Pontiac 1996 Grand Prix Owner's Manual page 240

I
RECOMMENDED SAE VISCOSITY GRADE ENGINE OILS
FOR BEST FUEL ECONOMY AND COLD STARTING, SELECT THE LOWEST
I
SAE VISCOSITY GRADE OIL FOR THE EXPECTED TEMPERATURE RANGE.
HOT
WEATHER
"F
100
+
80
+
60
+
40
0 -
7
"C
t
38
+
27
+
16
t 4
- I
-
18
COLD
4
LOOK
FOR MIS
SYMBOL
L
l l l L
SAE 1OW-30
SAL 5W-30
PREFERRED
I
WEATHER
00 NOT USE SAE 2OW-50 OR ANY OTHER
GRADE OIL NOT RECOMMENDED
As
shown in the chart, if you have the
3.1L
engine,
SAE 5W-30
is best for your vehicle. However,
you
can
use
S f S 1OW-30 if it's going to be 0°F (-18°C) or
above. These numbers on an oil container'show its
viscosity, or thickness. Do not use.other viscosity oils,
such as SAE 20W-50.