GMC 2003 Savana Van Owner's Manual page 259

What Kind of Engine Oil to Use
Oils recommended for your vehicle can be identified by
looking for the starburst symbol.
This symbol indicates that the oil has been certified by
the American Petroleum Institute (API). Do not use
any oil which does not carry this starburst symbol.
If you choose to perform
the engine oil change
service yourself, be sure
the oil you use has
the starburst symbol on
the front of the oil
container. If you have your
oil changed for you, be
sure the oil put into
your engine is American
Petroleum Institute certified
for gasoline engines.
You should also use the proper viscosity oil for your
vehicle, as shown in the viscosity chart.
RECOMMENDED SAE VISCOSITY GRADE ENGINE OILS
HOT
WEATHER
"F
+
100
t
an
+
60
t
40
t
20
0
-
"C
+
38
t
21
t
16
+ 4
- 7
-
18
1 - 1
I-
SAE
5W-30
LOOK
FOR
THIS
SYMBOL
RECOMMENDED
, I -
SAE
I
1
OW-30
ACCEPTABLE
AVAILABLE
IF 5W-30 IS NOT
C LD
WEATHER
DO NOT USE SAE
1OW-40,
SAE 20W-50 OR ANY OTHER
VISCOSITY GRADE OIL NOT RECOMMENDED
5-1 6