I run 0w30 amsoil in my 96 jimmy and I just changed the rear diff fuild to some of there 75w90 and all is good so far. I've read nothing but good things about amsoil.
There is an amsoil distributor in brampton somewhere, open to the public, you have to buy some sort of membership though. I use amsoil 2stroke race synthetic in my sea-doo and it runs like the first time I ever rode it.
live fast, die quick, drive a bimmer