Tire pressure is usually used to refer to cold inflation pressure, the pressure of air in your tires when they are cold and haven’t heated up from driving. This affects the longevity of your tires, and your gas mileage, and having the ideal pressure is safer than running on tires that are overinflated or underinflated. When your tires are inflated properly, they will handle better and hold the road better, making your entire driving experience more pleasurable and safer.
First, of course, you need to find out what the ideal tire pressure for your car is. If you look at the tires themselves, you will see a pressure listed. In the United States this is usually expressed as Pounds per Square Inch, or PSI. The number actually on your tires, however, is not usually the ideal pressure. Rather, it is the maximum pressure that can be safely used, which is normally quite a bit higher than your ideal.
Each car has an ideal tire pressure suggested by the manufacturer. If you check your owner’s manual, it should list the appropriate pressure for your exact model of car. If you don’t have an owner’s manual, or if your owner’s manual doesn’t have this information, check inside the driver’s side door jamb. A sticker is usually affixed to this part of the door that includes all sorts of information about your car, including the recommended ideal pressure. For most cars this is generally around 30 PSI (2.1 kg/cm).
To get the best mileage out of your tires, you may want to actually go away from the manufacturer recommended ideal pressure. Although their recommendation will usually result in the smoothest possible ride, it may not result in the best cornering or the best mileage. To determine this ideal tire pressure, take the maximum listed on the walls of the tires themselves, and reduce this by around 10%. That will generally result in a pressure that will give you the most benefits for everyday driving. Of course, for longer trips, or when bearing a heavy load, you may want to increase the tire pressure closer to the maximum.
Maintaining an ideal tire pressure has both financial and environmental benefits, both of which have been touted a great deal in the past few years. For one thing, keeping an ideal pressure reduces the wear and tear on your tires, and in conjunction with regular rotation this keeps your tires fit for a maximum period of time. For another, it can increase your gas mileage dramatically. People on average see a gain of about 2 MPG (117L/100km), which can save the average driver anywhere from $50 US Dollars (USD) to $100 USD a year.
This can stack up quickly as the millions of drivers on the road start taking their tire pressure more quickly. For the price of a $10 USD pressure gauge, and a five minute test once a month, Americans could save an estimated 40 million gallons (151 million litres) of gasoline each day. In a world where people are constantly looking to save money and the environment, it’s an obvious step to take.