What additives would BRP oil have VS Castrol GTX or Amsoil or Mobil 1, I'm just curious, I'm not doubting you and I appreciate your comment but i'm struggling try to understand if the manual states you can use any 10-40WT API SH,SG,SJ, which have all been superceeded by SM which are far superior then why not.
SG,SH,and SJ oils are from the late 90's in 2004 for my GTX that's what was recommended, just would like to understand why BRP oil is better.