Raithan

Hey guys, in the summer when I put my wheels back on, I'm gonna buy some performance tires, I was looking at the Kumho ECSTA Supra 712's.. I was wondering, I have 15 inch wheels (don't ask me why, I got lazy and just settled for what I found).. right now I have P195/60/R15 tires on them, do you guys think P205/50/R15's would look ok? Thanks..

Random

205 50's would mess up your speedo /odo readings.

Go with 205 55 or 215 50's. However, how WIDE are your rims. 215's are almost 8" wide and would NOT work on 6" rims....

Raithan

The rims are 15 by 7.. My main problem is that I think it looks stupid to have such a thick tire surrounding the rim... My mistake was in buying 15 inch rims and after I had them on, I stepped back and looked at it, and it just looks weird to have small rims and big tires, so I was hoping to take the profile down a little bit. So either a 205/55/15 or 215/50/15? Thanks again.

Iago

If you take down the profile without enlarging the diameter of the rim, you are going to throw your speedometer and odometer off. They're calibrated to work with a set TOTAL wheel + tire diameter. Getting a lower profile tire on the same size rim will make that total diameter smaller, which will cause your speedometer to register speeds higher than what you're actually going.

Raithan

Can't you have that adjusted though? On my old car I think I had my speedo reclibrated when I first got it.. I can't remember for sure if I did though. But I was thinkin if I went lower profile, I could have the speedo recalibrated, or if nothing else, couldn't I just use the cheese method of driving w/ next to a friend who has cruise control on? smile.gif Thanks guys

Guilty

I had a set 205/50/15 on my stock tiby wheels looked okay but it made it sit lower then usual. I don't know how much the speedo was off b/c I usually drive fast and pass people all the time so it didn't seem like there was any difference between them. But I know it will throw speedo off.

KayJai

It won't be off that much,... here, use this to find out what tire size you need. http://www.miata.net/garage/tirecalc.html

If stock is 195/60/15's and you want to go to 205's you'll need 205/55/15's to keep the speedo somewhat close.
Or you could just get it re-calabrated,...
Weird thing is, our tire size up here is 195/55/R15's a little bit of a lower profile, guess the speedo is setup different,.. I'm going to be getting the same tires you are next spring.

Mario

Sent you a mail with a simple excel model. Plug in your original specs and then just plug and play. The closer the total diameter the more precise the speedo!

Raithan

Thanks guys for your help.. I guess though changing tire size wouldn't really help my cause, basically I'm trying to get a lower profile tire because I don't like how high the wall is on my current ones, and I guess the only way I can do that w/o screwin up speedo and odo is to get bigger rims.. I'm kinda pissed I didn't think before I bought 15s. Thanks for your help anyways though guys. I'm thinkin I'll go with 205/55/15s... at least they're a lil bit wider so I'll have a bit better grip.

Mario

You can go wider with the 50's or 55's. 195 60 15 is 24.21 inches in diameter, 205 55 15 is 23.87 is ok, 215 55 15 is 24.31 is ok too and 225 50 15 is 23.85 which is ok The best is 215 55 15 (don't know if available) second best 205 55 15 and 225 50 15 (available?)and are on the limit but ok in my opinion.