U.S. vehicles were all 5 quarts (except the Dodge 3.9L) hence the emergence of the 5qt jug. Only recently did oil sumps get crazy large. I credit this to high mileage OCI's.Even when Ford went to the 3v 5.4 they only upped it to 7 qts.
But then again, for decades the Chevy 350 was a 5 qt sump.