Engine Oil Additives; When To Change Engine Oil - GMC C series 2002 Owner's Manual

As in the chart shown previously, SAE 5W
your vehicle. However, you can use SAE 10W
_ _
-
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
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.
R
GM Goodwrench 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
synthetic oil or an SAE 0W
easier cold starting and better protection for your engine
at extremely low temperatures.
-
30 is best for
-
30 if it's
-
50.
-
30
-
30 oil. Both will provide

Engine Oil Additives

Don't add anything to your oil. The recommended oils
with the starburst symbol are all you will need for good
performance and engine protection.

When to Change Engine Oil

(GM Oil Life System
Your vehicle has a computer system that lets you know
when to change the engine oil and filter. This is based on
engine revolutions and engine temperature, and not on
mileage. Based on driving conditions, the mileage at
which an oil change will be indicated can vary
considerably. For the oil life system to work properly,
you must reset the system every time the oil is changed.
When the system has calculated that oil life has been
diminished, it will indicate that an oil change is
necessary. A CHANGE OIL light will come on. Change
your oil as soon as possible within the next two times
you stop for fuel. It is possible that, if you are driving
under the best conditions, the oil life system may not
indicate that an oil change is necessary for over a year.
However, your engine oil and filter must be changed at
least once a year and at this time the system must be
reset. It is also important to check your oil regularly and
keep it at the proper level.
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