I have the Orange Electronics TPMS which monitors all 4 tires press/temp simultaneously. I had an issue where my one tire had a serration and was leaking quite nicely (even with plugs), but a couple months ago, I put a patch on the inside and it finally stopped. The tire in question usually rides at 39-40psi when warm, so when I leave work today and get on the highway, I am shocked to see 45psi for that tire. <br>Now this Orange Electronics TPMS is something that I wouldn't buy again, probably. Sometimes it doesn't get the readings right away and can take up to 30 minutes for any one of the tires to read, but this only happens 10% of the time. I thought maybe the data transfer from the sensor to the receiver was screwy, so I checked the pressure when I got home and sure enough, it was 45. <p>All other tires read their normal values.<br>The only explanation is that someone put air in my tire, lol.