The 2015 GMC Sierra 1500 requires Dexos1 Gen 2 synthetic motor oil, with 5W-30 being the most commonly recommended viscosity for its gasoline engines. Always verify the exact specification for your engine and climate in the owner’s manual or on the oil fill cap.
Oil specifications by engine
The Sierra 1500 offered several gasoline engines in 2015, and all are designed to use Dexos1 Gen 2 oil. While 5W-30 is the typical viscosity for these engines, the exact requirement can vary by engine and operating environment.
- 4.3L V6 EcoTec3 — Dexos1 Gen 2, typically 5W-30
- 5.3L V8 EcoTec3 — Dexos1 Gen 2, typically 5W-30
- 6.2L V8 EcoTec3 — Dexos1 Gen 2, typically 5W-30
Note: Always verify in the owner’s manual, on the engine oil cap, or with a GMC dealer for the exact oil specification for your specific vehicle configuration and local climate.
How to confirm the correct oil for your Sierra
To ensure you use the right oil, follow these steps:
- Refer to the owner’s manual to confirm Dexos1 Gen 2 approval and the recommended viscosity (commonly 5W-30 for 2015 Sierra models).
- Inspect the oil fill cap on the engine for Dexos1 Gen 2 branding and the viscosity rating.
- Check the driver-side door jamb service label for oil type and capacity recommendations.
- If still unsure, contact a GMC dealer or a qualified mechanic to confirm the correct specification for your engine and climate.
Following these steps helps ensure you’re using the correct Dexos1 Gen 2 oil and viscosity for your Sierra 1500.
Where to buy Dexos1 Gen 2 oil
Most auto parts stores stock Dexos1 Gen 2-approved oils compatible with GM engines. Look for bottles labeled Dexos1 Gen 2 with a viscosity of 5W-30; in some markets, other Dexos-approved viscosities may be available, but always verify with your manual.
Choose a reputable brand and ensure the product carries the Dexos1 Gen 2 certification to meet GM engine requirements.
Summary
For a 2015 GMC Sierra 1500, use Dexos1 Gen 2 synthetic motor oil. The most commonly recommended viscosity is 5W-30 across the engine options (4.3L V6, 5.3L V8, 6.2L V8). Always confirm the exact specification for your vehicle with the owner’s manual, the oil cap, or a GMC dealer to account for your specific engine and climate.