We have found some info in forums and added our own, so we have calculated and calibrated operating hour numbers for you.
The results we got on farming simulator 2017 tractor operating time:
You may multiple game time as much as you want, but operating time will be counted as a real world time.
All this information is stored on your farming simulator game folder under save game vehickles.xml file.
We understood that operating hours are not counted as vehicle do not works but as you start engine, or go in your tractor, operating hours starts to walk by.
If your tractor is dirty or rusty, it has same operating time value as a new one shinning farming simulator tractor value.
The whole cost of your tractor are calculated by operating hour count and count of vehicle are owned by you.
The best price you can get for selling your tractor in farming simulator game is 75 percent, and the lowest price is only 5 percent per tractor.
All vehicle value mostly counts as days you own that vehicle.
Most of vehicles, maybe and all has 600 days of working on operating hours.
Regular income are counted same way as an operating hours and are calculate by time you own that tractor.