20.08.2019 13:15
The load index affects the weight that the tires can carry, the comfort in the car and the fuel consumption - that's why. Remember to pay attention to the tire load index when selecting new tires. The numbers are printed on the sidewall of the tire. And do not take this indicator lightly: car manufacturers do not in vain recommend using certain values and indices when choosing tires, this is of great importance.
What is load index
The index shows the maximum load in kg per tire at the maximum permissible speed. Speed limits are marked there, on the sidewall of the tire, next to the possible carrying capacity.
The higher the index, the heavier and tougher the tire itself. Tires that are too stiff interfere with the comfort of the vehicle and their weight negatively affects suspension life and fuel consumption. Low-index tires are light and soft, but wear noticeably faster.
What are the load indices
The operating instructions for the car will help to determine the correct index - the manufacturer always indicates the permissible speed and load indices. The figure is added up based on the weight of the car, its technical characteristics, formulas, tests and other magical knowledge that are available only to the engineers of a particular brand. Therefore, when choosing tires, stop at those indices recommended by the manufacturer of your car: this way the ride will be more comfortable, and technical units such as suspension will last longer.
Load indices are designated by numbers from 0 to 279. The standard indicator of the carrying capacity of a passenger car is from 62 to 126. For small A-class cars, tires with an index of 60 are used, each wheel can withstand up to 250 kg. Tires of B-class cars can withstand up to 315 kg, index 68. For representatives of C-class, tires are marked with index 75 - this is 385 kg per tire. The tires of minivans and crossovers are capable of withstanding up to 545 kg, this is index 87. The wheels of SUVs and commercial vehicles are the most capable - they can hold up to 775 kg, this is index 99.
Car tire speed indices
If the load index is marked with numbers, then the speed readings are indicated in Latin letters and are located in the same place - on the sidewall of the tire. The index shows what maximum speed the tire can withstand. You can see all values in the table:
Load Index Table
The index shows how much weight one wheel can withstand. Tires for passenger cars and off-road cars withstand weight in the range of 250-1650 kg. You can find more information about the designation of the load index in the table:
How to calculate the tire load index for a car
The tire load must be multiplied by 4 - by the number of wheels. Subtract the weight of the vehicle and the weight of the passengers from the total. The remaining value will show the vehicle's carrying capacity - the weight of people and luggage that can be accommodated in the vehicle without compromising safety. Otherwise, the tires will deteriorate faster, and will deform on the road with holes and irregularities.
It is not safe to drive at the maximum speed allowed by the tires with the maximum load on the tires. The load index indicates the maximum weight of the vehicle. We advise you not to come close to the upper border.
The main weight falls on the rear wheels: the main cargo is stored in the trunk, and passengers are placed on the rear seats. Take this into account when calculating the load.
Decryption
The easiest way is to calculate the maximum load according to the table that we have posted above. Car tire store managers should also be savvy in decoding indices.Pay attention to the indices recommended by the car manufacturer - they must be indicated in the car's operating instructions. The greater the difference between the indices between the tires you have selected and those recommended by the manufacturer, the less comfort you will feel while driving.
Truck tires are marked with two load indices. This is because trucks often run on twin wheels. Again, the double designation shows the load when using one or two wheels. There are no other differences in the tire load index between passenger cars and trucks.
Healthy
Almost all online tire shops have an online calculator that can help you calculate your tire load index. To understand which tires with which index you can buy, you will need to enter the values of the vehicle weight and the maximum total weight of luggage, driver and passengers. based on materials 110km.ru
Tire Load Index- conventional numerical designation that shows what mass load the tire can withstand in long-term operation. This information is necessary in order to choose the right tires, and thereby ensure a safe and comfortable ride on the car. To decipher the tire load index, a table is used, where the numerical designations of the index and the normal values of the mass that correspond to them are given. Below we will give you such a table, as well as give information about speed index, which is also important when choosing a tire. The rest of the information about the designations on the tires, you can.
Load value (MAX LOAD) and tire pressure
Determination of the load index
First of all, it must be remembered that the numerical values of the load index given on the tires are conditional! That is, these numbers do not represent the absolute maximum mass for which the tire is designed. As the load index increases, so does the maximum permissible weight of the machine for which it is designed.
However, in the application plan, many drivers when buying new tires are interested in a simple question - which tire load index to choose in one case or another? It's easy to answer. There are two options. The first is to inquire about the relevant information in the manual for your car or in reference books. Many automakers directly indicate information that for a specific model a tire with such and such a load index is needed (the same applies to the speed index, although the selection is easier there, but more on that later). The second option is to do the calculations yourself.
Load index for passenger cars can be calculated based on the unladen weight of the machine at maximum load. That is, the mass of the equipped vehicle (with a fully filled fuel tank, process fluids, repair kit, spare wheel, etc.) is added to the mass of the maximum number of people accommodated in it (for passenger cars usually it is 5), as well as a certain mass of additional cargo (here it all depends on the specific car, for small cars it can be 100 ... 200 kg, and for SUVs - over 500 kg). The approximate value of the indices for different types of cars:
- 60 - load up to 250 kg - for A-class cars;
- 68 - up to 315 kg per wheel - for representatives of the B-class;
- 75 - 387 kg per wheel - for C-class cars;
- 87 - 545 kg load - for minivans and crossovers;
- 99 - 775 kg - for SUVs and light commercial vehicles.
Further, the resulting maximum mass must be divided by four (for traditional cars with four wheels). And then add 35 ... 40% of the stock. Having carried out such simple calculations, you will get the absolute value in kilograms that the tire must withstand. The final stage is the choice of the symbol for the load index of the machine according to the table. Note that you must select the factor corresponding to the closest HIGHEST absolute value.
In order not to bother calculating the load index required for the tires of your car, it is possible to quickly calculate everything on a special calculator. He will immediately give you the required number.
Often, stores already have several options for specific car models, from which you can choose the most suitable one for you in terms of quality, price and manufacturer.
Actually make a stock for rear wheels especially if you often carry heavy loads. However, do not be zealous and choose tires with a too high index. The fact is that the more load the tire is designed for, the more rubber is used for its manufacture. Accordingly, such a tire will be heavier, and hence the three negative factors.
First, the engine will have to spend extra effort (and hence fuel!) To turn a heavy wheel. Second - a heavy tire will be very stiff, so it will be uncomfortable to ride on it. Third - with heavy tires, the suspension of the car experiences additional stress, which means that its normal operation is reduced.
Next, we present for you the promised table that will help you decipher the tire load index (here you will find values for tires for all types of cars - cars, SUVs, trucks, and so on). For passenger cars and SUVs, tires with an index value of 60 to 125 are used (respectively, from A-class cars to heavy SUVs).
| Load index | Maximum weight, kg | Load index | Maximum weight, kg |
| 0 | 45 | 100 | 800 |
| 1 | 46,2 | 101 | 825 |
| 2 | 47,5 | 102 | 850 |
| 3 | 48,7 | 103 | 875 |
| 4 | 50 | 104 | 900 |
| 5 | 51,5 | 105 | 925 |
| 6 | 53 | 106 | 950 |
| 7 | 54,5 | 107 | 975 |
| 8 | 56 | 108 | 1000 |
| 9 | 58 | 109 | 1030 |
| 10 | 60 | 110 | 1060 |
| 11 | 61,5 | 111 | 1090 |
| 12 | 63 | 112 | 1120 |
| 13 | 65 | 113 | 1150 |
| 14 | 67 | 114 | 1180 |
| 15 | 69 | 115 | 1215 |
| 16 | 71 | 116 | 1250 |
| 17 | 73 | 117 | 1285 |
| 18 | 75 | 118 | 1320 |
| 19 | 77,5 | 119 | 1360 |
| 20 | 80 | 120 | 1400 |
| 21 | 82,5 | 121 | 1450 |
| 22 | 85 | 122 | 1500 |
| 23 | 87,5 | 123 | 1550 |
| 24 | 90 | 124 | 1600 |
| 25 | 92,5 | 125 | 1650 |
| 26 | 95 | 126 | 1700 |
| 27 | 97 | 127 | 1750 |
| 28 | 100 | 128 | 1800 |
| 29 | 103 | 129 | 1850 |
| 30 | 106 | 130 | 1900 |
| 31 | 109 | 131 | 1950 |
| 32 | 112 | 132 | 2000 |
| 33 | 115 | 133 | 2060 |
| 34 | 118 | 134 | 2120 |
| 35 | 121 | 135 | 2180 |
| 36 | 125 | 136 | 2240 |
| 37 | 128 | 137 | 2300 |
| 38 | 132 | 138 | 2360 |
| 39 | 136 | 139 | 2430 |
| 40 | 140 | 140 | 2500 |
| 41 | 145 | 141 | 2575 |
| 42 | 150 | 142 | 2650 |
| 43 | 155 | 143 | 2725 |
| 44 | 160 | 144 | 2800 |
| 45 | 165 | 145 | 2900 |
| 46 | 170 | 146 | 3000 |
| 47 | 175 | 147 | 3075 |
| 48 | 180 | 148 | 3150 |
| 49 | 185 | 149 | 3250 |
| 50 | 190 | 150 | 3350 |
| 51 | 195 | 151 | 3450 |
| 52 | 200 | 152 | 3550 |
| 53 | 206 | 153 | 3650 |
| 54 | 212 | 154 | 3750 |
| 55 | 218 | 155 | 3875 |
| 56 | 224 | 156 | 4000 |
| 57 | 230 | 157 | 4125 |
| 58 | 236 | 158 | 4250 |
| 59 | 243 | 159 | 4375 |
| 60 | 250 | 160 | 4500 |
| 61 | 257 | 161 | 4625 |
| 62 | 265 | 162 | 4750 |
| 63 | 272 | 163 | 4875 |
| 64 | 280 | 164 | 5000 |
| 65 | 290 | 165 | 5150 |
| 66 | 300 | 166 | 5300 |
| 67 | 307 | 167 | 5450 |
| 68 | 315 | 168 | 5600 |
| 69 | 325 | 169 | 5800 |
| 70 | 335 | 170 | 6000 |
| 71 | 345 | 171 | 6150 |
| 72 | 355 | 172 | 6300 |
| 73 | 365 | 173 | 6500 |
| 74 | 375 | 174 | 6700 |
| 75 | 387 | 175 | 6900 |
| 76 | 400 | 176 | 7100 |
| 77 | 412 | 177 | 7300 |
| 78 | 425 | 178 | 7500 |
| 79 | 437 | 179 | 7750 |
| 80 | 450 | 180 | 8000 |
| 81 | 462 | 181 | 8250 |
| 82 | 475 | 182 | 8500 |
| 83 | 487 | 183 | 8750 |
| 84 | 500 | 184 | 9000 |
| 85 | 515 | 185 | 9250 |
| 86 | 530 | 186 | 9500 |
| 87 | 545 | 187 | 9750 |
| 88 | 560 | 188 | 10000 |
| 89 | 580 | 189 | 10300 |
| 90 | 600 | 190 | 10600 |
| 91 | 615 | 191 | 10900 |
| 92 | 630 | 192 | 11200 |
| 93 | 650 | 193 | 11500 |
| 94 | 670 | 194 | 11800 |
| 95 | 690 | 195 | 12150 |
| 96 | 710 | 196 | 12500 |
| 97 | 730 | 197 | 12850 |
| 98 | 750 | 198 | 13200 |
| 99 | 775 | 199 | 13600 |
The designations of the load index and tire speed on the side surface of the rubber are next to each other. And this is not without reason, since they are interconnected. Unlike the load, the speed index is designated by letters of the Latin alphabet (from A to Z). For example, you can find on the tire the values 92S or 88T, which will be the combined designation of the two mentioned indices.
The speed index is specially placed next to the load index. This information gives an idea of how. what kind of load the tire can withstand at its maximum permissible speed.
The decoding of the tire speed index is very simple. The closer the letter is to the end of the alphabet, the higher the speed the tire is designed for. The only exception is the letter H, located between U and V. So, we give you a similar table with which you can clarify what maximum speed this or that tire is designed for.
| Maximum speed, km / h | |
| A | 40 |
| B | 50 |
| C | 60 |
| D | 65 |
| E | 70 |
| F | 80 |
| G | 90 |
| J | 100 |
| K | 110 |
| L | 120 |
| M | 130 |
| N | 140 |
| P | 150 |
| Q | 160 |
| R | 170 |
| S | 180 |
| T | 190 |
| U | 200 |
| H | 210 |
| V | 240 |
| W | 270 |
| Y | 300 |
| VR | >210 |
| ZR | >240 |
| (W) | >270 |
| Z | >300 |
How to choose load and speed indices
Decoding of load and speed indices
European regulations ECE-R54 mandate all tire manufacturers to apply load and speed index values to them. In this case, the load index is usually indicated single installation wheels per axle on one side. If the rubber can be used for double installation, then two values are indicated, separated by a dash. For example, 102 / 100R. The first number is for a single installation, the second is for a dual installation. Tires have this double designation. Commercial class, which, in accordance with the same rules, can be installed not only on cars, but also on small trucks and vans (that is, on commercial vehicles). Such tires are additionally designated with the letter C or the word Commercial.
Do not install tires on cars with load and speed indexes lower than prescribed in the documentation.
As for the speed index, it not only affects the maximum permissible speed for which the tire is designed. The fact is that you cannot go for a long time (more than half an hour) at this very maximum speed. This is due to excessive tire wear. In addition, it is life-threatening, because at high speeds the rubber must work in normal and not critical modes. Therefore, it is allowed to drive for a long time at speeds 10 ... 15% lower than the maximum permissible. Especially such reasoning is relevant for bad roads, when rubber constantly falls into holes, potholes and bumps.
Do not exceed the speed limit and do not drive for a long time at the maximum speed allowed for rubber.
When choosing a rubber according to the speed index, as in the case of the load, one cannot choose very “high-speed” tires. The fact is that the higher the speed the tire is designed for, the softer it is. Accordingly, it will have better and more reliable grip on the road surface. However, this much wears out faster(remember how often tires are changed in Formula 1 races). That is why it is not recommended to buy very high-speed tires for ordinary cars used in urban environments.
Outcomes
We are sure that the above information will help you understand what the load and speed indices of tires mean, whose designations are located behind the tire size value. This will help you make the right choice. At the same time, do not forget to leave a small margin of 10 ... 20% for both indices in order to ensure your driving comfort and safety on the road.
When planning to buy tires for a car, knowledgeable motorists pay attention not only to the size, seasonality, manufacturer and its warranty, but also to the tire load index. Despite the fact that it can be specified in different ways, it is not difficult to read such an index. This means that, with a minimum of knowledge, the vehicle owner can easily determine whether the rubber is suitable for his car or not. Initially, it will be clear how the car will behave at maximum or, conversely, minimum load. In fact, this index is an indicator of the carrying capacity of the vehicle. It determines what the maximum number of kilograms can be on one wheel. Thus, a two- or three-digit number on a line is no less significant than a dimension or, for example, a speed index.
And what is the threat of ignoring the tire load index? What can be the result of the choice of rubber, where the load index is less than necessary? Despite the fact that exceeding this indicator by 10-30% is considered quite acceptable, a long run with the use of such tires will result in increased tire wear. At the same time, the controllability of the car gradually deteriorates, and the car begins to behave not quite predictably during lane changes or braking. An unfavorable result may be overheating not only of the tires themselves, but also of the brake mechanisms. Agree, this is a lot to refuse to buy rubber, where the tire load index is lower than required.
But what if you buy tires where this figure is higher than necessary? Buying rubber with a reserve is also a wrong decision, which threatens with big problems with the control of an unloaded car. In addition, exceeding the recommended load index is fraught with the following:
The wheels will become much more "oak", the suspension will wear out faster, and there will be obvious discomfort when driving;
Controlling an unloaded car will require a lot of effort, and, moreover, the vehicle will slow down worse;
Tires with a high load index are often not designed for high speed driving.
It is also worth knowing that tires with a high load index are very demanding on the rims. Therefore, having bought such a rubber, it is necessary to frequently check the air pressure in the wheels and pay close attention to the quality of the disks and their evenness. Thus, when choosing tires, one should focus on an acceptable level of load, adhering to the principle of the “golden mean”. It is worth knowing that the values are indicated per wheel, not the total weight of the vehicle. However, the optimal indicator is not calculated by simply dividing the number indicated in the data sheet by the number of wheels. In most cases, the weight that falls on the rear and front axles of a car is not the same. Therefore, read the description of the vehicle, which will help determine which tire load index is sufficient for your car.
The table below shows the code decoding of the tire load indices
What are the tire speed indices characterized by?
You've most likely seen the letters A through Z on the side of car wheels. This is an index that determines the speed limit for tires, subject to the maximum load of the vehicle. The indicator, in determining which the lifting capacity factor is taken into account, is necessary for the balanced operation of all machine units. If there is no such marking on the wheels, driving at a speed of 110 km / h is unacceptable.1. The speed indicated in the index cannot be exceeded categorically, but the realities of domestic roads are such that it is highly desirable to subtract another 10-15% from this indicator.
2. The speed index is related to the type of tire (summer, winter or all-season). When choosing tires for the cold season, you should pay attention to tires with an H index or, perhaps, more.
3. It is imperative to take into account the following regularity: the higher the index, the softer the rubber and the better the adhesion to the road surface, but at the same time the more rubber wear.
4. If you plan to use tires with different speed ratings, put the hardest rubber on the drive axle to ensure even tire wear.
5. There is a lot from the tire tread. International standards define an equal load factor for passenger cars, however, the speed index for identical tires can vary from 180 to 240 km / h. Moreover, this indicator does not in any way depend on the manufacturer or on the year of manufacture of the vehicle.
Tire speed index table
And you pay attention to such a characteristic of the tire as the load index. Your ride safety depends on the selected load index. If, for some reason, the tire collapses during movement, especially on slippery surfaces, or at high speed, the car may lose control and this will lead to trouble.
I'll start right away with an example. Take a balloon, inflate it, and then squeeze it hard. Burst? If not, they squeezed weakly; if it burst, squeezed strongly. These are the terms that denote the load on the tire. If a one-year-old child sits on the ball, he may not become anything, and if a stocky man sits down, it will burst, because the load on the ball has been exceeded.
The wheel is still more difficult, because not only is pressure exerted on it, it also turns. The more pressure is exerted on the wheel, the greater the load begins to be experienced by the side of the wheel (the part that shorts against the curbs). If the permissible load is exceeded, the cords will start to be damaged and a “hernia” will come out at the wheel, which looks like a lug. If a hernia has crawled out, it is no longer possible to ride such a wheel. Firstly, it will no longer spin evenly, and there will be vibration while driving, and secondly, the tire can collapse at any moment.
How to choose the load index
I select the load index based on the maximum weight of my vehicle divided by four. If the car weighs 1400 kg, and I can pour 60 liters of gasoline into it, load 120 kilograms of luggage, and put five people (together with sleep) weighing 120 kilograms, then the maximum weight of my car will be 2180 kilograms or 545 kilograms per wheel, which corresponds to index 87, however, if I really plan to ride with such a load, I need to create a reserve and raise the index by a couple of points, that is, choose index 89, which corresponds to 580 kilograms per wheel.
Maximum load or overload
If the estimated weight of the car has approached the limit mark, or crossed it, and the trip cannot be postponed in any way, drive in compliance with all safety rules. First of all, drive at such a speed at which you are guaranteed to be able to hold the car when the wheel collapses, and secondly, be prepared for trouble. If you can't go slowly, and you don't want to get into trouble, divide the load into parts, or get rid of unnecessary things on the trip.
Table of tire load indices and corresponding masses
| Indus | Load, kg | Indus | Load, kg | Indus | Load, kg | Indus | Load, kg |
| 50 | 190 | 70 | 335 | 90 | 600 | 110 | 1060 |
| 51 | 195 | 71 | 345 | 91 | 615 | 111 | 1090 |
| 52 | 200 | 72 | 355 | 92 | 630 | 112 | 1120 |
| 53 | 206 | 73 | 365 | 93 | 650 | 113 | 1150 |
| 54 | 212 | 74 | 375 | 94 | 670 | 114 | 1180 |
| 55 | 218 | 75 | 387 | 95 | 690 | 115 | 1215 |
| 56 | 224 | 76 | 400 | 96 | 710 | 116 | 1250 |
| 57 | 230 | 77 | 412 | 97 | 730 | 117 | 1285 |
| 58 | 236 | 78 | 425 | 98 | 750 | 118 | 1320 |
| 59 | 243 | 79 | 437 | 99 | 775 | 119 | 1360 |
| 60 | 250 | 80 | 450 | 100 | 800 | 120 | 1400 |
| 61 | 257 | 81 | 462 | 101 | 825 | 121 | 1450 |
| 62 | 265 | 82 | 475 | 102 | 850 | 122 | 1500 |
| 63 | 272 | 83 | 487 | 103 | 875 | 123 | 1550 |
| 64 | 280 | 84 | 500 | 104 | 900 | 124 | 1600 |
| 65 | 290 | 85 | 515 | 105 | 925 | 125 | 1650 |
| 66 | 300 | 86 | 530 | 106 | 950 | 126 | 1700 |
| 67 | 307 | 87 | 545 | 107 | 975 | 127 | 1750 |
| 68 | 315 | 88 | 560 | 108 | 1000 | 128 | 1800 |
| 69 | 325 | 89 | 580 | 109 | 1030 | 129 | 1850 |
| 130 | 1900 | ||||||
