How Do I Know When I Need New Tires?
The primary functions of tread are to divert water from beneath the tire, to improve traction and to avoid hydroplaning on wet roads. As tire tread wears down, it becomes less reliable. Find out when you need new tires in this video, or read about it below.
Tires become completely unsafe when they’re worn down to 1⁄16 of an inch. Many people prefer to replace their tires even sooner, especially when driving in adverse weather conditions.
Check Your Tread Wear Bars
All tires sold in the United States today have what are called tread wear bars. These are small raised bars of rubber in the grooves of your tire. Look at the tread pattern and you’ll see these bars running between the tread blocks. As your tires wear, these bars will become flush with the tire’s tread. When this happens, it’s time to replace the tires.
Do a Penny Test
An easy way to check the tread on your tires is to do the penny test. Take a penny and place Lincoln’s head in one of the grooves of the tire tread. If you can see all of Lincoln’s head, it’s time to replace the tire.
If the penny goes in enough that the tire tread is at least as deep as Lincoln’s forehead, your tires are generally considered safe and do not need replacing. Make sure when you’re administering the penny test that you check all four of your tires.
While you’re at it, check a few spots on each tire to look for any irregular tread wear. This could indicate a wheel misalignment, need for tire rotation or both. Talk to one of our tire experts if you think your tires are wearing unevenly.
How to: Choose Snow Tires
Do I need to buy winter tires or can I just get snow chains?
What the heck is siping?
When do I have to have studded tires and when will studless do?
If you’re wondering how to pick the right tires for winter, or whether you need them at all, here are answers to the eight most common questions about winter tires.
(A lot of people still call tires used in the cold months “snow tires,” but it’s more accurate to call them “winter tires.” For purposes of this article, we use both terms to mean tires designed for winter driving.)
1. “Do I need snow tires?”
Winter tires are important for safe driving if you live somewhere that gets snow, ice, sleet or freezing rain and temperatures of 40 degrees or colder. They’re also the right option if you routinely make trips through snow zones or the mountains during the cold months.
Learn about the difference between all-season tires and snow/winter tires here.
2. “If my tires are marked ‘M+S’ on the sidewall am I good to drive on snow?”
Some all-season tires have an M+S rating. This stands for mud and snow. These tires have a more aggressive tread design to deliver better traction in a variety of conditions using larger tread blocks and wider gaps between them. The purpose of these tires is to achieve optimal tire life along with good performance in most weather conditions.
But it doesn’t mean they’re adequate for winter driving. In slick conditions, they don’t deliver the traction, control and short stopping distance that you get from a snow tire.
If you want safer driving on packed snow or ice, look for tires made with the right compound and branded with the Mountain Snowflake. This means they’ve actually been tested and certified to perform in winter conditions.
3. “I have all-season tires, so I don’t need snow tires. Right?”
Wrong. Don’t believe it? See this driving comparison between all-season and snow tires.
If you’re driving on snowy or icy roads, only winter tires will give you good stopping ability and secure handling. This is because they’re built very differently. How?
Different compound. Summer and all-season tires are made with a stiffer rubber compound. This helps the tire retain its shape when it’s rolling on hot pavement. Winter tires are made with hydrophilic (that’s “water-loving”) rubber which stays softer and more pliable in winter weather. This more flexible rubber is one reason you get more traction on snow and ice.Another reason is tread design. Winter tires have a higher “void-to-lug” ratio, meaning there are larger grooves between the blocks of tread (the lugs). The tread blocks also have irregular, sharp edges.
When a tire with wide grooves and biting edges travels over packed snow, it cuts through and scoops some of the snow into the voids on the tire surface, allowing the tread to stay in closer contact with the road. Then the velocity of the tire ejects this snow from the grooves. This is how winter tires provide more aggressive traction than all-season tires.
4. “Should I get my snow tires siped?”
Most snow tires are already siped, with small patterned slits on the lugs that create extra edges for better road grip. Additional safety siping can be done for a fee on new or used tires. If you’re regularly traveling on slick roads, the added traction from custom siping is a good way to improve starting, stopping and rolling traction.
5. “Is it okay to buy used winter tires?”
Before you jump on that set of “lightly used” winter tires on Craigslist, do three quick checks. First, verify they’re the right size. You can look in your vehicle owner’s manual or right on your existing tires’ sidewall close to the rim for the series of numbers. (Here’s a primer on what they all mean.) If you’re not sure the tires you’re considering are the correct size, call a tire dealer and make sure.
Second, measure the tread depth by using a tire tread depth gauge. You can pick one up at any auto parts store for under five bucks. Or have a tire store tech do it; it should be free. Take measurements in multiple places in the grooves on each tire.
A new tire typically has 11/32nds of an inch in tread depth. A rule of thumb is that if there are 6/32nds of an inch or less in tread remaining on a winter tire, it’s about to lose a good deal of snow performance. So think carefully about whether you’re going to get what you’re paying for.
Third, be sure there’s not a problem with uneven wear. Did your tread gauge measurements show any tread depth difference between the four tires? It’s really common for tires to wear differently over time. If the disparity between any two tires is more than 3/32nds of an inch, pass on those used tires. Driving with mismatched tires or putting the wrong size on your vehicle will NOT save you money in the long run. You’re risking big repair bills for your transmission.
It’s also a bad idea to put winter tires on only the front or back. This creates a big difference in traction between your axles. And this will mean less steering control, not more.
6. “Can I just buy chains instead of snow tires?”
Tire chains can be important — and are sometimes required — for traction when you’re traveling in the mountains or on icy roads. But they’re not made for driving at highway speed or on bare pavement. You risk damaging your chains if you try this.
Don’t think of chains as a substitute for winter tires but as an option you need to have ready when you’re driving on snow.
Depending on the conditions and your state’s rules, traction controls in snowy areas will range from requiring only the minimum — like M+S tires on the drive axle — up to chains on all tires, including all-wheel and four-wheel drive vehicles. Here are California’s chain controls, for example.
7. “Do I need studded snow tires or studless?”
The tire dealer will consider your driving habits, where you’re traveling and typical winter conditions in your area when recommending what you need.
Studless snow tires work well on slush and packed snow. They get traction through wide, deep grooves and lots of irregular surfaces with sharp edges. This allows the rubber to cut through snow and grip the road.
Studded tires provide the best traction you can get, even when you're encountering ice or packed snow. Studs are lightweight, small metal spikes that are staggered across the tread. They help break through packed snow and ice-covered roads to give you better traction. Note: Extra tread depth is needed to accommodate studs, so studded tire size options are limited. Also, the times of year when studded tires are allowed on the road vary by state. Here’s a guide to studded tire regulations.
8. “Should I buy winter tires with rims?”
It’s a question of time and money. Here’s a way to decide:
- Assume you’ll have your snow tires for five years.
- Total up the cost your tire dealer will charge for swapping out tires twice a year (ten times) if they’re not on rims. (Les Schwab will swap out tires purchased at our stores at no charge if they’re mounted on separate wheels.)
- Compare that figure to the price of the rims to see if there are savings.
- Factor in a bit more waiting time, since it takes the shop longer to unmount and remount the tires on the rims each time.
- Weigh whether the tradeoff in any money saved is worth the extra waiting room time.
Also consider the extra wear and tear on your tires that comes with unmounting and remounting tires on only one set of wheels. Especially with low-profile tires, it’s not uncommon for an inexperienced tire tech to damage the inside edge of a tire near the beads, the places where the tire gets pried off and pushed back on.
If you’re leaning toward separate wheels for your winter tires, here are some tips on selecting the best wheel finishes for winter conditions.
Check out tests from the Tire Industry Association in this video to see what the difference winter tires can make.
The Bottom Line on Picking Winter Tires
Some all-season tires are marketed as working equally well in summer and winter. That may be true in dry, mild climates where the seasons don’t vary much. But you’ll only get confident traction, braking and control on snow and ice with a winter tire. If you live in a place with winter weather, you’ll need tires marked with the Three-Peak Mountain Snowflake for safest handling. Because not all tires with a mountain snowflake have a winter compound, ask your tire dealer what you really need.
Want more tips on winter road safety? See 19 Winter Driving Resources You Can’t Do Without.SHOP WINTER TIRES
TPMS Light Coming On in Cold Weather? Here’s Why
If your TPMS (tire pressure monitoring system) warning light goes on during a cold snap, it may not mean your tire has a leak.
Tire pressure can decrease about 1 PSI (pounds per square inch) for every 10 degrees the temperature drops. It's not due to air escaping, but rather the air inside the tire condenses, taking up less space when it's cold. This is temporary, because driving will heat up the tire and increase the tire's pressure.
Tires also lose about 1 PSI per month just from seepage of air around the edge of the rim and through the tread itself.
These two factors combined can cause the air pressure in a tire to go 25 percent below the recommended fill pressure. This is what triggers the sensing transmitters inside your tires to illuminate your TPMS dash light. Whenever your TPMS light comes on, have your air checked and bring your tires up to the proper pressure.
Winter Tire Pressure
Temperature changes overnight or from cold winter days can affect your tire pressure. This can cause the low-pressure indicator to appear. Large swings in temperature between day and night can affect the pressure in your tires by up to 10 PSI.
The light may shut off on its own after you drive 20 minutes or so, as the air in your tires warms and expands and proper inflation level stabilizes.
Regardless, you should get your air checked right away. The TPMS light means your tires are at least 25 percent below the proper air pressure. This is a safety risk, especially if you’re carrying a load close to your vehicle’s max capacity. There’s a greater chance of tire failure, compromised handling and increased wear and tear on your tires. Your gas mileage could also suffer.
When you top off your tires, the TPMS light will go off as the tire regains the proper pressure.
Note: If the warning light is flashing, this is a problem with the vehicle’s TPMS system, not your tires, and you should take your car to the shop.
One More Reason Your TPMS Light May Go On
Your TPMS light may flash if your vehicle’s onboard computer can’t detect the sensor because you’re using a spare tire. They typically don’t have TPMS sensors.
How to Get Winter Tire Pressure Right
Once a month, have your pressure checked when the tires are cold (meaning the car is parked outside and hasn’t been driven in four hours) and inflate them to what’s indicated on your placard located on the inside of your car door.
For more information regarding TPMS with your vehicle, please review your owner’s manual.
Les Schwab Tech Tip: How Flat Tire Repair Works
The tires on your vehicle come in contact with a lot of roads, highways, and more. Sometimes items on those roads include nails, screws, or other objects that can find their way into your tires. This is typically what causes a flat. At Les Schwab, we’re proud to fix flat tires across the West, and get you and your family safely back on the road. Here’s a quick rundown of our process that helps us fix almost 2-million flats at year — often at no charge.
Step 1: We put your vehicle on a lift and perform an inspection. This includes looking over the tread of the tire, the sidewalls, stem (air valve), and looking for exposed belts. This first step can often tell us if your tire can be repaired or needs to be replaced.
Step 2: We remove the wheel and tire assembly. To find all possible issues, we submerge the whole wheel and tire assembly in a water tank to locate and mark the cause of the leak. Once again, the tire expert will determine if the flat can be repaired.
When Replacement is Necessary
According to the Tire Industry Association guidelines, all repairs on any tire are limited to the tread area, not on the shoulder or sidewall. If your tire is damaged beyond repair, or the sidewall is damaged, the tire should be replaced.
Step 3: If it can be repaired, the technician working on your vehicle will remove the tire from the wheel and prep it inside and out.
Step 4: Oftentimes, we remove the object and drill the damaged area at the angle the object entered the tire. We then buff and clean the inside, cement it, then apply a plug/patch combination and sealer. Depending on the angle of the puncture, a 2-piece patch may be required.
Step 5: Before reinstalling the wheel, we double-check the patch by placing the tire and wheel in a water tank. This is done to verify the patch was done properly and there are no leaks.
Once your tire is back on your vehicle, we’ll check the pressure on all four tires. Then, we’ll ensure Tire Pressure Monitoring System is reset as part of our World Class Customer Service. After that, you’re good to go.
Get the Les Schwab Tire Warranty
When you buy your tires from Les Schwab, they come with our Best Tire Value Promise, including free flat repairs. And when you bring your flat tires into Les Schwab for repair, you’ll go home with information on your repair, your tire’s tread depth, air pressure, and information on what caused the leak.
Schedule a Flat Repair