How can we be sure that your case is the same as mine HotShot? You didn't have any sensors installed, whereas mine are installed but I want to know how long it would take for the system to recognize that the PSI was low.

 

It will not be immediate. It will take about 10 - 20 minutes for the light to come on. I just had a recent experience were I parked my car on the street and when I came back someone had watered their lawn and my passenger side tires were sitting in water. About 10 minutes after I drove away my TPMS light came on. I pulled over and checked my tires and everything was OK so I continued driving. After I got on the freeway and drove another 10 minutes the TPMS light went off. That's when I realized the cold water had lowered the pressure in the passenger side tires enough to trip the light, but when the tires heated up the light went out. The next day when I drove the car, no light.

 

Again, how will I know when to turn off my car? My TPMS light isn't on so I won't know if it worked. I want to be sure that if I"m leaving my car running for 20+ minutes that I"m not just wasting gas. PLEASE HELP.

 

When you hit the reset button, the psi reading at that time will be reference point. I don't think it does not do anything when psi goes up but I was told when a tire loses more than 6 psi, it'll trigger the warning light.

 

Yea those sensors can be tricky