Post summary: Start planning for new tires when tread depth approaches 4/32 inch, especially if you regularly drive on wet roads. Replace tires when the tread reaches 2/32 inch. A sidewall bulge calls for immediate replacement, and recurring air loss, new vibrations, or uneven wear warrant an inspection. Check the DOT date code and follow your tire and vehicle manufacturers’ age guidance, even if the tread looks good.
Tires are easy to forget about. They just sit there doing their job, right up until the car feels a little loose on a wet road or someone at the oil change mentions your tread is "getting there." So when should you replace tires, really?
Here's the short answer. Start shopping for new tires for your car when your tread gets down to around or at 4/32 of an inch, and don't let it go past 2/32. You'll also want to replace a tire that has damage like cracks or bulges, or one that's simply gotten old, even if the tread still looks okay. Let’s talk more about how to tell what’s going on with your tires.
How to tell if you need new tires: check your tread
Tread is the grooved part of the tire that touches the road. Those grooves push water and slush out of the way so your tire can grip the pavement. As they wear down, your tire has a harder time doing that, and you'll notice it most when the roads are wet or snowy.
Tread depth is measured in 32nds of an inch. Most new passenger tires start somewhere around 10/32. Here are three easy ways to see where yours are now.
- The penny test
Grab a penny and slide it into a tread groove with Lincoln's head pointing down. If you can see the top of his head, your tread is at 2/32 or less. That tire is worn out and needs to be replaced now. - The quarter test
This one gives you a little more warning. Put a quarter in the groove with Washington's head pointing down. If the tread doesn't reach the top of his head, you're under 4/32 and it's time to start shopping.
Try it in a few spots on each tire (inside edge, middle and outside edge). Tires don't always wear evenly, so one spot can tell a very different story than another. - Look for the wear bars
Every tire has small raised bars molded across the bottom of the grooves. They sit at 2/32 of an inch. When the tread wears down flush with those bars, the tire is done. If you're seeing them easily, don't wait.
Tire replacement tread depth
You might be thinking, "If 2/32 is the limit, why replace at 4/32?" It's a fair question.
Consumer Reports tested this. In their testing, tires worn to 4/32 took more time to stop on wet pavement compared to the same tires brand new. You can read more in
Consumer Reports' guide on when to replace your tires.
So 2/32 is the point where a tire is finished. 4/32 is the point where you start planning for new ones, before your stopping power drops off any further.
7 signs you need new tires
Tread depth is the big one, but it's not the only thing to watch for. Here's what else tells you a tire is near the end.
1. Your tread is low
If you failed the quarter test, or the wear bars are showing, that's your sign. Browse our new and used tires and we'll help you find a set that fits your car and your budget.
2. You see cracks in the sidewall
The smooth side of the tire is the sidewall. Small cracks there (sometimes they look like tiny spiderwebs) mean the rubber is breaking down. It's especially common on tires that sit outside a lot or don't get driven much. A few hairline cracks are worth having someone look at. Deep ones mean replacement.
3. There's a bulge or blister
A bump on the side of your tire means the inside structure is damaged, usually from hitting a pothole or curb. Air is pushing through a weak spot. This one isn't a "keep an eye on it" situation. A bulging tire can fail suddenly, so get it replaced as soon as you can.
4. The tread is wearing unevenly
Run your hand across the tread. Is one edge way more worn than the other? Do you feel a scalloped, up and down pattern? Uneven wear usually points to a problem with something else on the car, like alignment or worn shocks and struts.
Something to keep in mind, though, is if you put new tires on without fixing the cause, they'll wear out early, too. A wheel alignment or a look at your shocks and struts can save your next set.
5. You feel a vibration you can't explain
Some shaking in the steering wheel or seat can come from wheels that need balancing. But it can also mean a tire has damage inside that you can't see from the outside. If a vibration shows up out of nowhere, have it checked.
6. One tire keeps losing air
If you're topping off the same tire every week, something's going on. It could be a nail, a leaky valve stem or a problem where the tire meets the wheel. Sometimes it's a simple flat tire repair. Sometimes the damage is in a spot that can't be fixed safely, and you'll need a new tire instead.
7. Your tires are getting old
This is the sign most people never think about, so let's give it its own section.
Tire age replacement: how old is too old?
Tires age even when they aren't being driven much. The rubber breaks down over time from heat, sun and plain old air. A tire can have plenty of tread left and still be way too old to trust.
How to check your tire's age
Look on the sidewall for the letters "DOT" followed by a string of numbers and letters. The last four digits are the date the tire was made. The first two are the week, and the last two are the year.
So if yours ends in 2721, that tire was made in the 27th week of 2021. (Heads up: the full code is sometimes only printed on one side, so you might have to check the inner sidewall.)
So when should tires be replaced because of age?
Tire makers don't all agree on this. Some recommend replacing tires at six years, and others treat ten years as the outer limit. The U.S. Tire Manufacturers Association points out that you can't predict a specific tire's life from its age alone, since heat, storage and how you drive all play a part. That's why they recommend having older tires checked by a tire professional. You can read their guidance on the USTMA tire facts page.
Our advice? Once your tires hit the five or six year mark, have someone take a look each year. And don't forget your spare. It's often the oldest tire on the car, and it's no fun to find that out on the side of the road.
How long do tires last, and how often should you replace them?
There isn't one magic number, and anyone who gives you one is guessing. How long your tires last depends on the type of tire, how and where you drive, and how well they're taken care of. A good place to start is the mileage warranty on your tires. You'll find it on your receipt or the tire maker's website.
Most of the time, it's the tread that tells you when to replace them, not the calendar. Age just sets an upper limit.
You can stretch the life of your tires with a few easy habits:
Check your tire pressure once a month, even if your car has a tire pressure light
Get your tires rotated on the schedule in your owner's manual
Have your alignment checked if the car pulls or you hit a nasty pothole
Give your tires a quick look when you fill up for gas
None of that takes long, and it adds up to more miles before you need a new set.
When to replace tires before Michigan winter
If you live around here, you already know the roads can go from fine to slick overnight. That's what makes fall the best time to check your tires.
Consumer Reports found that all season tires start losing their snow grip well before they look worn out. Their advice is to make sure you still have at least 4/32 of tread in the middle of winter, even if that means replacing tires a little earlier than you would otherwise. So if your quarter test is close right now in October, your tires probably won't make it through to spring with enough grip.
Cold weather also lowers your tire pressure, so that tire light might pop on the first frosty morning. Check your pressure once it gets cold and top it off to the number on the sticker inside your driver's door.
Getting new tires before the first snow means you're not stuck scrambling once the roads turn icy. And you'll feel a lot better driving to work on that first slick morning!
Tire replacement in Ionia, MI
Still not sure if your tires have another season in them? That's what we're here for. Swing by and we'll check your tread, look over the sidewalls and read the age on every tire, spare included. If they're fine, we'll tell you. If they're not, we'll help you find the right replacement.
Blundy-Hoppes has been helping drivers with tire replacement in Ionia, MI for more than 40 years. We see folks from all over Ionia County and nearby towns, including Belding, Saranac, Lake Odessa, Portland and Lowell. You'll find us at 3765 S State Rd on M-66, just south of Meijer. Give us a call at (616) 527-0670 to check prices or set up a time.
Your tires are the only part of your car that actually touches the road. Taking five minutes to check them is worth it!
Frequently Asked Questions
How many years do tires last?
It depends on how much you drive and how well you take care of them. Many people wear out their tread before age becomes a problem. If you don't drive much, age can catch up first. Tire makers differ on the limit, with some recommending replacement at six years and others setting ten years as the max. Once your tires are five or six years old, have them checked every year.
Do tires go bad if you don't drive much?
Yes. The rubber in a tire breaks down over time even when the car sits in the driveway. That's why a low mileage car can still need new tires. Look for cracks in the sidewall and check the date code on the DOT number.
Is 4/32 tread depth safe?
At 4/32, your tires still have some grip left, but they won't stop as well on wet roads as they did when they were new. That's why 4/32 is a good time to start shopping. Plan to replace them before they reach 2/32, and sooner if you'll be driving on snow this winter.
How often should you check your tire pressure?
Check it at least once a month and before long trips. Do it when the tires are cold, before you've driven very far. Use the pressure listed on the sticker inside your driver's door, not the number printed on the tire itself. That number on the tire is the maximum, not the recommended pressure.
