How to know the right tire pressure


How to Check Tire Pressure with a Tire Pressure Gauge

Maintaining proper tire inflation is relatively simple and essential to the overall tire performance of your vehicle. A properly inflated tire will provide longer life, quicker steering response, better fuel efficiency and a smoother ride than an improperly inflated tire. Both underinflation and overinflation can cause headaches like premature treadwear and possible tire failure. The best way to ensure you're getting the most out of your tires is to check your tire pressure on a monthly basis. 

Knowing how to use a tire pressure gauge is very simple. Here’s how to check tire pressure and refill your tires.

Items You Need When Checking Tire Pressure

    Tire pressure gauge

    Air compressor

    Pen and paper

    Your tire pressure gauge can be digital or standard. Auto parts stores typically carry both. Many auto parts stores sell portable air compressors that run from your car battery or 12v power port. Alternatively, you can use the air compressor found at most gas stations. They usually cost $0.50 or $1.00 to use.

    HOW TO CHECK TIRE PRESURE

    1. START WITH COLD TIRES IF POSSIBLE

    Vehicle manufacturers specify PSI – literally “pounds per square inch” of pressure – assuming tires are cold. Tires are considered cold when the vehicle has been parked for three hours or more, or if the vehicle has been driven less than a mile (1.6 km) at moderate speed. PSI is the unit your pressure gauge uses to provide readings.

    2. CHECK THE MANUFACTURER’S RECOMMENDED PSI

    Look on the driver’s side door jamb or your owner’s manual to find the recommended cold tire PSI for your front and rear tires.  If you cannot find it, you should consult your vehicle dealer, manufacturer, or a qualified tire professional.

    3. WRITE DOWN THE PSI FOR EACH TIRE

    If your front and rear tires require different pressure levels, write down the correct PSI for each to avoid getting confused as you move around your vehicle checking tire pressure.

    4. CHECK TIRE PRESSURE WITH YOUR GAUGE

    Remove the valve cap from one of your tires. Then place the pressure gauge on the valve stem and press down hard enough so the hiss sound disappears and your gauge provides a reading. With a standard gauge, the air pressure will push a small bar out from the bottom of the gauge. Measurement units are etched into the bar. A digital gauge will show you the reading on a screen.

    Write down the reading and repeat this process for all four tires.

    5. FILL TO THE RECOMMENDED PSI

    Use an air compressor to refill any tires with low pressure. Many air compressors are different, so read directions carefully to be sure you’re using it correctly.

    If you’re using the air compressor at a gas station, be sure to park so that the hose will reach all four tires. Insert change into the machine until you hear the motor running. Fill each tire by placing the end of the hose over the valve stem and pressing on the lever.

    Using a gas station air compressor means your tires might be “hot. ”  If it is necessary to adjust inflation pressure when tires are “hot”, set their pressure to 4 psi (14 kPa) above the recommended cold inflation pressure. Recheck the inflation pressure when the tires are cold.

    After filling your tires, use the gauge to check pressure again. At this point, it’s ok if you overfilled the tires because you can always let some air back out. Never drive on overinflated tires. Overinflation can result in decreased traction, premature wear, and decreased impact absorption. 

    6. REPEAT: CHECK TIRE PRESSURE MONTHLY

    Make the above procedure a monthly ritual. Regularly checking your tire pressure is the best way to ensure your tires never dip far below the optimal PSI.

    TIRE PRESSURE GAUGE ACCURACY

    Accuracy matters and you should keep that in mind when choosing a gauge. For just a few dollars, you can find a quality, accurate tire pressure gauge that gives accurate readings. If you’re not sure which one to purchase, ask a professional technician which he or she prefers.

    A digital tire pressure gauge will provide accurate readings, but don’t forget that it operates on a battery. If you think having to replace the battery will prevent you from using it, it’s best to go with a standard gauge.

    It’s best to use your personal tire gauge versus those available attached to air hoses at service stations. Of all the pressure gauges out there, they’re the most likely to be weathered, and possibly inaccurate.

    CONTINUE YOUR JOURNEY

    There’s never a good time for a flat. That’s why Bridgestone DriveGuard tires are masterfully engineered to keep you moving for up to 50 miles at speeds up to 50 MPH without disruption.

     

    CONTINUE YOUR JOURNEY

    There’s never a good time for a flat. That’s why Bridgestone DriveGuard tires are masterfully engineered to keep you moving for up to 50 miles at speeds up to 50 MPH without disruption.

    See Details Find Your Fit

    What Is the Recommended Tire Pressure for Your Car?

    From a safety and cost standpoint, tire maintenance is one of the most important things you can do for your car. The easiest way to care for your tires is both quick and inexpensive: maintain the correct tire pressure.

    What is the recommended tire pressure?

    The recommended pressure for tires varies by the type of car and tire. Because maintaining your tires is so crucial to your safety and your car’s overall performance, it’s important to know what tire pressure is correct for your vehicle.

    To learn what your tire pressure should be, look for your manufacturer’s recommendation, which is printed on a label inside your car. Depending on the vehicle, this label may be on the edge of the vehicle’s door, on the doorpost or in the glove box. The label will usually give recommendations for the front and rear tires as well as the spare, and it’s important that you stick to those guidelines. Even after you’ve replaced your tires, the same pressure guidelines on your car’s label apply to new tires of the same size.

    Pressure recommendations are based on readings taken from a tire pressure gauge. Check the pressure first thing in the morning or wait at least three hours after driving; this provides sufficient time for them to cool back down.1

    What happens if you drive with low (or high) tire pressure?

    Driving on underinflated tires is one of the biggest causes of tire failure, according to the National Highway Traffic Safety Administration. And not having enough air in your tires can lead to other problems. Under-inflated tires wear out more rapidly, handle poorly and reduce fuel efficiency. On the other hand, overinflated tires are more susceptible to damage from road irregularities, and they also result in a bumpier ride. Overfilling your tires is just as dangerous as underfilling them, so it’s important you know what is recommended for your vehicle.

    How to check tire pressure

    Knowing how to check tire pressure is critical to your safety and to keeping your tires in good working order.

    Use a tire pressure gauge

    When it comes to choosing a gauge, you typically have 3 options:

    • Stick-type pressure gauges — Have a ruler-like rod that slides in and out of a sleeve to measure air pressure
    • Dial pressure gauges — Feature a numbered dial with a watch-like hand
    • Digital pressure gauges — Display numbers on a digital screen
    Digital pressure gaugeDial pressure gaugeStick pressure gauge

    Put the pressure gauge into the valve stem, making sure the gauge is evenly and firmly pressed onto the stem. If you’re using a pen-style gauge, read the number on the rod that pops out of the sleeve. Read dial pressure gauges as you would a watch with one hand. With a digital pressure gauge, simply read the number on the screen. 2

    Find Tire PSI

    Find your tires’ recommended PSI in the owner’s manual or on a sticker just inside the driver’s side door. The proper PSI is crucial to your safety and the car’s longevity. Underinflated tires can overheat and wear unevenly; overinflated tires can blow out.1

    Temperature has a direct effect on your air tires’ air pressure, so for an accurate PSI reading, make sure to check tire pressure when tires are cold. If it’s cold outside, then you can assume your tires are losing PSI and you should check even more frequently. This will help to ensure maximum safety. Take your car to a mechanic you trust for a professional assessment.3

    How to check tire pressure without a gauge

    If you happen to find yourself without a tire gauge and your car doesn’t have an indicator for low tire pressure, there are several things you can do to figure out whether your tires need to be inflated.

    • Feel the wheels. Press on your wheels using your hand or foot. Are the tires firm or do they have some give? If your they feel soft, it’s time to add more air.
    • Eyeball the wheels. Do you see any flattening? If your answer is yes, then your tires probably need more air.
    • Load weight onto your vehicle. If you see your tires sagging a bit with more weight added to your car, then you probably need to inflate them more.
    • Pay attention to how your ride feels. Do you notice your rides feeling bumpier than usual lately? Do you hear noise when steering or have difficulty steering? These are signs that your tires may be low on air.4

    How to maintain proper tire pressure

    Of course, knowing your recommended PSI isn’t enough. You have to ensure you’re checking your tires regularly. Experts recommend you check air pressure once a month.5 Your car’s tire pressure monitoring system TPMS measures the amount of air in your tires to let you know whether your tires are properly inflated. 1

    Frequently checking your PSI becomes even more important in the fall and winter, when outside temperatures drop and weather conditions fluctuate causing your tires to lose air more quickly. Generally, your tire will gain or lose 1 PSI for every 10-degree change in temperature, which means if you have a sudden drop of 30 degrees, you could lose 3 PSI overnight. If your tires were already low, this could cause tire damage, steering problems or even a flat tire.3

    Knowing and maintaining the right air pressure is important to the safety and longevity of your tires. All it takes is a tire pressure gauge and a few minutes of your time.

    Once you have the right tire pressure, make sure you also have the right coverage. Learn more about how Nationwide auto insurance can help protect you and save you money.

    Sources:
    1 https://www.pirelli.com/tires/en-us/car/driving-and-tire-tips/how-to-read/recommended-tire-pressure, Accessed April 2022.
    2 https://www.consumerreports.org/cro/tire-pressure-gauges/buying-guide/index.htm#:~:text=There%20are%20three%20types%20of,of%205%20to%2099%20psi., Accessed April 2022.
    3 https://www.firestonecompleteautocare.com/blog/tires/should-i-inflate-tires-cold-weather/, Accessed April 2022.
    4 https://rxmechanic.com/how-to-check-tire-pressure-without-gauge/, Accessed February 2022.

    What tire pressure should be? — magazine Behind the wheel

    What should be the pressure in the tires of the car? Does it need to be adjusted and what will happen if the pressure is changed in one direction or another?

    Wheel replacement

    Two friends conversation:

    - Hello, I lowered the wheel!

    — Absolutely?

    - No, only from below ...

    Humor from the Web

    The law is the law

    Let's start with platitudes. The pressure must be as specified by the vehicle manufacturer. And since the average modern driver usually does not have such information, especially for him, a "cheat sheet" with the necessary numbers is hung on the middle pillar on the driver's side or on the gas tank hatch cover.

    Manual - tire pressure

    A relatively rare solution: the "reminder" is located on the gas tank cap.

    A relatively rare solution: the "reminder" is located on the gas tank cap.

    An important point: pressure should be measured only on cold tires. By the way, especially for pedants: cold tires are those on which the car has been without movement for at least 5 hours.

    Manual - tire pressure

    This "cheat sheet" nestled on the driver's door. An example of how tire pressure recommendations change depending on tire size.

    This "cheat sheet" nestled on the driver's door. An example of how tire pressure recommendations change depending on tire size.

    Since car manufacturers allow the use of tires of different sizes, the pressure may also be different. In addition, the pressure in the front and rear tires has the right to both differ and be the same.

    Instruction - tire pressure

    And here there is no difference in recommendations: what is in front, what is behind is the same.

    And here there is no difference in recommendations: what is in front, what is behind is the same.

    What is the danger?

    Related materials

    Seasonal tire change: everything car owners need to know

    Reduced pressure leads to an increase in tire deformation, greater heating during wheel rolling, and accelerated wear of the outer tread tracks. Perhaps even a violation of the integrity of the frame. As a result, fuel consumption increases. If you hit a hole in the road, the likelihood of damage to both the disk and tire is higher.

    Increased pressure is an overstrain of the cords, increased wear of the middle part of the tread. In addition, when driving on a bad road, the shocks that are transmitted to the suspension and body will become more noticeable for riders. When hit in a pit, the likelihood of a tire burst increases.

    Uneven pressure on all four wheels is the worst thing! At the same time, the car, while driving, inevitably leads the wheels with lower pressure to the side - in fact, sideways movement begins.

    How often to check?

    Inflating a wheel

    Tube tires of the past required a weekly check, especially before the advent of butyl tubes. Then the pressure began to be checked less often, and nowadays, as a rule, they are limited to visual inspection.

    Tube tires of the past required a weekly inspection, especially before the advent of butyl rubber tubes. Then the pressure began to be checked less often, and nowadays, as a rule, they are limited to visual inspection.

    In a good way, you need to check the tire pressure at least once a month. And before a long journey - just a must.

    Related materials

    Budget Tire Compressor Test: Wrong Bees

    Seasonal variation

    The air pressure in an enclosed space changes by approximately 0.1 bar for every 10 degrees of temperature change. This allows, having installed summer wheels in April, not to worry about the pressure in them until the end of August, when the air temperature begins to drop. Having pumped up the wheels at the end of summer, you can already reach the seasonal shift. But having installed winter tires in October, with the first frosts, you should check the pressure a couple more times: when the temperature drops to minus ten, fifteen, and when it goes over minus twenty. But from the middle of winter until the moment of changing the wheels to summer ones, there is again a period of relaxation.

    Electronic brains

    Electronics are increasingly thinking for us. Now, a tire pressure monitoring system is being installed on parts of production cars. Moreover, some simply read the wheel speeds through the ABS sensors: after all, a flat tire rotates faster, since its radius is smaller than that of inflated wheels. There are also sensors that evaluate the amount of air pressure and send information via radio to the "brains" of the car. Such devices can also be purchased separately: sensors - in the wheels, and the receiver - in the car.

    By the way, a lot depends on the road you are going to take.

    Mazda 6

    The owner's manuals supplied with the vehicles indicate that it is recommended to increase the pressure by 0.2-0.3 bar before driving for a long time on expressways. We advise you to follow these recommendations on all cars: it will not get worse.

    The operating instructions supplied with the vehicles state that it is recommended to increase the pressure by 0. 2-0.3 bar before driving for a long time on expressways. We advise you to follow these recommendations on all cars: it will not get worse.

    Overload

    I don’t want to discuss overload: this, you see, is not the case. But, unfortunately, many deliberately overload the car several times a year, not only stuffing the interior and trunk to the eyeballs, but also attaching a trailer, which additionally loads the rear wheels of the tractor. In such cases, we advise you to increase the pressure in the rear tires by at least 0.2–0.3 bar. Tires will only thank you.

    Zero control

    If you doubt the accuracy of your pressure gauge, then we advise you to check it immediately after leaving the tire shop, where you were set the obviously necessary pressure, to measure it with your own measuring device (separate or as part of the compressor). So you determine whether your pressure gauge is "lying" a lot. For the future, right on the dial, you can put a mark of the correct value.

    Pressure gauge

    Of course, it is better to have your own, known to be correct pressure gauge, but such a toy is not cheap.

    Of course, it is better to have your own, known to be correct pressure gauge, but such a toy is not cheap.

    Downplaying

    If terrible ice caught you on summer tires, say, in the country, and you need to drive some distance along an absolutely icy road by any means, then you should reduce the tire pressure to approximately 1.6 bar. Is it bad for tires? Yes. But an accident will cost more. In addition, in such a situation, one does not have to wait for high speed, and overheating of tires at near-zero temperatures most likely will not happen.

    I want to be a T-34!

    Everyone knows what caused the excellent maneuverability of Soviet tanks? That's right: wide tracks, that is, low pressure on the ground. We, having an ordinary, non-all-wheel drive car, are also able to provide it with a similar cross-country ability. If the wheels of the car sink into sand, snow or sticky mud, then it makes sense to lower the tire pressure. And not only driving, but also driven wheels.

    Infiniti

    We know from experience that it is often possible to get out of the "black spot" by reducing the pressure to 1.2 bar.

    We know from experience that it is often possible to get out of the "black hole" by reducing the pressure to 1.2 bar.

    In a very critical situation, if you know that you have a fairly narrow disc and a relatively wide tire (such a wheel has a lower chance of self-disassembly), you can reduce the pressure to 1.0 bar.

    driving on grass

    Stalled on wet grass? Try to relieve pressure.

    Stalled on wet grass? Try to relieve pressure.

    Pressure reduction is also useful in other cases - for example, to overcome diagonal hanging. If you reduce the pressure in the wheels on which the car rests, their height will decrease and there will be a chance to “hook” on the suspended wheels. Of course, if the car has already laid down on the bottom, then it is too late to reduce the pressure - this will only interfere.

    Swamp walker

    A concrete example of the effect of pressure on flotation. In this case, the pressure is very low, and the contact patch of the wheel with the coating is much larger than that of a conventional car.

    A concrete example of the effect of pressure on patency. In this case, the pressure is very low, and the contact patch of the wheel with the coating is much larger than that of a conventional car.

    In general, the pressure in tires, as well as in vessels, is better to keep normal. Any deviation has its negative consequences. Tell us, have you ever had to adjust tire pressure to improve flotation?

    Tire pressure: your norm

    What should be the pressure in the tires of the car? Does it need to be adjusted and what will happen if the pressure is changed in one direction or another?

    Tire pressure: your standard

    Air pressure in the wheels.

    When to measure and how to inflate

    Tire pressure significantly affects driving parameters: comfort, car handling, economy and safety. It is important to maintain the pressure recommended by the manufacturer and check it regularly. Let's figure out how to do it right.

    What causes incorrect tire pressure

    When driving on asphalt, incorrect tire pressure (both high and low) leads to a decrease in the contact patch with the road. An overinflated wheel clings to the surface only in the central part, which leads to its rapid wear. A poorly inflated tire, on the contrary, "sits" on the sidewalls, leaning on the shoulder areas of the tread and pushing the central part inward. Here's what it looks like:

    Both under-inflation and over-inflation in tires create many problems for the driver.

    Negative effects of excessive tire pressure:

    1. Increased wear of the central part of the tire tread.
    2. Reduced ride comfort, hardness of potholes and road bumps.
    3. Increased load on the car's suspension due to reduced tire damping effect.
    4. Risk of tire damage and herniation due to shock loading (getting into a pit or pothole).
    5. Reduced control stability due to reduced contact patch.

    Negative consequences of insufficient tire pressure:

    1. Increased wear of the tread sidewalls (shoulder areas).
    2. Severe deformation of the rubber when driving over bumps, which increases the risk of tire damage.
    3. An increase in tire temperature, which threatens to delamination of the carcass and can lead to tire explosion at high speed.
    4. Increased risk of hydroplaning on wet roads.
    5. Risk of tire breaking.
    6. Increased fuel consumption.

    Reduced pressure hits the driver's pocket hard: a pressure drop of 20% (which is not uncommon: it is enough, for example, to deflate the wheels to 1.8 atmospheres instead of the manufacturer's prescribed 2.2) reduces tire life by 25-30% and increases fuel consumption fuel by 3%.

    What should be the tire pressure

    There is no universal tire pressure: it depends on the size of the tires, the characteristics of the car (primarily weight) and road conditions. Therefore, it is important to follow the factory recommendations, maintaining exactly the tire pressure that the engineers expected when designing the car.

    The recommended pressure for your machine can be found in the operating instructions and on the sticker in the door frame. If, depending on the configuration, tires of several dimensions were installed on the car, then the pressure recommended for them may differ - look in the table for your exact wheel size. The manufacturer may prescribe an increase in tire pressure at the maximum load of the machine. For the spare tire (Spare tire), the required pressure is also indicated on a separate line - note that it is much higher than the standard one.

    Pressure units

    So, you have found the required pressure parameters, it remains to decipher them. In physics, pressure is measured in pascals, in real life - in anything: in bars, atmospheres, pounds-force, kilogram-force ... Drivers and tire workers usually use the term atmosphere, but such a unit is often absent on pressure gauges (pressure measuring devices) . Let's clear up this confusion.

    Atmosphere is a non-systemic unit of measurement, approximately equal to atmospheric pressure on the surface of the Earth. Since it has become widely used, it was necessary to somehow equate it with correct physical units. For simplicity, one atmosphere is considered equal to one bar, one kilogram-force and one hundred kilopascals.

    In addition to the technical atmosphere (at), there is also the physical atmosphere (atm), which is slightly larger. Again, for convenience, they are considered equal. But all these assumptions introduce an error, so if you need accurate tire pressure, measure it correctly - in pascals or bars. Moreover, manufacturers usually indicate the pressure in these quantities.

    Imperial pounds-force (aka PSI, “psy”), popular in the USA, is more difficult to translate, here you can’t do without a calculator. In the table, we have collected together all pressure units with exact values, and also approximately brought them to each other to simplify calculations:

    1 atm ≈ 1 bar ≈ 1 kgf/cm² ≈ 100 kPa ≈ 14.5 psi

    Pressure units

    Pascal
    (Pa)

    Bar
    (bar)

    Technical atmosphere
    (at)

    Physical atmosphere
    (atm)

    PSI
    (psi)

    1 Pa

    1 N/m²

    10-5

    10. 197•10-6

    9.8692•10-6

    145.04•10-6

    1 bar

    105

    1x106 dynes/cm²

    1.0197

    0.98692

    14.504

    1 at

    98066.5

    0.980665

    1 kgf/cm²

    0.96784

    14.223

    1 bar

    101325

    1.01325

    1.033

    1 bar

    14. 696

    1psi

    6894.76

    68.948•10-3

    70.307•10-3

    68.046•10-3

    1lbf/in²

    How to measure tire pressure correctly

    It is advisable to check tire pressure daily, before driving. But this is only possible with a very measured rhythm of life. In reality, checking at least once a month is already an excellent indicator for the average driver. But before traveling a long distance, checking the pressure and visual inspection of tires and rims should be done in any case.

    It is necessary to measure the pressure in cold tires, that is, before driving. During driving, the tires heat up, which increases the pressure by about 10%. Therefore, never release supposedly excess air from hot tires: after cooling, the pressure will be below normal. If you had to inflate a hot tire during a trip, inflate it 10% more than the nominal value, and check the pressure again when the wheels have cooled down - no earlier than 3 hours after stopping.

    Always check the pressure in all tires. Different tire pressures seriously affect handling and can cause the car to pull to the side. Do not forget about the "spare tire": it should always be inflated in case of an unexpected wheel change on the road.

    When tire pressure needs to be adjusted

    For long periods of driving at high speeds (more than 160 km/h), car manufacturers recommend increasing tire pressure by 0.2-0.4 bar above the recommended value. This will slightly improve the handling of the car, although it will negatively affect comfort. But such advice is relevant for driving on high-speed autobahns, and not for everyday urban use, especially in Russia.

    Before a long trip on a dirt road or a road with a muddy surface (mud, snow), it is reasonable, on the contrary, to reduce the pressure in the tires - this will improve the grip. In summer, it is worth limiting yourself to reducing pressure by 5-10% of the nominal value, and in winter - by 10-15%.

    Low-profile tire pressure

    The pressure in low-profile tires (especially non-standard sizes) must be monitored especially carefully. Low profile tires have two features: a low sidewall (profile) height and a large rim diameter. If the tire has the correct air pressure, only the tread is in contact with the road. Low pressure causes the sidewall of the tire to bend, causing it to touch the roadway and wear out quickly, up to complete abrasion. And punching a low-profile tire in a pit at low pressure is much easier.

    When inflating low profile tires, you need to focus on the pressure indicated for a full load of the machine and the maximum allowable pressure for a particular tire. It is indicated on the sidewall, next to the inscription max pressure, in one of the accepted units of measurement: kilopascals (KPA), bars (BAR) or pounds-force (PSI).


    Learn more