My 11HP Robin EH34 (Subaru) powered generator just got me through hurricane #3. That engine has had regular oil changes every 2 days with Mobil 1 15-50. Other than that, it ran continuously, including fill ups. With the extended power outages associated with hurricanes that little generator really got a workout. Overloaded plenty of the time too! It ran my entire house, 1.5hp well pump, washer, gas dryer, window AC, fridge, all the lights and big screen TV/computer. Often all at once.
This last hurricane we burned nearly 140 gallons of gas! The previous hurricanse even more gas per storm. Plus we used this generator for building our house.
I have got to say that the Robin engine is fantastic. It has a counterbalancer so it runs smoothly. I have no idea how many hours on this unit but it is way up there. By the way, the oil still comes out amber after every 50 hours.
The engine is strong enough to warrant spending the money on a sorely needed new generator head!
Chris