6.6L Duramax Oil Capacity
The 6.6L Duramax takes 10 quarts (9.5 liters) of oil with a filter change, and 15W-40 is the standard grade. That capacity is the same for every model year (2001-2026).
Key takeaways
- Capacity: 10 quarts with a filter change - the same for every model year.
- Viscosity: 15W-40, or 5W-40 (cold climates or heavy towing).
- Look for oil meeting API CK-4 / GM dexos2 (check your model year).
- Fitted to: Chevrolet Silverado 2500HD, Chevrolet Silverado 3500HD, GMC Sierra 2500HD.
Oil capacity by model year
| Model years | Capacity (with filter) | Viscosity |
|---|---|---|
| 2001-2026 | 10 qt(9.5 L) | 15W-40 · 5W-40 (cold climates or heavy towing) |
Capacity is consistent at 10 quarts with a filter change across every generation - LB7, LLY, LBZ, LMM, LML and L5P. Without a filter change it is about 9.2 quarts.
Oil for the 6.6L Duramax
You need 10 quarts of 15W-40 heavy-duty diesel oil meeting API CK-4 / GM dexos2 (check your model year) - that is more than one jug, so buy accordingly. Change the filter with it.
Shop 15W-40 diesel oilYou need about 10 quartsShopAs an Amazon Associate we earn from qualifying purchases, at no extra cost to you.
Shop 15W-40 diesel oilTrucks with the 6.6L Duramax
Looking for a specific year instead? Look up oil by year, make and model.
Frequently asked
How much oil does a 6.6L Duramax take?
The 6.6L Duramax takes 10 quarts (9.5 liters) of oil with a filter change, and 15W-40 is the standard grade. That capacity is the same for every model year (2001-2026).
What oil viscosity does the 6.6L Duramax use?
2001-2026: 15W-40, or 5W-40 (cold climates or heavy towing). Look for oil meeting API CK-4 / GM dexos2 (check your model year).
Which trucks use the 6.6L Duramax?
Chevrolet Silverado 2500HD, Chevrolet Silverado 3500HD, GMC Sierra 2500HD, GMC Sierra 3500HD. It ran from 2001 to 2026.
Should I fill it to exactly 10 quarts?
No - treat the capacity as a guide and finish on the dipstick. Published capacities are nominal, and how much drains out varies with temperature, how long you let it drip, and whether the filter holds oil. Add most of it, run the engine briefly, then top up to the mark.