I have noticed something about how my bike uses oil.
Last weekend I did a 250 mile round trip two up ride with the missus, gentle slow speed and low revs were the order of the day. I had topped off the oil when we started and when we got back it had not used a single drop and was still bang on the correct level.
This morning I did a 90 mile fast, high revving ride and when I got back the oil level had dropped below the level of the sight glass, so maybe half a quart in total.
That is a huge difference in oil consumption based solely on riding style. What is the likely cause and I should I be worried?