What is a good (RX-8 Rims on a FC) Tire size with 8mm spacers?
 

will the stock 225/45 18 work?

I can get amazing tires for 155 a piece. im just wondering if ill experience any rubbing! please respond fast i need to order soon...
http://www.discounttiredirect.com/di...w=false&cs=225

you might find this trie size calculator useful:
http://www.miata.net/garage/tirecalc.html

According to it, the 225/40/18 is the closest to the stock 205/60/15.
It also says that with the 45s the speedometer will be off by 5.2% vs 2% with 40s, so take that in to account.

haha figures someone posts after i did all the math!

heres what i came up with:

First three numbers are tire width in mm.
Second two numbers are Aspect Ratio of the tire width.

Stock FC Tire & Rim Size - 205/60 15"
205 x .40 = 123 mm = Stock FC tire hight
15" x 25.4 = 381 mm = Stock FC rim hight
[(Stock tire size hight x2) + stock rim hight] = (123 x 2) + 381 = 627 mm or 24.69"

Used same equation to come up with the rest of the numbers.
Prices are for the tire im interested in the different sizes.

Sizes smallest to largest
205/60 15 = 627 mm or 24.69"
225/40 18 = 637 mm or 25.08" = $147 Each
245/40 18 = 653 mm or 25.72" = $182 Each
225/45 18 = 660 mm or 25.97" = $155 Each

o and thanks for the post the speedometer thing is good info

This one is much better, though the site was down for a couple days a week or two ago for some reason.
http://www.rims-n-tires.com/rt_specs.jsp

just ordered these :icon_tup:
http://www.discounttiredirect.com/di...w=false&cs=225

I think you're gonna need a fatter spacer. It looks like the RX8 wheels are 18X8 with a +50 offset, just like the 16X8 FD wheels. Those wheels are going to push in almost an inch toward the suspension. The stock suspension has less than 1/2" clearance with the stock wheels. Your 8mm spacers will help, but it just sounds too tight.
I put a set of FD wheels with 245/45-16s on my TII with stock-dimension struts. Wound up using 20mm spacers in the front and 25mm in the rear. The tires were damn near touching the struts up front and they didn't overhang the wheels by much at all.

Nicely done, Scrap. +1

At least somebody gave a definitive reason for why it would or would not work.