Understanding tire sidewall markings

Do you have trouble understanding sidewall markings on your car’s tires? If yes, don’t worry!

This guide provides a complete explanation of tire sidewall markings and their importance. You will learn why it is essential to check your car’s tire’s regularly and understand all the symbols that appear on the sidewall.

Let us begin our journey to learn more about tire sidewall markings!


Tire sidewall markings provide a great deal of information about the tire construction, size, purpose and manufacturer. Having an understanding of what these figures mean is essential when shopping for car tires. In this guide, we will review the basic features and specifications of tire sidewalls to help you become more informed and make the best choice for your vehicle.

In addition to reviewing sidewall markings in general, we will also cover the types of tires available and their specific markings that have to do with treadwear ratings, tire directions (mounting) as well as traction and temperature ratings. Further engaging in this study will equip drivers with an overall better understanding of what their cars need so they can achieve maximum performance on all kinds of terrain.

Explanation of the importance of understanding tire sidewall markings

Tire sidewall markings are the most visible part of a tire and are used to identify, classify and provide information on individual tire models. Properly understanding them is important in order to know your best option(s) when purchasing a new tire and also to help ensure you’re maintaining appropriate tire ratings for your specific vehicle.

The sidewall markings provide details about the tire’s load index, speed rating, overall diameter, width, construction type and maximum inflation pressure. All these parameters can be useful when selecting a replacement or when evaluating an existing set of tires. Let’s take a closer look at each of them:

Load Index: The load index indicates the maximum amount of weight the tire is capable of carrying safely as assigned by the Department of Transportation’s Tire and Rim Association. It’s usually given as a number (for example: 78).

Speed Rating: This code indicates the maximum speed at which the tire can safely carry its rated load and is usually given as a single letter (for example: S or T).

Width: The width refers to how wide your tires are in millimeters (mm), not including any raised tread sections or decoration (for example: 205).

Construction Type: The construction type states how the various layers that make up your tires are put together (for example radial/radial or bias belted/radial) . This should always be checked with each new set of tires purchased.

Maximum Inflation Pressure: The minimum recommended inflation pressure for your tires, normally expressed as “psi” (pound per square inch). If you over-inflate beyond this level it could cause serious damage down to loss of vehicular control due to over-inflation.

Tire Size

Tire sizes are marked on the side of all passenger car tires. The size can also be written on the tire itself but can vary from manufacturer to manufacturer. Every tire size is composed of a string of letters and numbers that tell you the type, width, aspect ratio, construction type, wheel size, load index and speed rating.

Type: This tells you whether the tire is made for high performance or winter driving. Example: P for Passenger car or LT for Light Truck

Width: This is the width of the tire in millimeters from sidewall to sidewall. Example: 215mm (measured tread width)

Aspect Ratio: This is the height of a tire’s sidewall expressed as a percentage of its section width. Example: 65 (the sidewall height of 65%)

Construction Type: This identifies whether your tire has radial cords or bias cords (diagonal). Example: R for radial construction or D for diagonal bias ply

Wheel Size: This identifies the size of wheel it fits on in inches. Example 15” Wheel Spread

Load Index & Speed Rating- The load index indicates how much weight can be supported by a single tire when properly inflated, while speed ratings represent how fast a given makes and model can safely travel at peak performance depending on road conditions. Load Index examples- 91 Load Index Speed Rating example- H (Up to 130 mph/ 210 kph )

Explanation of how to read tire size markings on sidewalls

The sidewalls of any tire will bear a variety of different markings. These markings are codes that provide essential information that you need to understand in order to make the right decisions when it comes to buying tires. Here’s an explanation of how to read what can seem like an intimidating jumble of numbers and letters.

Most tire sidewall markings start with a letter, P or LT, followed by a string of numbers. The first number following the letter refers to the width of the tire in millimeters. The second number refers to the aspect ratio, which is expressed as a percentage and indicates the relationship between the height of sidewall and width. Next is another letter that signifies construction — R for radial — plus a two- or three-digit number indicating wheel diameter in inches. Finally, there’s another letter representing the load index and another for speed rating.

In some cases, light truck tires have additional letters following these specifications indiating other features such as extra load capacity or traction ratings. For example, Q marks all-season tires; T marks temporary-use spares; ZR is used for high-performance tires; LT indicates light truck applications; Winter Tire symbols include M&S for mud & snow and M+S for mud + snowwith Symbol mountain snowflake outline (3PMSF). Some tires also include max inflation pressures expressed in psi (pounds per square inch). Be sure to cross reference that information with your vehicle manufacturer’s recommendations when shopping for a new set or individual tire replacement.

Finally, don’t forget other important details like rim size as well as UTQG ratings (treadwear, traction performance , temperature resistance ) – which provide guidance on potential tread life and may help inform ultimate purchase decisions.

Overview of the information provided in tire size markings (width, aspect ratio, rim diameter, etc.)

Tire size markings provide important information regarding the size, rim diameter, type and load rating of a tire. All this information is labeled on the sidewall of the tire in either metric or inches. The numbers indicate the width, aspect ratio, rim diameter and capacity of the tire. This information enables motorists to select a suitable replacement tire for their vehicle and helps to ensure that it is compatible with their drivetrain and suspension components.

The tire width is indicated by a 3-digit number on the lower left portion of the sidewall. This number represents the section width in millimeters when measured from one sidewall to another (across the tread). The aspect ratio is indicated by a 2-digit number following an “R” symbol which can be seen beside it on wider tires; this designates that profile or sidewall height as a percentage of its respective width.

Next you will find two digits indicating rim diameter in inches that identify both wheel size and load index rating for proper fitment of aftermarket rims for your vehicle; also noted are symbols for radial & directional tires along with speed rating designation codes such as ‘H’ or ‘V.’

Even more details can be found regarding overall body construction & depth/groove angle via segmented line markings (‘SL’= symmetric performance) or mesh pattern indication reveals unique handling characteristics : whether summer or winter drivability etc.. These give an indication of how a specific tire may act under certain conditions -Heat Resistance & Wet Traction Grades further help you make an informed decision when selecting your next set of tires.

The Source - Explain My Tire Sidewall Markings

 Speed Rating

Speed ratings indicate the maximum speed at which a tire can carry a load while being properly inflated. Speed rating is expressed by a letter, ranging from A (the lowest) to Y (the highest). It is important to check the vehicle manufacturer’s specifications for your vehicle for the appropriate speed rating for your tires. The benefit of knowing this is that it will help you select a tire that has more than enough capacity to meet your performance needs. Here’s a list of common speed ratings used:

-L (75 mph)

-M (81 mph)

-N (87 mph)

-P (93 mph)

-Q (99 mph)

-R (106 mph)

-S (112 mph)

-T (118 mph)

-U (124 mph)

-H (130 mph)

-V (149mph)

-W (168mph)

-W (168mph)

-Y (186mph)

Explanation of how to read speed rating markings on sidewalls

Understanding the speed rating markings on your tire’s sidewall is an important step in selecting the right tire for your vehicle and driving style. The speed rating indicates how fast the tire can safely go, with higher numbers representing faster speeds. It is important to use a tire with a speed rating that matches or exceeds the manufacturer’s recommendation for your specific vehicle.

Speed ratings use codes of one or two letters (such as “Q” or “H”). These ratings may appear immediately following the tire size markings on your sidewall, and will indicate the maximum sustained velocity of your tires in either kilometers per hour (kph) or miles per hour (mph). Some examples of speed rating codes include:

  • Q – up to 160 kph/100 mph
  • R – up to 170 kph/106 mph
  • S – up to 180 kph/112 mph
  • T – up to 190 kph/118 mph
  • U – up to 200 kph/124 mph
  • H – up to 210 kph/130 mph
  • V – up to 240 kph/149 mph

It is very important that you choose a tire with an adequate speed rating for your vehicle and driving style, as exceeding the appropriate speed limit could cause improper handling resulting in an accident. Pay attention to both the code used as well as its specific meaning when shopping for new tires.


Overview of the information provided in speed rating markings (maximum speed capability of the tire)

The maximum speed capability of the tire, as indicated by the last characters of the tire size code, is provided in a single letter or a combination of the letters Q and S. The letter or letters correspond to a specific speed which identifies the tires performance and maximum recommended speed for safe operation. For example, a tire durometer marked with “P215/65R15 95S” indicates that it has a speed rating of 95 mph (153 km/h).

The majority of passenger car tires have been assigned speed ratings from S (112 mph / 180 km/h) up to Y (186 mph / 300 km/h) with most today falling in the range of T to H. These range from 118 mph / 190 km/h up to 130 mph / 210 km/h respectively.

Passenger car tires intended for higher speeds such as H-rated, V-rated, Z- and even W-speed rated tires are generally intended for higher performance vehicles such as luxury automobiles with much more powerful engines than your average family car. So before you buy a high-speed rated tire, make sure it’s appropriate for your vehicle.

It is important to note that while manufacturers design their tires to handle certain speeds under ideal conditions; they do not in any way guarantee that driving at these speeds is safe or legal on public roads. Always obey posted speed limits and drive safely according to changing road conditions.

Load Index

An essential part of understanding how your tires are constructed is decoding the load index. The load index indicates the maximum amount of load your tire should be able to meet or exceed when properly inflated. It is important to use a tire that matches the load shown for your vehicle on its tire placard, which is usually located on the driver’s side door jamb or glove box.

The load index rating typically begins with an alphabetic character marking from 75 through 137, with numbers from 75 to 99 representing individual pounds in increasing increments while 100–137 is interpreted slightly differently depending on whether it’s used in Europe or North America.

Explanation of how to read load index markings on sidewalls

When you buy a new set of tires, it’s important to understand the tire sidewall markings. These are the letters and numbers that can be found on the tyre walls and allow you to determine various characteristics about the tire. One of these is known as the load index, which provides information on how much weight each tire is designed to support.

The load index for a tire can be found inside a pair of numbers and/or letters located directly after the aspect ratio. This code conveys information on how much weight your tires can hold. It is directly related to the Maximum Load Rating (MLR) stamped on the sidewall, which is represented in kilograms or pounds of force (kPa). To make your job easier, we have provided an index below that explains each possible rating associated with a particular code.

For example, if there is an 80 next to your aspect ratio, then this relates to a maximum load capacity of 450 kgs (992 lbs.). If you see an ‘LT’ next to your aspect ratio, this stands for light truck and usually means the maximum load rating varies depending on rim size — consult with our experts to get up-to-date advice here.

Load Index Rating:

0 – 454 kg/1000 lb : 53

5 – 505 kg/1100 lb : 54

6 – 556 kg/1215 lb : 55

7 – 608 kg/1350 lb : 56

8 – 661 kg/1460 lb: 57

9 – 714 kg/1570 lb: 58

10 – 767 kg / 1690 lb: 59

Overview of the information provided in load index markings (maximum weight capacity of the tire)

The load index on your tires is an important numerical code that indicates the maximum amount of weight your tire can support when properly inflated. It is important to match the load index of your vehicle to the tires being installed on it to ensure safe operation.

The load index is usually located in the sidewall markings of a tire and refers specifically to the theoretical maximum weight capacity of a single tire or axle; not its entire vehicle combination or total capacity. Load indexes range from 0-255, with higher numbers indicating greater weight capacity.

How To Read Tire Sizes & Sidewall Markings Like a Pro | TractionLife


It’s important to consult your owner’s manual or speak with your mechanic to find out what kind of tires are right for your car. In general, most cars require tires that have sufficient load and speed ratings and may need specific tire sizes or types in order to perform optimally.

It is also important to pay attention to the expiration date of your tire. Most tires have a lifespan of up to six (6) years regardless of how many miles you put on them, so make sure you check for the expiration date before you buy a new set.

Finally, knowing how to decode the sidewall markings from your tire can help you stay informed about the specifications and care instructions for every set. The sidewall markings contain useful information such as speed rating, load index, tire size, and more. With this knowledge at hand, it will be easier for drivers and car owners alike to pick out the perfect set of tires for their vehicle.

Recap of the importance of understanding tire sidewall markings

When it comes to keeping your car running smoothly and safely, understanding tire sidewall markings is of the utmost importance. The sidewall markings list important tire related information such as speed rating ratings, load index, size designation, as well as the manufacturers brand and logo. Knowing this information can help you get the best performance out of your tires while helping you to make sure they are operating at their peak efficiency.

It is essential to verify that the wear on your tires is uniform and that they are providing good road-holding ability. The primary wear indicators on a tire’s sidewall show you how much life is left in your tires. It is important to remain aware of these indicators in order to ensure safety and prevent an accident or unnecessary damage to your vehicle. In addition, selecting a tire with a recommended or approved speed rating will help ensure proper performance no matter what type of driving you do.

It’s also wise to reference the load index when selecting a replacement tire because it communicates how much load capacity a given tire can handle at its maximum inflation pressure , allowing you to select one that meets or exceeds your vehicle manufacturer’s recommendations. Understanding all these features printed on a tyre allows us to make an informed decision when buying any new set of tyres for our vehicles and keeps us safe while driving our vehicles on roads every day.

Encouragement to use this knowledge to make informed decisions when selecting tires for your vehicle.

Making an informed decision when selecting tires for your vehicle is important as the wrong type and size can create multiple safety issues. Understanding tire sidewall markings can help you navigate the many tire options available so that you select the best option for your vehicle. Knowing what each of the numbers and letters indicate can assist in purchasing tires that meet specific speed, load, wear and traction ratings for your make and model of car. It is essential to consult a professional before making any decisions about tires, as there are significant safety concerns associated with incorrect tire choices.

By recognizing the information presented on a tire’s sidewall, you can more easily compare different types and brands of tires according to size and ratings for maximum performance on dry or wet roads; resistance to aquaplaning; concentration on steering precision; brake appearances; fuel economy/low rolling resistance to reduce operating expenses as well as treadwear guarantee/warranty periods from manufacturers. All this is symbolised by individual codes which appear around the tread area that identify the type of tyre along with PSI (pounds per square inch) pressure recommendations according to load carrying capacity and inflation levels. Each digit refers to specific characteristics such as width, type of construction, radial or bias ply, rim diameter recommended and speed rating. Combined with other letters shown on sidewalls such information equips you with all necessary facts concerning tire maintenance before changing them over when necessary.

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