Tire pressure sensors
 

Any reason I should NOT buy a set of wheels with sensor already installed in them? Can they be removed? Is it even necessary to take them off, or will they cause any fit problems? Never had a vehicle with them so not sure of the implications.

If these wheels are for your Box, no reason not to buy them. All the TPMS is is a fancy valve stem. Inside the wheel is a little plastic square that slides thru the valve stem hole. It's held in place by a metal retainer that slips on the outside of the tire (keeps it from falling back into the tire). They can be replaced with regular valve stems. The inside plastic section contains the monitoring system and a battery that runs out of juice somewhere around 6 yrs.

If you are buying wheels with them in place, but do not actually have a TPMS in the car, they will not cause any problems, and so you can just forget they are there.

TPMS has got to be one of the lamest “federal nanny” items every conceived; you cannot imagine how much unnecessary money is spent on these systems every year.

Basically, each wheel has a pressure monitor under the valve stem that transmits a signal to the system in the car. Because the sensors carry a battery, eventually they will go dead and the TPMS will start alarming because it cannot see the sensor. That will require replacing the sensor (most are not designed for battery swaps), and depending upon the brand, the sensor can cost $100 or more each, plus the charge to break the tire bead, install the sensor, reset the tire bead, and rebalance the wheel. All because a $1.50 battery went dead.

Most manufacturers’ use “proprietary” TPMS components, which typically mean you have to buy replacements from them. Some aftermarket replacements have become available, but only for the most popular cars. When these systems became mandated in 2007, several OEM’s, Porsche included, had so many problems with them that the Feds gave them temporary “Papal dispensation” to turn them off until they could come up with a fix. By far, the biggest issue was that the sensors are wildly inaccurate in their pressure measurements, but that have been mostly fixed by now.

All this because the “average driver” would not spend $5 for a pressure gauge and check their tires from time to time…………

We have been replacing them on cars that are sometimes only two or three years old; and many of the dealers seem to feel they are not a warranty item.............

Thanks all - these are for the Boxster. Was doing some googling, I had no idea they were now manditory on all vehicles produced after 2007! Good to know they won't be a big deal.

Apparently Ford didn't get that note either because my 2010 escape does not have these.

Maybe it's not be categorized as a "light motor vehicle"? Or else Wikipedia is wrong (imagine that!)

"In the United States, the Firestone recall in the late 1990s (which was linked to more than 100 deaths from rollovers following tire tread-separation), pushed the Clinton administration to legislate the TREAD Act. The Act mandated the use of a suitable TPMS technology in all light motor vehicles (under 10,000 pounds), to help alert drivers of severe under-inflation events. This act affects all light motor vehicles sold after September 1, 2007. Phase-in started in October 2005 at 20%, and reached 100% for models produced after September 2007. In the U.S., as of 2008 and the EU, as of November 1st 2012, all new passenger car models (M1) must be equipped with a TPMS."

Also Wikipedia claims we can thank Porsche for the development of the 1st TPMS!:
"The first passenger vehicle to adopt tire-pressure monitoring (TPM) was the Porsche 959 in 1986, using a hollow spoke wheel system developed by PSK"

Tire-pressure monitoring system - Wikipedia, the free encyclopedia

There may not be an actual pressure sensor/display, some cars use the ABS sensors to detect a low tire by the reduced rolling radius.

Which can be even more problematic if the TPS warning continually lights up on the dash - the only part to replace is the ABS wheel $en$or.

I was responding to the comment about a '10 Escape not having TPMS, I'm sure it does.