I currently have s stock setup 225/45/18 blah blah blah stock 18s blah blah....oh and stock offset, idk what is it +50?? anyways...

I am looking for tires though and i cant really afford rims yet...sooo, i was wondering if i should just buy another set of the stock size 225/45/18 or is there a size that i can get a little bit more width out of using my stock rims.

 

245/40/18 works well.
Many people have done this conversion.

 

is that not to wide for the 8" in wide stock rims?

 

nope, Pico speaketh the truth

 

well than thats grwat, i can find a 235 cheaper than a 225 for some reason, what yall think about the kumho ecsta mx ku15, im lovin the price and all i do is a little spirited driving from time to time, nothing to serious.

 

245/40 not 235.

 

Have tried 255s but they don't work well on 8' rims . 245 is biggest tyre that works

 

how do the 235/40s work? i found a set local for pretty cheap.

 

You will have more wheel gap, your speedo will read high, you will rack up mileage faster, but your car won't explode.

 

by racking up mileage u mean more mpg's or less lol...

 

255's mount easier on the stock RX8 rim than they do a stock 350z rim!

That said, not many places will mount a 255 or larger on the stock rim, you will have to find a specialty shop, or help mount it, it's a 2 person job with that wide.

Im sure you could fit wider than a 255 on the stock rim, you would need a stiffer tire for racing i assume.

245/40 is the key number. A good combination of agility and extra beneficial grip.

 

I'm not sure on the actual percentage it is off (it's only a few percent), but say you drive 100 miles. The odometer will show 103 or 104 miles because the tires rotated a few hundred more times than the stock sized tires would have.

It will give you an artificial mpg boost. http://www.miata.net/garage/tirecalc.html That will show you actual numbers.

 

245x40 on the stock 18x8 +50 rims are the most popular upgrade and close to the stock circumference (so the mileage/mph will closely match - nothing to do with actual mpg).

 

would a 265/35/18 possibly fit on the rear stock rims?

 

Do/did you happen to own a mustang? Just curious

 

no lmao just askin cuz i found some staggered set of falkens haha, yeah i went with 245/40s, thanks all for your inputs