I just finished towing a 3,000 lb trailer 1,600 miles. The truck consumed about 16 ounces of oil. It holds 4 quarts of oil - so 1 pint or 1/8th of capacity. Changed oil just before the start of the trip.
Due to headwinds the truck ran at 2,000 rpm or 3,000 rpm at 60 mph. Most was at 2k rpm but...