So I bought these caps because my old car doesn't have a gauge on the dash, it just warns me of low tire pressure. So I bought them because I had a friend who liked them and found them useful for letting them know which tire is going flat rather than playing a guessing game. Installation was easy at first and I loved it. The next few weeks seemed fine with no complaints. Then, about the third week, I noticed a low air pressure sign somewhere in there on the dash. I went to check which tire. To my surprise everything turned green, I thought the sensor was defective or too cold. Ignore that I drove on for a day or two. The sensor never triggered and when I checked the caps I didn't notice a difference in color but I did objectively see a reduction in one tire. When I went to fill it up with air I was amazed to see a tire rated at say 20psi when my standard is 32-34psi. Replenish on the go, I felt fine. It happened the next week and again a week later. Afraid that something was wrong with the structural aspects of the tire, I went to the dealers. (I know some preferred dealers, but I'm new to cars and don't want to change mechanics often). The dealer examined the tires and said the tires themselves are good. The only thing that could have contributed to the low air message I received could be related to the hubcaps. The mechanic informed me that the caps release pressure to indicate if the tire is green/yellow/red. He suggested going back to the basic caps and see if I run into a problem. I paid the $60 bill to be asked to switch to old caps. Three weeks into this visit, plus or minus a few days, there are no more low air pressure warnings and I wish they were wrong. I think so. My experience with the product was terrible and it cost me a total of $70 to go to the mechanic and purchase the product. PSI which I didn't like he said between 32-36. I don't like writing bad reviews, but I have to admit that I was very disappointed with the product.