A local gasoline distributor is highlighting their "earth friendly" fuels, stating all their grades of gasoline have 75% less sulphur than competing brands. I know sulphur in general is a bad thing, especially regarding acids in the crankcase. But I also seem to remember that sulphur can act as a lubricant. My question is if that is true, what is the relationship between sulphur in fuel and engine wear? Is low sulphur fuel overall a good thing for engines, or is it only an environmental thing?