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Once you have determined it’s time to buy tires, you’ll need to know what size tires are correct for your vehicle. Depending on what you drive, you may be interested in how to find the right tire for your…
This information is usually inside your car’s doorjamb, in your owner’s manual. To ensure your current tire or a replacement tire you may be looking at matches your vehicle’s requirements, it will be good for you to understand how tire sizing works. You may have never paid attention to the string of numbers and letters on every tire, but it’s a gold mine of information.
If you’re unsure of how to read tire measurements from your tire walls, the information and graphics below will tell you how to read tire size, understand and interpret it. If you decide you want to substitute a new size or tire type, consult an authorized tire retailer who can expertly advise you, because many optional tire sizes may have different load capacities and could require wheels of a different rim width or diameter and different inflation pressure.
Not sure you need new tires? Our Tire Replacement Guidance article will help you determine whether it’s time to retire your tires.
Most passenger cars, SUVs and light pickups (1/2 ton and smaller) will come with tires that are either P-Metric or Euro-Metric. For P-Metric tires, you’ll see the letter “P” before the number sequence begins: P225/70R16 97H. P-metric is a designation standardized by the Tire and Rim Association for a “passenger car” tire type. For Euro-Metric there will be no preceding letter before the number sequence begins: 225/70R16 98H. Euro-Metric is a designation standardized by the European Tyre and Rim Technical Organization for a “passenger car” tire type.
Both P-Metric and Euro-Metric size tires are designed to primarily be used on passenger vehicles, which can include cars, minivans, SUVs, and other light duty pickup trucks.
If your vehicle is an SUV, Pickup truck or van, you might see a different type of size designation on your placard that is specific for heavy duty light trucks and vans, especially common on ¾ ton and larger pickup trucks and vans. There are two common size types in this category, LT-Metric and Euro-Metric Commercial (aka C-type). Both size types are metric and so use the same structure as P-Metric and Euro-Metric but have some different characters in the size that differentiate them from their passenger car cousins. LT-Metric tires will have the letters “LT” before the size number sequence: LT245/75R17 119/116R Load Range E. Notice that there are two load index numbers and a Load Range, see the section on Load Index for more info. LT-Metric is a designation standardized by the Tire and Rim Association for a “light truck” type tire.
Euro-Metric Commercial or C-Type tires will look very similar to a passenger Euro-Metric size except that there will be a “C” right after the rim size: 23/65R16C 121/119R. Notice that the C-type tires also have two load index numbers. Euro-Metric Commercial, or C-Type is a designation standardized by the European Tyre and Rim Technical Organization for a light truck type tire. Light truck tires are designed to be used on vehicles capable of carrying heavy cargo and are usually only specified by a vehicle manufacturer on vehicles exceeding a certain load capacity.
Other types of tires that fall into the Metric sizing type are Temporary Spares, they start with “T”. If you see a size that starts with “ST,” that means “special trailer” and is only for use on a trailer.
Regardless of whether you are looking at a P-Metric, Euro-Metric, LT-Metric, Euro-Metric Commercial, T or ST tire the numbers in the size mean the same thing.
The first number to appear in your tire size information is the width, in millimeters, of the correct tires for your vehicle: P225/70R16 91S.
Tire width always refers to the measurement from one sidewall to another. Thus, a tire with the measurement “P225” is for a passenger vehicle and has a nominal width of 225 millimeters.
After the slash mark, the next number you see is for the tire’s aspect ratio, which essentially tells you how tall your tire’s profile is: P225/70R16 91S. Aspect ratios are delivered in percentages. Tire makers calculate the aspect ratio by dividing a tire’s height off the rim by its width. If a tire has an aspect ratio of 70, it means the tire’s height is 70% of its width.
Lower aspect ratio tires, such as a 60 series, generally offer vehicle handling performance advantages over higher aspect ratio tires, such as a 75 series, but a typical trade off can be ride harshness.
After the aspect ratio comes a letter that indicates the type of internal construction maintaining your tire’s stability: P225/70R16 91S.
There are two types of construction that you may see on the sidewall of a tire:
Radial tires are the most common tires on the road in the United States today; thus “R” will usually be shown in the tire size designation. Radial construction means the tire’s internal ply cords are oriented in a radial direction, from one bead over to the other, essentially perpendicular to the direction of rotation. You may also occasionally see RF indicating a run flat tire or ZR indicating a tire that is a speed rating higher than V.
The next number is the diameter code, in inches, of the rim onto which the tire can be mounted. For example, a tire with the P225/70R16 91S would fit a rim with a 16-inch diameter.
Load index can be a confusing subject because there are so many different caveats, but we will try to explain everything here.
The next figure after the rim size in the sequence is your tire’s load index, which tells us how much weight, in pounds, the tire can support when fully inflated: P225/70R16 91S
We call it the load “index” because the number doesn’t tell us the precise number of pounds the tire can carry, at least not by itself. However, the number does correspond to a specific load capacity listed in an index. Beginning with 1 and ending with 150, numbers in the load index represent carrying capacities of 99 to 7385 lbs.
There are two types of load types for passenger tires though, Standard Load and Extra Load. If a tire is Standard Load there will be no markings indicating it but if it is Extra Load the letters XL will appear after the size and load index.
Standard Load Euro-Metric: 215/55R17 94V
Extra Load Euro-Metric: 215/55R17 98V XL
Passenger car tires like P-Metric and Euro-Metric will only have one load index number where LT-Metric and Euro-Metric Commercial (C-Type) will have two numbers separated by a slash.
The first number is the load index if the tire is used in a single application, the second number is the load index if the tire is used in a dual application. Passenger type tires cannot be used in a dual application. Light truck tires will also have a Load Range that is indicated by a letter, such as Load Range E. Load Range is an older term that is still commonly used in the industry so you may hear your tire dealer reference it but the load index numbers are the best way to ensure you have the proper tire.
One important but often misunderstood facet about load index is that the load index numbers between standards organizations (P-Metric vs Euro-Metric) are not necessarily on the same scale. Meaning that two tires in the two different systems that have the same load index number could have different maximum load capacities. This is why it’s important to not only look at the load index number but also verify the actual load capacity.
The final figure in a tire size sequence is the speed rating, which is indicated by a letter: P225/70R16 91S.
Just as your load index number corresponds to a specific load, your speed rating letter corresponds to a particular speed capability based on a standardized laboratory test.
For example, a tire with speed rating “S” is rated for up to 112 mph, while a tire rated “R” is up to 106 mph. Remember that this isn’t a recommended cruising speed. Of course, you should always follow legal speed limits on roadways.
Replacement tires must have the same or higher speed rating as the vehicle’s Original Equipment to maintain vehicle speed capability. If a vehicle has tires with different speed ratings, it is the speed rating of the “slowest” tire that dictates the vehicle top speed.
There is one last sizing type that you should know about, especially if you are in the market for off road tires for a light truck or SUV. It’s called a Flotation size and the numbers in this sizing format are very different from the Metric formats.
Flotation sized tires are similar to LT-Metric tires in application except for a few important points. Number one, they cannot be used in dual applications and number two, an equivalent size tire may have different load capacity than its LT-Metric counterpart.
The first number in the Flotation tire size is the overall diameter in inches. Pretty straight forward.
The second number is the section width (sidewall to sidewall) measurement in inches. Again, fairly simple.
After the section width comes a letter that indicates the type of internal construction: 33X12.50R17LT 120Q.
This is the same as is found in the metric sizing systems.
There are two types of construction that you may see on the sidewall of a tire:
Radial tires are the most common tires on the road in the United States today; thus “R” will usually be shown in the tire size designation.
Radial construction means the tire’s internal ply cords are oriented in a radial direction, from one bead over to the other, essentially perpendicular to the direction of rotation.
The next number is the diameter code, in inches, of the rim onto which the tire can be mounted. For example, a tire with the 33X12.50R17LT 120Q would fit a rim with a 17-inch diameter.
The letters LT will be after the Rim Diameter indicating that this tire type is intended for Light Truck vehicles similar to the LT-Metric and Euro-Metric Commercial (C-Type) tires.
Load Index and Speed Rating have the same meaning and format as the tires using the metric sizing system. Note that since flotation tires cannot be used in a dual application there will be only one load index number instead of two.
Another group of stamping on certain types of tires is the Uniform Tire Quality Grading or UTQG. This grading and stamping is required for passenger car tires (i.e. P-metric and Euro-metric) in the all season and summer categories. Dedicated winter tires, Light Truck (LT-Metric, Euro-Metric Commercial, Flotation) and Motorcycle tires are excluded from this requirement.
Quality grading is designed to make the tire purchase decision easier for you. Ideally, the system is intended to provide simple, comparative data so you can make an intelligent buying decision. However, the ratings are based upon test results achieved under special conditions. This means it’s possible to misinterpret the comparative data as it relates to your individual driving habits, conditions, etc. You should still rely on your service or tire professional for assistance.
Quality grading designates the comparative performance levels of a tire based on government-specified tests but commissioned by the individual tire manufacturers.
All tire manufacturers are required to grade regular and all-season passenger tires in three categories:
UTQG
Treadwear
The treadwear grade is a comparative rating based on the wear rate of the tire when tested under controlled conditions on a specified government test course for 6,000 miles (9,600 km). For example, a tire graded 150 would wear one and a half times as well on the government course as a tire graded 100. However actual tire performance depends on driving habits, road characteristics, service practices, and other factors that can influence the outcome.
Traction Grades AA, A, B and C
The traction grades from highest to lowest are AA (the highest), A, B and C. They represent how well tires stop on wet pavement as measured under controlled conditions on specified government test surfaces of asphalt and concrete. C-rated tires will have the lowest traction performance.
WARNING: THE TRACTION GRADE ASSIGNED IS BASED ON A WET BRAKING (STRAIGHT AHEAD) TRACTION TEST AND DOES NOT INCLUDE CORNERING (TURNING) TRACTION.
Temperature Grades A, B and C
The temperature grades A, B, and C represent the tire's resistance to the generation of heat and its ability to dissipate heat when tested under controlled conditions on a specified indoor laboratory test wheel. Sustained high temperature can cause the tire’s material to degenerate and reduce tire life, and excessive temperature can lead to sudden tire failure. The grade C corresponds to a performance level all passenger car tires must meet under the Federal Motor Vehicle Safety Standard No. 109. Grades A and B represent higher levels of performance on the laboratory test wheel than the minimum required by law.
WARNING: THE TEMPERATURE GRADE IS ESTABLISHED FOR A TIRE THAT IS PROPERLY INFLATED AND NOT OVERLOADED. EXCESSIVE SPEED, UNDER INFLATION, OR EXCESSIVE LOADING, EITHER SEPARATELY OR IN COMBINATION, CAN CAUSE HEAT BUILDUP AND POSSIBLE TIRE FAILURE.
DOT Quality Grades
All passenger car tires must conform to other federal requirements in addition to these grades.
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Tires
What would you say if you had to describe your tires in a few words? You might say something like, “They’re black, grooved, rubbery, and round.” While you’re certainly right, you’re missing some key information—and it’s printed right on the tire! Find out what your tire numbers mean so you can make the best, most informed decisions about your tire and car care.
For the purpose of this piece, let’s pretend we’re looking at a tire with 215/65 R15 printed on its sidewall. What do the numbers on this tire mean?
“215” in this sequence refers to the tire’s width in millimeters.
In other words, this tire is 215 millimeters wide, from sidewall to sidewall.
“65” in the sequence is the aspect ratio of the tire. The aspect ratio is a percentage, and it tells you the ratio of the tire’s height to its width. In this example, the aspect ratio number “65” means that the tire’s height is 65 percent of its width.
The “R” in this sequence refers to the construction of this tire. Specifically, the “R” means that the layers run radially across the tire. The majority of tires on the road today are radial tires, in which the internal layers are perpendicular to the axis of rotation (and the direction of travel).
The other letter you might see here is a “D,” which denotes a tire that has a diagonal or bias ply construction. These tires have plies that are laid out in a diagonal, or crosshatch, pattern.
The very last number in the sequence, “15,” is the diameter of the tire.
This is an important number—this is the number you’ll refer to when you need to know your tire size! The “15” indicates that this particular tire would fit a rim with a 15-inch diameter.
Now that you know how to read numbers on tires, you'll be able to describe your tires with much more knowledge and accuracy than, “black, grooved, rubbery, and round.” Check out our latest tire deals and head to your nearest Firestone Complete Auto Care to chat it up with people who speak tire, too! Our technicians are here for everything you need, from tire repair to tread depth checks.
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There are more inscriptions and drawings on the sidewall of any tire than there is free space.
Each icon has its own function, but it is not always possible to reveal its ins and outs without a hint. In addition, a completely new marking has appeared this year.
The tire's make and model are usually printed in the largest font. It is understandable: this is what the buyer pecks at. It is interesting that the same data in encrypted form is also on the protector - in the form of thin colored stripes. They are needed in order to be able to identify the rubber lying in the warehouse, because only its working surface is in the field of view of the workers.
Tire size is a mystery for many. It seems that there are no problems in everyday life: what numbers are indicated on the sidewall of a standard tire, with such you need to buy a winter or summer one to replace a worn one. But what exactly do they mean? For example, let's take the index 225/50 R17 98 N on the Continental tire.
Continental PremiumContact 6
Continental PremiumContact 6
Additional characters may be assigned to the tire model name.
For example, SUV means focusing on crossovers and SUVs (reinforced sidewall, large load capacity), C - on commercial vehicles (from the English cargo, "cargo"). It happens that a tire is welded specifically for a particular auto concern and is intended for primary assembly on a conveyor or sale through its official dealers. So, at Continental, the indices A0 and R01 are reserved for Audi, J for Jaguar, N0, N1, N2 for Porsche, M0, M01 for Mercedes.
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Summer tires do not carry any additional markings. The letters M + S from the English Mud, “mud”, and Snow, “snow”, are on tires that are basically suitable for cold climates, but are not purely winter. The latter are indicated only by the snowflake and mountain peak icon. The inscription All season (or the abbreviation AS), we think, does not need to be translated. On top-level tires, you can find an image of an umbrella.
This is an indication of excellent performance on wet pavement.
Often, information about the maximum load and maximum pressure is put on the tire in plain text, without allegorical codes and pictograms. Look for the phrases Max load and Max pressure respectively.
Tires with reinforced sidewalls are gaining popularity around the world, allowing you to drive several tens of kilometers after losing pressure. Usually they simply write Run Flat, although there are also original designations. So, the Continental concern puts the SSR marking on puncture-resistant models.
European tire company websites list rubber labels for noise, efficiency and environmental friendliness. The first is indicated by a number from 1 (quiet) to 3 (loud). Wet grip coefficient and fuel consumption coefficient is a letter from A (best) to G (worst). In Russia, such a classification is not yet applied.
One of the key parameters is the date of manufacture of the tire.
You should also look at it when buying a new set, not to mention a used one. It is not recommended to ride on tires for more than five or six years from the date of issue, although it is not prohibited either by law or by the manufacturers themselves. The date of manufacture is indicated by four digits in an oval. The first two are a week, the second two are a year. For example, 3119stands for "boil" of the 31st week of 2019.
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When mounting asymmetric rubber on wheels, the words Outside (“outer side”) and Inside (“inner side”) will tell you the correct location. On the wheels installed on the car, the owner should see only the first inscription. If there are none on the tires, there are no outer and inner sides on the tread, it is symmetrical in operation.
On both sides of the directional models, the word Rotation is mandatory.
The arrow located next to it will tell you the direction of rotation of the wheel when the car moves forward.
Continental tires are marked with TWI for critical tread wear marks. On summer models, they are supplemented by indicators with cross and drop marks. They signal that the rubber has not yet reached the minimum tread height, but it is no longer enough to feel confident in the rain.
And there are also VAI indicators on the tread. They are applied symmetrically in the left and right shoulder areas. With the correct installation of the wheel, they change as the rubber wears in exactly the same way. Discrepancies are a reason to visit the wheel alignment stand. So far, the technology is used only on truck tires.
Russia introduces mandatory tire labeling in order to combat "gray" deliveries. The unique Data Matrix code is highly secure and readable through several layers of packaging.
It is declared that it cannot be faked or copied, and the information sewn into it is readable even if it is partially damaged. The code can be decrypted by each buyer. To do this, it must be scanned with a special mobile application "Honest Sign". After that, information about the manufacturer and importer, the characteristics of the product, the date of putting into circulation in Russia will be displayed on the screen of the gadget.
Compulsory marking introduced from November 1, 2020. From this day on, production, import to Russia and purchase from manufacturers and importers of rubber without marks of the established sample are prohibited. Since December 15, the entire circulation of non-marking tires has been banned. Warehouse balances were allowed to be tagged until March 1, 2021.
Mandatory marking introduced from November 1, 2020. From this day on, production, import to Russia and purchase from manufacturers and importers of rubber without marks of the established sample are prohibited.
Since December 15, the entire circulation of non-marking tires has been banned. Warehouse balances were allowed to be tagged until March 1, 2021.
Continental has been at the forefront of technology testing in Russia and is fully prepared for its implementation. During 2019, together with hundreds of other companies from different industries in our country, he generated thousands of codes, working out the system. Moreover, on a global scale, the company has already prepared solutions for integrating electronic chips into tires, which allow monitoring their condition, including the degree of wear.
| 86 | 530 | 96 | 710 | ||||||
| 77 | 412 | 87 | 545 | 97 | 730 | ||||
78 | 560 | 98 | 750 | ||||||
| 79 | 437 | 89 | 580 | 99 | 775 | ||||
| 80 | 9009 50076 90 | 600 | 100 | 800 | |||||
| 81 | 462 | 91 | 615 | 101 | 825 | ||||
| 820003 | 92 | 630 | 102 | 850 | |||||
| 83 | 487 | 93 | 650 | 103 | 8750002 500 | 94 | 670 | 104 | 900 |
| 85 | 515 | 95 | 690 |
| Speed index | Q | R | S | T | H | V | W | Y | VR | ZR | ZR (Y) ZR (Y)0561 Photo: Continental Badges and letters on tires: deciphering all the symbols! There are more writing and graphics on the sidewall of any tire than there is free space. Each icon has its own function, but it is not always possible to reveal its ins and outs without a hint. In addition, a completely new marking has appeared this year.Badges and letters on tires: deciphering all the designations! Badges and letters on tires: deciphering all the designations! There are more writing and graphics on the sidewall of any tire than there is free space. Each icon has its own function, but it is not always possible to reveal its ins and outs without a hint. In addition, a completely new marking has appeared this year.Badges and letters on tires: deciphering all the designations! Our new video Large crossover Lada, almost VW from Kaluga, "native" Muscovites: plans for the auto industry revealed0003 So here's the deal! 7 imperceptible reasons for excessive fuel consumption Frame, eternal diesel, LEDs, a bunch of chips . Did you like the note? Subscribe and you will always be in the know! Driving in Zen News smi2.ru how to read, what it means, what it takes :: AutonewsPhoto: Shutterstock adv.rbc.ru See also Numbers and letters on a car tire provide all the necessary information about it. True, it is not easy to read them - here, even in the designation of one parameter, several measurement systems can be used simultaneously. In addition, many values are expressed in special indices. We decipher all important labels for the buyer.
adv.rbc.ru What is a tire markingA tire marking is information about its properties printed on the outer rim. This is a huge amount of useful information. Here are the parameters of the tire that can be read from it itself:
What does tire marking mean? Therefore, these data are usually the largest and most visible.The size designation is written in the form XXX/XX R XX. For example 225/65 R17. The first three digits are the tire width in millimetres. In our case - 225 mm. The second digit is the height, but not in millimeters, but as a percentage of the width. In our case, its height is 146.25 mm (225 * 0.65). The third number after R is the outside diameter of the wheel or the inside diameter of the tire in inches. In our case, this is 17 inches or 43.18 cm. Do not confuse - this is the radius, not the diameter. The letter R itself stands for the radial design of the tire, which confuses many. Sometimes Radial can be written separately on the bus - the meaning is the same. In addition to the radial, there is also a diagonal design (D), but these are not found today. Load and speed indices Two numbers and a letter immediately follow the size. Two digits - capacity or load index. This is a complex system of values, in which the larger the number, the greater the load, but the step size between the values is not constant. Therefore, it is easier to just know the most common of them:
The index value is the load on each wheel individually. To calculate the total load capacity, multiply by 4. This value can also be written elsewhere in a simpler form: Max load - xxx kg. Photo: Shutterstock The letter after the two digits of the load index is the index of the maximum speed for which the tire is designed. It starts with A, but the values relevant for modern machines start from the second half of the Latin alphabet:
This is not the limit, but the maximum "comfortable" value. In exceptional cases, you can even exceed it by 20-30%, but it is better to avoid this. Date of manufactureAnother key parameter is the timing of the tire. Usually it is indicated in a rounded rectangle, but may be without a frame. The first two digits are the week, and the second two are the year. Wear resistance, grip, temperatureAlso, three more parameters are usually indicated on the tire - wear resistance margin, grip quality class and temperature index. The wear index is denoted by the word treadwear. Its unit is 480 km. Multiply the number next to that word by that value. If treadwear is 400, it means that under test conditions at the test site, such a tire has worn out after driving 192,000 km. Also, this parameter can be designated separately as the abbreviation TWI. Traction is a measure of how well a tire grips on wet road surfaces. It has values from AA - the best level, to CC - the worst. Tires for regular passenger cars usually have class A, and the highest class is for sports and racing. Temperature is the tire's ability to withstand heat when driving at a certain speed.
For modern passenger car tires, the most common value for this index is A. Photo: Shutterstock European certificateThe letter E with a number indicates that the tire complies with the rules of the European Tire Standards Association (ETRTO) and has a corresponding certificate . The number indicates the country that issued it - but this does not matter, since the ETRTO requirements are the same. In this case, the tire can be produced anywhere. Suitable weatherThe weather conditions in which it is permissible to use this tire are also usually indicated:
Winter tires must have a first, second or third designation. Suitable vehicle classOn some tires you can find the designation of the type of car for which they are intended:
Other designationsIn addition, the tire may be marked:
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find out here. 
.. - everyone needs such a GAS! 
These are the codes for the load capacity and speed limit of the tire. 
There are three values here: 
