For future reference (If in America) Take a penny and check to see if the tread is lower than the top of Mr. Lincoln's head in 3 spots of the tire. If it's above, the tires are still semi good.
lucky mine pulls to the left.. not like it used to, the gay tire techs at walmart suck and didnt fill the tires up all the way and was killing my mileage. Gas cost a lot when your 17.