I just got a 98 subaru legacy brighton awd wagon. It ha the 2.2l boxer, 5speed manual with 152,500mile. I was looking in the manual that the oil is 7.5k oci's. It says 5w30 below 100 degrees, or 10w30/40. and it states thinner oil to be choosen for fuel efficency, heavier oil for engine protection and lubracation. so it seems that subaru wants a heavier oil to be used. also it says it is requemended to use sae30wt, sae40wt, 10w-50, 20w-40, 20w-50 under severe operation. I was wondering what you guys have to say?