GMC 2010 T-Series, Owner'S Manual

Page: 166 / 294

What Kind of Engine Oil to Use
Look for three things:
. CJ-4
Oils designated as API CJ-4 are required for the
vehicle. The CJ-4 designation can appear either
alone or in combination with other American
Petroleum Institute (API) designations, such as API
CJ-4/SL. These letters show API levels of quality.
. SAE 10W-40 or SAE 15W-40
SAE 10W-40 or SAE 15W-40 is best for the
vehicle. When it is very cold, below
− 18°C (0°F),
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-30 or SAE 20W-50.
. American Petroleum Institute (API) symbol
5-18