I change my oil once per year because I never seem to ride over 16,000km. I used to work for Imperial Oil/Exxon and we had free use of the lab. After my oil change of 1 year at 15,000km my oil tested 30% life remaining. I would have no worries running and oil change to 20,000km. This is not seat of pants, or this is what I like, or my buddy does this, it's chemistry plain and simple. As a former oil technician I stay out of the dreaded oil threads as it's like comparing which pagan cult you support. Oil is chemistry - testing it works. If you brought an oil sample to my lab I could tell you the brand, viscosity and even the brand of additives you put in there. Every country has a lab, if you really want to know get your oil sampled. 5000 miles is a waste of oil, same as drinking a dozen beer and throwing 1/2 of each bottle away. It's your money, go ahead and waste it if you want. If you want to change your oil every second weekend, no one has the right to stop you, have at it.