Stock suspension is doing that to your tyres?!
What tyres?
What type of driving?
Wheel alignment settings?
My fronts are not too bad, the rear of mine was fairly bad even though mine is at vspec height. I found out the wheel alignment place was too lazy to adjust the factory rear camber bolts to the most positive setting, as you have to remove the diffuser....
I tend to drive pretty hard into, through corners and don't do much if any launching (that will wear the inside of the tyres quickly). I still want to put in camber bush sets in the back at some point though, especially if I go a little lower. Some wear comes down to driving style, tyre hardness, tyre pressure, wheel alignment etc.