It is now time to trade in the Duramax/Chevy.
I have not pulled a trailor in the last 18 months so I am getting something smaller (Suburban).
I have over 230,000 miles on it, averaged 17 mpg, pulled trailers from TX to 36 states.
It brokedown twice.
The alternator went out at 200K+ and a wire rubbed in two shorting out the electrical system at 180k+.
The injectors were replaced under warranty and that was it, other than routine wear items, brakes, belts, hoses, ball joints.
Do not need a truck like this any more but have kept it for 18 months because it is such a good one.
Dependable, comfortable, and quiet.
Still drives great going down the highway.