Miata wheel & tire options: Grassroots Motorsports forum: Grassroots Motorsports Magazine

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March 1, 2011 10:01 p.m. ea_sport Reader

I have one quick question about wheel and tire options for a '96 Miata. I am considering either a TRMotorsports C3M 15X9 or 949Racing 6UL 15X9 for the wheel, for tire I am pretty much set with Hankook R-S3 225/45/15. The purpose is for a fun car, autocross and some track days.

Here's my question, I know I won't be competitive so I am not sure if the approx. 3 lbs per corner weight advantage of the 6UL is worth approx. the extra $440 (after factoring in the mounting and balancing which are free with TireRack and the additional shipping charges for separate wheel and tire purchases). What do you guys think?
March 1, 2011 10:43 p.m. Javelin SuperDork

The 6UL looks $440 better to me than the C3M.
March 1, 2011 11:06 p.m. ea_sport Reader

I 100% agree that the 6UL looks better than the C3M. I was hoping the C3M is more like the MT1. But the question is whether the relative better look and the 3 lbs weight advantage per corner is worth $440 for a wheel-tire combo with a total value of around $940 shipped, mounted and balanced? That's almost 50% more expensive.
March 2, 2011 12:17 a.m. unevolved Dork

Is there any particular reason you're running the 15x9s with 225/45/15 RS3s? That tire works quite well with the 15x8s, which would save a bit of money.
March 2, 2011 6:02 a.m. mw HalfDork

I would personally buy the c3m's. With the money saved, you could almost get another set of tires. I bet the fresh tires would offset the weight penalty half way through the season.
March 2, 2011 10:06 a.m. Keith SuperDork

15x9s are faster than 15x8s, but you can get a 15x8 C1 from Tire Rack as well.

There's no absolute answer for this question. Are the 6ULs a superior choice, technically? Yes. Are they more expensive? Yes (don't forget to add the lug nuts and 8 valve stems for an apples/apples comparison). Are they worth the extra money? Only you and your budget can answer that.
March 2, 2011 11:18 a.m. ea_sport Reader

Although I like the look of the 6UL better I think I'll go with TRMotorsports since it is way cheaper and I am not that competitive so probably 3 lbs per corner won't make that much difference for me. For a more serious autocrosser it probably makes a difference but most likely not for me.

Keith, the 15X8 C1 is only $10 cheaper than the 15X9 C3M so I'll probably go with the C3M. I agree I should've included the lug nuts and the valve stems for apples/apples comparison.
March 2, 2011 11:23 a.m. Duke SuperDork

Keith wrote:

15x9s are faster than 15x8s, but you can get a 15x8 C1 from Tire Rack as well.

There's no absolute answer for this question. Are the 6ULs a superior choice, technically? Yes. Are they more expensive? Yes (don't forget to add the lug nuts and 8 valve stems for an apples/apples comparison). Are they worth the extra money? Only you and your budget can answer that.

Keith, I'm looking into this same question. Do I need to roll the fenders with a 225/45/15 on 9 inch rims?
March 2, 2011 11:28 a.m. Ian F SuperDork

unevolved wrote:

Is there any particular reason you're running the 15x9s with 225/45/15 RS3s? That tire works quite well with the 15x8s, which would save a bit of money.

According to Mr. Hollis, while the RS3 works well on the 8" rim, it works better on the 9".

One advantage of stepping up to the 9" rim now is if you get bored with ST* and decide to bump to CSP and those 275 A6's, you won't have to get new rims.
March 2, 2011 11:31 a.m. Keith SuperDork

Duke wrote:

Keith wrote:

15x9s are faster than 15x8s, but you can get a 15x8 C1 from Tire Rack as well.

There's no absolute answer for this question. Are the 6ULs a superior choice, technically? Yes. Are they more expensive? Yes (don't forget to add the lug nuts and 8 valve stems for an apples/apples comparison). Are they worth the extra money? Only you and your budget can answer that.

Keith, I'm looking into this same question. Do I need to roll the fenders with a 225/45/15 on 9 inch rims?

On a 1990-97, yes, a little bit. On a 1999-05, no.
March 2, 2011 11:35 a.m. unevolved Dork

Ian F wrote:

unevolved wrote:

Is there any particular reason you're running the 15x9s with 225/45/15 RS3s? That tire works quite well with the 15x8s, which would save a bit of money.

According to Mr. Hollis, while the RS3 works well on the 8" rim, it works better on the 9".

Interesting, I'd never heard that before. I'm guessing that's from stiffening up the sidewall a bit?
March 2, 2011 11:50 a.m. Ian F SuperDork

unevolved wrote: Interesting, I'd never heard that before. I'm guessing that's from stiffening up the sidewall a bit?

Something like that. Something about being able to run lower pressures for better grip but still maintaining a stiff sidewall. IIRC, he goes into more depth on the subject over on SCCAforums.
March 2, 2011 12:06 p.m. Duke SuperDork

In reply to Keith:

OK, thanks as always for the info! Maybe that will be next spring's budget issue / project.
March 2, 2011 12:37 p.m. Tom Heath Web Manager

Duke wrote:

Keith wrote:

15x9s are faster than 15x8s, but you can get a 15x8 C1 from Tire Rack as well.

There's no absolute answer for this question. Are the 6ULs a superior choice, technically? Yes. Are they more expensive? Yes (don't forget to add the lug nuts and 8 valve stems for an apples/apples comparison). Are they worth the extra money? Only you and your budget can answer that.

Keith, I'm looking into this same question. Do I need to roll the fenders with a 225/45/15 on 9 inch rims?

I did. It's not terribly difficult, but using the right tool is important.

Also, use LOTS of heat to keep your paint from cracking.