Engine Oil Additives; Engine Oil Life System - GMC 2005 Envoy Owner's Manual

If you are in an area of extreme cold, where the
temperature falls below 20°F ( 29°C), it is
recommended that you use 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

Do not add anything to your oil. The recommended
oils with the starburst symbol that meet GM Standard
GM6094M are all you will need for good performance
and engine protection.

Engine Oil Life System

When to Change Engine Oil
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.
5-18
When the system has calculated that oil life has
been diminished, it will indicate that an oil change is
necessary. A change engine oil light will come on.
See Change Engine Oil Light on page 3-45. Change
your oil as soon as possible within the next 600 miles
(1 000 km). 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. Your dealer has GM-trained people who will
perform this work using genuine GM parts and reset the
system. It is also important to check your oil regularly
and keep it at the proper level.
If the system is ever reset accidentally, you must
change your oil at 3,000 miles (5 000 km) since your
last oil change. Remember to reset the oil life system
whenever the oil is changed.
How to Reset the Engine Oil Life
System
The Engine Oil Life System calculates when to change
your engine oil and filter based on vehicle use. Anytime
your oil is changed, reset the system so it can calculate
when the next oil change is required. If a situation occurs
where you change your oil prior to a change engine oil
light being turned on, reset the system.