Driving around on underinflated tires is just a bad idea all the way around. Underinflated tires increase a car’s rolling resistance, meaning a drop in fuel efficiency since it takes more energy to move the vehicle down the road.
A single tire that’s down by ten pounds of air means a 3.3 percent drop in fuel economy…multiply that by all four tires, and you can figure on giving up ten percent of your gas mileage. The added friction and rolling resistance also means more heat is generated, and heat is the enemy of the internal structure of a tire. That heat will damage a tire to the point of failure. Studies show that underinflated tires are a full 25 percent more likely to fail, and at least half of one-car accidents involve a tire problem as a factor. And still, it’s estimated ...[more]