I hope the truck keeps a record of how much this was used. I wouldn't want to buy a used truck that nominally had 50,000 miles on it but also had another 5000 hours of generator duty on the engine without knowing about it.
After I moved to Vietnam, I learned pretty quickly that the numbers on ODO's, even digital ones, can be modified to whatever you want, for a few bucks.
US has very strictly enforced laws against odometer tampering.
"Major defendants in large odometer fraud prosecutions have received prison terms of up to seven years under current Sentencing Guidelines which do not permit parole. Sentences in the 18 month to three year range are common."
https://www.justice.gov/civil/case/federal-odometer-tamperin....
Things like Carfax discourage it as well. They have partnerships with oil change (and similar) services that record the mileage and date. Rolling back becomes obvious.
In countries like the US your authorised dealer will be recording the mileage every service, so you can't really cheat it and a consumer can ask the dealer network to check the milage.
However for engine life what you want to know is hours under heavy load and perhaps total revolutions.
I thought that much of the wear on an engine is load related, and non-linear, such that hours idling at low revs is utterly different from high revs at high power.
The odo reading is useful as an indication of wear on the drivetrain and suspension etcetera.
Hours is useful on a tractor/truck/boat because the engine is normally under load for a majority of the hours.
