I only run full synthetic and i personaly wont be changing my oil any more often then i do but i will check it each week now instead of once a month. All Gas engines burn a certain amount of oil and its not uncommon to see your car engine burn 1/2 qt to 1qt between oil changes. This is one reason they say always check your oil to maintain its level.

I will make sure to top off my oil, since i average about 50 hr per season i dont plan on changing the oil twice unless i see a problem with my oil, just top it off.

Good scale and good info, lets also remember that the scale is also a little off on the HP due to none of our boats make 400 hp and we all can go wake board speed, the props you run do help this factor and this is also a good reason to run the right prop for your application.