We put 210,000 on one of the brand new autos in about 9 months and a couple weeks. Original Clutch, original brakes and so on. The only things we did to it is reinstall software to the auto trans a few times, a few alternators and new suit of tires all around twice for two winters. The old tires still were good to go on trailers or solo trucks.
WHAT the tractor was planned at 210,000 was to be taken away from us and given to a solo. For a lucky solo its brand new. For us its starting to creak, split and make noises on that fiberglass and plastic from wear and tear. It wont last but half a million before being disposed of.
Easily disposed tractors.
When I started I drove trucks twice as old as I was alive. And you can EASILY wash them off, oil them up, juice em with fresh batteries and they will run another 30 years. Millions? Who the hell knows. The odos quit counting long ago. Original Engines, transmissions etc. Not necessarily original clutches, drive shafts, bearings etc.
Grades? HA. Anything beyond 18% into the 20's was a real test to try and break a engine and tractor trailer. Up and over we go.
If it did break trucks then its :
: product. Not the grades.