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Old 10-30-2003, 01:03 AM
akauth akauth is offline
 
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Quote:
Originally Posted by stcj
I drive 75-85 mph all the time, no problem. I deliver custom cultured marble hot tubs and counter tops, some times two hours away, still no problem.
I don't think I'd consider that "long term continuous" unless you're doing it all day. Or right after you arrive you're turning around right away and you're doing that pretty much daily.

I grabbed this from Firestone (I was actually looking for a chart though), but all the tire companies follow this rule of thumb concerning speed:

<<For continuous high speed driving, tire pressures should be increased by 3 to 5psi above the normal cold inflation recommended. However, for passenger tires, never exceed the maximum inflation pressure molded on the sidewall. The inflation pressure for light truck tires may exceed that molded on the tire by 10psi. Any recommended front to rear pressure differential should be maintained.>>

It's a linear relationship (kind of). If you drive 70 you'd increase it 1 psi, 80 2 psi, 90 3 psi, 100 4 psi, etc. Up to the max pressure of the tire.

Those are just "for instance" numbers but most of the manufactures will have speed vs air pressure charts that they can supply if they aren't on their web sites even.


Alan
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