Some tire/wheel/clearance help, please.

[MikeHTally]

I bought some 18x8 +50 offset RX-8 wheels at a pretty good price. Thinking of a 235/45x18 tire. From what I've read, there should be no issues with clearance in the fenders (stock suspension except for a Cobb RSB). However, I don't want to spend nearly $800 on tires to find they won't fit.

Also, will the TPMS sensors from the stock 18x7s work in the RX-8 wheels or do I need to spring for new sensors (ugh)? Apparently there may be a difference here, and I also don't want to have the TPMS lamp on, and I'd prefer not to add another $280 or so to the project.

Some input from someone who's done this exact thing would be appreciated. I could go for 225s, but I'd rather get 235s.

 

[wisniaPl]

tmps should work, and tires go with 235/40 instead of 235/45 it might be a bit to high and rub

 

[meha11]

use this, it is a great tool

http://www.wheelsmaster.com/rt_specs.jsp

 

[MikeHTally]

Wheelsmaster says 235/45s will fit with no issues. The suspension and brake clearance as well as the fender clearance differences are "acceptable for most cars". I'm just a bit leery of buying 235/45s to find it isn't quite so. I considered 235/40s, but I think I'd prefer 225/45s if the 235s won't work.

I'd just like to hear from someone who "bit the bullet" and tried this exact combo. I talked to Discount Tire, and they weren't sure about the sensors or the fit. They'd just want to try it and see what they get, which sounds very time-consuming and a trifle more expensive than perhaps it needs to be.

 

[Hank3]

Definitely keep up posted, Mike. Hopefully someone will chime in before tomorrow Someone has got to since I've seen a good number of members rock these wheels. Good choice in going with Discount, though. I've always had a good experience with them - especially the one by the flyover.

 

[fasteract]

I know that my stock TPMS's worked when transplanted to my RX-8 rims( Owner's manual has a section on activating them)...I can't help with the tire question..using 225/45-18's S0-3 Pole Position's. I'd suggest using the usual extra $$ needed for the larger tire size to upgrade the 225 quality, jusy my opinion. I have had DOT R tires in smaller sizes outhandle the snot out of their wider mundane brethren.

 

[udontknowjack]

tmps should work, and tires go with 235/40 instead of 235/45 it might be a bit to high and rub

+1

http://www.1010tires.com/TireSizeCalculator.asp?action=submit
23540/18 fit better anyways

235/40/18 or u'll be sorry

 

[Rotus]

I have this exact setup and I have rubbed. It's one very specific set of circumstances, though. Extreme extension and rebound of the suspension like when you hit a dip and then the rise on the other side (or vice versa). It rubs at the front (?) of the lip just a few inches above where the side skirt attatches to the fender. Took a small slice out of the tire, too.

I'll be getting the lip rolled as soon as I can find someone around here.

I still prefer the 235/40 over the 225/45, it's just the closest you can get to stock rolling diameter.

I just saw you were thinking of putting 235/45, don't.

 

[MikeHTally]

I talked to the dealer -- the sensor part number for both cars is the same, so that concern is taken care of. Still doin' homework, but it sounds like I'm 'bout to go with 225/45s. I'm too much the geezer to want the "rubber band" look.

 

[Rotus]

I talked to the dealer -- the sensor part number for both cars is the same, so that concern is taken care of. Still doin' homework, but it sounds like I'm 'bout to go with 225/45s. I'm too much the geezer to want the "rubber band" look.

You must be so much of a geezer that fractions were not yet invented.

215/45/18 sidewall height is 215mm * 45% = 96.75mm * 2 = 193.50mm

235/40/18 sidewall height is 235mm * 40% = 94mm * 2 = 188mm

225/45/18 sidewall height is 225mm * 45% = 101.25mm * 2 = 202.5mm

225/40/18 sidewall height is 225mm * 40% = 90mm * 2 = 180mm

235/40/18 is the closest to stock. Just because it's a 40 series doesn't mean it's thin.

 

[MikeHTally]

I'm well aware of how to figure out tire sizes, thanks. IMO, the stock 215/45s don't quite fill the wheel wells as they should. The 235/40s are a trifle smaller than stock and .6" smaller than 225/45s. Doesn't sound like much, but it'll be noticeable.

 

[ericrapp]

Faster act has a good point on traction and tires. If you are looking to appear more aggressive maybe lower the car little. Also I think some tires really can appear much different even though they might all be sized at 225/40/18s or whatever. Mike, I would suggest 40s with the 225. I think you will be pleased.

 

[MikeHTally]

Thanks for all the input folks. I have an appointment with Discount tomorrow. Still working on curb rash and dings on the RX-8 wheels. Tomorrow morning the wheels get a bath and I get my fur trimmed, then off to Discount for Yokohama S.drives, either 225/45 or 235/40s. I truly appreciate the input.

 

[Hank3]

How bad is the curb rash and dings Mike? Don't know if you've heard of Alloy Wheel Repair in town. I know the two girls that run the business as they live a block from where I live. They're actually gonna fix up my stock MS3 wheels soon. They've done good work on my WRX rims and my brother's 350Z rims. And they're a mobile service to boot!

 

[MikeHTally]

They're not bad -- mostly scratches and scrapes, plus a ding or two. I've filed down the worst and painted them with touch-up paint. I've not heard of Alloy Wheel Repair, though. I guess it won't hurt for me to contact them, thanks for the tip.

 

[Kain]

To piggyback off of this thread, those that have taken the stock TPMS & tires and installed them in RX-8 wheels, did you have to recalibrate the sensors?

 

[fasteract]

My experience with my MS3 and the TPMS swap to my RX8 rims followed the section in the Owner;s Manual where it tells you how you can "activate" the new sensors if you don't want to take it to Mazda...as far as "recalibrating" them to activate at another psi level, only the Dealer can do that per his laptop/OBDII. The Mazdaspeed 3 sensors will turn on the dash light at 5 psi below normal, door sill printed psi settings...I have never found a set that activates above the usual psi settings for obvious reasons.

 

[Mike V]

For what it's worth, I had 225/45 Kumho SPT on the stock wheels and had rubbing issues on the inner fender due to the increased height. You will most likely have issues with 235/45 but should be fine with 235/40.

 

[MikeHTally]

Pulled the trigger on a set of Yokohama YK520s. 225/45s nicely fill out the wheel wells. Man, I love the look of RX-8 wheels on the MS3. If someone will coach me, I'll post some pics tomorrow after she's had her bath (she's been slogging around in the aftermath of Fay). All I've been able to do is post thumbnails.

 

[Hank3]

Mike - you've got host your pictures first on a Web site (i.e. Photobucket). Then get the URL Photbucket creates for the picture(s), click on the yellow box with two mountains, insert the URL and you'll be good.