How car tire sizes explained


Tire Size Explained: What the Numbers Mean

Tire size can be confusing. Some numbers on the sidewall are listed in millimeters while others are inches. Plus, the right size for your car, truck, or trailer can differ depending on where and how you drive.

You can see your original equipment tire size in your owner’s manual or on the placard generally located on the driver’s side door jam. This is the sizing recommended by the vehicle manufacturer.

If you’re interested in switching out your tires for a different look or performance, a good place to start is the numbers and other indicators on your existing tires’ sidewall. Next, have a tire professional help you determine a tire size range that will fit your vehicle and driving needs.


Tire Size Meanings

Here’s what those numbers and indicators on the sidewall indicate and how to understand them:

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 capable of carrying heavy loads, towing trailers, or for those looking for an extra heavy duty option. These are often equipped on three-quarter or 1 ton trucks and SUVs.

ST stands for Special Trailer. These tire sizes are meant for trailers, including fifth wheels and other travel trailers, as well as boat 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 a 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. This may also be referred to as the section width.

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 indicated on the tire sidewall as 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 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% (.65). This gives you an answer of 5.5, 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. It’s the distance between the two bead seat areas (where a tire gets 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, when inflated to the tire’s maximum air pressure rating.

G: SPEED RATING The last letter is the tire speed rating. This indicates 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).


Tire Size Charts

Below you will find several charts that will help you understand tire sizing numbers, including a load index chart and speed rating chart.



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 is only an estimate. It’s important to stay within the sizing tolerances of your vehicle. Tires that are the wrong size could cause some pull in the steering wheel, rub against the suspension or body of your vehicle, reduce clearance on hills, or result in a stiffer or noisier ride.

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.

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Using Load Index & Load Range to Pick the Right Tires

When shopping for tires online, you’ll notice the terms load index, load range, and speed rating included within the technical specifications. (You can find these numbers and letters on your existing tires, located after the size of the tire. ) Understanding the meaning of load index and load range can help you find the right tire for your vehicle and your needs. As always, the experts at Les Schwab can answer all of your questions about what tires are right for you, but in this quick article, we’ll cover some of the basics of these indicators.

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Load Index

The load index of a tire is a number that correlates to the maximum safe carrying capacity of the tire when it’s inflated to its maximum pressure. Higher load index ratings mean your tires will be able to handle a heavier load. In this example, there are two numbers. The higher number (load index) is for single rear-wheel applications. The lower number is for dual-wheel applications. This indicates its load-carrying capacity when inflated to its maximum pressure. Remember, air pressure is what carries the load in a tire. You can find each tire’s carrying capacity with the chart below.


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 1819 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    
LOAD INDEX LOAD (lbs)
65 639
66 661
67 677
68 694
69 716
70 739
71 761
72 783
73 805
74 827
75 853
76 882
77 908
78 937
79 963
80 992
81 1019
82 1047
83 1074
84 1102
85 1135
86 1168
87 1201
88 1235
89 1279
90 1323
91 1356
92 1389
93 1433
94 1477
95 1521
96 1565
97 1609
98 1653
99 1709
100 1764
101 1819
102 1874
103 1929
104 1984
105 2039
106 2094
107 2149
108 2205
109 2271
110 2337
111 2403
112 2469
113 2535
114 2601
115 2679
116 2756
117 2833
118 2910
119 2998
120 3086
121 3197
122 3307
123 3417
124 3527
125 3638
126 3748
127 3858
128 3968
129 4079
130 4189
131 4299
132 4409
133 4541
134 4674
135 4806
136 4938
137 5071
138 5203
139 5357
140 5512
141 5677
142 5842
143 6008
144 6173
145 6393
146 6614
147 6779
148 6944
149 7165
150 7385
Load Range (Ply Rating)

On some tires, you’ll see a load range indicator on the sidewall, as shown here. Load Range is an older measure of tire carrying capacity equivalent to ply rating. The ply rating isn’t directly tied to the number of plies used in construction, so we recommend using Load Index when appropriate. Load ranges are arranged in alphabetical order starting with the letter “A”. The ply ratings (load range) combined with the tire size tell you the tire load capacity.

The load range on replacement tires must meet or exceed the recommendation on your vehicle’s door placard or owner’s manual. It can be higher than recommended but never lower.

LOAD RANGE PLY RATING
A 2
B 4
C 6
D 8
E 10
F 12

Les Schwab Tip: Some cars, including electric vehicles, may require tires with a higher load range due to weight with and without passengers.


We’re Your Tire Experts

If this seems confusing. Don’t worry. The pros at Les Schwab will show you all of your options, including the size, load range, and load index you need for work, weekends, or your daily commute.

Tire marking. How to correctly determine tire parameters

Do you want to choose a tire for your car, but do not understand tire markings well? It's not a problem! In this section, we will help you figure out what tire parameters are, what they mean, and which tire is right for your car.

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Explanation of tire markings.

195/65 R15 91 T XL

195 is the tire width in mm.

65 - Proportionality, i.e. profile height to width ratio. In our case, it is equal to 65%. Simply put, with the same width, the larger this indicator, the higher the tire will be and vice versa. Usually this value is simply called “profile”.

Since the tire profile is a relative value, it is important to take into account when choosing rubber that if you want to put tires with a size of 205/65 R15 instead of the size 195/65 R15, then not only the width of the tire will increase, but also the height! Which in most cases is unacceptable! (except when both of these sizes are indicated in the car's operating book). You can calculate the exact data on changing the outer dimensions of the wheel in a special tire calculator.

If this ratio is not specified (for example, 185/R14C), then it is equal to 80-82% and the tire is called full profile. Reinforced tires with this marking are usually used on minibuses and light trucks, where a large maximum wheel load is very important.

R - means a tire with a radial cord (in fact, almost all tires are made this way now).

Many mistakenly believe that R- means the radius of the tire, but this is the radial design of the tire. There is also a diagonal design (indicated by the letter D), but recently it has practically not been produced, since its performance is noticeably worse.

15 - wheel (rim) diameter in inches. (It is the diameter, not the radius! This is also a common mistake). This is the “landing” diameter of the tire on the disk, i.e. is the inside size of the tire or the outside of the rim.

91 - load index. This is the level of maximum permissible load on one wheel. For passenger cars, it is usually done with a margin and is not a decisive factor when choosing tires (in our case, IN - 91 - 670 kg.). For minibuses and small trucks, this parameter is very important and must be observed.

Tire load index table:

T is the tire speed index. The larger it is, the faster you can ride on this tire (in our case, IS - H - up to 210 km / h). Speaking about the tire speed index, I would like to note that with this parameter, the tire manufacturer guarantees the normal operation of the rubber when the car is constantly moving at the specified speed for several hours.

Speed ​​index table:

American tire marking:

There are two different American tire markings. The first one is very similar to the European one, only the letters “P” (Passanger - for a passenger car) or “LT” (Light Truck - light truck) are placed before the size. For example: P 195/60 R 14 or LT 235/75 R15. And another tire marking, which is fundamentally different from the European one.

Example: 31x10.5 R15 (corresponds to European size 265/75 R15)

31 is the outside diameter of the tire in inches.
10.5 is tire width in inches.
R - a tire with a radial design (older tire models were with a diagonal design).
15 is the inner diameter of the tire in inches.

Generally speaking, except for inches that are unusual for us, the American tire marking is logical and more understandable, unlike the European one, where the height of the tire profile is not constant and depends on the width of the tire. And here everything is simple with decoding: the first digit of the standard size is the outer diameter, the second is the width, the third is the inner diameter.

Additional information indicated in the marking on the sidewall of the tire:

XL or Extra Load is a reinforced tire, the load index of which is 3 units higher than that of conventional tires of the same size. In other words, if a given tire has a load index of 91 marked XL or Extra Load, then this means that with this index, the tire is able to withstand a maximum load of 670 kg instead of 615 kg (see the table of tire load indices).

M+S or tire marking M&S (Mud + Snow) - mud plus snow and means that the tires are all-season or winter. Many summer tires for SUVs are labeled M&S. However, these tires must not be used in winter, as winter tires have a completely different rubber compound and tread pattern, and the M&S badge indicates good flotation performance.

All Season or AS all season tires. Aw (Any Weather) - Any weather.

Pictogram * (snowflake) — rubber is designed for use in harsh winter conditions. If this marking is not on the sidewall of the tire, then this tire is intended for use only in summer conditions.

Aquatred, Aquacontact, Rain, Water, Aqua or icon (umbrella) Special rain tires.

Outside and Inside ; asymmetric tires, i.e. It is important not to confuse which side is the outside and which is the inside. When installing, the Outside inscription must be on the outside of the car, and Inside on the inside.

RSC (RunFlat System Component) - RunFlat tires are tires on which you can continue to drive a car at a speed of no more than 80 km / h with a FULL tire pressure drop (due to a puncture or cut). On these tires, depending on the manufacturer's recommendations, you can drive from 50 to 150 km. Different tire manufacturers use different designations for RSC technology. For example: Bridgestone RFT, Continental SSR, Goodyear RunOnFlat, Nokian Run Flat, Michelin ZP etc.

Rotation or arrow This marking on the tire sidewall indicates a directional tire. When installing the tire, you must strictly observe the direction of rotation of the wheel, indicated by the arrow.

Tubeless - tubeless tire. In the absence of this inscription, the tire can only be used with a camera. Tube Type - indicates that this tire must be used only with a tube.

Max Pressure ; maximum allowable tire pressure. Max Load - the maximum allowable load on each wheel of the car, in kg.

Reinforced or the letters RF in the size (for example 195/70 R15RF) means that this is a reinforced tire (6 layers). The letter C at the end of the size (for example 195/70 R15C) indicates a truck tire (8 layers).

Radial this marking on the rubber in the standard size means that it is a radial construction tire. Steel means that there is a metal cord in the tire structure.

Letter E (in a circle) - the tire meets the European requirements of ECE (Economic Commission for Europe). DOT (Department of Transportation - US Department of Transportation) is an American quality standard.

Temperature A, B, or C The temperature resistance of the tire at high speeds on the test bench (A is best).

Traction A, B, or C

Treadwear ; relative expected mileage compared to a specific US standard test.

TWI (Tread Wear Indiration) - tire tread wear indicators. The marking on the TWI wheel can also be with an arrow. Pointers are located evenly in eight or six places around the entire circumference of the tire and show the minimum allowable tread depth. The wear indicator is made in the form of a protrusion with a height of 1.6 mm (the minimum tread value for light vehicles) and is located in the tread recess (usually in the drainage grooves).

DOT - Manufacturer's coded address, tire size code, certificate, issue date (week/year).

Select tires / tire catalog

deciphering the marking of car tires. Selection of tires for your car

How to choose tires or wheels for your car

When choosing car tires and wheels, the main and often the only factor is the compatibility of these components with a particular make and model of car. Many motorists are familiar with technical specifications such as wheel settings or tire sizes. This, of course, is wonderful, because it allows you to very quickly select literally a few options on your own. However, there are quite a few such "advanced" motorists. There are far more of those who, for whatever reason, prefer not to go into such technical details about their cars.

It is for them, first of all, that the service is oriented, which allows you to automatically select car wheels and tires according to the make and model of the car. User participation in this process is minimized and consists only in choosing from the available options, first the brand, and then the model and year of manufacture of the vehicle. After a few moments, the system will automatically select from thousands of tires and rims exactly those that exactly match the recommendations of car manufacturers.

This is extremely important given the huge danger of using tires and wheels with unsuitable specifications. As a rule, such changes in the vehicle configuration are caused by the need to improve some of its driving characteristics or give it a more spectacular appearance. In real operation, such experiments end with a deterioration in controllability, damage to various suspension parts, an increase in fuel consumption, and a distortion of the current speed indicators. Some of these changes to the performance of the vehicle significantly reduce the level of safety, which is unacceptable.

That is why you should not neglect the recommendations of car manufacturers, which are based on the results of engineering calculations that describe the operation of various components and parts of the car, primarily the suspension. At the same time, all the most important indicators of safety, controllability and comfort are taken as the basis, each of which is verified during full-scale tests or using computer simulation technologies.

Automated wheel and tire selection system eliminates this scenario by offering at least several options based on user-specified data. This greatly simplifies and facilitates the choice, but, again, not for everyone. We recommend this category of motorists to contact the specialists of our company. They will provide more detailed information about a particular wheel or tire model, pointing out various nuances.

Where can you find your car's tire size?

When looking for a new set, you should be prepared for the fact that tire sizes are data, without which it is difficult to make a purchase. The size of wheels and tires is a fundamental knowledge that allows you to choose the right tires for your car, which means it ensures safe driving. There are several ways to check which wheel size is right for our car. You will find them first:

  • on currently used tires,
  • in vehicle manufacturer's recommendations,
  • in size charts.

The quickest way is to look at old tires. On the side wheels of the car there is a character string, for example 205/55 R16 91 H or 195/65 R15 91 T, which contains all the most important information. If the tires we are currently running match each other, all you have to do is buy new models in the same size.

Please note, however, that only buying a car from a dealership gives you the confidence that you have the right size tires fitted. On the other hand, in the case of used vehicles, it is necessary to check whether the dimensions and speed index of the tire correspond to the values ​​approved by the car manufacturer. The previous owner may have chosen the wrong tire size for the rim, or may have chosen a replacement that is different from the factory settings. That is why it is so important that the outer diameter of the tire and other parameters meet the requirements of the brand.

Check the marking on the wheel - you will definitely find the tire size there.

How do I know the tire size? Want to know what car tire sizes mean? You do not know how to decipher these numbers and letters?

To explain this, for example, we break down the designation 195/50 R15 82T:

  • 195 tire width expressed in millimeters
  • 50 tire profile height. The value, expressed as a percentage, means the ratio of the height of the tire to its width. In this case, the value "50" means 50 percent of 195 mm - or 97.5 mm.
  • R radial construction - tire construction type
  • 15 The diameter of an automobile wheel (seat), which is also the diameter of the rim, is given in inches. In this case it is 15 inches
  • 82 Load index with value 82
  • T class speed rating T

Agricultural and industrial tire sizes look the same, but they can be more specific. For example, the tire designation XL refers to the so-called reinforced products

An alternative way to find the answer to the question: choose the right one is to look up the tire size in the car owner's manual. This information can usually be found in the vehicle specifications chapter. Recommended tire sizes are also often listed in the following locations: fuel filler cap, door sill (driver's side), post behind the driver, inside of the driver's side door (with locking mechanism). Refer to your service book for recommended tire sizes for your vehicle. If the size of car tires remains a mystery to you, ask a professional. Of course, you will get help at the tire shop or at the dealership of your car brand

Selection of rims by tire size

Many car enthusiasts who are preparing to buy new wheels to replace worn, damaged ones, or simply in connection with seasonal “changing shoes” often ask the same question - how to choose rims for tires by tire size?


Tire size on the label

To answer this question, you need to know the general parameters by which these two products are inextricably linked, in particular: this parameter always determines the correspondence of disks and tires, as well as their compatibility. So, the most popular wheel sizes are the range from R13 to R20, where the number indicates the diameter in inches, but many motorists mistakenly consider this value to be the radius.

  • The width of the rims, corresponding to the same value on the tire, which can only slightly fluctuate. This dimension on the wheel is indicated by the letter J, which is preceded by its value in inches. So, for example, the range 5.0J-6.0J corresponds to a tire width of 175 mm, 5.5J-7.0J - 215 mm, 6.0J-7.5J - 225 mm, and 7.0J-8.5J - 245 mm. Thus, the width of the disks and the width of the tires are absolutely interconnected indicators.
  • The next important indicator is the rubber profile, which determines the overall dimension of the wheel assembly. So, for example, for the R17 radiality on the Lada Kalina, you can put tires with a profile height of 40 to 45 mm, because the wheel arches and suspension structures are designed only for such a maximum dimension, but, for example, with the same dimension on a Toyota Land Cruiser 200 will easily fit a profile with a height of 100 mm.
  • Recently, rubber has been produced only tubeless, because the risk of an accident in the event of a puncture is minimal, and the edges of the tire, as well as the sides of the rim of the disc, have special rigid ribs that completely eliminate the passage of air after rubber and steel come into contact. However, with chamber rubber, it is necessary to look for discs suitable for it, and this is very problematic to do.
  • Those vehicles that actively drive off-road often use devices such as beadlocks - powerful bolted steel discs mounted on the inside of the wheel and pressing the rubber. These devices prevent the tire from rolling off the wheel rim even when it can no longer maintain pressure due to an accident.
  • Important! The best option when purchasing a disc is to have the rubber itself available, or at least know all its characteristics and be ready to always find it in a search engine on the Internet so that the seller can correctly select the disc of interest to his client with optimal parameters. Rim to tire ratio table0003

    You may be interested Parameters of wheels for Volkswagen Tiguan

    Tire height Tire size Optimum rim width in inches Minimum rim width in inches Maximum rim width in inches
    R13
    80 155/80/R13 4.5 4.0 5.5
    70 165/70/R13 5.0 4.5 6.0
    65 175/65/R13 5.0 5.0 6.0
    60 185/60/R13 5.5 5.5 6.5
    55 195/55/R13 6.0 5.5 7.0
    R14
    80 175/80/R14 5.0 4.5 5.5
    70 185/70/R14 5. 5 5.5 6.5
    65 185/65/R14 5.5 5.5 6.5
    60 195/60/R14 6.0 5.5 7.0
    55 205/55/R14 6.5 5.5 7.5
    R15
    80 185/80/R15 5.5 5.5 6.0
    65 195/65/R15 6.0 6.5 7.0
    55 205/55/R15 6.5 6.5 7.5
    50 205/50/R15 6.5 6.5 7.5
    45 195/45/R15 6.5 6.0 7.5
    R16
    60 225/60/R16 6.5 6.0 8. 0
    55 235/55/R16 7.0 6.0 8.0
    50 205/50/R16 6.5 5.5 7.5
    45 205/45/R16 7.0 6.5 7.5
    40 225/40/R16 8.0 7.5 9.0
    R17
    55 225/55/R17 7.0 6.0 8.0
    50 215/50/R17 7.0 6.0 7.5
    45 235/45/R17 8.0 7.5 9.0
    40 255/40/R17 9.0 8.5 10.0
    35 265/35/R17 9.5 9.0 10.5
    R18
    50 235/50/R18 7. 5 6.5 8.5
    45 255/45/R18 8.5 8.0 9.5
    40 265/40/R18 9.5 9.0 10.5
    35 295/35/R18 10.5 10.0 11.5
    30 325/30/R18 12.0 11.0 13.0
    R20
    40 245/40/R20 9.0 8.0 9.5
    35 275/35/R20 10.0 9.0 11.0

    Using the data of this table, any motorist can easily choose the rims he is interested in and not make a mistake, which will ensure a comfortable and safe ride.

    Common mistakes car owners make when choosing wheels

    Usually, not every driver can immediately determine correctly how to find out the size of the wheel from the tires for his car. The choice of disks according to parameters and tables is not the final instance, after which you can purchase a suitable set of products.

    Regardless of the size and type of tire, the disc can sit on it perfectly. This means that you need to familiarize yourself with the information about the mount. It defines 2 important characteristics:

    • drilling - this parameter determines the diameter of the mounting hole;
    • bolt pattern determines the number of studs and the size of each of them.

    Without taking into account these characteristics, an error and the purchase of an unsuitable product are possible, since there are a huge number of rubber variations.

    Motorists often purchase wheels with the maximum allowable width and at the same time do not monitor the value of ET - offset, do not resort to comparing disks. Departure - a characteristic of the disk (designated ET20, 25, 30, 35, 40), which indicates the distance in mm from the longitudinal plane of symmetry of the disk to the hub plane.
    The offset of the disk is considered 0 (if the axis of symmetry of the disk corresponds to the plane of the hub of the machine), positive (if the axis of the disk is closer to the center of the car, compared to the plane of the hub) and negative (if farther). Each specific car model has its own offset, which is calculated by the manufacturer in order to ensure the best handling and stability of the car, with minimal load on the hub bearings.

    In addition, from the point of view of economic feasibility, it is recommended to choose 2 sets of rims, which will allow you not to engage in beading when changing shoes seasonally (in spring and autumn). This task also damages the tires, which over time can release air at the points of connection with the disk, as well as the products themselves, which can subsequently be scratched and corroded. In addition, wheel beading requires additional financial investments (the cost of changing tires over several years is commensurate with the cost of a disk), and time costs, under sharply changing weather conditions. Therefore, the presence of 2 sets of disks will help save money, time, and also extend the life of both tires and disks.

    In general, tires, like wheels, can be purchased separately, but ideally it is better to buy them in one place at the same time. This will allow you not to get into a curious situation of detecting inconsistencies in the first or second product. In addition, this may lead to additional time spent on the exchange of products. Watch this video on YouTube0152

    Our tire calculator will show you visual differences in tire diameter, profile, radius, clearance and width. Dashed lines show the difference in size. At the top, you can see a visual representation of the old tire (original size), and at the bottom, a visualization of the new tire. Just as you noticed, the tire can be seen in lateral and frontal projection. You can copy the URL of the page and show it to other people and they will see the same comparison as you see.

    But how to understand all these values ​​and the difference in%? To do this, we created a tire calculator, it will help you understand the change in all the necessary characteristics and show the difference in% between the old and new tires, and even visually display how the wheel of the old and new sizes will look like. You just need to enter the tire width, profile and wheel radius. Usually they are displayed in this form - 19565 R15

    Some features of the selection of tires:

    • The wider the tires, the better the handling, but the resistance to aquaplaning is worse and rutting is felt more, and comfort is also reduced - low profile tires are stiffer.
    • Lower profile - heavier wheel. This is due to the fact that the disk is heavier than rubber, the mass of the wheel increases and this worsens the performance of the suspension. In addition, the mass of metal is distributed closer to the outer edge of the wheel and increases the moment of inertia (for cars with a powerful engine, this is not essential).
    • With an increase in the profile, the car becomes more rolly, less responsive to control, but it goes through bumps more easily, tires are less sensitive to sharp edges of pits, comfort becomes better.
    • A significant change in the outer diameter of the wheel leads to a distortion of the readings of the vehicle's instruments, in particular, mileage and speed.

    How does tire size affect fuel consumption?

    The narrower the tyre, the less fuel loss it ultimately has to bear. On the site, using the online tire calculator with fuel consumption, you can accurately calculate how tire size affects fuel consumption. The tire calculator with fuel consumption allows you to calculate the real fuel costs and it may differ from the on-board computer. The reason is that the car computer does not understand that we have set a different wheel size and continues to calculate the consumption in the old car rubber profile. You can find out your profile on the tire label.

    What is the tire profile width

    First of all, it is worth noting that the tread width is the distance between the outer sides of the sidewall. Measurements are taken when the tire is inflated.

    Protrusions on the surface of the sidewall are not taken into account.

    The metric system is the most commonly used. In this case, the tread width is indicated in millimeters. The parameter is quite convenient to handle, it is not indicated as a percentage, there is no need to perform calculations. If necessary, a quick conversion to the inch system is possible, for this you need to remember that one inch is equal to 2.54 centimeters. Manufacturers from the USA usually use the inch system. Manufacturers of American cars often give recommendations on the use of tires in such a system.

    Specifies the width of the profile on the tire sidewall. The first digit in the marking, for example, in a 235/45 R17 tire, will be 235 millimeters wide.

    The inch system is a little more difficult. The width of the profile is indicated by the second digit. For example, 31 × 10 R17, the parameter we need is 10 inches, when counting, we get our 254 mm.

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