[notanlines]

Surface temperatures of tires on a heavy fiver can easily reach 130-140 or more on a relatively warm day. I use the infrared EVERY stop and this is always 10-20 degrees hotter than the TPMS reads. As was stated, you are looking for the delta between the 2, 4 or 6 tires. If 3 read around 125 degrees and 1 at 145, it is time to stop and find the reason. Remember, TPMS will only give you the approximate temperature of the rim, not the surface of the tire. A combination of watching all three, pressure, surface temp and TPMS temp will usually keep you between the ditches.