Quote:
Magnesium compounds in motor oils are used primarily as detergents. The Mg atoms play the same role as calcium and sodium atoms do in the detergent compounds but each one behaves differently.
Here's a study comparing some different detergents. Mg detergents do worse in this study. Detergents can affect wear rates too which this study does not go into.
http://www.practicingoilanalysis.com/art...oup=OilAnalysis