What Does the PSI on Vehicle Tires Mean?

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What Does the PSI on Vehicle Tires Mean?

Every vehicle owner has heard the term ‘PSI’ at some point, but besides knowing it has something to do with their tires, many aren’t sure what it actually means. In truth, it’s super important that you find out because having your vehicle’s tires at the correct PSI can help you avoid gas stations by helping to increase your fuel economy by up to 3%. And just like having your tires rotated, it’s also great for improving your vehicle’s safety out on the road.

As an auto shop owner, being asked, “what does PSI mean in cars?” is something that I hear all too often. Often enough, that question is usually followed by, “so what PSI should my tires be?”. They’re both great questions, and I’ll do my best to answer them here.

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What Does PSI Stand for in Cars?

First things first, PSI stands for pounds per square inch. Simply put, this is the unit used to measure air pressure within your tire. You can find an accurate reading of what PSI your tires are right now using a tire pressure gauge, which you can pick up for around $20.

Your vehicle’s manufacturer will set a recommended PSI level, which is usually found somewhere in your owner’s manual, or on the door jamb of your driver-side door. On average, this tends to be somewhere around 35 PSI, measured when your tires are cold (i.e., when you haven’t driven at high speeds recently). Whatever PSI your vehicle requires, you should try to keep it at this particular pressure for optimum performance.

Why Is PSI Important?

Whether it’s too low or too high, incorrect tire pressure can impact both ownership cost and safety. Your manufacturer recommends a specific PSI for a reason, after all.

Underinflated tires cause quite a long list of issues, including:

  • Longer braking distances
  • Poorer handling
  • Accelerated sidewall wear (potentially leading to dangerous blowouts)
  • Lower fuel economy

Overinflated tires aren’t quite as bad but still create problems such as:

  • Less responsive steering
  • Accelerated tread wear

Tire PSI Maintenance and Performance Tips

Once you’ve found the recommended PSI for your vehicle, you should check the pressure of each of your tires around once a week (or at least once a month) and before every long road trip. If it looks like you have low tire pressure, top them up to the recommended PSI accordingly. If they’re too high, let a little air out until they’re just right.

It is also possible that your tires themselves have a PSI number molded into their sidewall, but feel free to ignore it. This is the number needed to meet the tire’s maximum load-carrying capacity—not what’s suitable for your vehicle.

It’s worth noting that your vehicle’s manufacturer may recommend a different PSI for the front and rear tires. They could also give you numbers meant for heavier loads or long-distance driving. So take all these things into account when filling up on air.

Manufacturer Recommended PSI Levels

Below you can find the manufacturer-recommended PSI levels of some of America’s most popular vehicles. Just remember that these numbers can change between year models.

Use the table below as a rough guide, but always check your owner’s manual or driver’s door sticker to get the exact numbers:
tire-psi-chart

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Car Tire PSI: Frequently Asked Questions

What PSI is best for car tires?

The answer to this question ultimately depends on your vehicle, but for cars (rather than SUVs and pickups), you can bet it’ll be somewhere between 30 and 35 psi. The best place to find the exact number that your manufacturer recommends will be in your owner’s manual or on the jamb of your driver’s side door. It could also be somewhere inside the fuel flap, on the glove box door, or under your trunk lid for older cars.

Is three over PSI too much?

While anything over your manufacturer’s recommended maximum PSI is too much, tires are better at handling overinflation than underinflation. Repeatedly overinflating tires leads to poorer handling and increased wear at the center of your tire’s tread, so you should always be careful not to fill them more than you’re supposed to. While you might think more air is better, there are no benefits to doing so.

What tire PSI is dangerous?

Technically, any PSI that isn’t your manufacturer’s recommended amount affects the safety of your vehicle, but it’s underinflation that poses the most problems. An underinflated tire’s sidewalls flex excessively, bringing more rubber into contact with the road surface. This makes it much more difficult to turn and causes the walls of the tire to deteriorate. Tire walls are naturally much thinner than the tread, so it doesn’t take long for them to wear through completely. If this kind of tire failure happens suddenly when you’re out on the road, it could cause a fatal accident.

Keeping You Driving with Confidence

Try as you might to keep your PSI at the correct pressure level; you can never totally avoid the risk of tire punctures and blowouts. Most extended warranty providers exclude your tires as part of a bumper-to-bumper warranty, but Endurance isn’t one of them. Not only does every Endurance coverage plan give you 24/7 roadside assistance, substitute transport, and trip-interruption costs as standard, but you also get free access for a year to Endurance Elite—which includes tire repair/replacement.

As the country’s most comprehensive vehicle protection program, EnduranceAdvantage also covers $3,500 in general maintenance costs per year. From alignment checks to tire rotations, just take your vehicle to the nearest ASE-certified auto shop, show them proof of your Endurance membership, and we’ll take care of the rest. It’s a cost-effective way to keep your tires in top condition and make sure you get the most gas mileage for your money.

If you’d like to know more about our extended warranties, don’t hesitate to get in touch. Fill in your details online now for a free no-obligation quote, or head back to our Learning Center for information, advice, and other useful articles.

A Vehicle Service Contract (VSC) is often referred to as an “auto warranty” or an “extended car warranty,” but it is not a warranty. A VSC does, however, provide repair coverage for your vehicle after the manufacturer’s car warranty expires. A VSC is a contract between you and a VSC provider or administrator that states what is a covered repair and what is not. Not all vehicles qualify for coverage; Endurance does not offer VSCs in California.