7k-8k miles. When I change the oil, I do notice some drop of the oil level on the dip stick, still within the normal range. And believe it or not this is still considered normal, so the engine does consume some oil. It becomes a problem if you have excessive oil consumption, and by that I mean significant drop after say 1k-2k miles, then you have worn piston rings. And as you said if you drive the car hard and at higher RPMs the oil consumption is worse.