oh man that looks pretty nicee!!! haha are those mercedes rims?? i wanna save up for 18'' rims but i read in the manual that its not reccomended to change the tire dimensions because it would mess up the AWD system or something like that

 

aslong as the rotational mass is the same. something like that.

 

^This. As long as you change the tire dimensions to match the size of wheel you're going for, you'll be fine. For 15" wheels you wanna be somewhere in the neighborhood of 205/60-15. 205/55-16 for 16" wheels, 225/45-17 for 17's and 225/40-18 for 18's. These are just estimates! The actual tires you need will depend on how low you are, how wide the wheels are, and the kind of look/fitment you're trying to achieve.

It's also important to keep the diameter if each wheel within 3% of the others so you don't grind up the center diff. This means buying tires one or two at a time is out, and don't ride the donut any longer than you have to.

 

alright thanks... i actually just wanna go with 17'' rims... with 225/45's like you said... but first things first... i gotta save up money for the st coilovers.. they're 750 or something like that on amazon...

 

225/45/17? Too wide. 205/40/17 is the way to go.

 

225? not too wide at all lol
i have 235 on my 17s

 

225/45 is the OEM spec for a 7.5" wide 17" wheel, that's why I posted it. I agree its a tad meaty, but I'm not low enough to stretch tires anyway :P

 

wait whatt? im confused here... if i lower my car and decide to get 17's do i get 225/45 or 205/45?? oh and also does anyone know if 17's will rub anything? i have 16's right now and i rub when i make sharp turns like U turns...

 

my 17s on coils rub, just roll fenders ill be good, I have 235/45/17

 

The tires should depend on the width of wheels. No one can say for sure what size tires you'll need until you decide on a width.

I personally run 205/40 on mine because I need the stretch. I was being funny when I said 225/45 is too wide. That's what most people run.