Global Machinery Company Sierra 1999 - Manual (Page 313)

yellow blue
6-15
As shown in the chart, SAE 5W - 30 is best for your
vehicle. However, you can use SAE 10W - 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.
NOTICE:
Use only engine oil with the American Petroleum
Institute Certified For Gasoline Engines
“Starburst” symbol. Failure to use the
recommended oil can result in engine damage not
covered by your warranty.
GM Goodwrench
R
oil meets all the requirements for
your vehicle.
If you are in an area where the temperature falls below
- 20
_F ( - 29
_C), consider using either an SAE 5W - 30
synthetic oil or an SAE 0W - 30 oil. Both will provide
easier cold starting and better protection for your engine
at extremely low temperatures.
Engine Oil Additives
Don’t add anything to your oil. Your dealer is ready to
advise if you think something should be added.
When to Change Engine Oil
Your vehicle has a computer that lets you know when to
change your engine oil. This is not based on mileage,
but on engine revolutions and engine operating
temperature. When the computer has calculated that the
oil needs changing, the Oil Life Monitor will indicate
that a change is necessary. The mileage between oil
changes will vary depending on how you drive your
vehicle
-- usually between 3,000 miles (5 000 km) and
7,500 miles (12 500 km) since your last oil change.
Under severe conditions, the indicator may come on
before 3,000 miles (5 000 km). Never drive your vehicle
more than 7,500 miles (12 500 km) or 12 months
(whichever occurs first) without an oil change.
The system won’t detect dust in the oil. So, if you drive
in a dusty area, be sure to change your oil every
3,000 miles (5 000 km) or sooner. Remember to reset
the CHANGE ENGINE OIL message whenever the oil
is changed.