On Mon, 20 Jun 2016 03:08:38 -0000 (UTC), Henning Schröder
wrote:

clare auf Sun, 19 Jun 2016 22:56:46 -0400 geschrieben ...

The 225 or 235 is the tire section width in mm.

How it tire section different than tread width?
Someone said they're different.
I never used the term "tire section", but, I always thought the
225 or 235 was the width of the tire on the road, which, to me,
is the tread width.

Is there a difference between tread width and tire section?

The tire section width is OFTEN the same as the tread width, but not
necessarily. Some tires have narrower tread than section width

A tire's section width (also called "cross section width") is the
measurement of the tire's width from its inner sidewall to its outer
sidewall (excluding any protective ribs, decorations or raised
letters) at the widest point. This measurement is made without any
load placed upon the tire and after the tire has been properly mounted
on its industry assigned measuring rim and has been inflated and reset
to its test pressure after 24 hours.

Because a tire's section width is influenced by the width of the rim
upon which the tire is mounted, the correct industry assigned
measuring rim width for the tire size being measured must be used.

The width of a tire mounted on a narrow rim would be "narrower" than
if the same tire was mounted on a wide rim.


I DID make an error - the sidewall hight changes by 7.5 mm - so the
diameter changes by 15mm - pretty close to 0 .6 inch.

Thanks for confirming the strange math where the height of the tire is
listed as an inch percentage of the mm "tire section" width.

So the ride height is a bit more than half an inch difference.
That's small (unless the spare is being used, where the spare is the
larger width).