https://www.i-club.com/forums/showth...10#post2149810

 

Jess, I am running 18x8.5 Advans on my STi and I am using 235/40/18 Falken FK452s, and i think it fits perfectly

 

what suspension are you running? i am going to check it out again at the meet, are you going?

 

18x8 Gram Lights +43offset with 235/40/18's. 225/40/18's are slightly smaller in diameter than stock...235/40/18's are slightly larger in diameter.

The 235/40/18's fill out my wheel wells very nicely...

I'm running Cusco struts with about 1.5 finger gap between the tire and wheel well opening.

To me, I've always wanted to run 255/35/18's on an 8.5/9" rim...this would ensure the correct diameter...very wide...

 

Tein Flex, and probably not going to tomorrow's meet, its so far out there lol

 

hmmm looks like 255/35/18 might be the winner

 

its all freeway miles you'll be there sooner than you think

 

I'll try to make it out there, if my friend doesnt host a spring break party at his house

 

Jess, I have lying around my room the formula to figuring about the best tires size +wheels comb when plus sizing from factory. Ill go digging around for it...

walter

 

Hey Jess,

I cant find it so Im just going by memory..

Calculate first by taking the numbers you get from using this formula for the stock rim and tires..

Formula:
(Measuring your Stock BBS Wheels


Width of tires x Aspect ratio / by 25.4 mm = x amount of inches of sidewall x2, +17'' rims = x amount of inces of tire and wheel.. So if you were going with 18'' rims, just enter the numbers that will give you close to the x amount of inches of tire & Wheel from doing the calculations for the stock wheel & tire combo.. Hope its not confusing, sorry if it is..

 

Click on the link below:

http://www.miata.net/garage/tirecalc.html

put in your stock tire size of 225/45/17

then put in your new tire size...it will calculate the difference between the two for you...and give you a graphic as well...

 

Brent thats a nice little calculator..
Thanks!

 

Thanks for all the help everyone.......I ended up talking to Dan at Suby Dude and he recommended 255/35/18 for my setup.....
So I went with the G-Force KDW2 as my tire choice.

 

I vote for this or wider if possible...wider is better in most cases.