* Your Owner's Manual: The most reliable source is the owner's manual that came with your motorcycle. Look for the section on engine maintenance and oil changes.
* Harley-Davidson Website: Visit the official Harley-Davidson website and use their service and parts lookup tools. You can usually find detailed information about your specific model.
* Harley-Davidson Dealer: Contact a local Harley-Davidson dealer. They can provide accurate information about your motorcycle's oil capacity.
* Reputable Online Forums: Search online forums dedicated to Harley-Davidson motorcycles, such as the Harley Owners Group (HOG) forum. You might find owners with similar models who can share their experience.
Please note that the oil capacity may vary slightly depending on the specific configuration of your Road King.