firechicken2k

i'm thinking of replacing my stock T/A wheels (16" diameter) with 17".

now, questions..

1. how much should i pay for someone (like TTP, or anyone else with tuning software) to change my tire size, so the computer knows about it?
2. will the speedometer be off, after that is changed, or will it be ok? if it will be off, what else will be needed to correct it?

thats it

BLCKBRD

iTrader: (6)

I think if you get the right size tires on the 17's then will not have to change the computer for the speedometer. The tires will just be lower profile, but the overall diameter should be the same. The tires will be (275?)/40/R17

02_Phase2_ZL1

If you have P245/50R16 tires on your car now, you can go to a 17X9 wheel with a P275/40R17 or a 18X9 wheel with a P275/35R18 tire and nothing will change. The rolling diameter of a P235/55R16, P245/50R16, P275/40R17 and a P275/35R18 are all exactly the same.

You would not have to have your computer reprogramed, etc.

firechicken2k

how come the rolling diameter is the same, when they are 16", 17", and 18" ?
and i wouldn't want 9 width.. id like 11 width, or at least 10.5 ..

any way i could do that?

AW/whiteZ-28

You go a bigger wheel and the sidewall gets smaller that's why. I have 335/30/18's in the rear and I didnt have to reprogram.

Put in your stock size tire in this site on the left and the tire you want on the right and it will tell how much off it is.

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

BLCKBRD

iTrader: (6)

You would get a 315/35/17 tire, it would be the same diamter as stock