On a roll with proper tire inflation.

Under-inflated tires create more resistance when rolling which in turn forces your engine to work harder. This of course results in greater fuel consumption. Having your tires properly inflated can increase fuel economy by up to 3.3 %. Not only that but keeping your tires properly inflated also increases your vehicles safety by improving its handling.
Tire pressure should be checked once a month as a 1 pound drop in psi (pounds per square inch or pound-force per square inch ) in all tires can make a great difference ( .4 % ). All you need to do this is a tire gauge, a basic one would cost you under $10.
To find the correct tire pressure for your vehicle , refer to your owners manual. Do not go off what is stamped on your tires as thats the maximum pressure for the tire not your vehicle. Once you know the correct pressure test with the tire gauge and fill as needed. Checking your tire pressure after you fuel up at the gas station is a great idea as you can use their air pump. Drive safe !