS2 for years, because it can be a very high pressure lubricant. But it normally is a very specialized use...it is spread liberally on the cam shaft lobes during final assembly. The cam lobes can easily be damaged in the first few SECONDS of running if not properly lubed. We always used MoS2 on the high performance engines we put together, BUT after running for about twenty minutes, we would shut it down, drain the crank case, add fresh oil (without MoS2) and a new filter. then run another couple hundred miles and change the oil again (Mobil 1 of course). The type of MoS2 we used was very thick and it was removed after the short initial run in because it was thought to eventually plug the filter. Whether this poses a risk in the current formulations (Luby-Moly, et al), I do not know. Personally, I wouldn't use it or other oil additives in a production engine, but would rely on the superior qualities of a fully synthetic oil like Mobil 1.