Originally Posted by subber
I drive an 04 WRX sedan. I installed a set of 17x8 Rota G-Force with 245-40-17 Michelin Pilot Sports. I've been running this set for 2 weeks now. First thing I noticed is the loud noise, stiff ride, and heavy, numb steering. The last one proving to be the most disturbing.
The downside is the loss of steering feel. The steering effort is also so much heavier. It feels like I'm driving a much bigger, heavier car. The steering feel is no longer light and delicate which I now realize I liked a lot. I can live with the noise and the stiffer ride. I was expecting some degradation in steering feel but I didn't realize it will be this much.
What do you guys think the biggest contributor to the difference in steering?
MOST of the heavier steering feel is a result of the lower offset. Rota's are +48 and stock are +53 (or +55 on some production runs). This causes a positive scrub radius, which, in english, means the center of the tire is no longer underneath the pivot-point of the steering. So instead of the tire pivoting cleaning around the pivot-point, it is now "wiping" around it. Effectively, you're swinging the tire to turn instead of spinning it in one spot.
Of course, stickier rubber also contributes, but it's mostly the scrub radius.