With gas prices fluctuating wildly, more focus has been put on hybrid technology and other creative ways to increase fuel efficiency. One of the easiest ways to increase fuel efficiency in any vehicle is inflate the tires with the proper amount of air. When a tire is pressurized at or near its capacity, it becomes more firm, so that when a car drives, its weight does not cause the tire to deform as much, so less of the tire touches the road. The result is that the friction between the tires and ground is reduced, so the amount of fuel needed to travel a certain distance is also reduced.
Essentially, the more air you put in your tires, the better off you'll be in terms of fuel efficiency. But each tire is only designed to handle a certain amount of pressure. Look at the sides of your tires to find out what the maximum PSI is for the tire. You can fill the tire up to the max, or just under, although most cars will have a recommended max pressure based on the weight of the vehicle itself, which is the safest measure to use. Filling up more than the recommended amount can be dangerous as it might cause the tire to explode or break. The maximum pressure on the tire itself is usually substantially less than the actual breaking pressure for the tire.
Another advantage of filling tires to a high amount of air pressure is that it typically makes the tire last longer. The main drawback is that stiffer tires make for a more bumpy ride on the road, though good shock absorbers can limit any noticeable changes. One should also be aware that as a car is driven, the friction of the tires causes them to heat up, and when air heats up, it expands. This means that tire pressure will increase somewhat as the car is driven, and also that shifts in temperature will affect tire pressure. Especially in places where it gets very cold, tire pressure can drop rapidly. In such conditions, tire pressure should be checked regularly and inflated often to keep up gas mileage and prevent the tires from being damaged.
