GMC 1994 Yukon Owner's Manual page 264

You
should look for this on the front
of
the oil container, and use only oils
that display this new symbol.
You should also use the proper viscosity oil for your vehicle, as shown in
the following chart:
LIGHT DUTY EMISSIONS -GAS ENGINES
RECOMMENDED SAE VISCOSITY GRADE ENGINE OILS
FOR BEST FUEL ECONOMY AND COLD STARTING, SELECT THE LOWEST
SAE VISCOSITY GRADE OIL FOR THE EXPECTED TEMPERATURE RANGE.
HOT
WEATHER
F
+
100
'80
'
+ 6 0
8
+ 4 0
'
+ 2 0
-
0 .
C
-
+ 3 8
-
+ 2 7
. + 1 6
. + 4
* - 7
' - 1 8
SAE 5W-30
PREFERRED
LOOK FOR
ONE OF THESE
LABELS
SAE 1OW-30
IF NEITHER SAE 5W-30 NOR SAE 1OW-30
GRADE OILS ARE AVAILABLE, SAE 30
GRADE MAY BE USED AT TEMPERATURES
ABOVE 40 DEGREES F (4 DEGREES C).
ANY OTHER GRADE OIL NOT RECOMMENDED
DO NOT USE SAE 1OW-40, SAE 2OW-50 OR
As shown in the chart, SAE 5W-30 is best for your vehicle. However, you
can use SAE 1 OW-30 if it's going to be 0°F (-I 8°C) or above. These
numbers on an oil container show its viscosity, or thickness. Do not use
other viscosity oils, such as SAE lOW-40 or SAE 20W-50.
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