going on 11 years and 130,000 miles on my F350 with a 6.0 I tow or haul heavy all the time and mostly in the hills. I have worn out a few things but nothing with the engine proper or transmission. I did replace the turbo at around 105,000 with a newer generation version due to worn adjustable vanes. At the same time I replaced the fan clutch. At 125,000 I replaced two faulty fuel pressure sensors and the EGR Valve. Any other issues have been worn out ball joints and tie rod bushings, all 4 disc rotors, new shocks tires and 5k oils and 15k fuel filer changes plus the 30k tranny fluid and filter change and 60k air filter changes...I'm happy