I owned a 100 percent stock 2005 F250 6.0 PSD that averaged 1000 mile per month before it was sold 10 years later. about 10,000 miles per year were either towing or hauling a camper.
Started with a 2006 Weekend Warrior FB2200 tag toy hauler over 11,000 lbs and went to hauling an Arctic Fox 811SB 4000 lb truck camper while towing a 20' Interstate 6000-8000 lb enclosed trailer the last three years of ownership.
Sold locally to a couple towing a tag travel trailer but have not kept up where or how it is doing the last two years.
Had to be towed once in 2013 due to failed high pressure oil fittings going to injector lines.