I am of the believe that is based more on use, meaning if you keep your tires aired up properly then the TPMS light rarely comes on causing the battery to diminish faster then normal…
This is based on experience from replacing them on customer vehicles as well as I have two 15yo vehicles with the OEM TPMS sensors… But no prof of any kind though…
That is not how my sensors work. They pretty much continuously send the actual pressure to the car.
So that means it’s time, not miles.
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Now I’m curious. I want to rip apart a failed one 
If I was doing this I would use a chip that supports deep sleep (many uC do have this feature) until pinged by the host to wake up. So if it’s sitting unused, the battery isn’t being sucked down unnecessarily. Once the vehicle is started and begins moving the host controller send a ping to the sensors to wake up and begin transmitting. Another option would be a controller chip with built in accelerometer so it can sense rotation to wake itself up. These are also prevalent in consumer electronics as well.
So in some ways it is a combination of time and miles (use).
Like any battery, the rate of self-discharge and degradation are also tied to environmental conditions. So in a hot climate, they probably deplete faster than in a colder climate.
TPMS sensors only transmit when the vehicle is on. All mileage is not the same obviously. If the vehicle is driven 30 mph on average, that’s ~2,900 hours of driving. If it’s primarily highway miles, say 55 mph average, then that’s only ~1,600 hours. Add to that idling time, etc. where the vehicle is on/running without being driven.
Another vote for waiting until the light comes on the dash.
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Probably a combo of both. Time, b/c most batteries self-discharge when not in use. Miles, b/c the transmitters are the biggest power drain, and only active when the engine is running presumably.
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The kid works for a Goodyear service center.
He says when they replace the tires they don’t replace the sensors unless the customer requests it be done.
Tester
As for the demand placed on TPMS batteries, here’s an interesting article from one TPMS vendor [1]:
TPMS Life Expectancy
The estimated life expectancy of an OE TPMS sensor is 5 to 12 years, with the average lifespan being 7 years. TPMS life expectancy is directly related to the number of radio frequency transmissions the sensors make. Driving habits greatly influence the number of RF transmissions a sensor makes in its lifetime. For example: sensors usually transmit when the vehicle is stopped and transmit more often when in motion. Maintaining a constant speed, such as when you’re on a highway, reduces the demand on TPMS sensors and allow the sensors to transmit less often. Drivers who often find themselves driving in start-and-stop type traffic will have a greater impact on the vehicles tire pressure monitoring sensors. Weather can also have an impact on tire pressure sensor battery life. Cold conditions allow batteries to last longer. Warmer conditions take more of a toll on TPMS battery life.
[1] TPMS Sensor Batteries, Life Expectancy, and Replacement | TPMSDirect
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May be true, in my gmc * can watch live tire pressures*I believe.
On my Pontiac reset procedure is with engine off, key on, then increase or decrease pressure
One by one until the horn honks and the turn signal comes on. So it transmits at rest but with the key on.
The relearn on the Acura is just to drive it above 15 mpg. So suspect it only transmits with the car on, but I don’t care.
I suspect the “live data” you’re seeing is whatever any given TPMS sensor last transmitted.
Like I said as part of the re learn you let maybe ten pounds out and the tpms responds within a second or two.
That would be true if the data transmission rate was once a start or every 3 seconds 
I can kind of watch my tires warm up while driving using the DIC display on my Trailblazer. The update rate does seem to be fairly frequent as one might expect while driving if the design intention is to detect a rapid deflation of a tire.
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TwinTurbo:
Yours and Barkydog’s replies made me dig deeper.
It appears some manufactures haved moved away from using the electromagnetic induction used for years and are instead using a Bluetooth Low Energy (BLE) standard.
See these two links for more info.
Thanks. I learned something new.
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Not being interested in the technical details, I am quite certain I get ongoing real time readings of my tire pressure. I’m also quite certain when the battery fails, the sensor needs to be replaced. Experiential not technical knowledge. I’m sure most shops would give you an old one to take apart or buy a new one for about $30. I’ve been known to take things apart just to look too, but there are limits.
Just to add to the confusion one Acura I had, I would get a failure to read signal, on a long trip with passengers in the back seat. Only with passengers in the back seat. The receiver was in the trunk. The dealer didn’t know what to do and traded anyway. I just theorized the passengers blocked the signal. I never made them get out to check pressure.
Me too. Until you posted those, I didn’t know that kind of detail about it. Thanks!
Normal tire pressure signal transmission rate is every 60 seconds, more frequently while moving during certain conditions. After a certain period of inactivity, the sensors go into park mode/sleep mode, a signal is transmitted every 13 hours.
Tire pressure sensors are awakened by a ping from the receiver or by motion. A signal will be transmitted instantly if there is a rapid pressure change of 6 psi or more.
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