I bought a lawnmower that has these oil change service intervals in the engine operating manual:
- After the first month or after 5 operating hours: change the engine oil
- Every 6 months or after 50 operating hours: change the engine oil
The trouble is, I use the lawnmower only 4 hours during a year during the growing season (which lasts about 3 months per year here). So the subsequent oil changes would happen approximately once every 12 years if I followed the operating hours interval. That I'm not going to do, so I think an oil change every year or two is useful. An oil change every 6 months doesn't make any sense since the lawnmower is not used during the winter, so half of the oil would remain completely unoperated. But if the lawnmower is not used for more than a half of the year, skipping one of the two yearly oil changes probably follows the manufacturer's instructions closely enough, if not exactly to the letter.
However, what should I do for the first oil change? I don't want to waste my time running the lawnmower needlessly to accumulate the 5 operating hours in a month, and not wasting my time and using a zip tie to run the machine idling would probably be somewhat unsafe. So I have to decide a proper time for oil change based on the conditions in which I actually use it.
One possibility is to just ignore the break-in oil change and do it according to the usual oil change service interval (which would be two oil changes per year if used around the year; if not, only one oil change per year slightly bending the rules). Then I get nearly 5 operating hours of usage at the time of the first oil change, but far more than a month of usage then.
Another possibility would be to change the oil right now. There's little over 2 hours on the machine right now and little over month of use.