FWIW I'm impressed with this oil in my Mazda turbo. Excellent consumption after hard driving on some warm days (38C) particularly when you consider it's a thin (13.95 cSt) 40W and engine has 205,000kms up. Using 3oz RX maint dose and added 125ml Militec-1 on Saturday. Seems strange this excellent oil isn't available in NA but then maybe Castrol Syntec 5W40 is the same oil?