HELP MICHELIN SUPER SPORTS QUESTION

Here's what you want to calculate that size.

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

The sizes you stated do not look right!

 

As an alternative, you can never go wrong speaking with the experts at the Tire Rack. They will tell you if they will work, or what will. You aren't obligated to buy from them. They are VERY helpful. 1-800-981-3783

John

 

The front tires may be OK but the rears in the size you stated are way off by nearly one inch in OD!

a 295/35/19 is close and a better choice to your OEM rear tire.

Stock OD for rear is 26.9"; OD for the 295/35/19 is 27.1".

So with this size it would be 2/10" larger in OD which would cause a 1% slower speedo reading.

Thus at 60 mph you are actually doing 60.6 mph which is acceptable.

So I'd go with 235/35-19 fronts and the 295/35-19 rears.

 

Greg- That is the problem, no 295/35 19s available. The 285/35 19s are 26.85" in diameter and the 295/30 19s are 25.97 " in diameter. 305/30 19s are a better match in diameter at 26.20", but the recommended rim width is 10.5"-11.5" and F430 wheels are only 10" wide.

DBL- It looks like those tires will work, but will add a 3.2% error (slow) to your speedometer. Your 225/35 19s are 25.20" in diameter, and the 235/35 19s you want to use are 25.48" in diameter. Stock differential is 26.85"-25.20" or 1.65". The ones you want to use are 25.97"-25.48" or 0.49" differential. Difference is 1.65"-0.49" or 1.16". Divide that by 25.20" and you get 4.6% differential. On the ragged edge of chapping off your ABS system, but probably ok.

How about some PS2s where you do not have to worry about it? The Super Sports will probably work, but no guarantees.

Taz
Terry Phillips

 

I did not pay attn to the unavailabilty issue.

He's got a few probs to keep OEM rims for sure.

325's will do as well but need a w i d e rim!!

 

Front 235 in OEM wheel works perfect

 

Yup, does not solve the problem of what to do with the rears, though. Close, but not 100%.

Taz
Terry Phillips

 

With all this talk of changing tire and rim sizes , I think some consideration of affect on the gearbox should be looked into. Going with wider than specified tires will affect the gearbox as I have read in a post by our friend Brian.

 

I used Bridgestone RE050 235/285 in OEM 19" wheels super good tire,295 can look baloney .
If you go aftermarket I have tested 245 30 20 315 25 20 no problems.

 

I have been watching this subject and I think there will be more sizes offered in the future. At least I hope so.

Dave

 

I exchanged emails with Michelin a few weeks back and they basically said that the rear size is not in development for them at the present time, and recommended I go with the PS2s.

 

I called Tire Rack to inquire about a similar subject. I am going with Bridgestone RE-11 which are unavailable in 225 but they have a 235. The rear is same size. He absolutely would not answer me regarding if they would work or not. He offered no suggestion, nothing. He kept saying they weren't the stock size and couldn't guarantee they would fit. He wanted no part of it. I posted here and found out the front will work just fine. My dealer, F of Ft Laud, actually beat their price so I'm going with them.

 

Gotta be a liability issue. Isn't everything nowadays (sigh)?

 

A bunch of us e-mailed Michelin to ask for sizes that would work for Ferraris, but they were 295/35 18s for the Maranellos and 355s. You guys should try the same thing for the 19" tires. They already make tires for the optional 575 19" wheels, but Maranello wheels are a full inch wider in front and 1/2" wider in the rear, so can take larger tires.

Taz
Terry Phillips

 

Stick with stock sizes. There're plenty of choices, and many much cheaper than PS2s and rated equally good. Go to tirerack's website, click on your model and year, and review all the different choices.