it's not all the same thing, but not contradictory either.
the API Grade SF refers to the AmericanPetroleum Institute spec for that service category.
the 5W30 refers to the oil viscosity.
here's a good primer on it all from the API
API MOTOR OIL GUIDE pdf

if i didn't scan through it too quickly, the SF is obsolete and the current spec you will find on oil is SM, for example.

hth

//bc

Last edited by trooperbc; 12/10/06 01:04 AM.
1992 sohc trooper 3.2l v6 automatic . . . as is

i love a good intermittent electrical challenge. . .especially when it's someone else's.