Decoding tires on a car: what do the numbers and letters on tires mean?

Have you ever taken a close look at the sidewall of a car tire? At first glance, it looks like a chaos of numbers, letters and pictograms. But in fact it's a whole characteristics language, which tells about the wheel size, its load capacity, maximum speed, seasonality and even date of birth. Without being able to “read” these markings, you risk buying tires that do not fit your car, or driving on worn tires that pose a safety risk.

In this article we will look at every letter and number on the tire - from standard designations to rare symbols that manufacturers encrypt for professionals. You will learn how to distinguish winter tires from all-season tires by markings (spoiler: it’s not always a snowflake!), what load index 91T and why tires with the same diameter may not fit your car. And also - how to check if what you are looking at is not a fake, simply by looking at the production date.

The material will be useful for both beginners who are choosing tires for the first time, and experienced drivers who want to understand the intricacies. Waiting for you at the end FAQ with answers to the most frequently asked questions and interactive widgets to test your knowledge. Let's start with the most important thing - the basic structure of labeling.

1. Basic marking structure: what do numbers like 195/65 R15 mean?

The most noticeable inscription on a tire is its size, for example, 195/65 R15 or 205/50 R17. These numbers determine whether the tire will fit your car. Let's look at them in order:

• 📏 195 — tire profile width in millimeters. The higher the number, the wider the tire (and the better the grip, but the higher the fuel consumption).
• 📉 65 — profile height as a percentage of the width. In our example, this is 65% of 195 mm. Low profile tires (for example, 40 or 35) look sportier, but have worse shock absorption.
• 🅱️ R — type of cord construction (radial). Almost all modern tires are radial, so the letter R does not mean "radius"!
• 🔢 15 — disk diameter in inches. This is a key parameter: if your wheel is 16 inches, you won’t be able to install a 15-inch tire.

Important: sometimes after R you can see the letter C (for example, 195/70 R15C). This means reinforced tire for commercial vehicles (minibuses, vans). Such rubber can withstand greater loads, but is harder to the touch.

Manufacturers sometimes add additional designations after the main size:

• 🔄 LT (Light Truck) - a tire for light trucks or SUVs.
• 🚗 P (Passenger) - a tire for passenger cars (rare, usually the size does not have a letter).
• ⚡ XL or Reinforced — reinforced tire with increased load capacity.

2. Speed and load indices: what do the letters 91T or 88H hide?

Next to the tire size, two key parameters are always indicated - load index (digit) and speed index (letter). For example, 91T or 88H. These designations indicate what maximum load the tire can withstand and at what speed it can be operated.

Load Index is a conditional number that corresponds to the maximum weight (in kg) per wheel. For example:

Index	Max. load (kg)	Example car
80	450	Small hatchbacks (eg. Daewoo Matiz)
88	560	Mid-size sedans (Toyota Corolla, Hyundai Solaris)
91	615	Crossovers and station wagons (Kia Sportage, Skoda Octavia)
100	800	SUVs and minibuses (Toyota Land Cruiser, Ford Transit)
120	1400	Trucks and motorhomes

Important: load index must be no lower what the car manufacturer recommends. You can exceed it (for example, install tires with index 95 instead of 91), but not lower!

Speed index shows the maximum speed at which the tire retains its properties. Here is a breakdown of the most common letters:

• 🐢 L — up to 120 km/h (for commercial vehicles).
• 🚗 T — up to 190 km/h (the most common for city cars).
• 🏎️ H — up to 210 km/h (sports sedans, crossovers).
• ⚡ V — up to 240 km/h (premium and sports cars).
• 💨 W - up to 270 km/h (supercars, for example, Porsche 911).
• 🚀 Y - up to 300 km/h (exotic sports cars like Ferrari or Lamborghini).

⚠️ Attention: If the speed index is indicated on the tire W or Y, but you drive a regular sedan, this does not provide advantages. But such tires are more expensive and wear out faster. Choose an index that corresponds to actual operating conditions.

3. Seasonality: how to distinguish winter tires from summer tires by markings

One of the most important parameters is tire seasonality. Manufacturers use several ways to indicate what time of year the tires are intended for:

• ❄️ Winter tires:
  • Snowflake against a mountain background (mandatory sign for Europe, 3PMSF — Three Peak Mountain Snow Flake).
  • Inscription Winter, Snow or M+S (Mud and Snow - mud and snow).
  • Tread pattern with deep sipes (microgrooves).
• ☀️ Summer tires:
  • Missing snowflake and inscription Winter.
  • Inscription Summer or Road (rare).
  • Less deep tread with a harder rubber compound.
• 🌍 All-season tires:
  • Inscription All Season, Any Weather or 4Season.
  • May have a snowflake 3PMSF, but not always.
  • Compromise tread (not as deep as winter ones, but with more sipes than summer ones).

All-season tires marked 3PMSF (snowflake) are legally considered winter tires in Russia and Europe, but in fact they are inferior to specialized winter tires on ice and snow. If you drive on snowy roads, it is better to choose full-fledged winter tires.

One more nuance: the inscription M+S (Mud and Snow) does not guaranteethat the tire is winter! This is simply an indication that the tread is adapted for mud and snow. In Europe, since 2018, a sign is required for winter tires 3PMSF (snowflake).

What happens if you drive on summer tires in winter?

Summer tires at temperatures below +7°C lose their elasticity, “tan” and lose traction. The braking distance increases by 1.5–2 times, and the risk of skidding on ice or snow grows exponentially. In Russia, a fine of 500 rubles is provided for driving on summer tires in winter (December–February) (Article 12.5 of the Administrative Code).

4. Date of manufacture: how to find out the age of a tire and why it is important

Even if the tire has never been used, it has expiration date. Rubber ages: rubber loses elasticity, microcracks appear, and grip deteriorates. The production date is looked for on the sidewall of the tire - this is a four-digit code in an oval, for example, 2523.

Explanation:

• 2523 = 25th week of 2023.
• 0819 = Week 8 of 2019 (February 2019).

The first two digits are the week, the last two are the year.

⚠️ Attention: Most manufacturers recommend replacing tires after 5–6 years from the production date, even if the tread has not yet worn out. For winter tires this period is reduced to 4 years - due to the softer rubber composition.

Where to look for the date?

• On the inside of the tire (wheel side).
• Sometimes on the outer sidewall (if the tire is new and not installed).
• If the code is erased, this is a reason to be wary: the tire may be old or counterfeit.

How to check the authenticity of a date? On new tires the code is stamped clearly, without blur. If the numbers are barely visible or look overdrawn, you may have relabeled (i.e. fake) rubber. You should also be wary if the production date too fresh (for example, the current year, but the tire is in stock at a promotional price) - this may be a sign of counterfeit.

5. Additional symbols: what do Tubeless, RunFlat or Rotation symbols mean?

In addition to the basic parameters, you can find a lot of other symbols on the tire. Some of them are critical, and some are just marketing. Let's look at the most useful ones:

Designation	Decoding	Importance
Tubeless	Tubeless tire (modern standard).	⭐⭐⭐
Tube Type	The tire requires a tube (rarely found, for example on bicycle or retro tires).	⭐⭐
RunFlat (or RFT, SSR)	A tire with reinforced sidewalls that allows you to drive up to 80 km when punctured (at speeds up to 80 km/h).	⭐⭐⭐⭐
Rotation + arrow	Directional tire: The arrow indicates the direction of rotation.	⭐⭐⭐⭐
Outside/Inside	Asymmetrical tire: Outside - outer side, Inside - internal.	⭐⭐⭐⭐
Reinforced or XL	Reinforced tire with increased load capacity.	⭐⭐⭐

Particular attention should be paid directional and asymmetrical tires:

• 🔄 Directed (with the inscription Rotation) must be installed strictly in the direction of the arrow. If installed incorrectly, water will not be effectively drained from the contact patch, which will lead to hydroplaning.
• 🔀 Asymmetrical (with inscriptions Outside/Inside) have different tread patterns on the inside and outside. When installing Outside should be outside Inside - inside.

If there is an inscription on the tire RunFlat, remember:

• ✅ You can drive on a punctured tire up to 80 km (but not faster than 80 km/h!).
• ❌ Not all tire shops know how to work with such tires - they are more difficult to board.
• ⚠️ After the puncture RunFlat- the tire cannot be repaired - only replaced!

Examine the production date (no older than 3–4 years)

Check availability of 3PMSF snowflake for winter tires

Make sure the load and speed index are not lower than the recommended ones

Inspect the sides for cracks or blisters

Check the direction of rotation (for directional tires) -->

6. Tread and Wear: How to Read the Indicators and Why Depth Is Important

Tread depth is not just a number, but guarantee of your safety. The following regulations apply in Russia (traffic regulations, appendix 1 to PTS):

• ❄️ Winter tires: minimum tread depth - 4 mm.
• ☀️ Summer tires: minimum depth - 1.6 mm.
• 🌍 All-season tires: as for summer tires - 1.6 mm, but experts recommend changing at 3 mm.

How to measure depth? Use wear indicators — small protrusions in the tread grooves. When the tread wears down to their level, it's time to change the tire. You can also use a coin:

• Insert the 10-kopeck coin into the protector with the eagle facing down.
• If you see the top of the eagle’s head, the tread is less than 4 mm (for winter tires this is critical wear).

Manufacturers often add to tires Colored wear indicators:

• 🟢 Green - new protector (depth 6–8 mm).
• 🟡 Yellow - medium wear (3-4 mm).
• 🔴 Red - critical wear (less than 2 mm).

⚠️ Attention: If the tire appears cracks on the sides or swelling (hernia), it needs to be replaced urgently, even if the tread is normal. Such defects can lead to a wheel explosion at speed!

Some tire models have asymmetrical wear, which talks about problems with the car:

• 🔍 Edge wear - low pressure in the tire.
• 🔍 Wear in the center - high blood pressure.
• 🔍 Sawtooth wear - problems with wheel alignment.
• 🔍 Local “spots” of wear - wheel imbalance or suspension damage.

7. Brands and technologies: what do labels like ContiSilent or Michelin Pilot mean?

Tire manufacturers often add the names of their technologies or series to the sidewalls. These inscriptions help to understand what features a particular model has. Here are the most common:

• 🔇 ContiSilent (Continental) - a tire with an additional layer of polyurethane foam to reduce noise.
• 🛡️ Michelin Pilot — sports series with improved grip at high speeds.
• ❄️ Nokian Hakkapeliitta - legendary winter tires with studs or Velcro.
• 🌊 Bridgestone Turanza — series for wet roads with improved water drainage.
• 🏜️ BFGoodrich All-Terrain — off-road tires for off-road use.
• 🔋 Goodyear ElectricDrive — tires optimized for electric cars (low rolling resistance).

You can also find symbols on the tire country of origin:

• Made in Germany - often found on premium tires (Continental, Michelin).
• Made in Russia - factories Nokian, Cordiant, Kama.
• Made in China - budget brands (Triangle, LingLong), but also some models Goodyear or Pirelli produced in China.

Important: country of origin does not always determine quality. For example, Nokian in Russia it produces tires using the same equipment and according to the same standards as in Finland. But little-known Chinese brands can save on rubber composition.

Another useful marker is DOT number. This is a unique bus identifier, which consists of:

• Manufacturer's code (first characters).
• Size range and models.
• Production date (last 4 digits, as we discussed earlier).

Using this number, you can check whether the tire is listed in a recall campaign (for example, on the manufacturer’s website).

FAQ: Answers to frequently asked questions about tire markings

❓ Is it possible to install tires with different speed indexes?

Technically possible, but not recommended. If the front axle has tires with the index H (210 km/h), and on the rear - with T (190 km/h), this worsens handling. In an emergency situation (for example, during sudden braking), the rear axle may lose traction before the front, which will lead to a skid. It is optimal that all four tires have the same speed index.

❓ What does the inscription mean Max Pressure on the bus?

This maximum permissible pressure in the tire (usually indicated in kPa or PSI). For example, Max Pressure 350 kPa (51 PSI). This value must not be exceeded - the tire may explode. However, you shouldn’t drive at maximum pressure: this worsens comfort and tread wear. The optimal pressure for your car is indicated in the owner's manual or on a sticker on the driver's door pillar.

❓ How to understand that a tire is studded?

Studded tires have several markers:

• Inscription Studded or Studdable (if the studs are not installed, but you can add studs).
• Tread pattern with holes for studs (even if they are not inserted).
• Sign M+S or snowflake 3PMSF (but this is not a guarantee of thorns - it could also be Velcro).

In Russia, studded tires can be used with October to April (times may vary in some regions).

❓ What to do if there is no production date on the tire?

No date - serious cause for concern. Possible reasons:

• Tire fake (counterfeit).
• The date has been erased (perhaps the tire is very old or was stored in aggressive conditions).
• Tire restored (relabeled after restoration).

Such a tire no place on your car — the risk of tread tearing or peeling is too high.

❓ Is it possible to drive on tires with different tread patterns?

This is not prohibited by law, but highly undesirable. Different tread on the axles leads to:

• Unpredictable handling (especially on wet roads).
• Accelerated wear of suspension elements.
• Risk of skidding when braking.

It is allowed to install different tires only in emergency cases (for example, to temporarily install a tire), but on an ongoing basis, all four tires must be the same or at least paired on the same axle.