Nice rigs!
I drive a 2006 International (Navistar) 8600 daycab three-axle tractor with 405,000 miles on it. It has a Cummins ISM engine, Eaton/Fuller ten-speed manual transmission and 11R22.5 tires. I pull a 53-ft Great Dane (standard) or Wabash (with liftgate) dry van; depending upon where I have to deliver.
If it is in the shop or otherwise being used, I drive a 2004 International 9200i daycab with the same engine & tranny as the other one. The '04, however, has nearly 520,000 miles on it!! Both are 80,000 pounds GCWR.
From time to time, I drive a three-axle straight truck (hate it) - a 2008 Sterling Acterra. it is powered by a Cummins ISC, coupled to an Allison six-speed automatic. It has a GVWR of 52,000 pounds!
I am a 'company driver' now, but was an owner-operator (local, short-haul) for nearly fourteen years; but that was long ago when diesel fuel was just $1.30 a gallon! Hard to see how some of these chaps survive nowadays with fuel costing nearly four bucks. Jeez!