So I finally got around to installing my TST-510 TPMS today. I've had it for about 9 months so far and just haven't gotten a "round tuit" to put the sensors on and program the system. Everything went on fine. Set the monitor as per instructions and everything seems to work..... EXCEPT.... my analog tire gauge says there is 100psi in each tire and the TPMS says 95....reading ambient temperature just fine. 95psi all around is fine for my load according to the pressure charts from Goodyear, but I'm now curious if my regular, analog gauge is right or if my digital TPMS is right. Any opinions??

I have three really nice fairly expensive air gauges, and none of them match when checking the pressure. So the answer is who knows. You would have to get a gauge that you know has been calibrated and is accurate, and compare it to that, but if good gauges don't even match where can you even find one you know is correct? Maybe NASA or JPL would have one?

Use a third gauge as a tie breaker?It's common to get different readings from different gauges, but 10# seems like more than normal. I like what you're doing: Trust but verify. Good plan!

GM I have three gauges and none of them match. Should I try a fourth?

I have one of the best tire gauges made by Milton. I also have a set up that ties two tires together as I inflate them. In other words, I inflate the two front tires at the same time so I know they are exactly the same pressure. I have tried two different TPMS systems and they both would vary by as much as 5 PSI on tires that I know are equal. I would not trust the TPMS for your tire pressure but I would get a good quality tire gauge to inflate your tires. Also remember that if you have tire valve stem extensions for the rear duals, they will not give you an accurate temperature of those tires.

rgatijnet1 wrote:I have one of the best tire gauges made by Milton. I also have a set up that ties two tires together as I inflate them. In other words, I inflate the two front tires at the same time so I know they are exactly the same pressure. I have tried two different TPMS systems and they both would vary by as much as 5 PSI on tires that I know are equal. I would not trust the TPMS for your tire pressure but I would get a good quality tire gauge to inflate your tires. Also remember that if you have tire valve stem extensions for the rear duals, they will not give you an accurate temperature of those tires.I'm thinking I'll use the TPMS as a "relative indicator" to know when something may be going wrong. I doubt I'll use it as the absolute in tire pressure or temperatures.

What's More Accurate? | Good Sam Community

27 Replies

Executive45
Explorer III
Sep 03, 2015
Seems like you need to find an "accurate" gauge. Then match it to your TMPS. If, as you indicated, the REAL PSI is 100 but your TMPS shows 95, simply adjust your TMPS as necessary. If you're supposed to be running 95 in your tires, set the TMPS at 90 or whatever corresponds to what you perceive to be the accurate PSI....then you can simply rely on the TMPS....Dennis
GMandJM
Explorer
Sep 03, 2015
msmith1199 wrote:
GM I have three gauges and none of them match. Should I try a fourth?

Sure....and don't stop til you get within 2 - 4 pounds ;)

As said, it's normal to have a little bit of difference. I think I've only seen a couple people post that they had their gauge and TPMS spot on on the same. They obviously had better gauges than I buy.
10forty2
Explorer
Sep 03, 2015
rgatijnet1 wrote:
I have one of the best tire gauges made by Milton. I also have a set up that ties two tires together as I inflate them. In other words, I inflate the two front tires at the same time so I know they are exactly the same pressure.
I have tried two different TPMS systems and they both would vary by as much as 5 PSI on tires that I know are equal.
I would not trust the TPMS for your tire pressure but I would get a good quality tire gauge to inflate your tires.
Also remember that if you have tire valve stem extensions for the rear duals, they will not give you an accurate temperature of those tires.

I'm thinking I'll use the TPMS as a "relative indicator" to know when something may be going wrong. I doubt I'll use it as the absolute in tire pressure or temperatures.
rgatijnet1
Explorer III
Sep 03, 2015
I have one of the best tire gauges made by Milton. I also have a set up that ties two tires together as I inflate them. In other words, I inflate the two front tires at the same time so I know they are exactly the same pressure.
I have tried two different TPMS systems and they both would vary by as much as 5 PSI on tires that I know are equal.
I would not trust the TPMS for your tire pressure but I would get a good quality tire gauge to inflate your tires.
Also remember that if you have tire valve stem extensions for the rear duals, they will not give you an accurate temperature of those tires.
msmith1199
Explorer II
Sep 03, 2015
GM I have three gauges and none of them match. Should I try a fourth?
GMandJM
Explorer
Sep 03, 2015
Use a third gauge as a tie breaker?

It's common to get different readings from different gauges, but 10# seems like more than normal.

I like what you're doing: Trust but verify. Good plan!
msmith1199
Explorer II
Sep 03, 2015
I have three really nice fairly expensive air gauges, and none of them match when checking the pressure. So the answer is who knows. You would have to get a gauge that you know has been calibrated and is accurate, and compare it to that, but if good gauges don't even match where can you even find one you know is correct? Maybe NASA or JPL would have one?

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What's More Accurate?

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