Having the tires on your vehicle inflated to the proper air pressure can make a big difference to the actual mileage you receive out of the tires and it could have an affect of the gas mileage you get per mile driven.
The illustration above shows three tires inflated to different levels. The first tire shows an under inflated tire. When a tire is under inflated the center of the tire is pushed in forcing the shoulder of the tire to wear out prematurely.
The tire on the far right shows a tire that has been over inflated. A tire that is over inflated will force the center of the tire to push outward and pulling the shoulders of the tire off the road. A tire that is over inflated will wear out prematurely in the center of the tire.
The picture of the tire in the middle shows a tire that is properly inflated. When a tire is properly inflated the tread foot print sits evenly on the road. This will allow the tire to achieve maximum tire life, improved gas mileage and assures the greatest overall handling performance.
The air pressure in tires should be checked once a month. The tires should be checked cold before the vehicle is driven.
To find out how much air pressure should be in each tire check the tire placard located on the door jamb of the driver's front door.