How to Tell if Tires Are Overinflated
A tire that's overinflated feels harder than it should, wears faster in the center of the tread, and gives a stiffer, bouncier ride.
Check the pressure against the number on the door jamb, not the number on the tire
The tire itself lists a maximum pressure, not the right pressure for your car. The correct number is on a sticker inside the driver's door, and that's the one to use. If your gauge reads higher than that number, the tire is overinflated.
You can also look at the tread and feel the ride. A tire that's overinflated tends to wear more in the middle of the tread than at the edges, and the ride feels harsher over bumps because less of the tire is in contact with the road. Neither of those is as reliable as a gauge, but they're worth noticing.
Check pressure when the tires are cold
Driving heats up the air inside a tire and raises the pressure reading. If you check pressure after driving even a short distance, the number will look higher than it really is, and you might let air out of a tire that was fine to begin with.
Check first thing in the morning, or after the car has sat for a few hours. That's when the reading reflects the tire's actual pressure rather than the heat from the road.
If you have to check after driving, knock a few pounds off your expectation for what a normal reading looks like, but a cold check is always more accurate.
This matters for insurance too, in a roundabout way. Tires that wear unevenly from being overinflated for a long stretch can affect how your car handles, and that's part of what an insurer or inspector might ask about after a claim involving a loss of control.
Use your own gauge, not the one at the pump
The pressure gauges built into gas station air pumps are often inaccurate, sometimes by enough to matter. A separate tire gauge, the kind you keep in the glove box, gives a more reliable reading.
Check all four tires, not just the ones that look low or feel off. A tire can be overinflated without looking any different from the others.
If you just filled up at a station and the reading looks unusually high, try again with your own gauge before you let air out. It's common for the station gauge and your gauge to disagree, and your gauge is the one to trust.
If you're not confident reading a gauge or finding the right number for your car, an auto shop or a dealership service department can check it for you in a few minutes.
Questions people ask about this
Can overinflated tires cause a blowout?
Overinflation makes a tire more rigid and less able to absorb impact, which raises the risk of damage from a pothole or road debris. It's less common than a blowout from underinflation, but it isn't impossible, especially combined with heat or an old tire.
Does overinflating tires improve gas mileage?
It can slightly, because a harder tire rolls with less resistance, but the difference is small and not worth the tradeoff. You lose traction and even tread wear, and the ride gets rougher, for a fuel savings that's barely noticeable.
How often should I check my tire pressure?
Checking once a month is a reasonable habit, along with before any long drive. Temperature swings change tire pressure on their own, so a tire that was fine last month can be over or under now even if nothing happened to it.
Why does my tire pressure light come on in cold weather?
Cold air makes the pressure inside the tire drop, which can trigger the warning light even though nothing is wrong with the tire itself. Check the pressure when this happens rather than ignoring the light, since it's also how you'd notice a real leak.
Do overinflated tires affect my car insurance rate?
Tire pressure on its own doesn't affect your rate. What matters is whether poor tire condition contributes to an accident, since that can affect a claim or how a future rate is set. Ask your insurer directly if you want to know how they'd view a claim involving tire condition.
If tire wear or an accident has you thinking about your coverage, it's worth seeing what else is out there.
Check the pressure on all four tires this week with your own gauge, while they're cold, against the number on the door jamb sticker rather than the number on the tire. Write that number down somewhere you'll see it, like your phone or the glove box, so you're not guessing next time. If a tire keeps reading high after you've let air out, or the tread looks uneven, have a shop take a look before it turns into a bigger repair. And if you're ever filing a claim where tire condition might come up, ask your insurer directly how they handle that rather than assuming.
