Kind Of Engine Oil To Use - GMC T-Series 2007 Owner's Manual

What Kind of Engine Oil to Use
Look for three things:
•
CJ-4
Oils designated as API CJ-4 are required for
your vehicle. The CJ-4 designation can appear
either alone or in combination with other
American Petroleum Institute (API)
designations, such as API CJ-4/SL.
These letters show API levels of quality.
Notice: Use only engine oils that have the
designation CJ-4 for the diesel engine. Failure
to use the recommended oil can result in
engine damage not covered by your warranty.
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