215/40/16 or 205/45/16

Eric Witherspo

215/40/16 or 205/45/16

by Eric Witherspo » Sun, 31 Jan 1999 04:00:00


>If I move to 16 inch rims, would it be best to put 215/40/16 *** on
>them?  The faq on miata.net says 205/45/16 are the best fit but the
>215 size seems to be almost an exact match for the stock tire in
>diameter when I use the tire calculator...
>Help?

Don't worry so much.  All this concern with getting to w/i 1% of
stock (or whatever insanely small tolerance you choose) is kind
of silly.  Why?  Because tires will wear ~3/4" in diameter over
their life (~3+% change).  Plus, with tire pressure (which the Miata
will demand much lower than the sidewall rating), effective diameter
is also different from what the calculator would state.

Meaning:  if someone's tried both sizes, and they have a
reasonable explanation (ride, fit, fender clearance, etc.)
for why one size is better, I'd say that opinion is more
significant than a small delta on the size calculator.

IME, 205/50/15's can hit the fender, so 215's on heavier 16"
rims will be quite likely to hit the fender.  That's probably
the basis for choosing 205 over 215.

Will Bro

215/40/16 or 205/45/16

by Will Bro » Sun, 31 Jan 1999 04:00:00

What width wheel?  My vote goes to whatever combo gives the
straightest sidewall.  IMO, a wide tire with a bulging sidewall will
give crappy handling akin to Jello(tm).  fwiw, I run 205's (RE71) on a
15x7 wheel and would not run a wider tire on that size wheel.  OEM was
supplied with 195's on a 6" wide wheel, and don't like that combo at
all (tire too wide for the wheel)

\/\/

Leon van Dommel

215/40/16 or 205/45/16

by Leon van Dommel » Sun, 31 Jan 1999 04:00:00


>their life (~3+% change).  Plus, with tire pressure (which the Miata
>will demand much lower than the sidewall rating), effective diameter
>is also different from what the calculator would state.

I don't know about that.  The height of the axis might change a bit,
but it does not seem to me that circumferential tire length (distance
travelled per revolution) would change much with tire pressure.

Leon
--
Leon van Dommelen, the man, and Bozo, the '96 white PEP Sebring Miata

"What? You do not need a reason to drive, you need a Miata to drive."

Doug Hagerma

215/40/16 or 205/45/16

by Doug Hagerma » Tue, 02 Feb 1999 04:00:00

I thought that the important number was the "revolutions per mile", which is
mostly determined by the circumference of the belt in the tire...

>Why?  Because tires will wear ~3/4" in diameter over
>their life (~3+% change).  Plus, with tire pressure (which the Miata
>will demand much lower than the sidewall rating), effective diameter
>is also different from what the calculator would state.