Engine Oil Additives - Chevrolet 2005 T-Series Owner's Manual

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SAE 15W-40
As shown in the viscosity chart, SAE 15W-40 is
best for your vehicle. However, you can use
SAE 10W-30 at temperatures above 0°F (−18°C).
When it is very cold, below 0°F (−18°C), you should
use SAE 5W-40 to improve cold starting.
These numbers on the oil container show its
viscosity, or thickness. Do not use other viscosity
oils such as SAE 10W-40 or SAE 20W-50.
This doughnut-shaped
logo (symbol) is used on
most oil containers to
help you select the correct
oil. It means that the oil
has been certified by
the American Petroleum
Institute.
You should look for this on the oil container, and use
only those oils that display this logo.
®
GM Goodwrench oil of the recommended viscosity
grades meets all the requirements for your vehicle.

Engine Oil Additives

Do not add anything to your oil. The recommended oils
with the API service symbol are all you will need for
good performance and engine protection.
When to Change Engine Oil (Vehicles
Without the Engine Oil Life System)
Change engine oil and filter every 12,000 miles
(20 000 km), or every 12 months, or every 600 hours
of engine operation, whichever occurs first. See
Scheduled Maintenance on page 6-5.
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