Tire Maintenance & Safety

Top 5 Symptoms of Worn Out Tires

Last updated 4/25/2023 - Originally published 4/24/2023
Written by SimpleTire

Tires are a necessity, and they’re something that too many drivers don’t give enough thought to until there’s a problem. The thing about tires, though, is that once they start to wear down to a point where they need to be replaced, they aren’t just an inconvenience – they’re downright dangerous by then. Worn-out tires mean that you can easily lose traction on wet pavement, while braking, or rounding a corner, not to mention the possibility of a catastrophic blowout at highway speed. When they get to that point, there’s no going back, and no way to get a little more life out of them. We’re going to talk a little about how to recognize tires that are really at the end of their service life, what to do about it, and how to make sure you get the most miles and years out of any set of tires.

Why tire maintenance is critical

Your doctor insists that you take care of yourself, right? Plenty of exercise, keep your weight down, drink plenty of water, and eat right. That’s because maintenance is important and because any problem is easier to address at Stage 1 than at Stage 4. So if you’re smart, you make sure your car’s oil is changed regularly, you stay on top of things like the air filter and transmission fluid, and brakes, all in the interest of good maintenance.

Your tires are no different. Things like regular tire rotations, inspections to look for any upcoming problems, proper inflation and good driving habits are crucial, not just for getting the most out of a set of tires but for staying safe and ensuring a good driving experience. It’s also important to mention here that failing to observe things like inflation and tire rotations can void a tire warranty, and you sure don’t want that to happen.

5 signs your tires are worn out

The good thing about tires is that it isn’t really a mystery that takes a lot of diagnosis from a professional when they’re starting to hit the end of the line. You can just do a little inspection and figure out how much service life they really have left in them.

Tire tread

This, of course, is one of the big ones. Tires that have tread that’s worn past its minimum depth are dangerous because they can’t evacuate water from the tire’s contact patch, raising the chances of hydroplaning and losing control on wet pavement. They also won’t get adequate traction while cornering or braking, which can very easily lead to a collision or a sudden, unplanned trip down a ditch or median.

State law prescribes a minimum tread depth of 2/32” to pass a safety inspection. Here’s an easy way to get your tire’s tread depth using the penny test:

  • Take a penny and insert it into a tread groove. If the tread reaches the Lincoln Memorial, your tires are at 6/32” tread depth and you’ve got some good life left in them.
  • Now, take a quarter and insert it into a tread groove, Washington’s head down. If the tread reaches the top of George’s head, you have 4/32” tread left. 4/32” is still legal, but you’ll notice some dropoff in traction and performance with tread that’s that shallow.
  • The last test would be to insert a penny into the tread groove with Abe’s head pointing down. If the rubber touches Lincoln’s head, your tires are at the minimum tread depth of 2/32” and should be replaced as soon as possible.

Modern tires also feature “wear bars” that are molded into the base of the tread grooves at a right angle. If these wear bars are exposed and flush with the tread surface, your tires are at 2/32” tread depth and need to be replaced.

It’s worth mentioning here that you also need to keep an eye out for uneven, irregular tread wear. Uneven tread wears along the tire’s inside or outside edge is almost always a sign of poor wheel alignment. Your vehicle leaves the factory with wheels set at predetermined angles (as designed by the automaker’s engineers) for the best handling, braking, steering, and road manners. Worn steering parts or a hard hit on a curb, pothole, or railroad tracks can be enough to skew a wheel out to one side and knock the steering components out of spec. If that happens, you'll have a tire that “tries” to steer the vehicle to one side or another as it gets dragged along by the rest of the wheels. That will scrub tread from the tire’s inner or outer edge and result in a distinct pull to one side when you’re trying to keep the vehicle in a straight line. It doesn’t take much of a difference in alignment angles – a wheel that’s ⅛” off of spec will steer the car 11 feet off of a straight line in the course of a mile, if not corrected by the driver.

And again, a tire that’s damaged due to poor wheel alignment won’t be covered by warranty.

Air pressure

This one is crucial and is neglected by too many drivers. If you’ve ever ridden a bicycle with an underinflated tire, you know it’s no fun. It takes so much more effort; it’s like you’re riding through wet cement and it makes the bicycle’s handling mushy and sloppy. It’s the same thing with tires as tires that are low on air have extra friction and rolling resistance, which means a hit on fuel economy, heat buildup, and terrible handling and braking performance. That heat buildup is the enemy of any tire and can lead to premature tire failure and a wear pattern where the inner and outer edges of the tire wear prematurely.

When you check tire pressure, don’t go with the PSI rating that’s embossed on the tire sidewall. Instead, look at the sticker that’s on the vehicle’s door frame or check the owner’s manual for proper inflation for your tires. Don’t check inflation when the tires are hot, since air expands when heated and you’ll get an erroneous reading. Use a good-quality tire gauge and check when the tires are cold. As for fuel economy, a tire that’s down by 1 psi of air pressure is enough to cost you 2/10 of a mile per gallon, which can add up pretty fast.

Tire sidewall cracking

Tires have a service life (or shelf life, perhaps) in terms of time elapsed, and not just mileage. A tire that only has 20,000 or 30,000 miles on it can still be due for replacement after five or six years of being exposed to the sun’s UV rays and the elements. In extreme cases, it can end up with a tire that’s dry-rotted to a point where it practically falls apart.

A tire that’s showing surface cracks on the sidewall isn’t too much cause for concern, but it should be checked on regularly. Deeper cracks in a sidewall can mean a tire that may be in danger of failing, simply because the rubber compound itself is degraded and weakened.


As we mentioned above when discussing tire pressure and inflation, long periods of excessive heat buildup are bad for a tire in every sense. That heat can weaken the rubber compound, damage the tire’s internal structure of steel belts and fabric plies, and generally shorten tire life. A tire that’s been overheated should be watched closely from that point on.


Wheel balance is something that should be done with every tire rotation (which should be performed every 5-7,000 miles). The reason is that as tires wear down, they start to lose the mass of rubber in the tread area, which affects balance. Worn tires can be hard to balance, and a tire that’s severely worn might be starting to develop problems in its internal construction that will lead to vibration or shimmy.

A few other notes that are worth mentioning:

  • Tire engineers put a lot of work into designing tires that are quieter on the highway, with various technologies that cancel noises, resonance, and overtones. As a tire wears and loses rubber, it will become noisier on the road, partly because there’s just less rubber to absorb noise and sound frequencies.
  • Worn tires also deliver a rougher ride, since there’s less rubber to cushion the ride.
  • When you’re inspecting tires for wear, also keep an eye out for things like bulges in the sidewall, any signs of splits or bulges in the tread itself, and exposed cords or steel belt wires. Any of these mean that a tire is in imminent danger of failing and needs to be replaced right away.

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