Not a lot of replies in power sports forum and this more applies to passenger oil anyway. I am thinking of changing my polaris ranger over to a non UTV/ATV specific full synthetic oil either Castrol Edge 5w50 or Amsoil signature 5w50. The big issue with polaris is fuel dilution and oil shearing. How do I know which of the two is better suited for me? I was leaning towards the castrol edge since I have read it has higher levels of ZDDP and is recommended for classic car which the ranger is flat tappet cam. I currently use Amsoil UTV 5w50 but it is designed for use with wet clutches and the ranger does not have one. Thanks for the help