Ya that sounds pretty normal. To be honest i am surprised at how long my tires last here in arkansas. when i was living in california i went through tires about every 30,000 miles. I was up in the hills outside sac though and i didn't really think about my tires back then. haha
There are two kinds of people: those who say to God, "Thy will be done," and those to whom God says, "All right, then, have it your way."
C. S. Lewis