Accuracy of TPMS
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Joined: May 2003
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Accuracy of TPMS
Has anyone verified the accuracy of the displayed pressure in the app?
Mine has been consistently over by 2 psi on the left front and left rear.
I have 3 reliable gauges, including a digital, that I've been using over the years and they show same measurement, so I'd think is the car's issue.
Mine has been consistently over by 2 psi on the left front and left rear.
I have 3 reliable gauges, including a digital, that I've been using over the years and they show same measurement, so I'd think is the car's issue.
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Joined: Nov 2018
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From: San Francisco Bay Area
2019 C63CS
They are not very accurate. Not a EQS specific issue. First off, they only have a 1 psi resolution. Three of mine in the C63 are consistently about 1-2 psi high. The information in the app itself is useless, because it's the last pressure when the car was shutoff and not the actual current pressure. So the app pretty much always shows hot pressure. Not really even sure why it's there, other than I suppose seeing if there's large enough difference between the tires that are supposed to be at the same pressure, but depending on how much sunlight hit each tire, and how many left and right turns you made not all tires are at the same temperature after a drive. So you always have to compensate for temperature. 10F is 1 psi difference in pressure.
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They are not very accurate. Not a EQS specific issue. First off, they only have a 1 psi resolution. Three of mine in the C63 are consistently about 1-2 psi high. The information in the app itself is useless, because it's the last pressure when the car was shutoff and not the actual current pressure. So the app pretty much always shows hot pressure. Not really even sure why it's there, other than I suppose seeing if there's large enough difference between the tires that are supposed to be at the same pressure, but depending on how much sunlight hit each tire, and how many left and right turns you made not all tires are at the same temperature after a drive. So you always have to compensate for temperature. 10F is 1 psi difference in pressure.
I'd say the sensors are pretty accurate even if not really needed. The intention is to watch after pressure drops, leaks or punctures where 10 times higher inaccuracy would still be acceptable. The car now also shows the tyre temperature for those who want to compensate the reading accordingly (not sure but I assume the cluster pressure reading is absolute, not compensated for the temperature).
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Joined: Jan 2022
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I've never checked tyre pressure from the app while driving. A continuous update for some other person, other than the driver does not seem to be important. The title however was about TPMS as such, not about the issues of the app. Current tyre pressure readings are available from the instrument cluster all the time (except for the very start of the journey, a drawback of the new battery saving sensors).
I'd say the sensors are pretty accurate even if not really needed. The intention is to watch after pressure drops, leaks or punctures where 10 times higher inaccuracy would still be acceptable. The car now also shows the tyre temperature for those who want to compensate the reading accordingly (not sure but I assume the cluster pressure reading is absolute, not compensated for the temperature).
I'd say the sensors are pretty accurate even if not really needed. The intention is to watch after pressure drops, leaks or punctures where 10 times higher inaccuracy would still be acceptable. The car now also shows the tyre temperature for those who want to compensate the reading accordingly (not sure but I assume the cluster pressure reading is absolute, not compensated for the temperature).
