Every car sold in the U.S. after 2007 has tire pressure monitoring, or TPMS. Most cars will have metal valve stems instead of rubber, which can be serviced by replacing the valve core, seal, nut, and cap. Costco charges for "servicing" the TPMS, but in my case, and most likely yours and everyone else's, didn't do anything except put a pretty green cap on the stem. This is a scam and I have seen it before. Beware. 60 minutes for tire change, 30 minutes waiting in line at membership for a refund for the TPMS rebuild that was not done. They are betting you will not want to wait even if you do catch onto the scam. Big thumbs down.
Best place for tires. Got new tires from Costco. They offer a life time warranty.