Re: Installing larger rims/tires...

[CJMarshall@aol.com]

I agree with your logic, but disagree with your actual calculation.  You can't
go by the diameter to calculate speedo variance.  You have to use the
circumference of the tire and see how much that has changed to be able to
determine %+/- from stock.  An interesting thought that I'll work on.

Chuckem



In a message dated 1/25/99 7:07:09 PM Eastern Standard Time,
sundie@lunaticfringe.org writes:

> There's a certain amount of "work around" you can do in the case of
>  getting larger rims.  If you lower the profile, you can (usually) find a
>  profile/rim combination that's pretty close to your standard.
>  
>  For instance, before i went and changed to my winter tires, i checked a
>  few things out, did a few calculations...
>  
>  with the winter tires on (195/55/r15), the profile of the tire/rim is
>  102% of standard (205/50R15), and with the summer tires on (215/45/r15),
>  the profile of the tire/rim is 98% of standard.  I could have gone with
>  the standard sizing, but i wanted narrower tires for winter, and wider
>  for summer...
>  
>  What this means, in working terms, is that with the winters on, and my
>  speedo says 100, i'm actually going 102, and with the summers on, 98.
>  
>  I figured this was pretty safe range.
>  
>  You can do the same thing, if you go to larger rims.  Just look around
>  for tires that have a lower profile, do some simple math, and there you
>  have it.
>  
>  I WOULD suggest doing all of this BEFORE you buy the tire, though.
>  
>  Anyone care to take a guess on how much 2%+/- difference from stock will
>  make your car act?  I'm noticing pretty much nothing...
>  
>  Sundie....
>