Supercharger Oil Change..

Well today I changed my s/c oil. pee-you that stuff does stank. Anyway, I used a spray bottle pump. Worked like a charm. I filled the 20oz mountain dew bottle up 1/4 of the way. So I figured I got out about 5oz. When I took the cap off it was not at the bottom of the threads leading me to believe it was low. It was very dirty compared to the new clean oil. Which brings me to my question. Should I run the new oil for a tank or 2 and change it again since it was so dirty? Just to make sure it has good fresh oil for the next 20,000 miles or so. thanks.

Oh, and it took 1 1/2 bottles to fill to the bottom of threads...

Change it out annually and you will be good to go.