what milage do cummins and detroit engines usually need an overhaul on average?

I have a glider with a factory rebuilt 60 series. 840k miles on it, doesnt leak a drop. 15000 mile intervals for oil changes, never add a drop of make up. Limit my idle as much as I can. Oil samples look great.
Always rotella, except last 2 changes, first was castrol, this one motomaster, but it's made by shell. Still cant get rotella anywhere.

 

Gliders are a crap shoot.. we have had a few that lasted 1M before needing anything. Others have self destructed under 200k.

 

Why I always liked CATS.

 

Learning them early

 

I know the older 855 Cummins around 800.000 some haven’t been opened up at all .

 

My ISX I sold at 750K had awesome oil samples. Change every 20K along with filters.

It's got to be pushing 900K now.

Delvac 15-40 CK-4 mineral

 

This is my personal experience with first hand experience of my trucks and ones owned by good friends. One 2013, two 2015, and five 2016 and newer. All cummins isx13 engines well taken care of, oil changes every 12-15k miles.

None made it past 830k miles. And when they fail, it’s spectacular. Like rod through the engine block spectacular.

 

the isx models?

 

I ran a 60 series 2.2 million. No problems...should've kept it.

 

15L’s are no different. 2 CM2250’s on my fleet installed picture windows in themselves.