Why have a square wheel setup and different tires? It's not wrong I guess just seems odd.

With stock alignment you may need to roll the rear fenders slightly.

With everything I read I was worried the 265s would fit in the front. I would rather have them all the same.

I agree it might be tight, I just don't have experience to say. But if you think so, maybe go with narrower front wheels too then. I have 8.5 front and 9.5 rear for that reason.

Thanks. I just don't understand tire sizes. Every time I think I have it I read another thread and it makes no sense to me. The larger the first number, the wider the tire right?

First number is section width in mm. So that's how wide the tire is (not at the tread but at the widest point). Second is aspect ratio. So the height of the sidewall as a percent of section width. Third is rim diameter in inches.

If you have a 225/40R18, it's 225mm wide at the widest point (this is a nominal measurement so can be off a couple mm). It's 225*40%=90mm tall sidewall. It fits an 18in rim.

If you have a 235/40R18, the width is the same but the sidewall is larger (235*40%=94mm) so the outside diameter of the tire is larger too.


I have 19x8.5 +36 front with 245/35R19 and 19x9.5 +43 rear with 255/35R19. I have Michelin Pilot Super Sports and everyone will tell you I can fit 265/35R19 tires but I had those and they rubbed. I went to 255 to clear stock fenders. What nobody seems to get is that section width is not tread width and that it's a nominal measurement anyhow. Michelin runs wide here.

I am on stock alignment, was on stock suspension but now on MazdaSpeed shocks and springs, stock fenders, no issues.

Look, it’s more likely to rub in the rear with 265 with 9.5 +35, but might depend more for n the actual tire because the manufacturer can put any number on it they want and the width varies between manufacturers. If it’s that big of a concern to you then just put 255 on all four corners. Regardless, use the same size all around. You can then rotate any wheel to any corner. Unless you’re Richie Rich and throwing money at expensive tires is no big deal. No offense to anyone, but the people who put non-square setups on this car are not too bright. They don’t understand the subject any more than you do.

Thanks Team, took me until the last post to home in on an answer :banghead:
OEM suspension setup and ride height with no intention to lower. I hate spacers but ran 25mm on all 4 corners to see how much i could get away with on stock rims with 225/45 DWS continentals. No rubbing, but it sure looks like it should !
Time for wheel replacements, and 100% agree with staying square. Strongly Considering ESR SR07 18x9.5 +35 with 255 tires on Teams recommendation above. This would seem to result in the same flush appearance as my spaced stockers. Would like to stay with the 45 profile though, to preserve some semblance of riding comfort, unless someone talks me out of it.
What do you think ?

it should be fine, but as far as how close it will be to the fender, you should confirm what you have now, measure to the fender, and then calculate how that compares to what the new setup is.
.

Front and rear:
18" diameter
9.5" width +38 offset

Completely stock suspension setup, and also looking for tire ideas also. This is my first time changing rims so any other tips would be appreciated.

I run 18x9.5" wheels with a +45 offset and the inside lips would grind against the suspension components at full wheel lock, so perhaps the extra 7mm of clearance on your +38mm setup will save you from that. I fixed that with 20mm spacers myself. As far as tire-scrubbing, they were fine with 225/40, 235/40, and 245/40 tires. I hear 255/35 tires can work as well, but 255/40 and up will require some fender-rolling, gutting, flaring, etc. (more extreme as your size of tire increases). I'm currently running 265/40 in front and 275/40 in rear, and dropped about 1.5-2" on KONI Yellow struts and TEIN S.TECH springs, and I only get rubbing on the front tires at full wheel-lock - but I have aggressively rolled/gutted/flared all of my fenders to accomplish this so I don't know how far you wanna go there.

You might wanna consider a minor suspension drop as well, 18" wheels with low-profile tires look kind of goofy with the wheel-gap that stock suspension causes.


https://cimg6.ibsrv.net/gimg/www.rx8...306ddb0cbe.jpg
https://cimg4.ibsrv.net/gimg/www.rx8...874aef8475.jpg
https://cimg0.ibsrv.net/gimg/www.rx8...a9c559a130.jpg

Hi all,

I've got a stock RX-8. No suspension/camber mods, rolled fenders or anything. Wanting to change my wheels and my local dealer gave me these sizes as options for the wheels that I wanted.
18X9.5 +22
18X8.5" +30

I've also got recently purchased tyres with this specs 245/40/18.

Really looking into getting the wider 9.5 as they will look better but not sure if the offset is enough for the tyres. Is this too aggressive?

Appreciate all the help.

You will have a fair amount of work to do with 9.5 +22
You will have to find about 3/4 inch with camber and fender work... not going to be too easy

The 8.5 +30 would fit better but its no wider rim than stock... so you have to decide if thats what you want.

9.5 x 45 fits without much work... so thats about the same outer position as the 8.5+30 ,give or take.

I think you have to decide how much work you want to do and start there

Hey Dann,

Thanks for the info. Unfortunately, 9.5 +45 isn't available for those wheels. You reckon rolling my fender or chaging tyres would be enough to make the 9.5 +22 work? My car is a 2010 s2 by the way, not sure if that makes any difference.

Not easily.... camber and a heavy roll or pull will do it though. Others have made that offset fit.

You could just find another wheel?

Or go with the 8.5 if you don't plan on running bigger than than the 245 tires

Rx8 fitment
 

I am looking for wheels for my 2005 rx8. I’m really looking to fill in the gap between the fenders and wheel and I’m having a hard time understanding. I want to run a 18x9.5x38 rim all around and a 245/40/18 tire and I’m wondering if this will rub my car is currently not lowered but I will lower the car after the rims to be flush if needed. So what do you say will it fit perfectly?!?

That size should fit... will likely need a fender roll, but should be close depending on the tire sidewall profile

what tire sidewall profile would you recommend though? Do you think if I lower the aspect ratio to 35 rather than 40 that I will fit? I have never done a fender roll and reluctant to do so. I know it will be inevitable as I plan to lower the car in the future.

Its more the tire brand.. some have square profiles and some more rounded.

I think that it won't matter with the 245 tires
its more of a problem with 275's

the taller/bigger the tire OD is the more likely you are to have trouble, keeping it below 25.5” is best

just stating that for the 19” and up wagon wheel peoples ...
.

275/30/19 on 19x9.5 +50
 

275/30/19 on 19x9.5 +50 all around? OD is 25.5 and the rim will extend 19.1mm more than stock both inside and outside. Will that hit suspension strut? Rub during turns? I don’t want to go lower offset - I have attached a photo of just how little space I have left on the outside with stock sport suspension at full load with 20mm spacers on stock rims with 245/40.
https://cimg2.ibsrv.net/gimg/www.rx8...a9206b23a.jpeg

Cosmis MRII
 

I'm thinking of running this setup, MRII Hyper Bronze Wheel 18x9.5 +15mm 5x114.3. I am on ksport coil overs
WILL IT FIT

I hope you're good with a fender roller

Not easily for sure at that offset. You are going to need to find about an inch someplace

no problemo ...


https://cimg7.ibsrv.net/gimg/www.rx8...4468911286.jpg



https://cimg8.ibsrv.net/gimg/www.rx8...c0dadcaf13.jpg

Will Tire be flush
 

So I plan on running black RPF1s wheels 18/9.5+38 with Achilles ATR sport 2 tire 245/40/18 on stock suspension. I’m worried that the wheel will poke out of the fender!!! I really just want to get the flush look do you think that the wheel will be flush or stick out of the fender and if you have an estimate of how much?