I do most of the service on my ISX600, the oil capacity is 48 quarts with filter. After each change I refill 44 quarts and it sometimes may require one more. My oil dip stick has been calibrated and I have always wondered where the other 4 quarts are hiding. I know some stay in the block but 4 quarts? Also based on a previous post on air filters the Fleetquard was...