ford focus rims fitment?

[Robert Deis]

On Thu, 23 Jan 2003, Aaron Ryba wrote:

> What size tire sidewall would one have to put on a 16"
> rim to keep the same rolling diameter as the stock 14"
> rims w/ 60(?) sidewalls (or whatever is stock).

Depends- the sidewall number is an aspect ratio, so the sidewall heighe
actually depends on the tire width.  There are some online calculators-
maybe at tirerack.com?

Ifyou don't find them, the formula goes like this:

rolling diameter = rim diameter + 2*(tire width x aspect ratio / 100)

Tire width is milimeters, rim diameter is usually inches, so you have to
convert them.

Example: 14" rim with 185/70 tires has a rolling diameter of
14" + 2*(7.28" * 70%)  = 24.7"
           ^-- converted from 185mm

> -Spedo/ milage misread(in owner's favor(?))?

Will read lower than actual. Odometer will as well.


--
------------------------------------------------------------------------------
  Rob Deis                  "Let the people know beforehand what the law
  MiB3347                      is and what they are to expect."
  rdeis at io.com                              -- 18th Congress, Rec. 75