I read about riders who get lots of miles from their rubber, 10,000 miles and some say more. Whether I run Metzelers or Michelins (PR3) I seem to never get past 6,000. I ride between 5,000 and 7,000 miles per year with maybe 10 - 15% on dirt roads. Give me some advice here, should I move to Bridgestone's? Am I missing something? Is going beyond 6k unusual ??