What Should My Tire Pressure Be?

Most car manufacturers and tire companies recommend a pressure between 30 and 35 pounds per square inch (PSI). The higher of those pressures are usually required on larger vehicles, while smaller sedans and hatchbacks usually call for between 30 and 32 psi.

Remember, these are cold tire pressures. That means you should set your pressures before you drive your car. Drivers who check their tires at service stations risk under-filling because they’re taking a hot reading as if it was cold.

Where Can I Find the Recommended Tire Pressure for my Car?

Your car, truck, or SUV will have the recommended tire pressure displayed in the owner’s manual. It will also be shown on a placard on the door sill of your car, usually inside the driver’s door, just under the lock jam. Some vehicles also show this info inside the fuel cap lid, or under the hood on the rail that runs in front of your radiator.

How Often Should I Check Tire Pressure?

You should check your tires at least once a month. It’s true that all newer cars haver a Tire Pressure Monitoring System (TPMS), however the basic versions of these are set to go off only when your tires lose 25 percent of their recommended pressure. That means by the time the light has gone off, you might be as much as 8 PSI under inflated. That has an impact on braking and steering and can even damage your tires.

More advanced TPMS show live readings. On those cars or trucks it’s prudent to check in before you start your drive at least once a week.

Pressures drop sharply with sudden weather changes, so if you’ve had a cold snap, better check them out then too.

How to Check Your Tire Pressure

If you have one of the advanced live reading systems we mention above, you can check your pressure using the onboard display. You should always check before you start driving. You should also validate  the accuracy of your system with a separate gauge at least once every three months.

Why do Tire Pressures Matter?

Improper inflation can affect braking performance, handling, and even fuel economy. Under-inflated tires don’t provide a stable enough platform for your car when steering. They also cause more flexing in the sidewall, which can damage them over time. When you’re braking hard, under inflated tires collapse and don’t provide enough stability. Lastly, under-inflated tires cause extra drag, which hurts fuel economy by as much as 4 percent for every three PSI.

Over-inflated tires also cause poor braking and cornering performance because your contact patch becomes smaller. In extreme cases you’ll feel your steering is more light, and the whole car will feel more skittish on the road.

The most noticeable impact of less extreme over-inflation is the damage it causes to your tires. They’ll wear unevenly, and quickly with too much air pressure.

Regular maintenance of your air pressure is an easy, free way to preserve your tires and improve your vehicle’s safety.

Photo credit: Pakpoom Phummee/Shutterstock