Tire pressure strategy
 

Tire pressure strategy

Started by Lin, July 09, 2010, 09:42:11 AM

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Lin

Okay, so tire pressure is supposed to be set with the tires at ambient temperature and not in direct sunlight.  My thought was, that since we are in a desert, the ambient temperature is likely to be lower most places we go.  With that in mind, I was thinking of setting the tire pressure about 5#'s higher than the table reads.  Hence, I would be a little high at home, though well within the tires' range, and would not be low when the climate changes.  Does this make any sense?
You don't have to believe everything you think.

BG6

Run your pressures for the conditions that you are in.  If you are in different conditions tomorrow, check them tomorrow.


bevans6

5 lbs high is fine.  Obviously too low is the problem, but I don't notice much variation due to ambient temperature.  I'll tell you what happens with my tires - I set them to 85 PSI all around in June 2009, temps around 80.  I ran them all season (I check them every time I take the bus out of the driveway), then when I went down to Savannah in December it was quite cold out, they went down to about 82 PSI - still within spec so I just left them.  Forward to March/April and I am going down to Palmetto Cove, tires still at 80 - 82 PSI, I just left them and had a good time.  Now it's June, temps are high, the pressures are up to 85 PSI again.  I felt that I wanted to go down to 80 PSI in the drives, so - a full year after I last actually added air to the tires - I had to sit and bleed out 5 PSI.  They hadn't lost a thing in over year, which I found very odd.  Yes, I verified my gauge was accurate, I checked it against my buddies big-bucks digital gauge.

Firestone FS560 Plus, which someone just told me are manufactured domestically, not off shore.  Not that I have anything to compare them to, but they sure seem fine to me.

Anyway, to your point, i don't think relatively minor changes in ambient temp make all that much difference to cold PSI, and 5 PSI over the chart pressure is actually often recommended!

Brian

1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Allison MT-647
Tatamagouche, Nova Scotia

Iceni John

I've been checking my bus tires every month or so, thinking they may bleed out some air even when sitting.   It sounds like that's overkill!   I'm used to checking all my tires frequently, to get as early warning as possible if a slow leak develops  -  I check my car's tires each week, and my bicycles' tires every time I ride.   Maybe my bus doesn't need this much TLC!   I'm slightly neurotic about tire pressures, because I have recaps in the back and because I want to maximize tire life and fuel mileage.   Better safe than sorry.

John
1990 Crown 2R-40N-552 (the Super II):  6V92TAC / DDEC II / Jake,  HT740.     Hecho en Chino.
2kW of tiltable solar.
Behind the Orange Curtain, SoCal.

bevans6

Well, I continue to check the tire pressures at the beginning of every trip, and at each stop I thump them.  I just haven't had to add  any air.  Checking - that's a constant thing!

Brian
1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Allison MT-647
Tatamagouche, Nova Scotia

Sean

Quote from: bevans6 on July 09, 2010, 09:56:40 AM
Firestone FS560 Plus, which someone just told me are manufactured domestically, not off shore.

Just FYI, you can not tell where a tire is made by the make and model of the tire.  All manufacturers have plants worldwide, and many of them make the same model tire in several plants depending on markets.

You CAN tell where any individual tire was made.  The plant of manufacture is coded into the DOT number on the tire (just as is the week and year of manufacture), and you can look that code up in a table to find out where your tire was made.

Firestone, by the way, is a Japanese company.  So for Firestone, "domestic" means made in Japan, just as for B.F. Goodrich it means made in France.  That said, many truck tires for the U.S. market are made right here in the U.S., and that would include many Toyo, Yokohama, and other more "Asian sounding" brands.  Again, you need to check the plant code.  While every manufacturer does it to one extent or another, the cost of shipping finished tires overseas and paying import duties can exceed the cost of manufacturing them locally.

-Sean
http://OurOdyssey.BlogSpot.com
Full-timing in a 1985 Neoplan Spaceliner since 2004.
Our blog: http://OurOdyssey.BlogSpot.com