This being true (and it is), my concern about the fact that the bp of water when inside a tire is well above 212 F (100 C) is moot.  BTW, my dictionary defines steam as 1.  The vapor phase of water (David's definition), and 2.  the mist of cooling water vapor (the common usage by laypersons).  Both definitions are correct, but they mean different things.  Fact is, I think it is rare that laypersons think of water vapor at ambient atmospheric temperatures with the term steam.

Now, I suppose if one filled a tire with air that was saturated and dripping, as in a fog, using a pump or compressor, and not dried compressed air, some liquid water would be forced into the tire.  But that would not be very much liquid water.  It would vaporize whenever the temperature was high enough, but given there internal pressures, that would be hotter than street vehicle tires ever get.  I've never seen condensate emitted from a tire when air was bled from it.  I suppose there would be some if the tire had been filled with foggy air, got hot, and then was bled into cold air.  Don't think that happens often. DMc

---- Mike S <mikes@FLATSURFACE.COM> wrote:
> >Don, water vapor *is* steam, or vise versa.
>
> "Steam" is ambiguous. Most people think of steam as the visible water
> particles (liquid) which condense out when pure steam comes out of a
> tea kettle. But yes, the relative humidity in the air is steam (or
> water vapor), as is the water in a tire.
>
> > From racelinecentral.com (note this is for racing, not our kind of
> > driving:
> >
> >>Tire Temperature synopsis:
> >>
> >>Optimal temp range is between 190-240 degrees.
> >The boiling point of water at 13 psig is 246F -- slightly above
> >optimal range
>
> What type of race vehicle runs at 13 psi, except those swamp things,
> where heat isn't an issue?
>
>  From your source (racelinecentral.com):
>
> >NASCAR Winston Cup TRUE TIRE HISTORY...The tires are inflated around
> >50 psi.

--
David McNeely