Case in point. *NM*

the batteries can't be replace. You have to replace the whole sending unit. They're not cheap.

The entire unit is expensive to replace, but I've been told they should last 8 years or so. Go through the dealer and see if there is something wrong with the OBC, or if it's the device in the tire, see if they'll replace under waranty. It would be cool if in the future the batteries are "self winding" like a some nice watch. The rotation of the tires keep them juiced. Figure that one out, and you'd become rich. I'll only take a 10% fee on everyone sold.

SHOULD is the operative word. TPMS became standard in MY 07 and there have been a couple of posts about batteries going belly up, specially after hibernation. 8 years is probably under ideal conditions. I imagine things like temperature and how frequently you check would have a bearing on how long the batteries last.

Guenter
2014 Boxster S
GT Silver, 6 Speed Manual, Bi-Xenons, Sports Suspension (lowers car 20mm), Porsche Sports Exhaust, Porsche Torque Vectoring, Auto Climate control, heated and vented seats, 20" Carrera S Wheels, Pedro's TechNoWind, Sport Design steering wheel, Roll bars in GT Silver
[www.cyberdesignconcepts.com]

My 2005 STS TPM units are still functioning just fine coming up on 8 years (and in the Caddy, like Porsche, it gives you data on each specific tire). SilverBox, a 2008, coming up on 5 1/2 years TPM is also still functioning just fine. I check via the TPM system, tire pressures virtually every time I drive my cars. I don't believe how many times you check has any impact on battery life. My understanding is they activate once the wheels start rotating and shut down once the car has been sitting still for a while. I am not sure but think the only thing you trigger when you call for information is the receiving unit that runs off of the 12 volt system. As for any impact from hibernation, my cars only experience 7 consecutive weeks of none driving each year.

the sidewalls don't get compromised. this is on the 911, i ruined a boxster tire before it was noticable, checked the tires, drove about two miles and then noticed odd feeling stopped . had picked up a screw and by the time i noticed the sidewalls were affected and i was not going to chance driving with them after that.

in March on my 2007 Boxster. One of the sensors wasn't working, the dealer checked the battery life and only one sensor was out of juice.
They tried to disable the TPM but that wouldn't work.
They said I would have to replace all 4 sensors, I said lets try just one (their expensive) and luckily they all synced up.
I agree it is handy to check the pressure via the TPM but geez if I had the choice my trusty tire gauge would do the trick for a lot less $$$.

Quote
DougW
I agree it is handy to check the pressure via the TPM but geez if I had the choice my trusty tire gauge would do the trick for a lot less $$$.

TPMS is good for people who don't care about their cars and just drive them hither and yon. How many time have we all seen a car in front of us w/ one or more tires going flat, and the driver is oblivious even though the car is swaying and swerving from side-to-side.

I agree w/ you that people who drive high-end cars (except women) aren't in that category.

Driving a new-to-me '09S in Aqua Blue Metallic. It does .5 past light speed. I made the Kessel run in less than 12-parsecs.
Motto: If you have your top up, that storm outside had better have a name!
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Edited 1 time(s). Last edit at 05/13/2012 10:57AM by KevinR-MedinaOhio. (view changes)

Low profile, stiff side-walled tires won't give as apparent a sensation of pressure loss as more conventional tires, especially at the rear, and with moderate driving. Also, when a tire is going flat, the sooner the driver knows, the better, so as to correct the problem, especially these days with spare tireless cars. A ruined tire and/or rim would be a disaster.

Quote
KevinR-MedinaOhio
TPMS is good for people who don't care about their cars and just drive them hither and yon. How many time have we all seen a car in front of us w/ one or more tires going flat, and the driver is oblivious even though the car is swaying and swerving from side-to-side.
I agree w/ you that people who drive high-end cars (except women) aren't in that category.

I very carefully check the tire pressures in my cars frequently with a high quality hand gauge. However I find the ability to check each tire's pressure while driving after hitting a patch of strangely grooved pavement or other unusual and unavoidable piece of junk on the road reassuring and safer than having to pull over on a high speed road and check the tires with a hand pressure gauge.

I used to think these were annoying, but a few months ago, I noticed on my daily commuter Infiniti FX35, one tire was slowly losing pressure over a few days. That prompted me to take it to a tire shop, and they ended up finding a small nail in the tire. I'm convinced that if I didn't have the TPMS, I might've been caught on the side of the highway one evening after work changing a flat. Now, I wish my Boxster had it too.