The recommended oil weight for a 2001 Chevy Suburban depends on the engine it has. There were several engine options available that year. To know for sure,
you need to check your owner's manual. The manual will specify the recommended oil viscosity (weight) for your specific engine under various temperature conditions.
Generally, 5W-30 is a common recommendation for many GM vehicles of that era, but this is not guaranteed to be correct for your specific Suburban. Checking the owner's manual is crucial to avoid engine damage.
