For example, you may not be aware how much influence your tire pressure has on your car’s fuel expenditure. Under-inflated tires create more road resistance, which means your car’s engine has to work harder for each mile per hour. In addition, it also compounds other mechanical issues.

For each 1 point drop in psi, your gas mileage decreases a third of a percent. By checking your tire pressure regularly and inflating your tires accordingly, you can improve your vehicle’s fuel economy by over 3%. That may translate into saving seven cents a gallon or more, depending on current gas prices.

These significant savings require almost no special expertise, either. To test your tire pressure, you need only one small, very inexpensive piece of equipment. A simple, high-quality tire pressure gauge costs less than ten dollars. An economy air-pressure gauge costs less than five. The ideal tire pressure for your car is probably clearly visible on a sticker just inside the driver’s side door.