Aftermarket TPMS

[booster]

I think that I should throw in one bit information that might save some angst for people.


The sensors that screw on the valve stem are certainly common, and what we use, but using the temperature reading as anything but a relative reference is not a good idea IMO.


The sensor is hanging out in rapidly moving air, far from the tire itself with only a small area of metal (in bolt in sensors) and an even smaller, non moving much, amount of air that is connected through a small hole. Changes in tire temp will not happen near as quickly in the sensor for that reason, and ambient air will also cool the sensor by varying amounts depending on the ambient temperature. It is not unusual to have as much as 0 to 100 degrees difference between ambient and actual tire temperature.


It really isn't a big deal, IMO, as you can get a feel for actual temperatures by checking in various typical situations to see how your sensors are different than an infrared thermometer gives or even easier is just watch the pressure change on the sensor. At 80 psi you would get a bit under 2 psi change for every 10* difference in tire temperature and at 65psi a bit under 1.5 psi change for every 10* difference. From what I have tested by comparing to the infrared thermometer, this will be more accurate than the TPMS sensors on stems gives (we have had two different, high end, brands of them) as long as you note the pressure when you start out and the ambient temperature, which will be the same as tire temp most of the time at first drive.


Of course, none of these ways gives the actual temperature that probably means the most and that would be the temperature that is highest within the rubber casing itself. Only the tire developers and such would be able to do that. The infrared would be the best we can do and is quite good from all I have been able to find out.


Personally, I would not hesitate to have sensors without the temp sensor as they can be more confusing than useful, compared to other methods of knowing the tire temperatures. The internal temperature sensors are much more accurate I would think and could be useful.

[peteco]

Originally Posted by avanti

TST is robust and reliable. I cannot say whether they are the best value, but they are a safe choice.

Just be very sure that if you use stem-mounted sensors, you get 100% metal stems installed. Trust me on this one.

I have TST and it has been great for 4 years. My stems have rubber lower part and metal (brass looking) upper part, so sounds like these are not 100% metal. I do spray them with 303 rubber treatment whenever I treat the tires with 303, about every 1-2 months.