Excessive Rear Tire Wear
 

I have a 2009 370z with the sport package. I bought the car used in January 2010 with 3600 miles on it. When I purchased the car it was absolutely immaculate except that the rear tires were bald. I replaced these with the oem tires and got very low mileage on those as well. After this I decided to try the Hankooks (I think at about 11,000 miles), thinking these would last considerably longer. I now have around 17,000 miles on the car and the Hankooks are getting very close to needing to be changed.
I never spin the tires and have never had the car at the track. I enjoy spirited driving on occasion, but never abuse the car. I have owned several other sporty cars over the years and have never experienced this problem. I love the car but I am really getting tired of the trouble and expense.
I have read on here others saying they have got 20,000 miles on the oems and this makes me think there could be a mechanical issue causing the excessive wear. Any ideas?

What tire pressure are you running? My stock 18in tires lasted me about 7 k miles but that was def my doing lol.

If you drive on a lot of bumpy roads, it would cause additional wear on the tires. Tire pressure is also another thing.