The last Detroit I drove was a 6V92TTA, 350 mile turn-a-round each night, "took two full quarts of 40w oil just to get 'er to the Conoco station". No joke, two qts. each trip was totally normal, truck had less than 400,000 miles when they traded it. 5.5 -6 MPG but I have to admit we were loaded at 80,000 lbs. each night for half the trip and 50,000 - 60,000 lbs. on the other half.
