Tires & Rims Have Their Own Personality Quirks

After sitting for a few months the tires (215/70R14) on the '72 Satellite Sebring Plus have a variety of air pressure readings. The spare has 30# as well as two mounted tires, one has 33#, and one has only 25#. The two air shocks (which have separate fill hoses) are both down to nothin'. Going down the street to the service station to fill 'em up again.

I would run the rears around 28 PSI, otherwise you'll see the center wear out.

Right, I guess to fine tune these tires one should really take tread depth readings across the tire on occasion. What I like to do is use an infrared pistol thermometer across the tires after a short drive to see how even the tread temperature is across the width (which can also help diagnose front end alignment issues I think).

Well you didn't say which pressures came from where. Assuming they were all filled evenly, if the two that were at 30 lbs were on the same side and the 33 was on the sunny side of the car with the 25, I'd say you have a leak.

Because of the extreme temperature swings here our tire pressures can vary wildly.
Not just because the air expands and contracts from heat and cold, (yes, I know about nitrogen. Please don’t tell me) but because the cold can keep our tire valves from sealing correctly. I run my Jeep tires at around 36psi. Temperature drops to minus forty and you can have pressure around 22-25 psi. Whip out the air compressor and if the hose doesn’t break from the freezing you top off your tire. Remove the air chuck and the valve on the tire doesn’t seal because of the cold and your tire dumps ALL of the air out in your driveway. Or it leaks so slowly you don’t notice until next morning when it’s dark, minus forty, your tire(s) are now flat and you need to be at work in ten minutes.

On a related note for you guys in the high desert where you can get super hot daytime temps and cold nighttime temps; do you get wild swings in tire pressure?