Just changed my 97 Subaru Legacy 2.2L to Amsoil SSO 0W30 with an Ea020 filter to improve horsepower for a nav rally. Changed away from Castrol 5W50 which managed the piston slap well when hot, but felt sluggish in the weak, high mileage 2.2L.
Originally Posted By: ScoobySTeveD
Just changed my 97 Subaru Legacy 2.2L to Amsoil SSO 0W30 with an Ea020 filter to improve horsepower for a nav rally. Changed away from Castrol 5W50 which managed the piston slap well when hot, but felt sluggish in the weak, high mileage 2.2L.
Originally Posted By: addyguy
Moving from a 50wt. to a thin 30wt. WILL 'free up' some HP, as it will reduce parasitic losses due to drag. Will not increase amount of HP engine has.
Yes, this is what I meant. Using an oil with 10cSt viscosity instead of 17.4cSt @ 100C.
When you call up Royal Purple's tech line, they always seem to recommend the lowest viscosity possible to generate the most horsepower. Same as they did in this test, and it works. Look at the 5000rpm HP compared to the other brands:
-92 pontiac firebird v6 with 150,000 miles.
76 super synthetic blend 10w30 with purolator filter.
(in the next oil change im planning to use redline 10w30.)