Tire pressure guide


  • Nearly all tires lose pressure gradually over time, even if the car isn’t driven or the tire isn’t mounted on the car.
  • With a tire that is undamaged and properly mounted on the rim, most of the pressure loss comes from air migrating through the rubber sidewall, not through the inflation valve.
  • The valve stem’s dust cap is to keep dirt out, not air in.
  • Tire pressure drops as the weather gets colder. A typical car tire measured at 30 psi during 80-degree temperatures will register 25 psi when the outside temperature drops to 30 degrees.
  • While it’s convenient to keep a pressure gauge in the glove box, very hot or cold temperatures can impact performance. It’s better to keep your gauge at room temperature.
  • The air pressure within a tire is almost unaffected by the weight of the car. An unmounted tire inflated to 32 psi will still measure nearly the same when it’s mounted and bearing the weight of the car.
  • When checking and adding air to your tires, go by the automaker’s recommended pressure setting, which is usually located on a placard or sticker in the driver’s-side doorjamb or inside the glove compartment or fuel-filler door. This information may also be in your owner’s manual. Don’t go by “max pressure” figure found on the tire sidewall.


How to check and adjust tire pressure

Utilize a decent, very much kept up tire-weight gage. Try not to believe the gage on a service station’s vacuum apparatus to be precise.

Discover what the prescribed weight setting is for your auto. This data is generally situated on a bulletin or sticker in the driver’s-side doorjamb, inside the glove compartment or fuel-filler entryway. Likewise check your proprietor’s manual. Run of the mill expansion weights territory from 28 to 36 psi (pounds per square creep). Numerous bulletins additionally list the metric proportional in “kPa” (Kilopascal). Front-and back tire weight might contrast. Essential: Use the weight prescribed by your auto’s maker, not the “maximum weight” figure found on the tire sidewall. The prescribed weight gives the best blend of execution, ride solace, administration life, and efficiency.

Check the weight when the tires are chilly: after they’ve sat for no less than three hours and before the auto’s been driven more than two or three miles. Tires heat up as a vehicle is driven, which expands the gaseous tension and makes it hard to precisely survey any weight change.

Check every tire by first expelling the screw-off top from every tire’s swelling valve. Be mindful so as not to lose the tops, as they secure the valves.

Embed the end of the tire-weight gage into the valve and discourage it. On the off chance that you hear air getting away from the valve, push the gage in further until it stops. View the weight perusing. A few gages can be uprooted to peruse the weight esteem, however others must be held set up on the valve stem. Perused the gage directions for appropriate use. In the event that the weight is right, essentially retighten the valve top.

Keep in mind to check the weight of the extra tire. Space-saver “donut” saves frequently have high expansion weights, for the most part 60 psi.


How to add air to your tires

  1. If the tire-pressure reading is lower than the recommended psi figure, you’ll need to add air. If you don’t have a compressor, you can drive to a gas station and use its air-pressure hose. Another option is to buy a portable 12-volt tire inflator, which begin at about $20. Important: If you have to drive more than a few miles to reach a compressor, the pressure in your tires will rise somewhat. So, remember how much pressure you need to add, take another pressure reading when you get to the gas station, and adjust accordingly. Then check again when the tires have sat for three hours to be sure you have added the correct amount.
  2. To add air, first push the hose’s nozzle firmly into the tire’s valve, as you did with the tire gauge. Use your tire-pressure gauge to check the pressure again, and add more air if necessary.
  3. If the tire pressure is too high, lower it by pressing a nub on the gauge into the tire valve just far enough to let some air hiss out. Some gauges have a bleed-off valve and most basic gauges have a little prong that can be inserted into the tire valve for this purpose.
  4. When finished, be sure to screw the caps back onto the valve stems.