How to check tire pressure?

[Cherokee]

I use my Topeka D2 Smart gage.
Very accurate.
I over inflate to 36 psi then bump down the pressure with little release squirts of air until it just flips to 35 psi.
Had this thing ten years now.
Works great,
Eats batteries, 2032’s about four a year but I’m all over my tire pressures as the weather temps change.
Did you know a ten degree drop in ambient air temperature will drop your tire pressure one pound ?
Sun hitting half the tire in the July heat can raise it 2 or 3 psi.

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[Mabcim]

On my '24, I can toggle down with the steering wheel switch and get the pressure display on the screen in front of the driver. I forget if you have to enable that screen from the menu, but it's super easy.

Yes, that is how it worked on my ‘22 as well. ‘25s new dash is not that simple

 

[thekaj]

Piggybacking on this, how accurate are people finding the sensors? As the temperature has dropped, so has the PSI on all four tires (expected). I finally broke out the air pump when they hit 30, only to find that the gauge on the pump read near 35 on all four tires. I still added another 4 or so PSI to each, just in case, only to find the next day that the sensors were claiming they were below 30 now. It’s the same reading when it’s below freezing or above 40 degrees, pre-drive and after driving for an hour. It’s also been a few days, so plenty of time for it to take a new reading.

I don’t want to keep filling the tires until the sensors are satisfied if they’re over-inflated by nearly 25%. I suppose I could buy a cheap gauge to tell me which one is lying.

 

[Glen Baker LLC]

Piggybacking on this, how accurate are people finding the sensors? As the temperature has dropped, so has the PSI on all four tires (expected). I finally broke out the air pump when they hit 30, only to find that the gauge on the pump read near 35 on all four tires. I still added another 4 or so PSI to each, just in case, only to find the next day that the sensors were claiming they were below 30 now. It’s the same reading when it’s below freezing or above 40 degrees, pre-drive and after driving for an hour. It’s also been a few days, so plenty of time for it to take a new reading.

I don’t want to keep filling the tires until the sensors are satisfied if they’re over-inflated by nearly 25%. I suppose I could buy a cheap gauge to tell me which one is lying.

But which gauge do you believe?

I have several different tire pressure gauges I use and none of them agree with each other. Some are close, some are way off.

In the end, it's like chasing your tail.
OCD nightmare.

 

[PGAJayhawk]

The tire pressure screen for the 2025 is in the MENU button. Scroll down to Vehicle Maintenance and you will see Oil Life and Tire Pressure. Select Tire Pressure. This option is ONLY available when the vehicle is STOPPED. When in motion, Vehicle Maintenance is "greyed out" and you cannot access this info.

 

[thekaj]

But which gauge do you believe?

I suspect the external gauge is correct, but I'm hoping to get the thoughts on how everyone else feels about their sensors. The fact that the gauge read what the pressure should be on all four tires, and that I pumped in about 5 PSI for each tire and the sensors think I lost a little pressure after that, makes me think maybe the sensors aren't that great at colder temperatures. Yes, pressure goes down with the temperature, but the lack of registering me pumping more air in makes me suspicious.

 

[colinl]

Piggybacking on this, how accurate are people finding the sensors? As the temperature has dropped, so has the PSI on all four tires (expected). I finally broke out the air pump when they hit 30, only to find that the gauge on the pump read near 35 on all four tires. I still added another 4 or so PSI to each, just in case, only to find the next day that the sensors were claiming they were below 30 now. It’s the same reading when it’s below freezing or above 40 degrees, pre-drive and after driving for an hour. It’s also been a few days, so plenty of time for it to take a new reading.

I don’t want to keep filling the tires until the sensors are satisfied if they’re over-inflated by nearly 25%. I suppose I could buy a cheap gauge to tell me which one is lying.

I suspect the external gauge is correct, but I'm hoping to get the thoughts on how everyone else feels about their sensors. The fact that the gauge read what the pressure should be on all four tires, and that I pumped in about 5 PSI for each tire and the sensors think I lost a little pressure after that, makes me think maybe the sensors aren't that great at colder temperatures. Yes, pressure goes down with the temperature, but the lack of registering me pumping more air in makes me suspicious.

you do lose some pressure when attaching and removing a pump or possibly even just a gauge, but car tires have a very large amount of air volume so this usually isn't impactful. (if you bleed 2 seconds of air from a car tire it probably doesn't even drop 1psi, but if you bled 2 seconds of air from a 700x23 road bike tire, you've lost 30 psi.)

probably your pump gauge is wrong... but the key information that's missing from your two posts is the temperature of the tire when you put the gauge on it and saw 35. tire temperature has a LOT to do with tire pressure. let's say your tire starts at 10F because you've parked outside on a very cold night. then when you drive on a cold but dry highway, your tires will actually get relatively warm. probably not even 80F, but way above 30F. if you measure pressure when they're (somewhat) warm from highway use, you'll get a much higher reading than when they're cold in your driveway before any driving.

I find that the stock Motorcraft/Ford TPMS pressure sensors and what you see in Fordpass is relatively accurate. but another thing to bear in mind about pressure and temp is that tires get warm in the sun, also. if you parked outside in full sun on a cold day, the tires in the sun will be warmer and probably read 1-3 psi higher than tires on the other side of the truck in the shade.

 

[HeyBales]

Piggybacking on this, how accurate are people finding the sensors? As the temperature has dropped, so has the PSI on all four tires (expected). I finally broke out the air pump when they hit 30, only to find that the gauge on the pump read near 35 on all four tires. I still added another 4 or so PSI to each, just in case, only to find the next day that the sensors were claiming they were below 30 now. It’s the same reading when it’s below freezing or above 40 degrees, pre-drive and after driving for an hour. It’s also been a few days, so plenty of time for it to take a new reading.

I don’t want to keep filling the tires until the sensors are satisfied if they’re over-inflated by nearly 25%. I suppose I could buy a cheap gauge to tell me which one is lying.

The TPMS sensors go into sleep mode to conserve battery after they stop moving for a bit.

Any TPMS displayed pressure is prior received stale info at some point.

It's why the manual says to not use it as a pressure gauge when filling tires. Or checking as accuracy may not be great anyway.

 

[thekaj]

[

probably your pump gauge is wrong... but the key information that's missing from your two posts is the temperature of the tire when you put the gauge on it and saw 35

The temperature was in the low to mid 40’s. But that‘s the thing about the sensors. I’m never seeing any variation besides the slow lowering from 35 to 30 over a couple months. Start the truck in the morning at 25 degrees: 30 psi. 30 minute drive to work where it’s about 35 degrees: 30 psi. Start the truck after work when it’s about 45 degrees: 30 psi. 30 minute drive home at 40 degrees: 30 psi. I know there‘s a delay in the readings, but there’s enough temperature variation and road use that I should see some variation readings.

My old truck was notorious for giving me a low pressure warning even after over inflating the tires and confirming they were fine. To the point where I just ignored it. So I have a learned skepticism of these sensors. Which I will surely regret when I end up with a shredded flat tire.

 

[colinl]

[
The temperature was in the low to mid 40’s. But that‘s the thing about the sensors. I’m never seeing any variation besides the slow lowering from 35 to 30 over a couple months. Start the truck in the morning at 25 degrees: 30 psi. 30 minute drive to work where it’s about 35 degrees: 30 psi. Start the truck after work when it’s about 45 degrees: 30 psi. 30 minute drive home at 40 degrees: 30 psi. I know there‘s a delay in the readings, but there’s enough temperature variation and road use that I should see some variation readings.

My old truck was notorious for giving me a low pressure warning even after over inflating the tires and confirming they were fine. To the point where I just ignored it. So I have a learned skepticism of these sensors. Which I will surely regret when I end up with a shredded flat tire.

my guess would actually be that the telemetry isn't updating Fordpass. after you look at tire pressure, check the truck's location on the map.

any type of software bug is possible given this is Ford and how long some software recalls have been unresolved, but I have never seen an issue with TPMS sensors reading wrong.

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