[email protected] wrote:
On Fri, 21 Sep 2007 12:34:07 -0700, mpm wrote:
Things seem pretty slow in SED today, so let's talk about "Hot Air".
(Like the kind in your tires.)
Every so often I read something like this:
http://fleetowner.com/news/topstory/fleet_nitrogren_beats_air/sugges
ting Nitrogenis better than air for improved mileage, lower tire
wear, reduced Global Warming, etc....
The trick is you fill your tires withNitrogeninstead of compressed
air.
Huh?! Air is 78% (or so)Nitrogenanyway. Is there anything to this,
or is this a classic signal-to-noise problem...?? Notice too that the
article does not mention any service stations so equipped...
When I was in the USAF, at one point I worked on the SR-71
Blackbirdhttp://
www.google.com/search?hl=en&q=%22sr-71+blackbird%22
and they used drynitrogenin its tires. But the reason, they told me,
didn't have anything to do with gas mileage, it was so that when it
lands at about 300 MPH, the tires don't explode and burn. Hot rubber
and oxygen can get a little volatile.
But, for a car, the only difference I can think of would have to do
with condensation, and just using dry air should alleviate any risk in
that area.
IOW, if somebody's making a claim like that, and expecially[SIC] if
they're trying to sell you something (likenitrogen), then they're just
blowing smoke up your ears, so to speak.
Here's and idea where you can convert the air in yoyr tires to almost
100% nitrogen yourself:
http://www.createthefuturecontest.com/pages/view/entriesdetail.html?e
ntryID=383
Better yet, use Helium!
It is the most thermally conductive gas, so it would keep the tires
cooler while driving - especially at high speeds.
"Slight" disadvantage is that it diffuses out and so has to be
replaced frequently...