You can improve your gas mileage by up to 3.3 percent by keeping your tires inflated to the proper pressure. Under-inflated tires can lower gas mileage by 0.3 percent for every 1 psi drop in pressure of all four tires. Properly inflated tires are safer and last longer.
Most of us don’t get excited about tire pressure, or the gauges used to measure it. Yet according to the experts under-inflated tires are responsible for nearly 3.3 million gallons of wasted gasoline each and every day. Add in the benefits of safety and tread longevity from maintaining proper tire pressure, and tire pressure starts to become something of a necessity to look at and maintain.
According to experts, tires naturally lose about 1 to 2 pounds of pressure, measured in pounds per square inch (psi), every month. Each pound below the recommended psi lowers your distance by about 0.4 percent. Low tire pressure affects fuel economy by increasing the tires’ rolling resistance, which makes the engine work harder to move the car.
Ask yourself how long ago you last checked your tires, and be honest. Three months? Six months? Longer? With today’s high gas prices, that inefficiency can add up to significant money. At $1.50 a litre for gas, a vehicle with neglected tire pressure will require an extra $60 of gas each year compared to a car with properly maintained tires. You’ll find the correct pressure for your tires on a sticker that’s usually located around the driver’s doorframe; if it’s not there, check the glove box or owner’s manual. (Don’t use the psi number on the sidewall of your tires, that’s the “maximum permissible” pressure for those tires.) Finally, because “cold” tires are used to define proper pressure levels, check it before your trip or before driving more than a mile.