I don't know about the accuracy and speed of change but I can say it does respond. Fact in case. When I pull of the highway, pit stop or whatever, the temperature of the tires goes up usually 5-10 degrees fairly rapidly. I attribute it to lack of airflow cooling the tires. While not as accurate as in the tire it is seeing a change and reporting it. I watch the temperature and compare to the other tires. Not looking absolute temperature. I know my setup and they all run about the same, except for sunny side hotter than shady side. A variation is what I look for.