Buick 1993 Skylark Owner's Manual page 226

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
"SG/CC," "SG/CD," "SF,SG,CC;" etc. These letters
show American Petroleum Institute (API) levels of
quality.
I
0
SAE low-30 (V6 3.3L LG7 Engine)
As shown in this viscosity chart, SAE 1OW-30 is
best for your vehicle. However, you can use SAE
5W-30 if it's going to be colder than 60
O F
(
16 C)
before your next oil change. When it's very cold,
below O°F (-18 C), you should use SAE 5W-30.
RECOMMENDED SAE VISCOSITY GRADE ENGINE OILS
FOR BEST FUEL ECONOW AND COLD 16, SELECT THE LOWEST
SAE VISCOSITY GRADE OIL FOR THE El..
-_
.-J TEMPERATURE RANGE.
HOT
WEATMER
r
"F
k100
+
80
+
60
+
40
+
20
0
f
r
"C
.
+38
.+27
-
+16
. + 4
. - 7
.
-18
WEATHER
LOOK
LABEL
FOR THIS
IOW-30
1
-
-
above WF
SAE 5W-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