???'s about changing wheel size
Thread Starter
Pro
Joined: Mar 2009
Posts: 639
Likes: 1
From: Brookfield CT NCM#522998
???'s about changing wheel size
So my 86 coupe still has the stock sawblades on it(16"), but I would like to go to a 5 spoke that will most likely be 17", and 17" wheels offer a better tire selection as well. BUT, wont that screw up the speedomter? Is there a way to reset the something so that the speedo and tach are recalibrated for the larger wheel size?
Le Mans Master
Joined: Oct 2007
Posts: 9,715
Likes: 3,494
From: Akron Ohio
2025 Corvette of the Year Finalist - Modified
2024 C5 of the Year Winner - Modified
2023 C5 of the Year Finalist - Modified
2022 C5 of the Year Finalist - Modified
St. Jude Donor '09-'10-'11
The only thing the speedometer gear sees is the overall diameter of thw wheel and tire. If the 17" tire is the same overall diameter, or close, as the original 16s there will be no issue. 
of course, as long as the diameter of the tire is the same, then the diameter of the wheel is irrelevant. DUH...
Safety Car
Joined: Jan 2008
Posts: 3,939
Likes: 1
From: Vero Beach Florida
Use this site to find new tire & wheel size that won't change your speedo settings
http://www.miata.net/garage/tirecalc.html
You can move up to a 265/45 17
Which is 4/10th tallerthen what you have now
changes speed from 60MPH to 60.8MPH
or a 285/40X17 same height 59.9MPH
http://www.miata.net/garage/tirecalc.html
You can move up to a 265/45 17
Which is 4/10th tallerthen what you have now
changes speed from 60MPH to 60.8MPH
or a 285/40X17 same height 59.9MPH
Last edited by floridamale; May 18, 2009 at 03:08 PM.
