215/45/18 to 225/45/18

[Antonio DiMarco]

Anyone see an issue with increasing the tire width on a MS3 to 225? This would be on the factory rims? The factory tires are 215. Increasing to 225 gives you a helluva lot more choices.

 

[major error]

That jump will make your speedo readout 2.8% slow...
225/40-18 is only .7% fast.

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

 

[Antonio DiMarco]

I didn't realize...

That jump will make your speedo readout 2.8% slow...
225/40-18 is only .7% fast.

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

...That an increase in width effected height. Thank you for the info

 

[h0rde]

Actually according to the calculator, the change from 215/45 18 to 225/45 18 only causes a 1.4% speedo difference, not 2.8. I've got 225/45 18s on my stock wheels.

 

[ill_eagle94]

Could you go to a 245/40-18? Thats a bit closer to stock diameter.

I don't know the width of the stock rims, so it may not even be possible.

 

[h0rde]

Could you go to a 245/40-18? Thats a bit closer to stock diameter.

I don't know the width of the stock rims, so it may not even be possible.

245 probably wouldn't be a good idea on the stock wheel, that would be stretching a bit much.

 

[maczter]

245 probably wouldn't be a good idea on the stock wheel, that would be stretching a bit much.

There are some folks on here who've done it with little to no rubbing issues.

 

[WagonMan]

There are some folks on here who've done it with little to no rubbing issues.

You can go to a 245 on the stock rim with no rubbing, but a 245 on a stock rim is pushing it. That tire is too wide for the rim, you won't gain much in contact patch vs a 225, and 245s cost a lot more.

My winter tires are 225x45x18 on the stock rims and they work great. I think there is better selection in the 225x45x18 size then the 225x40x18 size. I really never noticed any speedo problems, but that being said the error is so small it is not worth worrying about.

 

[maczter]

You can go to a 245 on the stock rim with no rubbing, but a 245 on a stock rim is pushing it. That tire is too wide for the rim, you won't gain much in contact patch vs a 225, and 245s cost a lot more.

My winter tires are 225x45x18 on the stock rims and they work great. I think there is better selection in the 225x45x18 size then the 225x40x18 size. I really never noticed any speedo problems, but that being said the error is so small it is not worth worrying about.

(wiggle)

Hah. You're right. I totally missed the "on the stock rims" part of the post I was replying to. 245 wouldn't be wise on the stock rims. Need an 8.0 or 8.5 wide rim to run 245's safely, IIRC.

 

[Antonio DiMarco]

Maybe not speedo issues, but...

You can go to a 245 on the stock rim with no rubbing, but a 245 on a stock rim is pushing it. That tire is too wide for the rim, you won't gain much in contact patch vs a 225, and 245s cost a lot more.

My winter tires are 225x45x18 on the stock rims and they work great. I think there is better selection in the 225x45x18 size then the 225x40x18 size. I really never noticed any speedo problems, but that being said the error is so small it is not worth worrying about.

What about issues with DSC and antilocks? Or is the computer smart enough to compensate?

 

[WagonMan]

What about issues with DSC and antilocks? Or is the computer smart enough to compensate?

No issues at all, ABS worked fine, and seemed to work when it was supposed to. Same with DSC, never noticed any difference due to the different tire size.