Important Considerations:
* Engine Type: The specific engine (e.g., 4.8L, 5.7L) will influence the oil recommendation. The owner's manual will specify the correct oil type and viscosity for your particular engine.
* API Certification: Look for an oil that meets or exceeds the API (American Petroleum Institute) service classification specified in your owner's manual. This usually involves a designation like "SM," "SN," or a newer standard.
* Synthetic vs. Conventional: While conventional oil was common back then, synthetic oil offers better performance and longevity. You can use either, but check your owner's manual to see if there's a preference.
In short: Consult your owner's manual for the definitive answer. Don't guess; using the wrong oil can damage your engine. If you don't have the manual, you can often find a digital copy online by searching for your specific Tahoe's year, model, and engine.