The Motley Fool Discussion Boards

Previous Page

Automotive / Cars and Drivers

URL:  https://boards.fool.com/okay-im-bored-and-playing-with-excel-here-are-17125649.aspx

Subject:  Re: 10 millimeters; no big deal, right? Date:  4/26/2002  12:26 AM
Author:  jeffbrig Number:  3764 of 11881

Okay, I'm bored and playing with Excel.  Here are the possible 
combinations of tire width/aspect ratio on the 16 and 17 inch rims.  
The diff column is the percent change in the diameter/circumference of
the tire.  You'd probably prefer to have that be positive rather than 
negative, since the overall diameter will decrease as the tire tread 
wears.  Remember, +diff and you're going faster than the speedometer, 
-diff is slower than what the speedo says.


The closest overall combination is the 215/35 on a 17" rim, but it's up 
to you if you want to go that low profile.  Higher cost, generally 
better handling, reduced comfort.  Given the choice, I'd always go up a 
width, and try to offset with a lower profile.  I pushed my GS-R from 
195/55 to 205/50 on the stock rims with no problems.  

	width	ratio	rim	total diam.	diff
stock	205	50	15	23.07086614	0
	205	40	16	22.45669291	-2.66%
	205	45	16	23.26377953	0.84%
	215	40	16	22.77165354	-1.30%
	215	45	16	23.61811024	2.37%
	205	35	17	22.6496063	-1.83%
	205	40	17	23.45669291	1.67%
	215	35	17	22.92519685	-0.63%
	215	40	17	23.77165354	3.04%

If anyone wants a copy of the excel formula or spreadsheet to play 
around with, just post or drop me an email.

Gotta go play with the numbers for my car.....hmmm, if I had 18s 
instead of 15s....

Hope that helps,

Jeff





Copyright 1996-2020 trademark and the "Fool" logo is a trademark of The Motley Fool, Inc. Contact Us