You don't have an extra quart of oil that can be used, the filter is always full even if your sump goes dry. Think of it as having two cans of oil in the bed of your truck that you can't open. Added capacity is good, get a deeper or wider sump or go dry sump with a large reservoir, but don't depend on an oil filter for more usable oil. Change your oil every 3000 miles with a good filter or every 1500 miles with no filter to get rid of contaminants. The oil actually does a better job of getting rid of contaminants such as acid and water at 250 degrees than at 180.
Baldy
