I did a search the other day and it seems to be split. Many say it's a good lubricant,especially at high temperatures. Others say it can cause corrosion and other harmful reactions in engine materials. I've notice that several manufacturers are blending at least a small portion of moly in their newer oils. My truck takes six quarts of oil and sometimes I like to use one quart of Redline for its robust additive package but now I'm a little concerned. I have used a full load of Redline 10w-30 in the past and my engine seemed to like it.