How to find out what wheels are on a car

How to find out your rim size

The correct choice of wheel rims depends on the technical characteristics indicating all the parameters, namely width, diameter, offset, as well as DIA (hub mounting diameter) and PCD (drilling parameters).

You also need to know the marking designation. It indicates the standard parameters of any type of wheel products:

Markings are indicated on the inside. Typically, manufacturers duplicate them in accompanying documents and on packaging if the product is new.

Disk options

To determine what the marking means, you need to know the width and diameter of the wheel product.

Drilling or bolting

This is one of the most difficult parameters to study, indicating the diameter of the mounting bolts. Drilling is measured from the center area of the stud to the opposite area where the element is located on the wheel.

Quite often, manufacturers indicate the disc bolt pattern parameters using shot depending on the number of holes for fastening.

Let's assume the figures are 6/222.25. The first number shows the number of drillings for fastening the bolts, and the second number indicates the drilling in millimeters.

Disc offset

This indicator is marked with the English letters ET. What is ET in disks and why is it needed? The indicator indicates the distance from the plane of the wheel product to the middle zone of the rim. The mating surface of the wheel product indicates the pressing plane of the disk to the hub.

Departure parameters can be:

with zero indicator;
with negative;
with positive.

Zero offset indicates that the plane of the disc corresponds to its middle zone. Thus, the lower the indicator, the more the wheel product protrudes from the outside of the car. If the overhang indicator is increased, this means that the disc is deeper into the interior of the car.

It is also necessary to take into account the fact that depending on the width of the product, the overhang indicators differ. Manufacturers indicate in the documentation accompanying the vehicle a smaller offset value for wheels with a large width.

Diameter and other parameters of the disk schematically

What is HUMP(H)?

The hump is the protrusion of a ring on a disc rim. This element is used as protection against car tires coming off. Usually 2 humps (H2) are used for a wheel.

In some cases, a hump may not be used or only one may be used, depending on the vehicle configuration. Types of Humps:

combined (CH);
flat (FH);
asymmetrical (AH).

PCD Disc Parameters

The PCD value refers to the diameter of the circle of the center holes on the wheel rim. That is, this is the diameter of the holes for fastening the bolts.

DIA drive option

The DIA parameter indicates the diameter of the hole located in the center of the disk. Casting manufacturers prefer to create a large DIA center hole diameter. This is done to ensure that the wheels are applicable and universal for all types of cars.

Despite the fact that the size of the hub may differ depending on the vehicle model, the auto disk is installed using an adapter ring or bushing.

Marking

As an example, consider the markings of the 9J x20H PCD 5×130 ET60 DIA 71.60 wheel rim:

The number 9 indicates the width, measured in inches. To convert inches to centimes, the total figure is multiplied by 25.4.
The letter J indicates the design elements: the shape of the disc flanges. This parameter does not play an important role in the selection.
The letter X denotes the indivisibility of the disc.
The number 20 indicates the landing diameter of the wheel product. This indicator corresponds to the fit of a car tire.
The letter H denotes the presence of one hump or ridge on the rim.
The abbreviation is PCD 5×130, where the number 5 indicates the number of drillings for fastening the nuts or bolts and the number 130 indicates their PCD diameter in millimeters.
The ET60 marking indicates disc offset. In this situation the figure is 60 mm.
The DIA value 71.60 indicates the diameter of the center drill. Typically, DIA corresponds to the fit of the hub and is indicated in millimeters. If the DIA is greater than the hub diameter, then a centering ring is used to install the disc.

The following information is also included with the label:

ISO, SAE, TUV - these abbreviations indicate the organizations that tested the wheel product, similar to the Russian GOST. The standards that correspond to the wheel marking are also indicated.

Maxload indicates the permissible load on a car wheel. This indicator is indicated in kilograms and pounds.

What does parameter 700c mean?

This designation is used for large types of wheels on SUVs and Nivas. According to the accepted ISO classification, this figure is 29 inches. Typically 700c wheels are used for off-road racing.

Due to the use of 29 inch wheels:

management indicators are improved;
braking distance on unpaved surfaces is reduced and aerodynamics is increased;
the vehicle's cross-country ability on soft soils and sand increases;
it becomes possible to install powerful brakes.

To select wheels that match a particular type of car, it is recommended to determine the diameter of the wheel and analyze the markings indicated on the rim. Also, do not forget that safe driving ultimately depends on this element.

Wheel size

Reading time: 8 minutes

Car owners around the world are often faced with the problem of replacing their wheel rims. This happens due to forced reasons - when they are deformed, broken, worn out, or at the request of the car owner himself, due to a too unpresentable appearance, small size and for other reasons. Thus, the car accessories market is always ready to offer its customers a wide range of products and goods for every taste and budget.

What is the standard disk size?

The standard wheel size is a characteristic of the wheels that are installed by the automobile concern at the factory in accordance with the requirements of technology, the class of the vehicle, as well as strength calculations carried out by the engineering personnel of the enterprise.

Wheel store

Coming off the assembly line, the car acquires the following basic wheel rim parameters:

The shape of the rim flange, designed to securely fix the tire. This parameter for passenger cars, regardless of model and modification, is usually expressed in the letter designation J or JJ.
The width of the rim of the product, on which the final tire size depends. It is expressed in inches in increments of 0.5 units. As a rule, standard car brands have a range of this dimension from 4 to 12 inches, which corresponds to tires from 145 to 345 mm.
The most important parameter is the radius of the product, which is defined as the diameter of the rim without taking into account the edges and ranges from 12 to 24 inches, respectively, written as R12, R13, ..., R22, R23, R24. The radius of the tire, which should be similar to this value, as well as its profile, depending on the size of the wheel arch and the technical requirements of the manufacturer, depend on this important parameter. So, on the R16 for the Toyota Land Cruiser 200 you can install tires with a profile height of 90 mm. The same radius, but for the VAZ 2110, entails only low-profile tires with a dimension of 35-40 mm.
Also at the factory, the wheel offset range required for a specific brand is assigned, that is, the ET parameter, or the value in projection from the place where the disk is fixed to the hub to its mating plane on the inside. So, the larger the ET value, the deeper the wheel will sit under the wheel arch and vice versa. This disc dimension can be negative, and in this case the disc will protrude slightly beyond the dimensions of the body. The average range of this parameter is from -25 mm to +50 mm.
If the previous parameters allow for a slight variation in wheel dimensions, then such indicators as drilling and bolt pattern, as a rule, must be the same, otherwise the wheel simply will not fit on the hub.

Disc rim width and seat dimensions

Wheel drilling is the size of the central hole of the disk, with which it fits onto the axle. As a rule, it ranges from 50 to 120 mm, depending on the model, brand and class of the vehicle.
The disc bolt pattern is a parameter that determines the number of studs on the hub and their length. Designed for mounting wheels. For small cars, the studs are made with parameters 4×98, 4×100, that is, the disc is fixed to 4 anchors, each 98 or 100 mm long. In the case of business, premium class cars or SUVs, the number of fasteners increases to 5 or 10 pieces, and their length can increase to 150 mm.

How to determine the size of alloy wheels and stampings for a car

Of course, each original disk on a car is marked, and upon detailed inspection you can see a line with all the geometric parameters listed above. If for some reason, for example, in case of wear, this value is not readable, then you can always measure the wheel and display its marking yourself. This is done as follows:

To determine the width of a product, you simply need to measure its rim in millimeters with a ruler or tape measure, and then divide the result by 25.4 mm to convert it to inches.
The radius of the product is determined in a similar way, only here the diameter is measured. Many people mistakenly believe that the value with the R symbol indicates the radius of the disks, but this is fundamentally incorrect and it is the greatest distance between two points on the wheel rim that needs to be measured. In this case, for the accuracy of measurements, it is necessary to ensure that the measuring tool passes strictly through the center of the disk, because otherwise the car enthusiast will only be able to measure the chord, and the disk radius indicator will be incorrect. The result obtained must be divided by the same 25.4 cm to obtain the parameter value in inches. It should be noted that the measurement may well have an error of +/-5 mm, since radius can only be expressed as a whole number.
The most difficult thing is to measure the wheel offset, that is, determine the ET parameter. To do this, you need to lay the wheel flat, install a wooden strip on it, equal in length to the diameter of the metal part, and then measure the distance in millimeters to the mating plane of the disk. Then the wheel is turned over 180 degrees, and the procedure is repeated again, but for the reverse side of the product. The results obtained must be substituted into the formula ET = (X + Y)/2, where X is the first measurement, Y is the second, and ET is the desired offset indicator, all units here are indicated in millimeters.

Other disk size characteristics

To determine the drilling or diameter of the mounting hole, the car enthusiast only needs to measure the greatest distance between the edges of this perforation, and then look at the nearest typical value in the table of correspondences and deviations. The size of the wheel rim holes depends solely on the design of the hub for a particular car brand.

The size of stamped discs is determined according to the same scheme, without any special features.

Decoding the wheel size

So, in order to correctly decipher these inscriptions, below are some specific examples that a car enthusiast can see on his rims.

The owner of a Lada who has decided to change the wheels to more presentable ones, as a rule, sees on the disk the inscription 5.5J x 15 ET42 d56.1 4x98, which means a wheel disk with a rim width of 5.5 inches, a J edge shape, non-separable ( indicator “x”), with a radius of 15 inches, a positive wheel offset of 42 mm, a mounting hole diameter (drill) of 56.1 mm, mounted on 4 studs of 98 mm each (bolt pattern indicator).
The letter J, depending on the class, weight and model of the vehicle, can be replaced by JJ, K, JK, B, P or D, which must correspond to the marking of the purchased disk.

Determining wheel offset

Also on the wheel there may be a hump or H designation, for example, 6.0J x 17 H2 ET38 d65.1 5x112. Hump refers to special protrusions along the sides of the disc, which increase the reliability of fastening the rubber to the metal. So, this indicator can be marked as H - single hump, on one side of the wheel, H2 - double, respectively, on both edges, or X (truncated hump).
In addition, for drivers of minivans, pickup trucks and other vehicles designed to transport loads over 900 kg, it is very important to purchase highly durable products that can withstand significant loads.

In addition, an important indicator of the strength of the product is the maximum tire pressure characteristic, and on the rim, as a rule, they write a value such as Max PSI 50 Cold, that is, the maximum tire pressure cannot exceed 50 pounds per square inch, or after translation - 3.5 kilograms per square centimeter.

The prefix Cold means that such measurements should be carried out exclusively on a cooled wheel, because, as is known, when heated, for example, in hot weather, the gas inside the wheel expands and has a stronger effect on the rubber from the inside. Accordingly, together with the softening of the polymer material due to high temperature, when operating overinflated wheels, there is a high risk of their rupture, which can lead to an accident on the road.

The last thing that can be read on the rim is letters such as SAE, TUV, ISO or ROSTEST, and all these characteristics mean an indicator of the quality of the product, that is, that it has passed mandatory certification after a series of tests on special stands and in full complies with the Russian and international standards required for it.

Other methods for determining disk sizes

Often the buyer does not want to deviate from the sizes of car rims dictated by the manufacturer of the car brand he owns, and then it will be enough to select a wheel rim according to the characteristics specified by the manufacturer. Thus, in many large points of sale, consultants have a specialized program installed on their computers that makes it easy to select the right wheels.

The client turns to the hall employee for help, and the specialist enters the make, model, modification of the vehicle, its year of manufacture, as well as other parameters if the system requests them, into special fields in the program.

As a rule, such systems are interfaced with a warehouse accounting program, and the seller immediately has the opportunity to inform a potential buyer about the availability of products at the point of sale, about the brands that produce these products, as well as about their prices, and the client can immediately decide on the design of the grille, material, disk size, and also correctly calculate your budget for the purchase.

Thus, the client will always be confident in the quality of the product, as well as in the selection of the absolutely correct size, and the warranty will never be removed from his car. Of course, many car enthusiasts are not satisfied with the too harsh pricing policy of official dealers, but the guarantee of long, reliable and safe operation more than pays for all overpayments by the client, and if you find out the prices from brand representatives, they are not much different from other outlets selling quality products.

It should also be taken into account that an incorrectly selected wheel size often leads to rapid wear of the calipers, brake system, hubs and other suspension elements, which will result in much larger repair costs.

All about disk sizes!

Choosing rims for wheels - a few tips.

The main indicator that a car owner should know when choosing rims is, of course, the size. Wheel rims for your car are selected taking into account the size of the rim itself, the fit size of the car tire and mounting dimensions. wheel and tire size indicators is usually called the “rim-tire” dimension, and the mounting dimensions are called “wheel-car”.

Determine the rim-tire size of the disk.

The generally accepted diameter grid for mounting wheels on cars and SUVs ranges from 10 to 24 inches. The majority of cars are equipped with wheels of sizes 13, 14, 15, 16 inches.

the size of the disk has become increasingly popular lately - motorists change the disk size from 13 to 14, from 14 to 15, and so on. This is done in order to improve the driving performance of the car; low-profile tires contain less rubber and more metal in the starting material. If the wheels are steel, it is not always possible to increase the mounting size; if this is done, the weight of the wheel increases significantly. The best option is to use light alloy wheels - they do not make the wheel heavier and allow you to increase the mounting diameter.

Sports cars must be equipped with larger rims than regular cars. For example, a sports BMW M-3 requires wheels of at least 17 inches in size.

Rim width

The width of the wheel rim for a passenger car often does not exceed the following values: 3.5, 4.0, 4.5, 5.0, 5.5, 6.0 and 6.5 inches, and in some cases, wheels with a width of 7 or more are used up to 13.5 inches. Typically, rims of this width are mounted on sports and off-road cars, as well as small trucks.

How to choose the correct rim width.

There is one important rule in the automotive world: the width of the rim should always be 20-30% less than the width of the main tire profile.

For example, a car enthusiast is looking for a wheel with tires with parameters 195/70R15. The profile width of this rubber is 195 mm. In inches, this value will vary within 7.68 (to obtain the value, divide 195 by 25.4). If you subtract 25-30% from the resulting value, then the final number after rounding will correspond to the basic wheel standards. As a result, you can get a rim with a width of 5.5 inches - this is the type of car wheel that is most suitable for 195/70R15 tires.

The use of very wide or too narrow rims is extremely undesirable because:

the projection of the tire profile is disrupted
rubber sidewalls are deformed
the general characteristics of the car deteriorate
the required lateral rigidity of the wheel disappears

The maximum permissible deviation in rim width, which is acceptable for passenger cars, is no more than 0.5 - 1 inch (for a disk up to 14 inches), 1-1.5 (for a disk 15 inches or more). It is best to purchase a wheel rim that exactly matches the tire width.

Popular mounting sizes.

The main mounting dimensions of the wheel rim include the following parameters:

For example, PCD 100/4 has 4 bolt holes with a total diameter of 100 mm.

Attention! The holes themselves for fastening the wheel rim are made with sufficient tolerance to the diameter, so when choosing, you can make a mistake by a few millimeters, which will practically not play an important role. For example, on a car hub with a PCD 4/98 arrangement, discs with a PCD 4/100 are often used. Such parameters are almost impossible to distinguish by eye, but in practice and the quality of operation, a couple of millimeters can have a significant impact. The main symptom is the frequent loosening of the wheel nuts, as well as partial wheel beating while driving. Eventually the threaded connection will finally lead.

The diameter of the factory central hole on the disk (DIA designation). Standard car wheels (stamped), which are produced at the same factory as the car, have a hole already fitted to the hub axle. This hole on the wheel plays a role in installing and centering the disk. Very often, manufacturers (especially of alloy wheels) deliberately increase the diameter of such a hole, but this does not affect the quality of operation of the car, because in such cases the wheel is successfully centered according to the PCD.

Dimensions of bolts and wheel nuts. When replacing a factory stamped wheel with a cast one, it is recommended to use slightly longer wheel studs and bolts. This is due to the fact that a light-alloy car wheel is much thicker than a regular one and simple tightening elements simply will not cope with the task; accordingly, the car enthusiast will not be able to tighten the wheel. It is also worth noting the variety of bolt tightening methods. For example, on a new cast disk, the holes are designed to be screwed into a sphere, while standard bolts are screwed into a cone.

Overall wheel offset. The offset is the distance between the longitudinal plane of the car rim and the mounting plane of the assembled wheel. Departures can be zero, negative and positive. For each specific car model, the manufacturer provides its own reach, which is designed taking into account the weight of the car, its driving characteristics and other characteristics. The controllability, stability and general behavior of the vehicle on the road at different speed conditions, in particular on sharp turns, depend on the reach. If the offset is incorrect, the load on the wheel bearings, the chassis of the machine and the steering mechanism increases. German manufacturers designate wheel rims by offset ET (example ET35 (mm)) - if the offset is positive, in the case of negative ET - 35. In turn, the French designate the parameters with the words DEPORT, and in some cases OFFSET.

Attention! Never install rims with abnormal offset. The smaller the offset, the wider the overall track of the vehicle. This gives overall stability and an aggressive look to the car, but unnecessarily loads the suspension, hubs and axle shafts. Accordingly, it will not be possible to reduce the overhang because the wheel tires will rest against the suspension element or the brake disc.

What should be the marking of wheels for a car?

Where are the markings on the discs?

The main marking is most often stamped on the front surface of the disc. Depending on the country of production, the location of application may change, and the designation symbols also change.

Standard marking example: 7 1/2Jx15H2

The value 7 1/2 is the width of the wheel rim in inches (7.5 inches); The number 15 is the disc diameter (in inches).

The following symbols are quite difficult to decipher, but these meanings are of great value not for the consumer, but for the manufacturer and seller themselves.

The letter J is code information that is responsible for the design features of the edges of the wheel rim (angle of inclination, radius, rounding). Depending on the design, the rim may be marked JJ, JK, K or L.

H2 is a code value that carries information about the shape of the annular humps (protrusions) on the rim flange. These bumps hold the tire and prevent it from jumping off. There are a large number of humps:

H (Hump) - simple
FH (Flat Hump) - flat type
AN (Asymmetric Hump) - asymmetric
CH (Combi Hump) - combined

In rare cases, manufacturers do without humps completely. The rims are equipped with a factory special shelf SL (Special Ledge), the design parameters of which are adjusted so that the rubber holds with maximum reliability, without clinging to other parts of the rim.

Also indicated on the wheel rim:

main wheel offset (the value may be missing on American wheels, but in Europe the data is always available)
quality mark and manufacturer's mark
production date (year, week, for example, 0208 - this means that the disc was released in the 2nd week of 2008)
stamp of regulatory authorities (Alternative to domestic quality Quality Control Department). Many companies specifically brand their products not with ordinary numbers, but with whole images.
stamp of national quality standards
maximum load by weight (MAX LOAD in kg or lbs)

Additionally, the following is indicated on the wheel rim:

connection dimensions (PCD100/4)
maximum tire pressure for which the rim is designed (Example: MAX PSI 50 COLD)
type of production (FORGED-forged, cast, stamped and others)

The most prestigious are forged wheels, which are manufactured according to leading world standards.

Disc markings, symbols, terms on discs, designations

To choose wheels for your car, it is not enough to know the required diameter and the number of bolts for fastening. The disk must meet a number of parameters. The full disk size looks like this: 6.5×16 5/100 ET48 d56.1 . The ability to decipher symbols on disks will help you avoid mistakes when purchasing and disappointments when installing them on a car.

6.5 - rim width value . Indicated in inches. If you want to know the size in millimeters, then 6.5 must be multiplied by 2.54 (1 inch).

j (can be replaced by “ H2 ”) - for ordinary consumers these values are not important, because are service designations for manufacturers and sellers.

J is a value that encodes data on the design features of the edges of the rim flanges, such as their angles of inclination, radius/radii of curvature, etc.

H2 (short for Hump) - the presence of this designation indicates that there are annular projections (humps) on the rim flanges that keep the tubeless tire from sliding off the rim. The letter designation H means single (simple) hump. H2 - stands for double hump. There is also a Flat Hump - FH , Combi Hump - CH , Asymmetric Hump - AH . If there is an x sign between the designations of the width of the disk and its mounting diameter (as in this case), this means that the disk rim is one-piece, without humps.

5/100 - indicates the PCD value of the wheel (Pitch Circle Diameter). The number “5” is the number of fastening holes for nuts (bolts) on the disk, and in millimeters “100” is the diameter along which the fastening holes are located. If necessary, and there are no special instruments at hand, measurements can be taken with a regular stationery ruler.

IMPORTANT: The wheel mounting holes can be located on different diameters, which have a very tight tolerance relative to the central hole.

Warning! The mounting holes may have a small plus tolerance in diameter, which visually makes it difficult to accurately determine the PCD if it differs from the standard one by only 2 millimeters. For example, a wheel with a PCD value of 4/98 is often installed on a hub with a PCD value of 4/100. IS IT DANGEROUS. Only one nut (bolt) will be fully tightened. The mounting holes of the remaining 3 nuts will “lead”, as a result they will be undertightened or tightened skewed. As a result, the wheel will not be completely seated on the hub. When driving it will “beat”, there is a high risk that the nuts will gradually unscrew by themselves.

d - (example: d 66.6) - in millimeters indicates the diameter of the hub , or the value of the diameter of the central hole of the wheel. It is important that this parameter exactly matches the diameter of the vehicle hub mounting cylinder. Matching the sizes will ensure preliminary centering on the wheel hub, which will facilitate installation of the bolts.

ET - letter designation of disc offset , i.e. distance in millimeters from the mating plane of the wheel rim mounted on the car hub, and a conditional plane that runs in the middle of the wheel rim.

ET “positive” - the mating plane does not protrude beyond the conventional boundary.

ET “negative” - the mating plane is behind the imaginary plane.

In some countries, there is another designation for ET - OFFSET or DEPORT.

Examples of departure designations:

ET 46 - positive offset, 46 millimeters.

ET-20 - negative offset, 20 millimeters.

ET 0—zero offset.

Warning! It is dangerous to install wheels on a car whose disc offset differs from the standard one recommended by the car manufacturer. In an effort to give the car a sporty look, some car owners install wheels with a reduced offset. The car becomes a little more stable on the track, because... the wheel track becomes wider. And at the same time, the load on the car’s suspension and wheel bearings increases. And vice versa, it is impossible to increase the wheel offset - its wheel rim will rest against the brake disc. All this can lead not only to car breakdown, but also to an emergency on the road.

The wheel may also have the following symbols:

— Date of manufacture — (example: 0309) — means that the release date of the disc is the third week of 2009.

- ISO, SAE, TUV - the mark that is given by the regulatory body. This marking is confirmation that the wheel complies with international standards/rules.

— MAX LOAD 2000LB is the most commonly used value for the maximum wheel load capacity (in pounds or kilograms). In this example, the maximum permissible load limit is 2000 pounds, i.e. 908 kilograms. — PCD 4/100 — parameters of connecting dimensions; — MAX PSI50 COLD — maximum air pressure in the tire. In this example, no more than 50 pounds per square inch (3.5 kgf/sq.cm). “COLD” - translated as “cold” - a reminder that pressure measurements must be taken in a cold tire.

Recommendation from specialists at the online wheel store Kolesa Darom

Even if you feel that the technical terms are more or less clear to you, it is still better to select disks by consulting with a specialist directly at the time of purchase. This, at a minimum, saves money and time. And, as a maximum, it will save you from mistakes and, as a result, dangerous situations on the road.

Matching tires and wheels

In order to choose the right tires for the wheels, you need to know certain parameters, failure to comply with which will seriously worsen the car’s performance on the road. Since the tire fits on the rim of the disk, the width of the profile must be commensurate with it. Let us immediately note that, despite the widespread tuning in recent years, automakers categorically do not recommend this. After all, if the sizes of the wheels and tires vary greatly, the contact patch will not be even, which means that control may get out of control.

In general, the issue 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 the tire on the rim and the position of the wheels relative to the wheel arches, which includes negative camber, low seating and other delights that we will not talk about, since we consider it more important to tell how to choose the right one from the point of view of safety and comfort. tires to rims.

To choose the right tires for the wheels, you need to know the markings of the wheels.

Wheel rim marking R13 4×98 ET35 J5 D58.6

1. ET35 - departure. Distance from the mating plane to the center of the disk (in mm).

2. R13 - wheel rim diameter in inches.

3. D58.6 - diameter of the central hole for the hub (in mm).

4. 4x98 - the number of mounting holes and the diameter of the centers of the bolt holes (in mm).

5. J5 - rim width in inches (an inch is equal to 25.4 mm.)

Ideally, that is, to be sure of safety, the PCD of the disk (the diameter of the circle of the centers of the mounting holes) cannot be changed. In extreme cases, the sizes of the wheels and tires may differ slightly from each other, but then bolts with eccentrics 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 matching of tires and wheels should be one hundred percent.

The sizes of the wheels and tires must also match in their central hole, but if for certain reasons this is not possible, a mounting ring (also known as a spacer ring) will come to the rescue. The installation 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 car hub. If the installation ring is installed correctly, then the driving characteristics will not change. It is worth noting that stamped discs do not have mounting rings. They are installed only on alloy wheels.

The marking of the wheels does not indicate the maximum load ( MAX LOAD ); you can find out this parameter either in the passport that some manufacturers of domestic wheels attach to their products, or you can look for this information on the website of the wheel manufacturer. This information is not very important, since manufacturers usually make discs with a safety margin. But, if for some reason you decide to install, say, passenger car wheels on a jeep, then the maximum load of the disk will be an important parameter. And if you do not take it into account, the wheel may not withstand the load and become deformed, even falling into a small hole.

In addition, even if the sizes of tires and wheels match in all respects, there is still a risk that the wheel 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 due to the form of stamping or casting. Therefore, we recommend that you first try it on before beading a tire onto a wheel.

Correspondence table for tire and wheel widths