AIR PRESSURE IN CLASS A TIRES

Something I found that you need to be careful about..... a typical compressor rated for, say 150#, usually has and upper & lower range. That is, the compressor turns on and starts building pressure in a tank until it gets to the max (150# in this case) then it stops compressing. It won't start compressing again until the compressor drops to some preset level - maybe 85#. then it turns on and compresses back up to 150#. The numbers vary and are just illustrative. But you can see, if you're trying to fill 125psi tires, the compressor has to be more than 125. So you pump up your compressor to 150, start filling the tire. If you don't get the tire up to 150, then you need to disconnect the compressor (which is likely about 120# now) bleed it so it turns on again and builds back to 150#.

So... it is really the "turn on" number that is pretty important. you'd like it to be greater than your needed tire pressure. Only problem, this turn-on pressure is rarely advertised with a compressor!

Does this make sense to anyone?