James1970

I need to replace the tires on my 70'. Currently running 225/70 R15, Goodyears (10+ years old) on stock ralley wheels (15 x 4 I believe. How can I verify the rim size?)

According to TIRE RACK (www.tirerack.com), the stock tire for the 70' C3 was 205/75 R15 (can that be right?).

Questions:

1. Am I doing any damage running the larger 225's vs. 205's? (Since 1987 I've been running 225's with no apparent issues)

2. Two tires I'm considering:
a. Firestone Firehawk Indy 500. $66.00 ea. (ranked #1 on TIRE RACK).
b. Coker Tire BPGoodrich Redline Radial #18520 in 225/70 R15. $171.00 ea. (were redlines an option in 70'? Is this a unbranded TA Radial or one of lessor quality?)

Thanks for your input. I do appreciate the education.

Sincerely,

James1970

PRNDL

15 X 8 you mean?

See if you can make out the code stamped in the wheel on either side of the valve stem.

1. no, 225/70 are no problem. Guys run wider tires and a common question is, "How wide can I go" but 225/70 are very close to the original size.

2. redlines look cool, but I don't think were an option in 1970

http://www.idavette.net/facts/70.htm

looks like white stripe and white letter were options.

Not sure what quality the coker repros are.

Xakk

225/70 was stock for the rally rims.

MYBAD79

You have either 15x7 or 15x8 rims, on both you can fit a 225-70-15 tire without problems.
I just saw some nice whitewalls in 215-70-15 at the local Firestone shop, would look great on the rallies with the chrome trim rings. I think they sell these for around $50 each, it's one of their no-name brands, Futura or something ...

James1970

PRNDL,

Thanks for the 70' specification link. I'll check the rims this evening to verify they're 15 x 8 (thanks for catching my typo).

Believe I'll stay with the 225/R70-15's. Out of curiosity, what size would provide a slightly wider tread?

Finally, although I love the look of redlines, since they were not offered in 70', would clash against my Monza Red paint (more orange than red), and cost almost 3X more than a standard radial replacement, it's raised white letters once again!

Thanks to all forum members for your input.

Best Regards,

James1970

MYBAD79

front 245-60-15, rear 255-60-15

that's on the safe side, it won't rub

James1970

I noticed that Mid America is selling 255/60-R15's (no 245's offered, hmmm?). You SURE these are compatible with the 15 x 8 Rally rim? Any turning / handling / fender issues I should be aware of?

I'd love the look of a wider tire but as you can see, I'm apprehensive.

Regards,

James

MYBAD79

many run the 255-60s on all four corners, some rub, some don't... the C3s are all different... it's no issue on the rear axle but for the front I'd get the 245-60 to make sure there's no rubbing.
I'd get the tires locally, Discounttire (www.tires.com) should have several brands for $60 and up.
turning and handling issues ? Yes, it will be better than with the 225-70s

THE ROOSTER

a good ole boy told me "if it's round, run it"... I promise that's what I was told at a tire store... Want to know my next move??? LEAVE!!!

Jims79

James, you can get the 245/60/15 for the front at tirerack.com and matching 255/60/15 for the rear many brands to pick from

PRNDL

Here is a neat calculator that lets you compare, and SEE 2 different tire sizes overlaid.

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


Another thing to consider is that wider tires may look cool, but they can make your car much harder to handle, at least it did mine. Especially if your steering is a little loose to begin with, the wider tires will follow ruts in the road. I got a significant improvement in handling when I went from 235/60 to 225/70 tires.

MYBAD79

now that should be exactly opposite, the 225-70's sidewall is flexing so much ... ... it should be a lot worse than a 235-60 or 245-60. Did you only change the size or the brand/manufacturer also ?? FWIW, I used to run 275-40-17 Sumitomo tires on my DD and these were horrible, there could be a penny on the road and it would affect my steering wheel when hitting it..... terrible tires..... now I'm running the same size Goodyear Eagles and it's a huge (did I say HUGE?) improvement

KW

here is a couple of pics
225 70's



255 60's

James1970

Thanks to all for the additional information.

PRNDL: That tire calculator link is very cool!
RedBad79: Great insight!
KW: Thanks for posting the photos! I can now envision the difference.

Starting to lean toward the 255's.

Best Regards,

James

theandies

I run 255 60 R15 on all 4 corners with Rally’s. No rubbing at all. I do have offset t-arms but I was running the 255's before I installed them. One day I want to go to 10-inch rims on the back so I upgraded to the offset t-arms. Most people complain about the 255's rubbing up front. I am running Goodyear Eagle GT2's

Corz

235/60 and 255/60 here

James1970

ah, those sure don't look like Rally's....

BlueL36

Stock size on mine- the 215's. No need for bigger since I don't abuse the old '68. And I don't have issues with rubbing, wandering, or speedometer error.

6t9427

255/60 Comp TA's on 15x8 rallys all the way around. No rubbing.

Blue 74

Those are the sizes I'm running and the only problem I have had was one time while backing up, uphill, and turning to the left my left front tire rubbed the fender outer lip. I now believe this is because, like some others my car is not centered over the front tires. The drivers front tire sits about 1" farther out than the pass. side.
New tires scheduled for March and am staying with the same sizes.