Which Heavy Duty Truck?

CP4’s are not trash..but the are made for high sulfur European diesel..we have LOW SULFUR DIESEL in the United States..the lubricity isn’t there for the CP4 gears
EU limit for sulphur in diesel is 10 mg/kg (10 PPM) US limit is 15 PPM.

May be different additives used between EU and US diesel though, know some nasty is added over here to counteract the bio.
 
I put on about 50k a year for work, and have had at least 9-10 half ton trucks over the years. A couple of GMC's then all F150s. Decided to switch it up this year and picked up an F250. So far I am really impressed, it doesn't handle or drive like a "big truck" at all. Has a smooth ride, plenty of power...and I got 20 mpg doing 80 on the interstate. I really have to be cognizant going to the pump though, 34 years of driving gas vehicles is a hard habit to break when you fuel up!