I am sure the last time I did the change, we put in exactly 5 and 1/8th. And then while draining, I was storing the oil in the big 5 quart container to return to Walmart and this 5 quart was not entirely full the way it was before opening. So how ever I slice it, I did end up draining less than 5 and 1/8th.
Not sure if thats normal...