What's the 2004 Chevy Silverado 2500HD oil type?

The oil type used on the 2004 Chevrolet Silverado 2500HD depends on the size of the engine. The 6.0L engine requires an oil type of SAE 5W-30. The 6.6L engine requires an oil type of 5W-40 below 0F and 15W-40, 10W-30 when it is above 0F. The 8.1L engine will need SAE 5W-30 to survive. If You would like to know the capacities, then I can help You with that. The 6.0L engine will take up to 6 US quarts with a filter. The 6.6L engine can take up to 10 US quarts with a filter. The 8.1L will take up to 6.4 US quarts with a filter. Remember to change both the oil and the filter so that You keep Your motor as good as new.