V2Rocket

odd, i drove by one of those roadside digital speed signs that measure you as you go by...speedo indicated 50ish and the sign said like 46.

alex

Spencer- mine has done that since the accident, I don't know why. There is no evidence that the tires are rubbing on the fender and I don't have the plastic liners in. If I could find any marks on the fender or grooves on the shoulders of the tires it would help diagnose, but no dice. I almost started thinking it was a strut issue (it only happens when they are close to bottoming out)- like maybe they were damaged from the front of the car going airborne.

cie_lab

+1 on wrong offset. That would be my guess. I've always thought your wheels looked like they stuck out a bit too much.

V2Rocket

thats the thing, my wheels dont stick out at all

the fronts are 7's and they come out right to the edge of the fender and it looks really nice. the backs are 8's and still have maybe an inch to go before filling in that area.

ive never had this problem before so im 99% sure its the tires...maybe they're just too tall.

Erzengal

I think 225/50/15 will still be off. I had that before and my speedo didn't match those digital thingys.

cie_lab

I think 225/60s ARE taller than 215/60s. There's a very good website that graphically showes the differences. Put in the numbers and you'll see. It also gives speedo adjustments.

Of course, I can't remember the site. Google something like Tire Specifications or Tire Sizes or something like that.

cie_lab

Try this spencer:

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

V2Rocket

yea the 225/60s are 1.2 cm taller than 215/60s..that's more than enough to stop rubbing. if i got a 225/50 it would drop the diameter over an inch...speedo would read fast but whatever.

JohanvdWalt

I found that in my silver with standard size wheels the speedo is very optimistic about 15%, the red car with 235x40x18 and 265x35x18 its still about 2% optimistic.

Mongo

Hey Spencer where did you get your tires from? There are tire stores out there that have a Customer Satisfaction policy where they can swap the tires for you if you're dissatisfied with them at either no charge or a small additional fee.

I had Fuzion ZRis on my 944 at a 205/50/15 size and I hated them. For $60 more they put Bridgestone Potenza G009s on it with Road Hazard.

V2Rocket

costco in poway :/

Mongo

There's no guarantee with them?

alex

I've had very good luck with costco. I lost a rear tire (265/35/18) and they couldn't get another one. They told me to buy one somewhere else, bring the bad tire back, and they'd give me a cash refund for tread life. They did, it was over $100.

Not exactly what you are dealing with, but may be worth a try.

JohanvdWalt

Now that's the kind of people I like to support.

Johan

V2Rocket

ill have to read into the fine print...