Howdy,
1 of my units is a 2007 MEP-802A which had 14 hours on it. I picked that unit up in May 2015. That means it has been sitting around for 8 years with that same oil. Oil itself does start to fade after being introduced to fuel, heat, cold, heat, and use, and non-use. I know engines, and break-in procedures. I have rebuilt many engines, and long ago even worked with a top fuel dragster. That was different. The engine got pulled apart all the time.
Most MEP generator users are going to change oil due to time, than hours used. I have a 1993 Tractor which is finally getting to 7000 hours. That tractor gets used a lot. I know that even if I used a generator 20 hours a month, it would still last longer than I would ever need it.
If the oil change time is say 250 hours.... You might be looking at a long long time before the next change. Then again, if a major catastrophe hits, and you run the unit 24/7, you will be changing the oil for hours used.
The difference is also in the amount of oil used. These are small units. If the unit was large and used 5 gallons of oil at each change... that's another story.
The initial life of any engine and break-in is critical to its long life of service. That also can be some of the issues with units that have 100 hours and are blowing oil like crazy. Could come back to a bad break-in procedure.
Today's precision built engines are being built to better tolerances. Also, the engine technology has done away with some of the wear parts. Roller cams, roller rockers, computer aligned bores, cranks, pistons, rings...
