Lower Ride Height Resulting from Different Wheel/Tire Combo?
 

Hello folks, I have an '09 Sport on stock wheels/tires, Eibach springs, and wheel spacers (15mm and 20mm I believe). I've been looking into going to an 18 inch wheel and beefier tires.

OEM:
Front 245/40/19
Rear 275/35/19

Planned:
18x9.5 et12 (front) 18x10.5 et15 (rear)
245/45/18 (front) 275/40/18 (rear)

I've used the following calculator, Tire Height Calculator - Wallace Racing and found that the overall tire widths and heights in the end will be nearly identical for each setup.

So my question is, am I correct in thinking that my car would be lowered by half an inch after I make the switch, since the tire heights will be the same on either setup and I'm stepping down from 19 to 18 inch wheels?

Also, can you think of any issues like rubbing or clearing Sport brakes that I have not realized?

EDIT: I've included a comparison/model in post #5

Thanks for your time!

- Kevin

whats the overall diameter of your planned setup? I'm no expert but if your using a taller sidewall than your oem setup wouldn't that give you more of a lift?

Fronts gonna look goofy. I'm a 18x9.5 +25 and already stick out past the fender. Why go close to OEM sizes? Go wider and keep the overall diameter up.

that front 9.5 ET12 is going to have quite a bit of poke.

Hmmmm I see. I'm glad I asked then haha, thanks for your replies. I guess I'm a little confused, because I'm modeling my tire and wheel selection off of CCastro's car and his fitment looked spot on ( http://www.the370z.com/members-370z-...lid-red-z.html ).

His fronts were 18x9.5 +12. Maybe I'm underestimating the amount of camber he had, using BC Coilovers?

Also I should clarify, I don't intend to use the front wheel spacers currently in place on my car (I will however keep spacers on the rear, since I currently haven't located a +0 offset like the car linked above. +15 is lowest I see at the moment). Since my initial posting, I'm also looking into replacing my Eibachs with coilovers.

With those tire sizes your going to sit a little lower up front and a tad higher in the back from you factory setup. You have to remember usually when stepping down wheel sizes you might have to get a bigger sidewall or dump the car to get rid of the new "gap" leftover.

The BC coilovers will not give you any type of camber adjustment either, or any coilover for that matter. Your going to need aftermarket adjustable A-arms to adjust your front camber.

To achieve the fitment/look of Castro's car your probably going to need coilovers to get lower than your current Eibach spring kit.

Let me know if any of this sounds confusing or you need further explanation, I'll be glad to help.

Thanks Marti, that was quite helpful. I'll be sure to get in touch in the future :tup:

He looks like he has an a** load of camber. Might be great for the track but tires are going to go very fast. Not to mention he's so low adding to the camber his under carriage must be f'd!

Not necessarily (this is a big misconception), your toe has a bigger affect on tire wear than camber does, so as long as your alignment specialist can zero out the toe (if your going for the super slammed look) your tires shouldn't be wearing out too fast.

Not directed at you synolimit, but its just a big misconception that gets thrown around the community way too much.

Don't have aftermarket wheels, but I have base 18's with some meat on the tires..
Tried to fill up the gaps as much as possible without a drop. You can still fit your foot in there though :(

20MM spacers all around-
235/50/18 (going to try and get a 245/40/18 or at least a 245 when new tires are ordered)
275/45/18