Is buying a used but rebuilt semi truck a good deal?

Most of schlumberger trucks had less than 100k on them being close to 7-8 years old. Don't even remember the hours but they basically never shut em off.

 

Place I started turning wrenches at had a trio of steam trucks (mobile equipment cleaning services). They were 10 years old, about 40,000 kilometers on each and over 20,000 hours. I think one was pushing 23,000 hours.

You definitely don't want to be doing oil changes by mileage on those units. You'd have only done 2 oil changes lol.

 

The mechanics at Strasburg ohio camp did a good servicing them. Esp the emission systems, for all the idling we did we hardly had any issues on 1st gen 2010-2012 most units were. ISX12 425/1650

Maybe you can add some insight but i think one of the reasons for hardly any dpf/scr issues was how they had em geared. 1900 at 65 mph instead of being lugged down all the time. The food service gig was just the opposite. Progressive shift and 1250 rpm in top gear. Almost always had to do a forced regen after a 10. Typical Ryder equipment

 

You want to make heat. The high heat is what catalyzes the soot in the DPF. Plus at 425/1650 you are pushing that engine hard. The days of big bore 16L engines to pull legal gross weights are over. They're just too overkill IMO. The engine needs to work hard. If you're pulling 8 axles worth of weight through the mountains daily that 15L is right at home.