So, how often do you need to change your oil?
Throw that out on the forums and you'll get 10 pages of (different) answers.
Since I run the best oil, Amsoil , it ends up being a $50 oil change. The "book" interval does not really make much sense with track duty mixed with street riding, or track only duty in the case of my race bike, a CBR 600rr.
I love real data. I have decided to start an experiment. You can get your oil analyzed pretty cheap nowadays ($28).
I ran to where I felt I needed to change, which was 486 track only miles in this case. This was about 25 on track sessions counting practice and races. All of them would have been hard running. I changed the oil, then sent in the sample.
Drumroll...
The oil was still in good shape! I'm going to go to about 750 miles next time, which basically pays for this analysis. I'll share those results in a few months.
They did note some silica in there, which may be from a bad air filter. I've actually never changed it, but it always looked ok visually from the front air scoops. Maybe there is a bad spot or a seal not making. Either way, I'm ordering a new one. Bonus datapoint.
Anyway, I thought some of you might enjoy this.