TPMS in my new wheels seem to be reading high

[01tj]

After putting my new wheels and tires on I used a gauge and lowered the pressure to about 38. I went to work and home yesterday and the dash display showed 45 per tire. I lowered it more but I'm still showing 42, does something need adjusted.

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[Stuckinthesand]

Are you looking at the display after driving? Once the tires warm up it’ll show a higher air pressure. Check the display when first starting the vehicle after sitting overnight. That will be your cold tire pressure and when you should be airing the tires to what you want. Once they are warmed up the pressure will always be higher.

 

[01tj]

Are you looking at the display after driving? Once the tires warm up it’ll show a higher air pressure. Check the display when first starting the vehicle after sitting overnight. That will be your cold tire pressure and when you should be airing the tires to what you want. Once they are warmed up the pressure will always be higher.

It goes up a few after driving. This morning when I left the house it read 43 and after 10-15 minutes of driving it was 45. I went into the store and picked up a new tire gauge and it showed 38. Got in the Jeep and I'm back to 43

 

[Stuckinthesand]

It goes up a few after driving. This morning when I left the house it read 43 and after 10-15 minutes of driving it was 45. I went into the store and picked up a new tire gauge and it showed 38. Got in the Jeep and I'm back to 43

That’s new to me. Honestly have no clue why that would be doing it. I’d think like you and say possible sensors.

 

[redsyphon]

Same issue here. Digital guage shows 34.5 but my dash shows 38/39

Digital and dash used to match, but the discrepancy began after climbing to higher elevations (8k+)

I'm thinking the Digital guage is the correct one, but not 100% sure lol.

 

[Category5Bronado]

Did you reuse the stock tpms or put new ones in?

 

[Yellow Cake Kid]

Pressure inside the tire is a sort of de facto "absolute" pressure measurement. The air pressure within the tire is compared to a calibration prescribed when the TPMS was manufactured.

The hand held air gauges measure "gauge" pressure which, depending on the technologies used to make the measurement, provide a sort of relative pressure compared to the ambient or a prediction of the ambient air pressure.

That is just the beginning of the factors that will lead to conflicting readings.

For example; The accuracy of one, many, or all the measuring devices should be suspect.

For example; calibrating a meter is not very complicated but it is impractical to expect it to maintain calibration with changes in location and conditions.

On my JLUR the onboard TPMS reads about 3 PSI higher than my collection of hand held gauges. We live at 4500 feet above sea level, and often drive up to 11,000 feet, but the air here is so dry that the barometric pressure at our local air port has an annual average that is almost exactly the same as the annual average of the moist and lighter air found at sea level in Miami Florida. The popular adages and rules of thumb about air pressure elevation correction do not always apply very well. In other words, keeping track of the details can be confusing.

When accurate air pressure measurement is really important you may purchase and learn to use gauges made to overcome the basic limitations, but these devices are expensive and their use requires knowledge of and attention to details. For the daily driver there is very little benefit to bothering with the extra details.

It is practical to observe for consistent differences between gauges, so you may recognize when something significantly inconsistent is occurring.

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