RX-8 wheel/tire combo?

[shoogerfree]

I recently picked up some used RX-8 wheels. I'm thinking about getting 235/40/18's I want a tire wider than the stock MS3 tires, but not lower profile or taller. I want something as close to stock tire diameter as possible. Will there be any clearance issues with this size tire on RX-8 wheels? I'm on Cobb springs.

 

[CnoTataymo]

The tire closest to the stock tire diameter is indeed 235/40's. It's barely shorter. If you're on stock suspension, there are chances you will rub unloaded or not. With stiffer springs, you probably won't. Also, you might need to roll your rear fenders.

 

[Nliiitend1]

There is actually probably LESS of a chance of rubbing on the stock suspension. The Cobb springs are not stiff enough to prevent the compression of the suspension to a degree that would prevent rubbing.

I'll let you know after this weekend how a stock suspended car does with this setup, as I'll be getting my new 235/40R18 Kumho XSs (just arrived yesterday!) mounted onto my RX-8 wheels.

I'm hoping I won't need any fender rolling, but I have the tool handy if it comes down to it.

 

[shoogerfree]

There is actually probably LESS of a chance of rubbing on the stock suspension. The Cobb springs are not stiff enough to prevent the compression of the suspension to a degree that would prevent rubbing.

I'll let you know after this weekend how a stock suspended car does with this setup, as I'll be getting my new 235/40R18 Kumho XSs (just arrived yesterday!) mounted onto my RX-8 wheels.

I'm hoping I won't need any fender rolling, but I have the tool handy if it comes down to it.

Yes, please do let me know how it works out for you. I would also love to see some pics of the fitment if you can get them. Thanks.

 

[6262MS3]

I'm also interested in oem rx8 rims for next spring (stock rubber is done after two summers, ouch), so I'd love to know once and for all if 235's clear without rolling the rear fenders.

 

[SwampAss]

my 235s rub

 

[Mid_Life_Crisis]

I forget the offset of the RX8 rims. I have 235s on 8 inch rims with a 52 offset and not a sign of contact. I also have Cobb springs.

 

[shoogerfree]

I forget the offset of the RX8 rims. I have 235s on 8 inch rims with a 52 offset and not a sign of contact. I also have Cobb springs.

That's good to know. I believe offset is 50.

Cobb springs are stiffer than stock and only about an inch lower, so it may be less likely to rub with Cobb than with stock.

 

[Nliiitend1]

That's good to know. I believe offset is 50.

Cobb springs are stiffer than stock and only about an inch lower, so it may be less likely to rub with Cobb than with stock.

Not likely, since they still aren't stiff enough to prevent bottoming out. I would bet, judging by the spring rates and amount of drop, that a car on Cobb springs probably bottoms-out as much as if not more than a car on stock springs...

 

[Nliiitend1]

Yes, please do let me know how it works out for you. I would also love to see some pics of the fitment if you can get them. Thanks.

Well, I have the tires but they aren't mounted on the wheels yet. I did measure the width unmounted though, and they're a C-hair under 9.5 inches wide.

I'll give an update once they're mounted (hopefully Friday or Saturday).

 

[Mid_Life_Crisis]

I forget the offset of the RX8 rims. I have 235s on 8 inch rims with a 52 offset and not a sign of contact. I also have Cobb springs.

I should have mentioned that I almost always drive alone. When the family goes anywhere we take the wife's Ram Quad Cab. Never having anyone in the back seat might make a bit of a difference.

 

[Nliiitend1]

Tires right after delivery from TireRack's GA warehouse:

Here's the car after getting the tires mounted and "road force balanced" yesterday (I apologize if it looks dirty, as I didn't wash it for the pictures):

 

[MS3Zoom24]

What kind of tires did you get there?

 

[Nliiitend1]

They're the brand-mew Kumho AutoX/ST tire:

Kumho Ecsta XS (KU36)

 

[mysleeper6]

Ouch 180 treadwear...are you planning to use these for daily driving or just autox?

 

[Nliiitend1]

Ouch 180 treadwear...are you planning to use these for daily driving or just autox?

Uh, have you looked at the treadwear rating of the stock RE050As?

140

I know that you can't necessarily compare treadwear ratings across different manufacturers, but that's still a low number for an OEM tire...

I will be using these for both DD duty and AutoX/track days until they are gone, and then I will move on to the next set of tires.

 

[mysleeper6]

I know the stock treadware was bad too. I also bought a set of RX-8 wheels to use as my summer set up. I'm currently on Kumho Ecsta ASX 225/40R18 on the OEM MS6 wheels (420 AA A). I'm afraid of rubbing and don't want to roll the fenders, so I think I'm sticking with the same size for the summer tires. Looking at Kumho SPT (320 AA A) and the General Exclaim UHP (380 A A)

 

[shoogerfree]

Those look awesome! That's the kind of width this car needs. Looks perfect. Any rubbing?

 

[Nliiitend1]

Those look awesome! That's the kind of width this car needs. Looks perfect. Any rubbing?

Not yet, though I haven't driven the car fully loaded or with 3+ passengers yet. I'll try to update this thread if I experience any...

 

[PCspeed3]

Should I stay away from RX-8 replica wheels? I would like to get some come spring but I am having a tough time finding OEM.