oil change durations

Having always changed the aeroshell 100 sae50 change in my c85 every 25
hours, I'm considering extending the aeroshell duration to maybe 35 hours.

My flights are in Florida and usually around an hour (or sometimes two) and
am currently burning/losing up to 1/2 quart per hour when filled to 3-1/4
quart line on the dipstick.

Of course I'm thinking about oil cost and feel like adding that oil each
flight hour does help it's cleanliness and service life.

Comments (be gentle G)?

Thanks, Dick