Originally Posted By: 92saturnsl2
Originally Posted By: CATERHAM
Invariably when a heavier oil is recommended in another country the climate is hotter and/or the typical driving behaviour is different; i.e., they drive faster. Oil availability is also part of it. The 5W-20 grade is unique to NA.
I respect your knowledge and input on the subject, but is there any doubt in your mind about the US adherence to thinner oils? Is it CAFE oriented, or is it truly in the interest of wear protection? A compromise between the two?
Honestly, I'd sacrifice a smidgen of my fuel economy for the peace of mind knowing the engine will wear less-- Even if the car falls apart before the engine dies.
Asking if it is CAFE motivated is really immaterial, besides GM has not jumped on the 20wt bandwagon yet so one could argue that GM hasn't made any compromizes unlike Ford, Toyota and Honda et al who may have.
All you want to know is the optimum viscosity for your application. Since you're fortunate to have a OP gauge in your car that makes it very easy to determine. I guessed that the minimum OP spec' at elevated rev's for your GM engine is 50 psi.
(you can look it up to confirm and there is also a spec on idle to compare to). As long as you maintain that minimum OP there is zero benefit to running a heavier oil. Since the spec' oil is a light 5W-30 you will find you're running with a very large OP safety margin indeed.
Originally Posted By: CATERHAM
Invariably when a heavier oil is recommended in another country the climate is hotter and/or the typical driving behaviour is different; i.e., they drive faster. Oil availability is also part of it. The 5W-20 grade is unique to NA.
I respect your knowledge and input on the subject, but is there any doubt in your mind about the US adherence to thinner oils? Is it CAFE oriented, or is it truly in the interest of wear protection? A compromise between the two?
Honestly, I'd sacrifice a smidgen of my fuel economy for the peace of mind knowing the engine will wear less-- Even if the car falls apart before the engine dies.
Asking if it is CAFE motivated is really immaterial, besides GM has not jumped on the 20wt bandwagon yet so one could argue that GM hasn't made any compromizes unlike Ford, Toyota and Honda et al who may have.
All you want to know is the optimum viscosity for your application. Since you're fortunate to have a OP gauge in your car that makes it very easy to determine. I guessed that the minimum OP spec' at elevated rev's for your GM engine is 50 psi.
(you can look it up to confirm and there is also a spec on idle to compare to). As long as you maintain that minimum OP there is zero benefit to running a heavier oil. Since the spec' oil is a light 5W-30 you will find you're running with a very large OP safety margin indeed.