* Viscosity: Check your owner's manual for the recommended viscosity grades (e.g., 5W-30, 10W-30). The choice depends on your climate; 5W-30 is often a good all-around choice, while 10W-30 might be preferred in hotter climates.
* API Certification: Look for an oil with an API certification that meets or exceeds the requirements specified in your owner's manual. Older manuals may specify something like "SG" or "SH," while newer standards (though unlikely for a 2001 vehicle) go much higher.
* Type: Your owner's manual will specify whether conventional, synthetic blend, or full synthetic oil is recommended. Full synthetic is generally preferred for its longevity and performance, but a synthetic blend is a good compromise between cost and performance.
Where to Find the Information:
1. Owner's Manual: This is the most crucial resource. The oil recommendations will be in a section dedicated to maintenance or fluids.
2. Oil Fill Cap: The oil fill cap often has a recommendation printed on it. However, always defer to the owner's manual for the complete and most accurate information.
3. GMC Website: The GMC website might have resources or archived information for your specific vehicle year and model.
Without your owner's manual, I cannot give a definitive recommendation. Using the wrong oil viscosity or type can damage your engine. Please locate your owner's manual or consult a GMC dealership or trusted mechanic.
