GMC 2006 Envoy Owner's Manual page 374

What Kind of Engine Oil to Use
5-18
Look for two things:
•
GM6094M
Your vehicle's engine requires oil meeting GM
Standard GM6094M. You should look for and use
only an oil that meets GM Standard GM6094M.
•
SAE 5W-30
As shown in the viscosity chart, SAE 5W-30 is best
for your vehicle.
These numbers on an oil container show its
viscosity, or thickness. Do not use other viscosity
oils such as SAE 20W-50.