jjrbus wrote:
Tanks for the responses, greatly appreciated.
Color me confused. Van has been sitting since yesterday. PSI is not what I set it too yesterday
I checked pressure all 4 tires with monitor in my hand. Monitor is showing same pressure as tire gauge. I can live with this.
How Weather can change tire pressure
HERE"You're not imagining things โ your tire pressure is shifting with the weather. As seasons change and temperatures fluctuate, you'll likely experience varying levels of PSI.
Why Does Tire Pressure Change?
When air molecules experience cold temperatures, they move slowly and stick closer together โ taking up less physical space. In warmer temperatures, air molecules move quickly and spread out more โ taking up more physical space.
When the air molecules inside your tires heat up, they expand, often leading to increased tire pressure.
As you might expect, the opposite is true for cold air. If the temperature outside drops suddenly (like it does overnight in the fall and spring seasons), the air in your tires can become condensed, leading to a loss of pressure.
The relationship between PSI shifts as temperature changes:
Higher temperatures = higher pressure and overinflation
Lower temperatures = lower pressure and underinflation
"There is a direct relationship in the ambient tempurature vs air pressure.
Spring and fall can especially play mind games on you because of the large temperature changes that can happen from the time you check, fill, adjust the tires to the next time you check the tires pressure.
That is why I mentioned even direct sun hitting one side of your rig can give you a different reading from what you get on the side with no direct sun.
Tire manufacturers do not really specify what "cold temperature" is other than not being driven for a certain amount of time and basically is the tire temperature that is equal to the outdoor air temps..
Take your best guess and roll with it, with no sun directly hitting any of the tires set the pressure to your desired level while the tires are at ambient air temps.
The pressure can go up as the tire warms and can go down as the tire cools and if the ambient air temps goes up or down your pressure will follow that.
Don't overthink, you will see some variations in pressure even when driving according to the loads on each tire.
If you are concerned that your sensors may have an issue, in your case you can use the same tire and one at a time install on the stem and take reading.. If all readings match you are good. If readings are off (don't match) then perhaps you have a sensor that isn't calibrated well.
