We relate engine hours to auto mileage using every hour as equivalent to 50 miles (50mph). 100 hours would be 5000 auto miles, time to change oil & filter. 1000 hours would be 50,000 miles and 2000 hours would be 100,000 miles. These are mileages (hrs) when auto manufacturers suggest more extensive maintenance. We have farm tractor engines with over 8000 hrs still running fine and using no or very little oil. Keep in mind these are industrial engines and we strictly follow manufacturers suggested maintenance schedules. Check your dipstick before starting for use that day and note any usage over time. Usage of more than a quart at 100 hrs would indicate a mechanic should be consulted. (In my experience)