do i need one after puting on new wheels? (going from stock 16x6.5 with 205/55/16(i think.....) to a 17x8 with 235/40/17)
(driveing stock 05 wrx)

 

no, you should be ok. It is suggested to get an alignment done after you modify the suspension in any way. (i.e. lowering it or adding coilovers, etc)

 

It is always sugested having worked at Sears for about 5 years as a tech and a sales men. Changing the tires and wheels directly effect the suspension. You dont have to lower the car in order to do an alignment. One good way to figure it out would be if the cross bar is straight across or if the vehicle pulls ot the left or the right after installing the new wheels and tires.. again it is sugested.. also as a sugestion is to get an alignment every 6 months depending driving conditions, habbits, styles.