It is sometimes not easy for many novice motorists to choose for their iron friend on their own. This is because their marking reflects a large number of parameters and characteristics. This article will discuss the methodology for deciphering the size of the disk and choosing it for the car.
Reading Characteristics
The entire line of parameters printed on the disk can be divided into several components. It might look something like this: 7jx16 H2 5x130 ET20 d74.1. To decipher the size of the disk, you need to consider each element in order.
It is worth noting that sometimes the location of the parameters in the string can change places and slightly differ in characters. But the general algorithm for decrypting the size of a disk on a car is always the same.
Width
Wheel width is in inches and comes first on the specification line. In fact, this is one of the determining parameters when choosing. Based on this value, the tire width will be selected in the future. Marking examples: 8.5 12, 9.5.
Experienced drivers claim that the greater width significantly affects the handling and dynamics of the car.
Edge design marker
Immediately after the number with the width of the disk, the letter value follows. As a rule, for a car enthusiast, it carries little information and is used mainly by service specialists. In most cases, it is marked with the letter J. But it can also be JJ, K, JK, B, P, D.
Disc diameter
In rim dimensions, the bead flange design symbol is followed by the numeric value of the diameter in inches. It is also one of the main parameters. Changing the diameter of the disk in a larger direction can also change the size of the tire used. And this, in turn, will have an impact on handling on the track. For example, on low-profile tires, all the bumps in the road will be clearly felt, and the entire load will fall on the shoulders of the suspension.
Hampas
Next in order is the designation of humps. These are protrusions along the edges, which allow you to more securely mount the tire. They can take the values H, H2, X. Here H is a regular hump, X is a truncated one. The coefficient after it is the number of sides on which the hump is located.
PCD
The next parameter in order is sometimes referred to as PCD. It is marked something like this: 5x130. The first digit in the entry shows the number of disk mounting bolts, and the second - the diameter on which they are located in millimeters. This is one of the most important parameters when deciphering disk sizes.
The values can vary within very small ranges, up to tenths of a millimeter. Therefore, if the characteristic is not matched exactly, there is a possibility that the bolts will not be able to fall into place. As a result, the fastener will not be tight. This means that you will then have to carry out frequent balancing and repairs.
Departure
This parameter consists of numbers and letters. Maybe so - ET20. In short, it means the distance between the plane of the disk and Can be negative and positive. The first option will visually make the disk more convex relative to the car. The second is deep.
A significant change in disc offset affects the steering axle offset, increases bearing wear and, in some cases, worsens handling. Auto manufacturers strictly regulate the size of the permissible departure and grossly violating it means hitting some parameters of the car, which may worsen.
Center hole diameter
It is measured in millimeters and is indicated by letters and numbers. For example, so - d85. When deciphering the size of the disk, you should pay special attention.
Extra options
When deciphering the size of disks, other characteristics can be used. For example, the maximum disk load. Passenger cars use discs with a margin of safety, which should be enough for its needs. But if it turns out that it will be moved to another type of equipment, for example, an SUV, then the nearest small hole can damage the disk.
The load is usually specified in pounds. To get kilograms from them, you need to divide the existing value by 2.2.
When deciphering the dimensions of alloy wheels and subsequent installation, it may not fit the car. This state is called the X factor. And it is connected with the fact that alloy wheels can be of the most diverse shapes, while fully complying with the declared and required dimensions. Therefore, in order to avoid buying an unsuitable model, it should first be installed on the car, at least for a couple of bolts and slightly scrolled. If nothing interferes, does not rest, then the disk is ideal for a car.
How to choose the right disk?
In addition to technical characteristics, aesthetic properties, as well as the method of manufacture, can affect the choice.
Appearance is chosen based on personal preferences. Some people like more needles, some like fewer petals.
It is also worth knowing that wheels are divided into two broad categories: steel and alloy wheels.
Steel or stamped are made from a sheet of metal, subsequently connected by welding. This approach can significantly reduce the cost of production. In addition, steel wheels are easier to repair and rebuild. Although this is required quite rarely, as they have good strength. On the other hand, the stamped approach generates inaccuracies in production, which promises problems with subsequent balancing. Also, the significant weight of steel increases the overall mass.
Alloy wheels are lightweight. The process of their production allows you to create a wide variety of shapes and designs. They cost a little more, but as a result, aesthetics and practicality take such discs far ahead.
The light-alloy look is also in turn divided into two categories: cast and forged. The first type has a granular structure, which makes the product fragile. This is a known problem with alloy wheels. With prolonged use on rough roads, they tend to split.
The forged disc has a fibrous structure, which gives it special plasticity and prevents the disc from forming chips and cracks. It is very difficult to deform or destroy it.
A small decryption example
It is worth disassembling the markings on a single product. For example, to decrypt the sizes of disks on Valdai. There is such a designation - 17x6 6x222.25 Et115 Dia160. Here the wheel diameter in inches comes first. It is followed by the width under which the tires are selected.
Then follows the number of bolts and the diameter on which they are placed. These are 6 and 222.25 respectively. Et115 is the disc offset. In this case, it means that it is 115 mm inward from the mounting plane. That is, the disk is convex.
Dia160 is the diameter of the central hole in millimeters.
Finally
Careful decoding when choosing them will allow you to accurately select the necessary parameters and not become a victim of an unreasonable purchase. Knowing about their characteristics will be useful not only for novice motorists, but also for more experienced ones.
When selecting discs, it is necessary to take into account the parameters and quality car rims. Rims and wheels in general are considered a very important part of a car, respectively. selection of wheels must be accurate. Since well-chosen and correctly selected car rims will affect the level of contact of the car with the road surface, the smoothness of the ride and the ease of control in the future. In addition, from the choice of certain rims will depend on the trajectory of the braking distance. For accurate and correct selection of disks for a car, it is necessary to know all the parameters of the disk. After all, only the right parameters will help determine the wheels for your car, as well as significantly improve the aerodynamic qualities of the car and prevent premature tire wear.
Select rims by car make
When selecting car rims it is necessary to take into account a number of mounting parameters, which include the center distance to the hub, the width of the rim, the diameter and density of the axial hole of automobile disks. In order to independently determine all these parameters, you must have sufficient experience and skills, or spend time studying all these data and all sorts of nuances.
It has long been known that car wheels are almost a quarter of the total surface area of the car. Therefore, it is not at all surprising that most car owners strive to give their car ambition and individuality, while trying to choose wheels for cars, which will be the most suitable for the needs of motorists. Today, most car owners use cast wheel rims therefore, a large demand creates an offer. Such a variety of proposed models can greatly complicate the selection process. That is why the correct selection of the parameters of car rims is considered necessary in order to be able to evaluate the whole picture as a whole.
Today, selling tires and alloy wheels is more of a matter of trust. Because if you take into account a huge number of disc manufacturers and tires, buyers are often confused at the time of selection. Besides selection of wheels It is considered a rather complicated process that requires certain knowledge and skills in this area, since the choice also concerns the load and other permissible vehicle parameters.
Eg, stamped car rims are considered the cheapest of all existing types of rims. That is why such models of rims are installed mainly on budget cars. In addition, it is these rims that are considered the most durable and practically indestructible. Therefore, unlike all other existing types of automobile wheels, only stamped rims do not unfold during a strong impact, but only bend. Stamped car wheels are very easy to restore, after which they are used further.
How to choose the right wheels for the car?
To make the right choice and choose the right rims, in addition to knowing all the important parameters, it is necessary to distinguish between types of disks. In addition to the cheapest stamped wheels, there are also alloy wheels, the main advantage of these light alloy wheels their relative lightness is considered. Standard cast wheels, which are made of aluminum, are about a kilogram lighter than iron car rims.
In addition, cast wheels are almost completely resistant to corrosion, and besides, the manufacturing technology of these wheels provides an excellent opportunity to give them absolutely any shape, and this is too important for design.
It’s just that you shouldn’t idealize cast car wheels, because if an iron disk breaks, you can reanimate it very easily, but if microcracks appear on the cast car disk or the disk just cracked, unfortunately, this cannot be corrected and restored.
In addition to stamped and cast car wheels, there are also forged wheels. This type of rims is considered the same stamping, only hot. At the time of production of forged wheels, manufacturers use magnesium and aluminum alloys. Of all existing types of car rims forged wheels are considered the easiest. The difference between forged wheels and alloy wheels is that at the moment of impact, they do not crack, forged wheels simply bend, which is why they can always be repaired.
But if a motorist wants his car to look stylish, fashionable and beautiful, forged wheels will not be a very suitable option.
Recently stamped and forged car rims have been replaced by cast rims. Experts say that competent conduct selection of alloy wheels showcase your great sense of style. And it is simply impossible to argue with this, because the selection of rims is a necessary and important detail for any car, and besides, it is part of the image component. Therefore, most modern car owners do not save at all on the purchase of high-quality rims and do the right thing.
Internet shop of tires and disks "Dilijans" offers motorists a huge selection of high-quality car rims for various car brands.
In order to choose the right tires for the wheels, you need to know certain parameters, the non-observance of which will seriously worsen the car's behavior on the road. Since the tire is put on the rim of the disc, the width of the profile must be commensurate with it. We note right away that, despite the tuning common in recent years, automakers categorically do not recommend this. After all, if the sizes of disks and tires vary greatly, then the contact patch will not be even, which means that the control can get out of control.
In general, the question of matching tires and wheels can be considered from two sides. The first is the selection of tires and wheels based on the manufacturer's recommendations, and the second is this fitment. Fitment is the study of the fit of a tire on a rim and the position of the wheels relative to the wheel arches, which includes negative camber, low landing and other delights, which we will not talk about, because we consider it more important to tell you how to choose the right one from the point of view of safety and comfort tires to wheels.
To choose the right tires for the rims, you need to know the labeling of the rims.
Ideally, that is, to be sure of safety, the PCD of the disc (the diameter of the circle of the centers of the mounting holes) cannot be changed. In extreme cases, the sizes of wheels and tires may not match each other quite a bit, but then eccentric bolts are used for fastening, which allow you to install wheels with PCD 100 mm on cars with PCD 98 mm. However, it is worth noting that the maximum difference in displacement should not exceed 2 mm, and ideally, the tires and rims should still match one hundred percent.
The dimensions of the rims and tires must also match with their central hole, but if for some reason this is not possible, an adjusting ring (it is also a spacer ring) will come to the rescue. The adjusting ring has an outer diameter equal to the diameter of the hole in the disk, and the inner diameter corresponds to the diameter of the vehicle hub. If the adjusting ring is set correctly, then the running characteristics will not change. It should be noted that the discs do not have stamped mounting rings. Install them only on .
The labeling of the disks does not indicate the maximum load ( MAX LOAD), you can find out this parameter either in the passport, which some manufacturers of domestic wheels attach to their products, or look for this information on the website of the wheel manufacturer. This information is not very important, since manufacturers usually make discs with a margin of safety. But, if for some reason you decide to put, say, wheels for a car on a jeep, then the maximum load of the disk will be an important parameter. And if it is not taken into account, the wheel may not withstand the load and deform, even falling into a small hole.
In addition, even if the dimensions of the tires and rims match in all respects, there is still a risk that the rim will not fit on the car. The reason for this is the so-called X-factor, when the disc rests on the suspension parts or caliper, which is associated with the shape of the stamping or casting. Therefore, we recommend that you first try it on before beading the tire on the wheel.
Correspondence table for the width of tires and wheels
|
Tire height |
Tire size |
Disc Width (inches) |
||
|
R12 |
||||
|
82 |
125R12 |
3,5 |
3.0 |
4.0 |
|
70 |
145/70R12 |
4,5 |
4.0 |
5.0 |
|
R13 |
||||
|
82 |
145R13 |
4.0 |
3,5 |
5.0 |
|
80 |
135/80R13 |
3,5 |
3,5 |
4,5 |
|
70 |
135/70R13 |
4.0 |
3,5 |
4,5 |
|
65 |
155/65R13 |
4,5 |
4,0 |
5,5 |
|
60 |
175/60R13 |
5.0 |
5.0 |
6.0 |
|
55 |
195/55R13 |
6,0 |
5,5 |
7,0 |
|
R14 |
||||
|
82 |
145R14 |
4,0 |
3,5 |
5,0 |
|
80 |
175/80R14 |
5,0 |
4,5 |
5,5 |
|
70 |
165/70R14 |
5,0 |
4,5 |
6,0 |
|
65 |
155/65R14 |
4,5 |
4,0 |
5,5 |
|
60 |
165/60R14 |
5,0 |
4,5 |
6,0 |
|
55 |
185/55R14 |
6,0 |
5,0 |
6,5 |
|
R15 |
||||
|
82 |
125R15 |
3,5 |
3,0 |
4,0 |
|
80 |
185/80R15 |
5,5 |
4,5 |
6,0 |
|
70 |
175/70R15 |
5,0 |
5,0 |
6,0 |
|
65 |
185/65R15 |
5,5 |
5.0 |
6,5 |
|
60 |
195/60R15 |
6,0 |
5,5 |
7,0 |
|
55 |
185/55R15 |
6,0 |
5,0 |
6,5 |
|
50 |
195/50R15 |
6,0 |
5,5 |
7,0 |
|
45 |
195/45R15 |
6,5 |
6,0 |
7,5 |
|
R16 |
||||
|
65 |
215/65R16 |
6,5 |
5,5 |
7,5 |
|
60 |
225/60R16 |
6,5 |
6,0 |
8,0 |
|
55 |
205/55R16 |
6,5 |
5,5 |
7,5 |
|
50 |
205/50R16 |
6,5 |
5,5 |
7,5 |
|
45 |
195/45R16 |
6,5 |
6,0 |
7,5 |
|
40 |
215/40R16 |
7,5 |
7,0 |
8,5 |
|
R17 |
||||
|
55 |
225/55R17 |
7,0 |
6,0 |
8,0 |
|
50 |
205/50R17 |
6,5 | ||
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.
Find tires / tire catalogDeciphering 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 called simply - "profile".
Since the tire profile is a relative value, it is important to consider 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 indicated (for example, 185/R14С), 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- stands for the radius of the tire, but this is precisely 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 - diameter of the wheel (disk) 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- tire speed index. The larger it is, the faster you can drive 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 markings:
There are two different markings for American tires. 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.
For example: 31x10.5 R15(corresponds to European size 265/75 R15)
31
is the outside diameter of the tire in inches.
10.5
- tire width in inches.
R- a tire of a radial design (older models of tires 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- 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 M&S tire marking (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 pictogram (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 driving a car at a speed of no more than 80 km / h with a FULL pressure drop in the tire (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 sidewall of the tire 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 this is a radial tire design. 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 heat resistance of tires at high speeds on a test bench (A is the best indicator).
Traction A, B or C- the ability of the tire to brake on a wet roadway.
Treadwear; relative expected mileage compared to a specific US standard test.
TWI (Tread Wear Indication)- 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- Encoded manufacturer's address, tire size code, certificate, issue date (week/year).
Using the tire calculator, you can easily calculate how the outer dimensions of the wheel, ride height (clearance), speedometer readings and other characteristics will change when you install tires with a different size on your car. The calculator calculates all tire sizes in millimeters, and the vehicle speed in km / h.
Also, the calculator will help you calculate the required rim width for a specific tire size.
How to use the tire calculator:
First enter the standard size installed on your car, and then the one you want to install and click "calculate". The table on the right will show the results of the calculator's calculations.
Detailed information about tire marking in the section: tire marking.
We recommend that you install only the factory tire sizes that are listed in the owner's manual for your machine. Installation of non-standard sizes may void your dealer's warranty and may affect vehicle performance and handling.
Tire calculator for European tires
Old size:
new size:
145 155 165 175 185 195 205 215 225 235 245 255 265 275 285 295 305 315 325
/ 25 30 35 40 45 50 55 60 65 70 75 80 85
12 13 14 15 16 17 18 19 20 21 22 23 24
Found in catalogue:
175/70R13-
175/70R13-
When recalculating tire sizes on a calculator, it should be borne in mind that:
With an increase in the diameter of the rim (and, as a result, a decrease in the height of the tire profile so that the outer diameter of the wheel remains unchanged), the load on the car suspension increases, as well as comfort worsens (the car will become noticeably stiffer).
With an excessive increase in the tire profile, the car becomes a “roll”, it is worse controlled, and at critical values \u200b\u200bof the profile height, the tire may begin to cling to body parts and suspension of the car, which will subsequently lead to its destruction.
