ZeeVert

While I was learning about tire and rim sizes, I created an Excel spreadsheet similar to the Discount Tire calculator, with the addition of a formula that will give you the theoretical perfect aspect ratio for zero speedo error.

Here's a screen shot of it.
http://i2.photobucket.com/albums/y48...t/21bed732.jpg

Is anyone interested in having a look at it?

BADFNZ

iTrader: (19)

Looks good man. I'd like to download it if you want to post it up.

ZeeVert

I'll need a little help... how do I post it?

I'd like to have someone look it over, check it, and scan it before taking a chance on sharing a BAD file/formulas.

Deep Blue

How do you account for different wheel widths? For example a 275/40-17 on a 17X9.5 inch rim vs a 17X9 inch rim?

ZeeVert

I don't take into account wheel width. And I don't think anyone really can. As you pointed out, the actual tire width will change depending on what wheel it's mounted on and there's differences between tire manufacturers on diameters and widths (That's why you shouldn't mix brands on 4X4s).

So, the program only looks at theoretical sizes and differences, based on the manufacturers size.