What You Need To Know About Checking Your Tire Pressure
Maintaining Proper Tire Pressure Improves Fuel Economy
Proper inflation of your vehicle’s tires has been proven to save you as much as 11 cents per gallon, which is quite a lot for such a simple task for most drivers. Under inflation causes your tires to have more resistance while driving down the road, causing lower gas mileage for your vehicle. Who doesn’t want to save 11 cents a gallon?
Poorly Inflated Tires Can Turn You Into a Road Hazard
Having personally handled and repaired all different types of flat tires over the years, I know for a fact that improper inflation, whether that be over-inflation (having too much air pressure in your tires) or under-inflation (not enough air pressure in your tires), can cause your vehicle’s tires to have reduced performance and can lead to a flat tire or even a blowout while going down the road.
Improper Inflation Will Make Your Tires Wear Faster
Having a tire that’s under-inflated will cause the tire to wear unevenly, which will lead to you standing at the checkout counter at your local tire store, wondering how those tires you bought last year already need replaced. Keeping your tire inflation at your manufacturer’s recommended pressure will keep those tires on the road for longer and end up saving you money on premature tire replacement.
Supplies You’ll Need For Checking Your Tire Pressure
There’s only a few items that are required for properly checking tire pressure. Don’t worry about having to run to your local hardware or car parts store, you just might have some of the items already laying around.
- Tire pressure gauge (I keep mine in the glovebox)
- Owners Manual (Also found in the glovebox)
- Compressed air from a gas station or your own air compressor
How To Check Your Vehicle’s Tire Pressures (3-Step Guide)
- Find your vehicles recommended tire pressures
- Check your tire pressures
- Inflate or deflate the tire safely and properly
Step 1: Find Your Vehicles Recommended Tire Pressures
Finding out what your vehicle’s tire pressures should be is the first and most important step. In 2007, the NHTSA started mandating vehicle manufacturers to install a tire pressure monitoring system, along with a tire pressure label on vehicles, which are usually found in the driver’s side doorjamb. But before you go cleaning off that sticker in your driver’s door and trying to decipher all of the numbers, you may want to check your vehicles owners manual first.
These stickers can provide a barrage of information, such as load ratings and hot and cold pressures. Most of the time they are correct, but it’s always a good idea to check it against your owner’s manual first. I have seen first hand these labels going against what the manufacturer actually suggests, especially on higher end performance based vehicles. If your tires are staggered (different sizes on they front and rear), they may also take different pressures depending on the vehicle. Just make sure you take a close look in your manual. Now is also a good time to check your spare tires air pressure as well, if it’s accessible. Your spare tire will often have a higher pressure than your standard tire, so make sure you check the specs on that in your manual or on the tire itself.
You can also check the sidewall of your tire for a PSI rating, but on most tires, this will be the max inflation pressure that the tire manufacturer recommends, and if you follow that number you might end up with overinflated tires. You should never go over this pressure under normal driving circumstances, as it could cause damage to your tire, or even a blow out if your tires are worn.
I’ve see customers over inflate tires, causing terrible uneven wear, because they think it will help save fuel mileage for some reason. Don’t fall for the gimmicky tricks. Maintain your pressure as your manufacturer suggests.
Make sure you find an accurate pressure for your vehicle of what your manufacturer recommends, and keep those numbers on hand (or in your head) to reference for the next step, checking the pressures.
Step 2: Check Your Tire Pressures
Now that we’ve made it to the modern era, there’s more than one way to check your tire pressures. I recommend checking your pressures once a month or so, before you go out and run your weekend errands for instance, after your car has been sitting overnight.
Now is also a great time to take a closer look at your tires overall condition. Take a look at the tread life while you’re down there, and make sure there aren’t any visible issues with the tire, like a cut in the sidewall for example, or even a nail sticking out of your tread.
The traditional and fool-proof way has always been with your handy tire pressure gauge. You can pick these up at most gas stations, and they can always be found at any auto parts store. That’s what we’ll cover first. If you have a newer vehicle produced in 2012 or above, you might be able to hit a few buttons on your steering wheel or dashboard and check them much faster. I’ll cover that after we talk about using the handy gauge.
Typically, tires will lose around one PSI a month, and tire pressures will decrease one PSI for every ten degree drop in outside temperature. So during those fall months where the outside temps are starting to fall faster than the leaves on the trees, you’ll want to check your pressures regularly, as you’ll be losing pressure more rapidly during those big temperature drops.
Now, before you go jabbing anything into your tires valve stems, you always want to make sure your tires are cool to the touch. Hot tires you just pulled off the interstate can give inaccurate readings, and it can actually be dangerous to let hot air out of a hot tire.
Get your tire pressure gauge handy, and make your way to your vehicle. I like to start at the drivers front tire and work my way around to the back to the rear tires and back up to the passenger front tire. Remove your valve stem cap and make sure there’s no debris inside of the valve stem or in the open end of your tire pressure gauge.
Push the tire pressure gauge’s open end into your valve stem as parallel with the valve stem as you can, so that you’re able to get all the air released from the valve stem into the gauge and get an accurate reading. You’ll then see the bottom of the gauge come out of the housing. Take the gauge off the valve stem and read the pressure on the gauge.
In this above photo for example, the pressure is reading as 36 PSI. On this specific gauge, and most of the others like it, the increments are by twos between marks on the gauge, but check yours and make sure you understand what increments you’re dealing with specifically.
Now that you’ve checked your drivers front tire, make your way around the vehicle, inspecting the rest of the pressures against the recommended psi of your vehicle. You can leave the valve caps off until you’re totally finished with checking and adjusting your pressures. Just be sure to put them back on! You always want to make sure your valve caps are installed. You don’t want any debris getting into your valve stems.
As I stated in the last step, the NHTSA mandated that vehicles produced after 2007. So if you’re vehicle was produced after then, chances are you have a tire pressure monitoring system, better known as TPMS. Most systems installed after 2012 or so also have the ability to give you a read out of your current tire pressures, and not just the dreaded tire light that comes on and doesn’t tell you which tire is low. This is a quicker way to check your tire pressures if your vehicle has the technology installed.
Most TPMS systems are read out through your vehicle’s driver information center. Whether that be by your gauges or on another screen. Check your owners manual to see if you have this function equipped, and how you can navigate to this function in your vehicle. From here, you can read your tire pressures and move on to the next step in adjusting them.
Step 3: Inflate or Deflate Your Tires
Once you’ve got an accurate reading of all of your tire pressures, and you’ve found that one or two tires are out of specification by more than two psi, or maybe you’re just trying to top off that leaky tire you’re getting repaired later on, you’ll have to adjust them properly. The most common way people go about inflating tires is by using the air pump station at their local gas station.
Another option is getting yourself a small air compressor, usually powered by your cars 12V plug in where you’d put your phone charger. I have one for each of my vehicles, and it makes pumping up those low tires during big temperature changes a breeze. These compressors may not put out as much air as quickly as the larger service station compressors, but they get the job done just the same. And you won’t have to go digging around for quarters either.
If your tire is low on air and you’ve made your way to an air compressor, it’s time to grab that air hose and tire chuck, and fill those tires up to the proper spec.
Once the compressor has fired up and is building air, take the tire chuck and push it into your valve stem the same way you did the gauge. Squeeze the handle on the air tool if it has one, if not you just press it down to your valve stem, and it will actuate the valve in the tool to release air. Now you’ll hear air moving into your tire.
In my experience, you just want to fill air for about three seconds each time, and check with your tire gauge between filling it up. Once you’ve gotten close to or right on the correct psi and you’ve replaced your valve stem cap, you’re good to go.
If you’ve found your tire to be over inflated, maybe due to getting a little trigger happy with the air chuck, you’ll have to let some air out of your tire safely.
Again, never let hot air out of a hot tire you’ve been driving on. The temperature differential can be very dangerous. You could end up damaging your car’s tire to a state of disrepair, or worse, yourself.
As for the fastest and safest way to release some pressure, I recommend taking your tire pressure gauge and, rather than applying the full force you would to get a pressure reading, apply light force at a slight angle to where it doesn’t fully seat onto the valve stem. You’ll hear a hissing sound from the valve stem, and that’s what we want to hear. Do the same action you would filling up the tire, by letting air hiss out for around three seconds, and then checking it again with your tire pressure gauge.
Once you’ve got that pressure close to the manufacturer’s suggestion, you’re finished. Don’t sit there at the gas station or in your driveway and try to get them perfect. Your pressures will naturally change over time, and you don’t want to be that person hogging the air compressor spot either. Unless you’re airing up your tires for your NASCAR race, within two psi of the correct pressure is good enough for any vehicle
I’ve spent countless dreaded hours over my career getting the most picky customers tire pressures all the exactly perfect, all while knowing the tire pressures are going to change by one or two PSI once they take the vehicle out on the road and the tires warm up. Don’t be that picky person to yourself, or to anyone else. Trust me when I say, your tires will be fine once they are within that specification.
Other Valuable Resources on Checking Your Tire Pressure
Checking your tires air pressures can save you a lot of money over time. Whether that be for premature replacement, or fuel mileage, it’s always a good idea to check them over once a month.
Here are a few more articles I’ve found that dig a little deeper into some of the aspects we’ve talked about when it comes to checking your car’s tire pressure and maintaining them properly:
https://calrecycle.ca.gov/tires/info/justcheckit/tips/
https://www.fueleconomy.gov/feg/maintain.jsp
https://www.lesschwab.com/article/how-to-make-your-tires-last-longer.html
