How to Check Tire Air Pressure
First, check the decal in your vehicle's glove box or on the driver's side doorjamb for the correct air pressure, noting that the pressure level may differ for the front and rear tires. Recommended tire inflation pressures are always for COLD tires, which means you check the tires in the morning or after the vehicle has been sitting for a couple of hours. Driving heats up the tires and causes the air inside to expand, which will cause the readings to be several pounds higher. Next, use an accurate tire gauge; don't rely on the built-in gauge on a gas station air hose or compressor, as they tend to be inaccurate. An accurate gauge will give you a good reading and you can add or release air from the valve stem until your tires' pressure matches the recommendation.
Or, you could let a Big O Tires associate check the tire pressure for you... fast and free.
Note: Any recommendations provided on www.bigotires.com are general in nature. Big O Tires recommends that you always consult your vehicle's Owner's Manual, the vehicle manufacturer or an associate at your local Big O Tires store for vehicle specific recommendations.