Tire Size Explained: Reading the Sidewall
Tire size can be confusing. Some numbers on the sidewall are listed in metric while others are in inches. Plus, the right size for your car, truck or trailer can differ depending on tire use and your driving habits.
You can see your original equipment tire size in your owner’s manual. This is the sizing recommended by the vehicle manufacturer.
If you’re interested in switching out your tires for a different look or performance need, a good place to start is to look at the codes on your existing tires’ sidewall. Then have a tire professional help you determine a tire size range that will fit your vehicle and driving goals.
Here’s an explainer on what all the sidewall numbers and letters mean.
Tire Size Meanings
A: TIRE TYPE The first letter in the code tells you what class of tire it is.
P stands for passenger vehicle tire. P-class tires include cars, SUVs, crossovers, minivans and smaller pickup trucks.
LT means light truck tire, designed for vehicles that are towing trailers or have ¾- and 1-ton load capacity.
ST stands for Special Trailer. These tire sizes are meant for trailers, including fifth wheels and other travel trailers, boat trailers and utility trailers.
If there’s no letter before the first number, you have a metric tire most commonly referred to as European size. It’s also measured in millimeters but may have different load capacity than a P or LT tire.
B: TIRE WIDTH The three-digit number following the letter is the tire’s width (from side to side, looking at the tire head on) in millimeters. Also called the section width, this measurement is taken from outer sidewall to inner sidewall.
C: ASPECT RATIO The forward slash separates the tire width number from the two-digit aspect ratio. The bigger the aspect ratio, the higher/taller the tire’s sidewall, or “profile” as it’s sometimes called.
The aspect ratio is a percentage. It’s the height of the sidewall measured from wheel rim to top of the tread, expressed as a percentage of tire width. In other words, it’s sidewall height divided by tire width.
In this example, the aspect ratio is 65, meaning the sidewall is 65 percent as high as the tire is wide. To get the sidewall height, take the tire width of 215 mm and convert it to inches (8.46). Then multiply this by .65 and you get 5.5 inches, the sidewall height in inches.
D: CONSTRUCTION TYPE This single letter tells you about the internal construction of the tire.
R is for radial tires, the industry standard for most tires today. They have better road grip, lower rolling resistance for better gas mileage, ride comfort and durability than previous generations of tires. In a radial tire, the plies — layers of strong cords made of a blend of polyester, steel and fabric and coated with rubber — are laid perpendicular to the direction of travel.
D is for tires built with diagonal (crisscrossed) plies, called bias-constructed tires. They are also called conventional, x-ply, or cross-ply tires. Some motorcycle and trailer tires still use this internal construction.
Some run-flat tires are identified with an F followed by the type of internal construction.
E: WHEEL DIAMETER This two-digit number specifies wheel diameter in inches, how wide the wheel is across the center. It’s the distance between the two bead seat areas (where a tire gets slotted and tightly sealed onto the wheel).
F: LOAD INDEX The two-digit or three-digit number that follows the gap specifies tire load index. The load index symbol indicates how much weight a tire can support, based on the following standard chart. In our example, the load index is 89, which indicates the tire has a load capacity of 1,279 pounds.
G: SPEED RATING The last letter is the speed rating, which tells you the top speed it’s safe to travel at for a sustained amount of time. A tire with a higher speed rating can handle heat better and provide more control at faster speeds. The maximum operating speed of a vehicle is no more than the lowest speed rating of all tires mounted on the vehicle. (Of course, you should always abide by speed limits for safer driving.) Speed rating is usually, but not always, a single letter (see the chart).
LOAD INDEX LOAD (lbs) LOAD INDEX LOAD (lbs) LOAD INDEX LOAD (lbs) 65 639 94 1477 123 3417 66 661 95 1521 124 3527 67 677 96 1565 125 3638 68 694 97 1609 126 3748 69 716 98 1653 127 3858 70 739 99 1709 128 3968 71 761 100 1764 129 4079 72 783 101 819 130 4189 73 805 102 1874 131 4299 74 827 103 1929 132 4409 75 853 104 1984 133 4541 76 882 105 2039 134 4674 77 908 106 2094 135 4806 78 937 107 2149 136 4938 79 963 108 2205 137 5071 80 992 109 2271 138 5203 81 1019 110 2337 139 5357 82 1047 111 2403 140 5512 83 1074 112 2469 141 5677 84 1102 113 2535 142 5842 85 1135 114 2601 143 6008 86 1168 115 2679 144 6173 87 1201 116 2756 145 6393 88 1235 117 2833 146 6614 89 1279 118 2910 147 6779 90 1323 119 2998 148 6944 91 1356 120 3086 149 7165 92 1389 121 3197 150 7385 93 1433 122 3307
SPEED SYMBOL SPEED (mph) A1 3 A2 6 A3 9 A4 12 A5 16 A6 19 A7 22 A8 25 B 31 C 37 D 40 E 43 F 50 G 56 J 62 K 68 L 75 M 81 N 87 P 93 Q 99 R 106 S 112 T 118 U 124 H 130 V 149 W 168 ZR* Y 186 (Y) Above 186
*For tires having a maximum speed capability above 149 mph, a ZR may appear in the size designation... above 186 mph, a ZR must appear in the size designation, including a Y speed symbol in brackets.
Buying New Wheels or Changing Your Tire Size?
A tire size calculator is a quick way to see whether the tire size you’re considering will likely fit your car, SUV, sports car, light truck or crossover.
But remember that will give you just an estimate. It’s important to stay within the sizing tolerances of your vehicle. Tires that are the wrong size could cause pull in the steering wheel, rub against the suspension or auto body, reduce clearance on hills or result in a stiffer or noisier ride than you expected.
If you’re considering mounting a different tire size on your vehicle, check with a tire expert. Find out whether the tires and wheels you have your eye on are the right fit for your vehicle’s suspension, gearing and bodywork. And ask how any differences in revolutions per mile, tire speed, load index and speed rating will affect your ride quality and vehicle performance.
See how new tires and rims will look on your car or truck using our Virtual Wheels simulator, available at any Les Schwab.
Tire Rotation: It’s Preventive Care for Your Tires
Why should you care about tire rotation? It’s one of the easiest ways to extend the life of your tires and get the most miles out of them. Unlike daily flossing, it’s a chore you only need to complete a few times a year.
What’s Tire Rotation?
Rotating tires means moving them to different positions on your vehicle to promote even tread wear on all four tires.
No matter how you drive, front and rear tires can wear at different rates. Tires that are mounted on the power axle (the front two wheels on a front-wheel drive, for instance) wear more quickly than the “free rolling” tires on the other axle. (Axles being the heavy-duty bars that connect two wheels.)
Tire rotations even out wear so you get the most tread life from every tire. Regular rotations are especially important if you’ve got an all-wheel drive, because any significant difference in tread depth between tires means you’re looking at buying four new tires — or you’re risking big repair bills.
How Often Should You Get a Tire Rotation?
A good rule of thumb is every 5,000 miles or at least every six months. If you have an aggressive driving style, you’ve hit potholes or debris, or you don’t keep tires inflated properly, you should do it more often. All those are big factors in uneven tire wear.
It’s key to catch irregular wear early. Going too long between rotations may result in a wear pattern that can’t be remedied, no matter where the tire is moved on the vehicle. In that case, your tires could wear out prematurely.
Remembering to schedule rotations is easy if you’re swapping winter and all-season tires twice a year. Your tire store should be mounting your tires in the positions that are best for smoothing out tread wear whenever you make the seasonal changeover.
If you only have one set of tires here are some ways to get on a timetable with rotations.
- Watch your odometer and get your vehicle in every 5,000 miles.
- Put a reminder on your calendar for service at least twice a year.
- Sync rotations with the change of the clock from daylight savings to standard time and back.
- Check with your tire store; some will email you a service reminder when you’re due.
Tire Rotation Patterns
The standard tire rotation is front-to-rear, but there are multiple patterns that could work for your vehicle to promote longest tire life.
- Rear tires move to front on same side of vehicle
- Used when wear is normal, and also when tires have directional tread (are designed to roll in one direction)
- For front-wheel drive vehicles
- Front tires move straight back to the rear
- Rear tires cross to opposite sides on front
- Used when rear tires show uneven wear
- For all types of vehicles
- Front tires shift to opposite rear positions
- Rear tires cross to opposite front positions
- Used when there’s uneven wear
- For all-wheel, rear-wheel or four-wheel drive vehicles
- Rear tires move straight up to front
- Front tires cross to opposite rear positions
- Used when there’s uneven front-tire wear
- For staggered (differently sized) wheels
- Front two tires are moved to opposite sides on front axle
- Rear two tires are moved to opposite sides on back axle
Here are the factors tire technicians look at for proper positioning of tires during a rotation.
- What kind of drive is your vehicle (front-, rear-, all-, four-wheel)?
- Do the tires show uneven wear? Where?
- Do they have directional tread?
- Are there any custom wheel-tire setup considerations, like staggered wheels (different wheel sizes on front and back)? Any offset concerns?
You should also check your owner’s manual for any recommendations your vehicle manufacturer makes. Don’t hesitate to discuss them with your tire dealer.
After the Rotation
Be aware that you may notice a stiffer or slightly noisier ride after a rotation. This is due to the tread wear pattern evening out. But if your ride quality is truly uncomfortable or the issues don’t go away quickly, get your vehicle back to have it looked at. It could be that the irregular wear has gone on too long and tires need to be replaced.
Regular Tire Rotations Will Save You Money
Rotations are simple preventive maintenance that will extend your tires’ tread life. Getting them done on time may also help head off other problems. Irregular tire wear detected during a rotation can be a red flag for poor alignment. Misalignment impacts how your car handles, reduces fuel efficiency and needs to be corrected promptly.
To maximize the value you get from your investment in your tires, don’t delay tire rotations.
Did you know Les Schwab Tire Stores rotate tires bought from us for free, for the life of the tires? And we provide free rotation reminders by email, no obligation. Just ask at your local store.
5 Questions Any Good Tire Dealer Should Ask
Tires are a big investment most people make only every few years. If you want to make the right decision, you’ve got two choices:
- Become a tire selection expert.
- Become a tire dealer selection expert.
Option 2 is a lot easier. Make sure the salesperson asks you these five questions:
1. “What do you use your vehicle for?”
The best tire for a commuter in an economy car may not be the same as what’s needed for the family car. The tire that’s best for comfort and least noise for your long-distance commute may be overkill for a third car that's used less often. If you’re hauling loads or a trailer with your truck, that suggests a different choice than what’s right on a truck used for lighter duty.
Road conditions are a part of this equation. If you regularly go off-road, you’re driving streets with lots of potholes, or you live in a place with winding roads and tight curves, the salesperson’s recommendations will differ.
2. “What are your driving habits?”
If your dealer asks this question, they’re a keeper.
Literally and figuratively, tires aren’t one-size-fits-all. For example, a new driver in the family can change the ideal tire. So can your tendency towards conservative versus faster driving.
3. “Will you be doing any driving in winter conditions?”
You need tires that suit the weather conditions where you drive and your dealer knows that. A good one will ask.
All season tires are the choice for drivers in sunnier places. If you’re driving on snow or ice every year, you’ll likely have winter tires for cold months and a different set for warmer weather. Your dealer’s recommendation on what’s going to last longest and perform best will also be different if you live in a place with extremes of heat and cold than someplace with more consistent weather.
4. “What’s your budget?”
All these factors — driving habits, safety, longevity, comfort, handling, noise — have to be balanced with your budget. A good dealer is happy to explain the differences between a quality, basic tire, a premium tire, and everything in between, because it narrows the choices to what's best for you. You should never get the feeling the store rep is pushing a tire just because it’s on sale or it’s the most expensive.
5. “Here’s how our warranty works …”
OK, it’s not really a question. But the best dealers will bring this up. If you want to get the best value for the money, it’s really important to think this through. Service warranties can include free services worth hundreds of dollars over the life a tire. They vary substantially by dealer. Some features and limitations to find out about:
- Road hazards: If you run over a pothole, nail, or debris that damages the tire beyond repair, is the value of the tire covered?
- Expiration: How long is the tire covered? Three years? Five years? The life of the tire?
- Workmanship: Are both the tire and the quality of installation/repairs covered?
- Free services: Are regular inspections for wear, tire rotations and rebalancing included? What’s the cost to fix flats?
- Locations: How many stores will honor the warranty? The service warranty that comes with tires you buy at a dealer is an agreement with the dealer, not the manufacturer. A service warranty goes beyond the standard workmanship and material warranty you get from the company that made your tires. It can cover labor and free maintenance services. But your service warranty is good only at the retailer that sold you the tires. (If you’re weighing buying online, consider that if you get a flat, or a tire is defective, you have to get it off your vehicle and return it yourself.)
Find the right dealer and you don’t have to become a tire expert
Real professionals will be happy to talk your ear off about technical features — tread bars, siping, harmonic noise — or just give you the basic benefits of a tire in layperson’s language, your preference. Make sure they’re asking the questions above as a starting point. The answers will make the best choice obvious.
Do You Even Need a Spare Tire?
The fact that spare tires are no longer standard equipment on many newer-model cars can come as a nasty surprise when you get a flat tire. While most new light trucks and larger SUVs still come with a spare, here’s important news:
About 35 percent of vehicles now come from the factory without a spare tire.
Getting a flat tire is a major hassle and it can be costly. Here’s what to know about spares, including why more autos are coming without them, how to decide if you really need one and the upsides and downsides of inflator kits.
Which New Car & SUV Models Don’t Include a Spare?
On May 23, 2015, my 7-year-old granddaughter, my friend and I were stranded for four hours on I-84 west of Baker City, Oregon, with a blown-out tire and no spare. My brand new car did not come with a spare! I called my insurance emergency assistance four times. I waited for my insurance company to call and get a tow truck for about three hours. A local towing company wanted to charge me $530.00 to tow my car about 20 miles to Les Schwab in Baker City. I mentioned to the insurance agent that I wanted my car towed to Les Schwab so I could get a new tire. The insurance agent called Les Schwab and I spoke with Jake at the counter. Les Schwab came out with a new tire, changed it and we were back driving in about 30 minutes. I went back to the store and bought a spare. Thank you Les Schwab, you saved our day. Too bad the other businesses I dealt with on Saturday did not have your ethics for putting customers first. Thanks again for being there for us. You will be the first I call next time I need a tire changed, and I will recommend to my insurance company they need to put you on their call list.
– Penny M., Baker City, OR
The time to find out if your new or used car is going to come equipped with a spare is before you sign on the dotted line. Don’t rely on the sales staff to volunteer the news. It can be difficult to tell which models come with a spare and which don’t, since some trim levels will, but not all. Be sure by asking the sales rep directly. (And if you’ve recently bought a newer model car, be sure to check whether it has a spare, so you’re prepared with an alternative in case of a flat.)
Why Aren’t Some New Cars Coming With Spare Tires?
A bunch of factors are in play.
- Efforts to improve fuel efficiency. Removing the spare can reduce a vehicle’s weight by about 30 to 50 pounds, once you include the jack and wrench. It can also improve aerodynamics by reducing air drag from spare tire compartments that poke below the undercarriages of vehicles. These two factors can improve miles per gallon performance and help carmakers meet strict EPA standards for their full fleets, an attractive option for both car companies and energy-conscious drivers.
- Need for more space in smaller vehicles. A spare can take up significant room in compacts, sports cars and small sedans. There can be a trade-off between comfort and the space in small cars.
- Lack of storage space, especially in hybrids, diesels and electric vehicles. Batteries and emissions equipment for such vehicles sometimes now take up space where the spare used to go.
- Reduced manufacturing costs. Yep, a carmaker can save several hundred dollars by foregoing the spare in new cars.
What Are Alternatives to a Spare Tire? Are They Any Good?
Some new cars are coming from the factory equipped with tires or inflator kits that claim to make the spare tire unnecessary. There are upsides and downsides to all.
Run-flat tires are designed to allow driving for a limited distance after losing air from a typical puncture. They are built with either a reinforced sidewall or an internal support ring to carry the vehicle’s weight if the tire tread gets pierced. (The sidewall is the curbside face of the tire.)
Run-flats are made to travel from 10 to 50 miles under 50 mph when deflated, so you can get somewhere for service. Run-flats may also offer better control than standard tires when there’s a tire failure involving complete loss of air.
Downsides: Driving on a run-flat for even the shortest of distances will ruin the tire. It will have to be replaced. Plus, if you’re somewhere remote and get a flat, you may not be within range of the next tire repair shop.
Self-sealing tires have a lining coated with special sealant inside the tire. When an object on the road pierces the tread, the sealant material "surrounds" the hole. Then when a nail or other debris is removed, the sealant fills the full area.
Downsides: The self-sealing tire won't work if a puncture is more than about a quarter of an inch in diameter. They also don’t work for sidewall holes, so if an object goes through the tread to the sidewall you’re going to have a dead flat and won’t be going anywhere.
Inflator kits are a growing — but less-than-ideal — substitute to the spare tire. New autos with standard tires sometimes come with an aerosol seal kit. Such products offer a very temporary fix for minor tread punctures so you can get to a nearby tire store or service station for repairs.
Some are as simple as $10 canned products that plug small puncture holes by spraying sealant into the flat via the air-inflation valve and inflating the tire just a bit. Other tire-sealant kits include a small air cartridge and a replaceable container of sealant at a cost between $20 to $80.
Downsides: Tire sealant kits only work on small holes in the tread, and they don’t work at all for slits or holes in the sidewall.
Sealants also leave grime inside the tire that can affect your TPMS (tire pressure monitoring system), the safety equipment that alerts you if you’ve lost air in a tire. Any time you use a sealant you’ll need to have the TPMS sensors in your tires cleaned. And sealants can easily damage these sensors. You’re looking at a cost of $45 to $100 per tire if they need to be replaced.
When Is It OK to Go Without a Spare Tire? And Not?
If you’re buying a new car, here are five tips for deciding whether to get a model with no spare, based on where you live, what type of driving you’re doing, cost, safety and convenience.
- The freeway shoulder can be a dangerous place to change a tire. If you live in an urban area with 24-hour towing, and you’re doing mostly daytime driving, you may be good with no spare. Just be sure you have AAA towing service ($69 a year for the basic package), roadside assistance coverage included in your auto insurance policy, or one of the new, on-demand services. Without it, a standard tow (around 5 miles) will cost you an average $109, according to Angie’s List.
- Decide up front if you’re willing to go spare-less for the life of your vehicle. If you find yourself regretting your decision later, you’ll pay more for an aftermarket tire, jack and lug wrench (typically $150 to $300) than you do when the kit comes as original equipment on a new car. Plus, there may not be a space to safely carry them in your vehicle if you bought a spare-less auto model.
- If you take a lot of road trips, routinely drive in places with long distances between service stations, or travel a lot on rougher roads, you need a spare tire. Getting a flat in rural areas means you could be a hundred miles or more to the nearest repair shop. If it’s after business hours, you could be looking at being marooned for hours, paying for a hotel for a night (or more if it’s a weekend), leaving a vehicle loaded with gear or belongings on the side of the road, and paying a hefty towing fee over a long stretch of highway.
I lease my 2013 Hyundai. I came out after work to a flat tire. I opened my trunk and imagine my surprise when there was no spare tire. I called Les Schwab and they said they had a guy in the neighborhood and he would be right there. He came and put air in my tire and followed me to the nearest store. It was after closing, but they kept the bays open for me. They removed the screw from my tire and sent me on my way with no charge. Who does that? I am a fan and tell everyone I know!
– Peggy P., Sacramento, CA
- Get a spare tire if you travel with small kids, especially if you're taking occasional road trips. Getting stranded with a flat and no spare can mean several hours of waiting for a tow, even in an urban area. This is sure to be stressful for parents and possibly unsafe for tots, especially if it’s a really hot or frigid day.
- If you have medical needs that need daily attention, better have a spare.
Flat tires can be a major, costly hassle — or simply a slight inconvenience. Especially in the West, where distances between tire service can be long and lonely, a spare tire is the most cost-effective insurance that you won’t get stuck by the side of the road.
Does Hitting a Pothole Damage My Tires?
Hitting a pothole is never fun. But those holes in the road can do more than spill your latte. Potholes can puncture your tire or bend or crack your wheel. It can damage your tire’s sidewall or belts. Even a minor impact may knock your vehicle out of alignment. A pothole strike can damage your shocks or struts, or harm your suspension.
Give Your Vehicle a Quick Inspection
After hitting a pothole, check for any of the following signs of pothole damage.
- A bulge on the tire sidewall. This is an indicator that the tire was pinched between the edge of the pothole and the wheel causing the internal plies to be weakened or severed.
- Your steering wheel is no longer centered or the vehicle wants to pull to one side or the other. The impact may have been hard enough to affect the alignment or damage a steering or suspension component.
- You feel abnormal vibrations in the steering, seat or floor.
- You may hear a new noise when underway. Something may have been bent or displaced and could be rubbing on the tire/wheel assembly.
- A dashboard warning light appears.
How Badly Can Potholes Damage My Vehicle?
Hitting a pothole can cause bent wheel rims, internal tire damage, alignment problems, and shock and strut issues depending on the severity of the impact. This doesn’t necessarily mean you’ll puncture your tires or damage your vehicle, but if you have any concerns, get it inspected.
Below are some photos that show how potholes can damage wheels or rims.
When you take your vehicle to a tire technician or mechanic following a pothole impact, ask for an inspection that covers:
- Wheels/steering knocked out of alignment
- Damage to the tire’s steel belts
- Intact tire balancing weights
- Bent or cracked wheel rim
- Damage to shocks and struts
- Other broken suspension components
Tips to Minimize Pothole Damage
With summer and winter weather throughout the West impacting our roads, potholes are going to happen. Here’s what you can do to minimize the damage and possibly avoid these hazards.
- Always drive on tires that are properly inflated and in good condition. This will give you the best chance of absorbing the impact safely.
- Drive defensively. Slow down when you’re on an unfamiliar or rough road, and avoid distracted driving.
- Be alert to what’s ahead, and make sure you keep enough distance between you and the vehicle in front of you so you can avoid issues.
- Recognize that though you might miss the first pothole, there may be another waiting.
- When you can’t avoid a pothole, take your foot off the gas and hold your steering wheel tightly. Don’t brake. This will allow you to maintain the most control during the impact.
Les Schwab Has Experience with Pothole Damage
Our pros have seen plenty of pothole damage and can offer recommendations, including tire repair and replacement, alignment work, and more. Stop by your local Les Schwab for a free inspection. If you need new tires, wheels or alignment, we’ll help get you and your family quickly and safely back on the road.
Guide to Tire Pressure Monitoring Systems
Notice to our customers: Important changes affecting vehicles equipped with Tire Pressure Monitoring Systems have been put into place.Learn More
What Is a Tire Pressure Monitoring System?
TPMS stands for Tire Pressure Monitoring System. It is a feature on many late model vehicles that monitors tire pressure and warns the driver, with a light on the dash, if one or more of the tires’ pressure falls 25% below the original equipment manufacturer’s recommended tire pressure.
See the questions below to learn more about TPMS, and how to check if your vehicle is equipped with TPMS.
Why does TPMS exist?
As a result of tire-related safety concerns, Congress passed the TREAD Act in 2000. The TREAD Act requires vehicle manufacturers to install TPMS in new vehicles with a gross vehicle weight of 10,000 pounds or less.
What vehicles have it?
Passenger cars, SUVs, and light trucks. TPMS has been progressively introduced in new vehicles since 2005. Refer to your owner’s manual for more information.
How do I check to see if my vehicle has it?
When you start your vehicle, look at the dash for the TPMS warning lamp. If you see the warning lamp light up momentarily, your vehicle is equipped with TPMS.
What does it mean when the warning lamp is on?
The warning lamp should light up briefly when the vehicle is started. But if the light stays on, that means tire pressure is low in one or more of the tires, or the system is not able to read the sensors. In this case, you should have your tire air pressure checked. We provide this service for free at all of our Les Schwab locations.
What kind of maintenance is required on my TPMS?
Replacement or relocation of a TPMS sensor, or sometimes even just inflating a tire may cause the TPMS to get out of whack. Generally, recalibration is easy to perform: we provide this service to customers free at all Les Schwab Tire Centers.
Does this mean I don’t need to check my tire pressure?
Regardless of TPMS, we recommend tire pressure checks every 30 days. Properly maintained tire pressure decreases tire wear and improves vehicle safety, handling, braking and fuel mileage. Come in anytime for a free air check.
Use our Store Locator to find the Les Schwab nearest you.
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 Change a Tire
Changing a flat tire isn’t rocket science, but there are some important things to know to make sure you get that spare on properly in order to make it safely to the tire shop. Follow along as we show you, step by step, how to do it in this Les Schwab Quick Tips video. We cover:
- What to do before you get tools out.
- How to find the proper jacking point on your vehicle.
- How much to loosen lug nuts before lifting the car.
- How to make sure the spare goes on correctly.
- The proper order for tightening lug nuts.
How to Change a Tire
- Safety first. Keep clear of passing traffic, make sure your car is in park, set your parking brake and turn on your hazard lights. If there’s any doubt about whether you can stay out of harm’s way, it’s better to call roadside assistance.
- Check your owner’s manual. It should have tire-changing instructions, including the location of the jacking point.
- Get your spare and tools out. They are usually stored in a compartment inside the trunk. There should also be instructions on how to use the jack.
- Be sure the jack is positioned properly. Make sure it’s pointed the right way and placed in the proper jacking point on the vehicle.
- Loosen lug nuts about a one-quarter turn before jacking.
- Jack the vehicle up enough so the tire is not touching the ground.
- Remove the lug nuts, setting them somewhere where they won’t roll away.
- Pull the flat tire off, placing it underneath your vehicle behind the jack or, if it’s too wide to fit there, in another spot under the auto if possible. This is important in case the vehicle falls off the jack.
- Put the spare on, making sure the valve stem is facing you.
- Screw the lugs nuts back on by hand, finger tight.
- Lower the jack down until the tire contacts the road and is bearing some weight, but not all the way.
- Tighten the lug nuts in a star pattern, not a circle pattern, so the wheel gets seated snugly. This assures the wheel isn’t askew, and doesn’t then pop into the proper place while you’re going down the road, loosening some of the bolts and causing wobbling or worse — like the nuts breaking and the wheel coming off.