I wore them in the fall. In the spring they tried to air. I can't unscrew all four valve stem caps. They corroded/jammed the valve stems in a MN winter. When I try to unscrew them they get stuck in such a way that the whole valve rotates in the rim. This is on a Chevy van with 80psi tires. So it's not due to a lack of pressure. Now I have to replace all 4 valve stems which will cost north of $50. Cool. Unless you're in a sunny state that never snows, stay away.