Although often overlooked, maintaining correct tire pressure is one of the easiest things you can do to maximize fuel mileage, ride quality, and vehicle safety. Never done it before? Here is a quick how-to guide from ASE certified master technician Toby Schultz, Senior Automotive Editor at YourMechanic.
There is quite literally a lot riding on your tires, as they are the only part of your vehicle that should be in contact with the road. This means that proper maintenance of your tires is crucial. There are a few things you can do to maximize the life you get from your tires, not the least of which is maintaining the correct tire pressure. Running too high or too low of pressures can adversely affect rate of tread wear, fuel economy of the vehicle, as well as vehicle ride quality. If you have never had to check your tire pressure yourself, here is a quick rundown of how to do it.
Obtain a quality tire pressure gauge: a good quality tire pressure gauge can be obtained at any automotive parts store, usually for under $10.
Determine the correct tire pressure for your vehicle: Correct tire pressure varies between vehicles. The easiest way to determine the correct pressure for your vehicle is the tire pressure specification sticker, which is usually located in one of two places. On the driver door jamb, which is the part the door closes into, or on the inside of the fuel door. This sticker contains a plethora of numbers specifying the pressure in both psi (pounds per square inch) and bar (barometric pressure) for the front and the rear tires at partial load, as well as separate pressures for fully loaded vehicles. The pressure listed are also “cold” pressures, meaning that these pressures are specified on cold tires. If you are inflating tires that have been warmed up by driving, you may need to compensate these pressures, which will be covered later.
Check your tire pressure: First you should check the pressure in each tire to determine if you need to add some. Make sure the vehicle is parked securely. Remove the valve stem cap and set it aside for now. Take the tire pressure gauge, and firmly press the fitting straight onto the tire valve. The tire pressure gauge should now indicate the current pressure of the tires. It’s best to check the tire pressure cold If you need to check it after the vehicle has been driven more than about 15 minutes, you will need to compensate by subtracting about 3-5 psi from the current indicated pressure. This will give you what your current “cold” pressure would be, so you can accurately compare to the pressures listed on the sticker. Don’t forget to put your valve stem cap back on. If your pressures are OK, then you can stop here. If you need to add some air, continue on.
Locate a source of air: Most fuel stations will have an air compressor which you can use to fill your tires. Depending on your state, they may charge for use of it, though it is quite cheap. In California, for example, service stations provide air for free because having low tire pressure causes lowered fuel economy, which puts more pollutants into the air.
Adding air to the tires: Adding air is a simple process. Once again you will remove the valve stem cap and set it aside. The air hose (chuck) will have a tip similar to that of the tire pressure gauge. Simply push the fitting of the air chuck onto the tire valve, and air will automatically flow in. Some chucks have a button or lever that needs to be depressed to allow air to flow. Add air for about 5 seconds at a time, and check the pressure using your gauge after each 5 seconds until you obtain the desired pressure. If you overfill the tires and need to remove some air, the back side of the gauge has a small pin that you push into the center of the valve to release air. Do this slowly, as the pressure releases quickly. Don’t forget that you may need to compensate the pressure as noted above if the tires have been warmed up by driving for more than 15 minutes. Reinstall your valve stem cap and now you’re done.
While you’re checking the tire pressure is a great time to check the overall condition of your tires. It’s totally normal for tires to lose a bit of pressure over a long period of time. If you find yourself needing to add air more frequently, such as weekly or even monthly, you should have your tires inspected for leaks or damage by a qualified professional.
Toby Schultz is the senior automotive editor at YourMechanic.com. YourMechanic delivers mobile car repair by certified mechanics in over 700 U.S. cities. Their top-rated technicians can perform over 600 services at your home or office and will even answer your questions online.
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