I have TPMS, but I also use the infrared gun to discover if a tire or hub is getting unreasonably hot, even though there may not be a TPMS alarm. What I expect to see depends on the temperature, the road surface, how much sun is out, which side (sunny or not) the tire is on, etc. It only takes a minute to walk around with the IR when I first get to a rest stop. It also let me know that I should stay put to let brakes cool (and when I could go) one time after a long descent where the engine brake wasn't enough to keep my speed down.