The GMC Sierra’s 6.2 L EcoTec3 V8 uses Dexos1 Gen 2 synthetic oil with a viscosity of 0W-20, and the engine typically holds about 8 quarts (with a filter) of oil when serviced.
The 6.2 L EcoTec3 V8 powers Sierra models across multiple generations, and GM specifies a Dexos1 Gen 2 lubricant as the standard. This article explains the recommended oil type, capacity, and change intervals, noting there can be year-to-year variations.
Oil type and viscosity
The following guidance reflects GM’s typical recommendations for the 6.2 L EcoTec3 V8; the primary specification is Dexos1 Gen 2 with a 0W-20 viscosity. Some climates or model years may allow alternatives, but 0W-20 is preferred for fuel economy and cold-start protection.
Dexos1 Gen 2 0W-20 synthetic (recommended)
- Dexos1 Gen 2 certified 0W-20 synthetic oil (preferred for the 6.2 L EcoTec3 V8).
Concluding: The standard choice is Dexos1 Gen 2 0W-20 synthetic; verify your exact year/trim for any deviations.
Other Dexos1 Gen 2 options (when permitted)
- Dexos1 Gen 2 5W-30 synthetic oil may be allowed in some climates or for some model years as an alternative; always confirm with the owner's manual.
Concluding: If your manual allows, 5W-30 is a backup option, but 0W-20 remains the default for most Sierra 6.2L engines.
Oil capacity and change intervals
Details on how much oil the engine holds and how often it's changed:
- Oil capacity: approximately 8 quarts with filter (about 7.5–8.0 quarts depending on the model year and whether an auxiliary cooler or other equipment is installed).
- Recommended change interval: typically 7,500–10,000 miles under normal synthetic service; closer to 5,000–7,500 miles for severe-duty driving, towing, or extreme temperatures. Always follow GM's maintenance schedule via the owner's manual or built-in vehicle system alerts.
Concluding: Use synthetic Dexos1 Gen 2 0W-20 and follow the maintenance schedule; adjust for severe service as needed.
Where to source the right oil
You can purchase Dexos1 Gen 2 0W-20 synthetic oil from auto parts stores, GM dealerships, or reputable online retailers. Look for the Dexos1 Gen 2 designation on the bottle and ensure the viscosity matches the manual's specification.
Practical tips for owners
Tips to keep you on track: keep service records, verify oil type before purchase, and use the correct filter. If towing regularly or operating in extreme heat, consult the dealer for any additional recommendations or updates to GM's service bulletins.
Summary
For most 6.2 L GMC Sierra models, the recommended oil is Dexos1 Gen 2 synthetic with a 0W-20 viscosity, and the engine holds roughly 8 quarts with a filter. Always check your specific model year and trim in the owner's manual to confirm the exact requirement, as there can be exceptions based on equipment and climate.