This is a multi-part message in MIME format.
--===============6822341212725196918==
boundary="------------3162583F1CCB51D0A0AF3C58"
Content-Language: en-US
This is a multi-part message in MIME format.
--------------3162583F1CCB51D0A0AF3C58
Content-Transfer-Encoding: 8bit
I for one can't think of an explanation for this startling phenomenon.
Obviously, the ambient air pressure is less at altitude--known as
'adiabatic lapse rate' to nerds and pilots--which, theoretically could
cause the tires to expand, increasing their volume and lowering the
pressure (according to the Ideal Gas Law). But, I doubt steel-belted
radial tires expand or contract much, but air pressure in fixed volume
goes up about 1psi per 10degF IIRC.
Was there a 40degF difference in temperature between Portland and Big
Bear (California has been pretty warm the last few weeks, which I can
attest to since our A/C is on the fritz)? Also, temps vary when tires
are warmed by the sun or friction with the road, so if I can't check
pressure completely in the shade I'll under-fill the tires in the sun by
half a degree. So, my guess is a significant difference in air temps,
and asphalt absorbs a lot of heat which gets transferred to the tires
(Portland = (often) cloudy and cool; SoCal = (often) sunny and hot).
On 5/24/2021 8:20 AM, Jean Caron via Healeys wrote:
>
> Sounds like you have one of those rare wheels with self-adjusting
> pressure, I wonder when these became an option and on what model
> !!!!!! LOL!
>
> Jean
>
> Sent from Mail <https://go.microsoft.com/fwlink/?LinkId=550986> for
> Windows 10
>
> *Sent: *May 24, 2021 9:28 AM
> *Subject: *[Healeys] Conclave tire air pressure change trivia
>
> My Healey tire pressures went from 29 psi here in Portland, Oregon, to
> 33 psi at Big Bear Resort in California - 6,700 feet above sea level.
> I then lowered my tire pressures to 29 psi.
>
> Checked my tires today back in Portland - 70 feet above sea level and
> all tires at 25 psi.
>
>
--------------3162583F1CCB51D0A0AF3C58
Content-Transfer-Encoding: 8bit
<html>
<head>
<meta http-equiv="Content-Type" content="text/html;
charset=windows-1252">
</head>
<body>
I for one can't think of an explanation for this startling
phenomenon. Obviously, the ambient air pressure is less at
altitude--known as 'adiabatic lapse rate' to nerds and
pilots--which, theoretically could cause the tires to expand,
increasing their volume and lowering the pressure (according to the
Ideal Gas Law). But, I doubt steel-belted radial tires expand or
contract much, but air pressure in fixed volume goes up about 1psi
per 10degF IIRC.<br>
<br>
Was there a 40degF difference in temperature between Portland and
Big Bear (California has been pretty warm the last few weeks, which
I can attest to since our A/C is on the fritz)? Also, temps vary
when tires are warmed by the sun or friction with the road, so if I
can't check pressure completely in the shade I'll under-fill the
tires in the sun by half a degree. So, my guess is a significant
difference in air temps, and asphalt absorbs a lot of heat which
gets transferred to the tires (Portland = (often) cloudy and cool;
SoCal = (often) sunny and hot).<br>
<br>
<br>
<div class="moz-cite-prefix">On 5/24/2021 8:20 AM, Jean Caron via
Healeys wrote:<br>
</div>
<blockquote type="cite"
cite="mid:DM6PR17MB2507BA238E145706046CEAC9D1269@DM6PR17MB2507.namprd17.prod.outlook.com">
<meta http-equiv="Content-Type" content="text/html;
charset=windows-1252">
<meta name="Generator" content="Microsoft Word 15 (filtered
medium)">
<style>@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}.MsoChpDefault
{mso-style-type:export-only;}div.WordSection1
{page:WordSection1;}</style>
<div class="WordSection1">
<p class="MsoNormal">Sounds like you have one of those rare
wheels with self-adjusting pressure, I wonder when these
became an option and on what model !!!!!! LOL!</p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Jean</p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Sent from <a
href="https://go.microsoft.com/fwlink/?LinkId=550986";
moz-do-not-send="true">
Mail</a> for Windows 10</p>
<p class="MsoNormal"><o:p> </o:p></p>
<div
style="mso-element:para-border-div;border:none;border-top:solid
#E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm">
<p class="MsoNormal" style="border:none;padding:0cm"><b>From:
</b><a href="mailto:boyracer466@gmail.com";
moz-do-not-send="true">richard mayor</a><br>
<b>Sent: </b>May 24, 2021 9:28 AM<br>
<b>To: </b><a href="mailto:healeys@autox.team.net";
moz-do-not-send="true">Healeys</a><br>
<b>Subject: </b>[Healeys] Conclave tire air pressure change
trivia</p>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<div>
<p class="MsoNormal">My Healey tire pressures went from 29
psi here in Portland, Oregon, to 33 psi at Big Bear Resort
in California - 6,700 feet above sea level. I then
lowered my tire pressures to 29 psi.<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">Checked my tires today back in Portland
- 70 feet above sea level and all tires at 25 psi.<o:p></o:p></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<br>
</blockquote>
<br>
</body>
</html>
--------------3162583F1CCB51D0A0AF3C58--
--===============6822341212725196918==
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
_______________________________________________
Archive: http://www.team.net/pipermail/healeys http://autox.team.net/archive
Healeys@autox.team.net
http://autox.team.net/mailman/listinfo/healeys
--===============6822341212725196918==--
|