How To Tell What Type Of Tires You Have | Read The Sidewall

Your tire’s sidewall shows its size, service type, construction, load index, speed rating, and weather marking in one line.

If you’ve ever stood in the driveway staring at a tire and wondering what you’re even reading, you’re not alone. A tire sidewall packs a lot into a small space. The good news is that you do not need a shop scanner or a parts catalog to figure it out. In most cases, the answer is already molded into the rubber.

How To Tell What Type Of Tires You Have starts with one habit: read the full sidewall, not just the brand name or the wheel size. That single string of letters and numbers tells you whether you have passenger tires, light-truck tires, a temporary spare, winter-rated rubber, or something built for towing. Then the vehicle placard on the driver’s door confirms what the car was built to use.

How To Tell What Type Of Tires You Have From The Sidewall

The easiest place to start is the tire size line. It often looks like P215/65R17 99H. Each part has a job. Read it left to right and the tire starts to make sense fast.

• P = passenger tire
• 215 = tire width in millimeters
• 65 = sidewall height as a percentage of width
• R = radial construction
• 17 = wheel diameter in inches
• 99 = load index
• H = speed rating

The first letter is the fastest clue to the tire’s basic class. If the code starts with P, you have a passenger tire. If it starts with LT, it is a light-truck tire built for heavier loads and tougher duty. ST marks a special trailer tire. T often marks a temporary spare.

No letter at the front does not mean the code is wrong. Many Euro-metric passenger tires start with the width only, such as 215/55R17. That still points to a passenger-car tire. The service type is just written in a different style.

Start With The Letter, Then Read The Whole Job

Here’s where people get tripped up: “type” can mean more than one thing. The first letter tells you the service class. The tread name and symbols tell you what kind of driving the tire is built for. A tire can be a passenger tire and also be all-season. It can be a light-truck tire and also be all-terrain. Those are not competing labels. They stack together.

So if you want the full answer, pull two pieces from the sidewall. First, identify the service class from the size code. Then scan the rest of the sidewall for wording such as all-season, mud and snow, all-terrain, or run-flat.

What The Main Tire Categories Usually Mean

Once you know how the labels stack, the rest gets easier. A passenger tire is what most sedans, hatchbacks, crossovers, and many small SUVs run. An LT tire is common on pickups, work vans, and some larger SUVs. ST tires stay on trailers. A temporary spare is only for short-distance emergency use.

Tread category adds another layer. “All-season” is the default on many daily drivers. “All-terrain” usually shows up on trucks and SUVs that split time between pavement and rougher surfaces. “Mud-terrain” has larger tread blocks and a rougher road feel. Winter tires carry a snowflake-on-mountain symbol when they meet a winter traction standard. “All-weather” sits between all-season and winter use.

If you’re still unsure, compare the wording on all four tires. Mixed sets happen more often than people think. One axle may have a different model from the other, or the spare may follow a totally different code.

Marking You See	What It Tells You	What It Usually Means
P before the size	Passenger-car service type	Common on cars, crossovers, and many small SUVs
LT before the size	Light-truck service type	Built for heavier loads, towing, or tougher duty
ST before the size	Special trailer service type	Trailer use only, not for drive or steer axles
T before the size	Temporary spare	Short-term emergency use, often speed-limited
R in the size line	Radial construction	The standard construction on modern road tires
M+S	Mud and snow marking	All-season style tread, not the same as a true winter tire
3PMSF symbol	Three-peak mountain snowflake	Meets a winter traction test standard
XL or Reinforced	Extra-load casing	Can carry more load at the proper pressure
Run Flat, RFT, ROF, ZP	Run-flat marking	Can be driven for a limited distance after pressure loss

Use The Sidewall Symbols To Read Season And Duty

After the size line, scan for the words and symbols that tell you what kind of tire you’re dealing with day to day. The two weather markings people mix up most are M+S and the three-peak mountain snowflake symbol. M+S marks a tread pattern suited to light mud or light snow use. The mountain-and-snowflake symbol means the tire passed a winter traction test.

Then scan for duty markers. “XL” or “Reinforced” points to an extra-load tire. “Run Flat” or a brand-specific version of that wording tells you the tire can keep going for a limited stretch after a puncture, as long as the vehicle and tire were built for that setup. “Directional” or a rotation arrow means the tire must spin one way only.

You may also find the DOT code. The last four digits show the week and year the tire was made. A code ending in 2224 means week 22 of 2024. That is not the tire type, but it helps when you’re checking age while shopping for replacements.

Check The Vehicle Placard Before You Buy Anything

The tire sidewall tells you what is mounted on the car right now. The placard on the driver’s door tells you what the vehicle maker recommends. Those two things should match, or at least line up in load and size.

If the sidewall says one thing and the placard says another, trust the vehicle spec before spending money. NHTSA’s tire safety guidance points drivers to the tire placard and owner’s manual when choosing the right replacement size. That is the cleanest way to avoid buying tires that fit the wheel but do not fit the car’s load needs, ride height, or handling setup.

This step also helps with mixed markings. A used car may have one odd replacement tire, a temporary spare in the trunk, or truck-style tires added for looks. The placard cuts through that noise.

If You See This	You Likely Have	What To Check Next
P225/65R17 102H	Passenger all-purpose road tire	Model name for all-season, touring, or performance use
LT265/70R17 121/118S	Light-truck tire	Load range, towing needs, and pressure spec
ST205/75R15	Trailer tire	Trailer placard and axle rating
T135/80D17	Temporary spare	Speed limit and distance note on the sidewall
M+S only	All-season style tire	Tread pattern and brand model name
3PMSF symbol	Winter-rated or all-weather tire	Model name and whether all four match

Common Mistakes That Lead To The Wrong Call

A few slip-ups cause most of the confusion:

• Reading only the wheel diameter and ignoring the rest of the size line
• Mixing up service type with tread category
• Assuming M+S means the same thing as a winter tire
• Buying by sidewall pressure alone instead of using the door placard
• Forgetting that the spare may use a different code from the four road tires
• Ignoring load index and speed rating when replacing a worn tire

The clean fix is simple. Read the first letters, read the size line, scan for weather and duty markings, then compare that to the placard. That gives you a full read on what you have in a few minutes.

A Five-Minute Garage Check

1. Turn the front wheels so the full sidewall is easy to read.
2. Write down the complete code from one front tire and one rear tire.
3. Circle the first letter or letters: P, LT, ST, T, or no prefix.
4. Find any extra wording such as all-season, all-terrain, run-flat, XL, or M+S.
5. Check for the three-peak mountain snowflake symbol.
6. Open the driver’s door and compare the tire size on the placard.
7. Make sure all four road tires match unless the vehicle was built for a staggered setup.

Do that once and you’ll know whether you have standard passenger tires, truck tires, trailer tires, a temporary spare, or a winter-rated set. You’ll also know what to ask for when it’s time to replace them, which saves money and cuts out a lot of guesswork.

When The Markings Still Feel Confusing

If the code looks odd, the tire may be older, imported under a different sizing style, or mounted on a vehicle with a non-stock setup. In that case, compare all four tires, check the placard, and read the brand model name on the sidewall. Those three clues usually settle it. Once you know how the markings stack, the sidewall stops feeling like gibberish and starts reading like a label.