What is the oil capacity of a harley heritage softtail 1990?

The oil capacity of a 1990 Harley-Davidson Heritage Softail is approximately 3 quarts (about 2.8 liters) when using a standard oil filter. If you include the oil filter change, the total capacity can be around 3.5 quarts. It's always best to consult the owner's manual for the most accurate information specific to your motorcycle.