Tire Pressure

How Often Should I Check My Tire’s Air Pressure?

Today’s tires are marvels of high-tech engineering, but when driven on with insufficient air pressure they are prone to blow outs at high speed, especially when overloaded or in hot weather conditions. To prevent blowouts, maximize your fuel economy, and extend the life of your tire, we recommend checking the air pressure in your tires at least once a month. We will happily do this for free at any of our locations. Just stop in and we will fill your tires up to the proper pressure with regular air, or we can refill your tire with Nitrogen for a nominal fee.

How Do I Check My Tire’s Air Pressure?

To check the air pressure in your tire you will need an air pressure gauge to measure the pressure inside the tire, and a source of compressed air with an air hose and an air chuck. Locate the valve stem of the tire you wish to check, and remove the valve cap. Using the air pressure gauge, check the tire pressure by placing the end of the gauge over the tip of the stem and press down. The gauge will give you a measurement of the air pressure inside the tire. Add or remove air pressure to the tire until the desired air pressure is achieved.

Max Load and Air Pressure

The maximum load carrying capacity and inflation pressure that a tire is engineered to withstand is molded into the sidewall of every tire. The tire in this picture is designed to carry 1356 pounds when inflated to it’s maximum of 51 PSI. If the pressure is lower than 51 PSI, the tire will not be able to carry the entire 1356 pounds it was designed for. The tires for your vehicle will not necessarily require the max inflation amount, but it is critical to maintain proper air pressure in your tires so that the tires aren’t overloaded. (See below).

Air Pressure For Your Specific Car

The maximum tire inflation pressure molded into the side of your tire is not the amount of air you should put in your tires. Instead, look at the driver’s side door jamb for the vehicle placard which shows the recommended cold tire pressure (32 PSI) or your specific vehicle, along with the proper Tire Size (205/55R16), Speed Rating (H), and Load Index (91) that the vehicle was designed for. At the pressure designated on the placard, the tires of the correct size and load index will have been engineered to carry the weight of the vehicle and it’s passengers and cargo. Note that the tire pressure should be measured when the tire is cold. If you measure the pressure after the tires have heated up from driving, the pressure will be higher than if the measurement were taken when the vehicle has been sitting for a while.

Does Air Pressure Affect Vehicle Load?

The weight of your vehicle can be found on another door jamb sticker. For example the Gross Vehicle Weight Rating (GVWR) might say 3,828 pounds as shown for this Volkswagen Beetle. According to the vehicle tire placard, the maximum additional weight of the passengers and cargo for this example would be 772 pounds, for a total of 4,500 pounds, or 1,125 pounds per tire, which is less than it’s maximum load.

Max pressure means max load carrying capacity, but for this Beetle the engineers at Volkswagen have recommended a lower tire pressure to give some margin of error and to improve other tire attributes such as handling, ride comfort and traction.

Tire Pressure During Winter Conditions

During cold weather tires are prone to lose air quickly, especially when there is a sudden temperature drop. If the temperature drops significantly overnight we’ll usually have several cars waiting for us to open in the morning because their tire light went on. To avoid this situation, we recommend inflating your tires with an additional 3 to 5 pounds of air. This will keep your TPMS light from going on, and will prevent blow outs and premature tire wear during Chicago’s typical winter weather.

Optimizing Tire Pressure For Your Car

The tire inflation pressure shown on the vehicle placard is recommended by the engineers who designed your vehicle to give the best combination of ride comfort, handling properties, load carrying capacity, and rolling resistance, but you may decide to vary your air pressure to increase or decrease various vehicle characteristics affected by your tires.

Reducing a tire’s inflation will:

Increase fuel consumption
Reduce steering response
Reduce tire tread life
Reduce cornering stability
Improve ride comfort
Increase traction a bit
Lower load carrying capacity
Cause the edges of the tire to wear faster

Increasing a tire’s inflation will:

Give a stiffer ride
Increase steering responsiveness
Increased fuel economy
Higher load carrying capacity
Decrease ride comfort
Increase the likelihood of pothole damage
Cause the center of the tire to wear faster