I didn’t! I was shocked to learn this during my recent Green@Home training. As one of the energy-saving measures we practiced, we checked the tire pressure on a tire. It decreased from 29 psi to almost 25 psi as people checked the pressure. Then four people took turns and pumped the tire back up to 29 psi!
I’ve pumped many a flat bike tire, and that is a lot of work. I never imagined you could pump a car tire. But I guess pressure is pressure. The instructor said about 10 pumps per pound. Obviously, a flat car tire would take a lot longer to pump.
Anyway, properly inflated tires help to maximize fuel efficiency and also longevity of the tires. If you notice your tires are under-inflated and you have a bike pump with the Schrader valve–which is used for car tires and wider-rimmed (not road) bikes–you don’t even have to go to a gas station and put in quarters. Just pump them up.