Tirerack.com lists the treadwear rating on those tires at 160, which isn't overly great. That is a wear rating you'd expect to see on a much more high performance tire.
Honestly, I don't know what to tell you. The treadwear ratings are known to be very inaccurate, but it is the only way we can "judge" what treadlife should be.
I would expect with your driving style that you should see 25K--30K miles out of the tires. There are so many variables that can affect treadlife (tire pressure, rotating, driving style, roads, ect.) that it is hard to say for sure.
P/P, 5 spd.
- Stromung Stainless Cat-back. (It's Here!!)
- Hotshot CAI (At The Coaters.)