GMC 1993 Jimmy Owner's Manual page 277

KO704
What Kind of Oil to
Use:
Look for three things:
SG
"SG" must be on the
oil
container, either by itself or combined with
other quality designations, such as "SGICC," "SGICD," "SF, SG, CC",
etc. These letters show American Petroleum Institute (API) levels of
quality.
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