Tire Pressure Frequently Asked Questions (FAQ)

What is a tire “placard?” And where is it usually located?

A tire placard is really just a fancy name for a tire information label. This label contains several key pieces of information: (1) the vehicle manufacturer’s recommended psi (pounds per square inch) or kilopascals (kPa) of air pressure for your vehicle’s tires, (2) the maximum weight (or “load”) you should have in your vehicle. Load or weight limits are usually given in terms of number of occupants or total weight (in pounds or kilograms) & (3) the recommended tire size.
You’ll find the label located inside the driver’s side doorframe or doorpost. It may also be affixed to the edge of the driver’s door or the inside of the glove-box door or trunk lid. Next time you get in your vehicle, take a moment to locate your vehicle’s tire placard & make a note of the correct tire pressure & load limits for your vehicle. The same information is also located in your owner’s manual.

 
What does the psi number on the tire placard or label have to do with tire safety? What are the risks of underinflating or overinflating?

The psi, or pounds per square inch, number on your tire placard or label represents the pressure you should fill your vehicle’s tires with to ensure tire safety. Under- & overinflating tires can both be safety hazards. Overinflating tires can adversely affect vehicle maneuverability, make the ride harsher, & sometimes lead to loss of control & crashes. Underinflating tires – a potentially more serious problem – can result in tire stress due to overheating, irregular wear of tread, tire failure, & sometimes loss of driver control & crashes. So obviously you’ll want to know the correct psi for your vehicle, check your tire pressure at least once a month with a tire gauge, & adjust tire pressure accordingly.

 
How often should I check my tire pressure?

Keep in mind that a tire doesn’t have to be punctured by a foreign object, such as a nail, to lose air. All tires will naturally lose some air over time. In fact, underinflation is a leading cause of tire failure. So it’s advisable to check the pressure in all your tires, including the spare, at least once a month. There’s nothing wrong with checking more often. Circumstances may call for more frequent checks. For instance, checking pressure after driving on poor road surfaces or before embarking on a long road trip are good safety practices. Finally, always remember to use a tire gauge: you cannot tell if a tire is underinflated simply by looking at, kicking, or pressing on a tire.

 
I’ve heard that the best time to get an accurate reading of tire pressure is when tires are “cold.” What is a “cold” tire?

While some people think that the term “cold” tire relates to the outside temperature, it really has nothing to do with the weather. It can be 90 degrees outside & your tires can still be considered cold. Rather, a cold tire is one that hasn’t been driven on for at least 3 hours, which is the optimal time to get an accurate pressure reading. A tire that has been driven on for short distances — even just 1 mile — is no longer considered “cold.”

 
What about the psi number listed on the side of my tires? Should I fill my tires to that pressure?

Tires are manufactured for many different vehicle makes & models of vehicles. And the psi number on the side of a tire only reflects the “maximum permissible” inflation pressure for that tire — not necessarily the correct psi for your vehicle. When filling your tires, always follow your vehicle manufacturer’s psi recommendations. You’ll find this psi number on your vehicle’s tire information label, as well as in your vehicle owner’s manual.

 
Do I need to check my tires for anything other than correct pressure?

 When you perform your monthly tire pressure check with a gauge, it’s also important to visually inspect your tires. Look for & remove any foreign objects or debris that might have become wedged between the tire treads. Check for irregular wear patterns. Irregular wear patterns may mean your tires need rotating and/or your wheels need to be realigned. Take your vehicle in for servicing to correct these problems. If your tread depth is less than 2/32 (or 1/16) of an inch, it’s time to replace your tires.

 
How frequently should I rotate my tires? What happens if I don't?

Check your vehicle owner’s manual for specific recommendations on rotation timelines & patterns. In general, most vehicle manufacturers recommend rotating your vehicle’s tires every 6,000 to 8,000 miles. If you don’t rotate your vehicle’s tires, the difference is tread wear between the front & rear tires could eventually lead to adverse vehicle handling.

 
How much wear should I allow on my tires before I replace them? How do I know if they're "bald?"

Be sure to replace your tires when the tread wears down to 2/32 (or 1/16) of an inch. The tire’s built-in tread wear indicators, or “wear bars,” can tell you it’s time to replace your tires. When the tire tread becomes level with the “wear bars,” your tires only have 2/32 (or 1/16) of an inch of tread left & therefore should be replaced.
You can also use a Lincoln penny to determine when it’s time to replace your tires. Turn the penny so that Lincoln’s head is pointing down & insert it into the tread. If you can see all of Lincoln’s head, it’s time to replace your tires. “Bald” tires have a noticeably smooth surface caused by excessive wear beyond the 2/32 (or 1/16) of an inch replacement point. Such tires have reduced traction, which can lead to vehicle loss of control during braking & turning maneuvers.

 
What’s a tire blowout?

A blowout is a rapid loss of tire air pressure. This sudden loss of air pressure from a tire can cause a vehicle to lose control.

 
What should I do if I have a tire blowout while driving?

The goal in any rapid loss of tire pressure or “blowout” is to keep the vehicle balanced & controllable. Do not panic. Any over-reaction by the driver – including slamming on the brakes or abruptly removing your foot from the accelerator – can result in a loss of vehicle control.
In any blowout situation, it’s most important to first remember the 2 things you should NOT do:
Do not to step on the brake. As instinctive as it may be, it’s the worst mistake you can make in any tire blowout situation. Applying the brakes will cause an even greater imbalance on the vehicle’s stability.
Do not abruptly release your foot from the accelerator. This is the second worst mistake you can make. Rapidly releasing the accelerator causes the vehicle to transfer more of its weight from the rear tires to the front tires. With a flat tire, this can lead to loss of control of the vehicle.
Instead, in any blowout situation, you should follow these 3 steps:
Gradually release the accelerator .
Correct the steering as necessary to stabilize your vehicle & regain control. Look where you want the vehicle to go & steer in that direction.
Once your vehicle has stabilized, continue to slow down & pull off the road where & when you judge it’s safe to do so.
Remember, no matter which tire blows out — front or back — the do’s & don’ts for safely maintaining control of your vehicle are exactly the same. The only difference between a front & rear tire blowout is that you will feel the force of a front blowout more in the vehicle’s steering, while you’ll feel a rear blowout more in the seat or body of the vehicle.

 
Should I lower my tires' pressure to get better traction in the snow or off-road?

You should always keep your tire pressure at the psi level recommended for your vehicle by the vehicle manufacturer. Lowering your recommended tire pressure by even a few psi may results in a smoother ride, but it can lead to tire failure. Note: some vehicle manufacturers may provide a lower recommended tire pressure for lower vehicle loading conditions, e.g., if there are only 1-3 occupants in the vehicle. This should not be construed as recommending a lower pressure for use in snow or off-road.

 
When I get replacement tires, do I still follow the pressure & loading guidance on the vehicle’s tire information label?