GMC 1994 Yukon Owner's Manual page 266

If you cannot find oils with the new "starburst" symbol on the front of the
container,
you
should look for and use oils containing the following three
things:
0
S H o r S G
"SH" or "SG" must be on the oil container, either by itself or combined
with other quality designations, such as "SHKD," "SH,SG, CD,"
"SGKD," etc. These letters show American Petroleum Institute (API)
levels of quality.
less)
OR
SAE 10W-30 -Vehicles with Heavy Duty Emissions (8501 GVWR or
more).
0
SAE 5W-30 -Vehicles with Light Duty Emissions (8500 GVWR or
Energy Conserving
II
Oils with these words on the container will help you save fuel,
These three things are usually included in a doughnut shaped logo (symbol)
on most containers. If you cannot find oils
with the "starburst" symbol, you
should look for oils with the doughnut shaped symbol, containing the three
things noted above.
NOTICE:
If you use oils that do not have either the "starburst" symbol or
an API SH or SG designation, you can cause engine damage not
covered by your warranty.
GM Goodwrench@ oil (in Canada, GM Engine Oil) meets all the
requirements for your vehicle.
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