4.5 quarts. It depends on weather or not you replace the filter. I would always replace the filter, and that would be 4.5-5 quarts. Put 4.5 in and run it for 30 seconds, wait a min. Check the fluid level, and add more as needed.
HI
5 quarts with a oil filter change.. "ALWAYS CHANGE THE OIL FILTER." or you well leave a quart of dirty oil in the system.
OH After you have changed it ... start the motor .. watch for oil leaks around the oil filter and the drain plug. then shut it off and check the dip stick to make sure you have it full.
good luck
tim