The engine oil is so significant that no engine functions without it. It lubricates the engine, minimizing friction and reduces wear. Every engine has a recommended type of oil it uses as well as oil pressure (PSI) and quarts.
Therefore, you cannot use another type of oil not recommended for the engine else the engine will develop issues in due time. The 6.6 Duramax has an oil capacity recommended by the manufacture and that is what this article is all about.
The 6.6 Duramax oil capacity is 10 quarts (9.5 liters) of 15W-40 viscosity when the ambient temperature is greater than 0ºF and 5W-40 when the temperature is less than 0ºF with CJ-4 or CK-4 API.
6.6 Duramax Oil Capacity for all Generation
Below are the oil capacity for all the generations of 6.6 Duramax:
2001 – 2007 Oil Capacity
The 2001 – 2007 6.6 Duramax oil capacity is 10 quarts (9.5 liters) of SAE 15W-40, SAE 5W-40 and 10W-30 engine oil capacity.
However, the fact that you can use 10W-30 in a 2001 – 2007 6.6 Duramax engine doesn’t mean it is recommended. You can’t prefer 10W-30 over 15W-40 viscosity grade.
As a matter of fact, GM recommends using the 15W-40 over 10W-30 whenever the ambient temperature is greater than 0’F. Therefore, you can use a 5W-40 engine engine oil if the ambient temperature is below 0.F to get enough protection needed by the engine during cold starts and warm ups.
Don’t be confused. If you have a GM with a 6.6 Duramax engine, you can use SAE 15W-40 or SAE 5W-40. Your major concern should be to use a quality synthetic oil that provide greater resilience against oxidation, contamination and thermal breakdown.
When it comes to engine oil, the API should be considered as well. In that case, the 2001 – 2007 6.6 Duramax engine requires an engine oil API of CI-4 or CH-4.
2007 – Recent Model
The 2007 to recent model of 6.6 liter V8 diesel engine oil capacity is 10 quarts (9.5 liters) of SAE 15W-40 and SAE 5W-40 respectively.
As reiterated earlier, on no account should you use a 10W-30 oil viscosity with a 2007 to 2023 6.6 Duramax diesel engine. It is not recommended.
Therefore, when the ambient temperature is greater than 0ºF, you can use the SAE 15W-40 grade, but if the ambient temperature is less than 0ºF, the SAE 5W-40 viscosity is recommended.
Meanwhile, according to GM, you can use SAE 5W-40 in all ambient temperature but it is much better to use it when the temperature is less than 0ºF.
This is to say that if you cannot find oil with SAE 15W-40 viscosity when the season’s temperature is above 0ºF, you can go ahead with SAE 5W-40. It will still work.
The engine oil API for the 2007 – newer models 6.6 liter Duramax V8 diesel engine is CJ-4 or CK-4. The essence of using the required API for your engine is to prevent ash build ups in the DPF.
Oil Recommendation for a 6.6L Duramax Engine
You can make use of the Amsoil Max Duty Signature Series 15W-40 Diesel oil when the ambient temperature is above 0ºF and Amsoil Max Duty Signature Series 5W-40 Diesel Oil during cold weather or temperature below 0ºF.
The recommended engine oil above will ensure your engine is protected against all odds especially against fuel dilution and oil consumption.
How Often Do You Change Oil in a 6.6 Duramax?
You should perform an oil change in a 6.6 Duramx at 10,000 miles or when you see the “change engine oil” warning message on the dashboard.
However, for the sake of your engine, you can decide to change the oil at 5,000 miles or below depending on how you drive the car and how bad the oil has become.
You shouldn’t wait to get to 10,000 miles if the oil in the engine is already too dark. Once you check the oil and notices the change in color, you should perform an oil change immediately for the sake of your engine. The oil filter must be changed as well.
How Much Oil Does a 2015 6.6 Duramax Take?
The 2015 6.6 Duramax engines oil capacity is 10 quarts which is approximately 9.5 liters. The oil viscosity and API should be considered as explain earlier in this article.
Can I Use 5W-40 in My Duramax?
Yes, you can use a 5W-40 in Duramax but must be during winter when the ambient temperature is below -18’C (0ºF)
Can I Use 15w-40 Instead of 5W-40 Diesel?
For a 6.6 Duramax, you can use either of them when recommended. GM recommended using 15W-40 during hot temperature/season and 5W-40 during winter. You can also use 5W-40 at all seasons if you wish. However, its better to follow the manufacturer’s recommendation.
Final Thought
While making an oil change in a GM vehicle with a 6.6 Duramax engine, you must ensure to use the right oil capacity recommended by the manufacturer. The 6.6 Duramax oil capacity for all generations are 10 quarts which is approximately 9.5 liters with SAE 15W-40 oil viscocity in hot weather/season and 5W-40 during cold season.
