Rim dia.   406.4 mm = 16" x 25.4

            Eric                   86-VW4x4
            vw4x4@fyi.net          72-240z
            Pittsburgh, PA USA     1936-Chrysler

On Fri, 8 May 1998, Modl6971 wrote:

> In a message dated 98-05-08 01:23:06 EDT, vanagon@VOLKSWAGEN.ORG writes:
>
> <<
>  With a bit of math it is easy to figure out the height of a tire and from
>  there the circumference of the tire:
>
>  225/70R16 =
>
>  25.4mm = 1"
>
>  225 x .7 x 2 + 406 = 721mm = 28.4"
>
>  225 = how wide the tire is
>  70 = % of side wall to width
>  2 = two side walls >>
>
> What does "406" stand for in the equation. Michael.
>