Find your vehicle's correct tire pressure on the driver's door jamb
The correct air pressure for your tires is printed on a sticker inside your driver's side door, where the door latches when closed. This number — usually between 30 and 35 pounds per square inch (psi) for most cars — is what the vehicle manufacturer determined will give you the best balance of safety, fuel economy, and tire wear. It is not the maximum pressure printed on the tire itself; that number is the tire's limit, not your target.
Check your tire pressure when the tires are cold, meaning before you have driven the car or at least three hours after you stopped driving. Driving heats the air inside the tires and raises the pressure reading by 4 to 6 psi, which will give you a false high number. Early morning before a trip is the easiest time to check.
You will need a tire pressure gauge, which costs between $5 and $15 at any auto parts store or gas station. Digital gauges are easier to read than dial gauges, but both work. Many gas stations have free air pumps with built-in gauges, though the gauges on those pumps are often less accurate than a handheld one.
Key Takeaways
- Your vehicle's correct tire pressure is printed on a sticker on the inside of your driver's door, not on the tire itself.
- Check pressure when tires are cold — before driving or at least three hours after you stop — because driving heats the air and raises the reading.
- Underinflated tires wear faster, use more fuel, and can overheat; overinflated tires ride harshly and wear unevenly in the center.
- Check all four tires monthly and before long trips, and recheck after seasonal temperature changes since cold weather lowers pressure.
How to check and adjust your tire pressure
Remove the valve cap from the first tire — it is a small plastic or metal cap on the tire's outer edge. Press the gauge firmly onto the valve stem until you hear a small hiss of air. Hold it steady for a second or two, then read the number. Write it down for all four tires so you can compare them.
If a tire is low, drive to a gas station or tire shop with an air pump. Attach the pump hose to the valve stem and add air in short bursts of two to three seconds, checking the pressure between bursts. It is easier to add air than to let it out, so go slowly. Once you reach the correct pressure, replace the valve cap and move to the next tire.
If a tire reads higher than the door jamb number, you can let air out by pressing the small pin inside the valve stem with the back of your gauge or a small tool. This releases air slowly. Check frequently so you do not go too low.
Why the correct pressure matters for safety and cost
Underinflated tires — those below the manufacturer's number — flex more as they roll, which creates heat. This heat wears the rubber faster, especially on the outer edges of the tire, and can eventually cause a blowout. Underinflated tires also increase rolling resistance, meaning your engine works harder and you use more fuel. A tire that is 10 psi below the correct pressure can reduce fuel economy by up to 3 percent.
Overinflated tires — those above the manufacturer's number — are stiff and do not absorb bumps as well, making the ride harsher. They wear faster in the center of the tread because the middle of the tire bulges slightly outward under pressure. Overinflated tires also reduce traction slightly, which matters most in wet or icy conditions.
Correct pressure balances all these factors. Your tires last longer, your fuel economy stays where the manufacturer designed it to be, and your car handles and stops as intended. For a vehicle you drive 12,000 to 15,000 miles per year, the difference between correct and incorrect pressure can add up to hundreds of dollars in premature tire replacement over the life of the vehicle.
Temperature changes affect tire pressure throughout the year
Cold air contracts and warm air expands, so your tire pressure drops in winter and rises in summer. For every 10-degree Fahrenheit drop in outside temperature, tire pressure falls by about 1 psi. This means that tires checked in November may read 3 to 5 psi lower in January without any air actually leaking out.
Check your tire pressure at the start of winter and again at the start of summer. If you live in a place with large temperature swings between seasons, you may need to adjust pressure twice a year. This is especially important in winter, because low pressure combined with cold weather reduces traction and increases stopping distance.
What to do if a tire keeps losing pressure
If you check a tire and find it consistently lower than the others, or if it drops noticeably between checks, you likely have a slow leak. This could be a puncture from a nail or screw, a crack in the sidewall, a faulty valve stem, or a problem where the tire meets the rim.
A tire shop can find the leak by submerging the tire in water and looking for bubbles, or by listening and feeling for escaping air. Small punctures in the tread can often be repaired with a plug or patch for $10 to $25. Leaks in the sidewall or at the rim usually mean the tire needs replacement. Do not ignore a slow leak, because a tire that loses pressure gradually can fail suddenly if it drops too low.
Spare tires and all-wheel-drive vehicles need attention too
Check your spare tire pressure at least once a year, even if you have never used it. A spare that has been sitting for years may have lost pressure and will not hold you safely if you need it. The correct pressure for a spare is usually printed on the spare itself or in your owner's manual.
If you drive an all-wheel-drive vehicle, keeping all four tires at the correct pressure is especially important. All-wheel-drive systems distribute power to all four wheels, and if one tire is significantly underinflated, it will roll at a slightly different speed than the others. This can cause the all-wheel-drive system to work harder and wear out faster. Check all four tires together, and replace tires in pairs or sets rather than one at a time.
Frequently Asked Questions
Should I use the pressure number on the tire itself?
No. The number on the tire is the maximum safe pressure, not the target. Your vehicle's correct pressure is always lower and is printed on the door jamb sticker. Using the tire's maximum pressure will make your ride harsh, wear the center of the tire faster, and waste fuel.
How often should I check my tire pressure?
Check once a month and before any long trip. Also check at the start of winter and summer, since temperature changes affect pressure. Many people find it easiest to check when they fill up with gas.
Can I check tire pressure when the tires are warm?
You can, but the reading will be higher than the true cold pressure. If you must check warm tires, subtract 4 to 6 psi from the reading to estimate the cold pressure, or wait until the tires have cooled and check again.
What does it mean if all four tires are losing pressure together?
If all four tires drop pressure at roughly the same rate, you likely have a slow leak in each one, which is uncommon. More often, a drop across all four tires means the outside temperature has fallen. Check the weather — if it has been colder, that is probably why. If temperature has not changed and all four are still dropping, take the vehicle to a tire shop to check for leaks.
Do I need to adjust tire pressure if I am carrying extra weight in my car?
The pressure on your door jamb is set for normal driving conditions and typical passenger and cargo loads. If you are regularly carrying significantly more weight — like towing a trailer — check your owner's manual for a different pressure recommendation. For occasional extra weight, the standard pressure usually works fine.