The cost of gasoline has remained high in Japan and the past few years have been tough for many automobile owners. I came across an article online about fuel efficient improvement methods and would like to share it here. One idea is that we should make sure to check the tire pressure. If it is insufficient, tires will change shape and that will make cars consume a lot of gas. If the shape of a tire changes drastically, their rolling resistance will increase and cars will use more gas. Japan Automobile Federation[JAF] states that the energy efficient rate (I'm not sure if this is the right phrase - maybe energy efficiency rating?) will decrease by 2% in urban and by 4% in rural settings when we drive with a tire pressure of 50kPA(0.5kg/cm2) lower than proper value. For example, a car has a fuel efficiency of 20 kilometers per liter (km/L). The car needs about 500 liters of gas to run 10,000 kilometers (km). On the flip side (another option: On the other hand), if the car lowers its fuel efficiency by 4%, it will be 19.2 kilometers per liter. In that case, the car needs about 521 liters. If the gas price is 160 yen per liter, we will need to pay 3,360 more yen. That's why JAF suggests that we check the tire pressure on a monthly basis. I know (that) this might seem like a drop in the bucket, but I believe (that) the information will be very useful for everyone in the near future.