Pontiac 2003 Aztek Owner's Manual page 343

How to Check Lubricant
To get an accurate reading, the vehicle should be on a
level surface.
If the level is below the bottom of the filler plug hole,
you'll need to add some lubricant. Add enough lubricant
to raise the level to the bottom of the filler plug hole.
A fluid loss could indicate a problem; check and have it
repaired, if needed.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See Part D: Recommended
Fluids and Lubricants on page 6- 15.
5-48