On the shelves of car shops you can find several varieties of wheels:

  • stamped — inexpensive steel wheels, most often from the factory configuration of cars;
  • alloy wheels made of light alloys for every taste and shape;
  • forged — high-strength discs produced by hot volume stamping technology;
  • prefabricated — consist of a forged rim and a cast "plate", combine the advantages of cast and forged discs.

The most widespread are cast wheels. It is on them that they are often transplanted from "stampings", which is explained by the wide variety of shapes and the lightweight weight of such products. What is the gain? Alloy wheels reduce the overall weight of the car, provide responsive reactions to steering commands, and simply improve the appearance of the car.

On alloy wheels, even the conditional Daewoo Lanos looks completely different.

It's up to you to decide which disks to put on the car by type. And to make sure they fit, consider the following parameters:

  • landing size;
  • diameter of the hole in the centre of the disc (DIA);
  • number and diameter of mounting holes (PCD);
  • disk width;
  • wheel departure;
  • the shape and dimensions of the mounting bolts.
Hybrid Disks Flow Forming

Landing size

The diameter of the disk circumference in inches is indicated by the letter R and the number after it. This marking came from the segment of car tyres. The permissible diameters of the discs for a particular car are indicated in the operating manuals and on the stickers in the doorways. It is not recommended to deviate from them — the geometric incompatibility of the wheels changes the parameters of the suspension and accelerates the wear of the chassis components. However, exceeding the permissible diameter by an inch or two (provided properly selected low-profile rubber) usually passes without any consequences. In this matter, it is important to study the reviews of other car owners who have already tested larger diameter discs on board their "iron horse".

Diameter of the central hole (DIA)

The size of the central hole of the DIA wheel is indicated in millimetres. It must correspond to the diameter of the centering protrusion on the hub of the car. Deviation of this indicator in a smaller direction is not allowed, because the disk simply will not fit on the hub. If the mismatch turns out to be in a big way, you can centre the disk using a set of special spacer rings.

Diameter of the central hole of the wheel disk.
Interesting fact. Many manufacturers produce wheels with a central hole of a deliberately increased diameter and in addition to it they give a set of adapter rings. As a result, the disk can be installed on various car models.

Number and diameter of mounting holes (PCD)

The parameters of the "loosening" of the wheel must be strictly observed. They describe the distance from the bolts or studs to the centre point of the wheel, as well as the number of holes or studs on the rim. The PCD value is determined by the vehicle manufacturer and is written as a digit with a multiplier.

The "loosening" of the wheel is the number of fasteners and the distance between them and the centre point of the wheel.

Take, for example, the size of the PCD 5x110. He points out that there are 5 bolts on the rim with a diameter of 110 mm, "seated" at the same distance. Plus or minus, you can "play around" with unsuitable "loosening" parameters with the smallest difference in the diameter of the circle (1-2 mm) by resorting to the services of bolts with a "floating cone". The working conical part of them is made in the form of a separate ring and shifts relative to the longitudinal axis of the bolt when tightening.

Disks with hidden loosening

Disk Width (J)

The width of the rim of the wheel is measured in inches and is indicated by the letter J. Too wide wheels may come into contact with the fender of the car or its suspension components. In addition, it is the disk width parameter that affects the selection of a suitable rubber — it should be 25% less than the width of the tyre profile.

The disk width parameter directly affects the selection of a suitable rubber.

The use of too narrow or too wide discs is undesirable, since it is fraught with a violation of the design profile of the tyre. However, small deviations to the sides are still allowed: 0.5-1" for disks with a diameter up to 15" and 1-1.5" for disks with a diameter over 15".

Wheel Departure (ET)

The departure of the ET disc determines the deviation of the wheel centre from the attachment point to the hub. It can be zero, positive (the hub of the disk protrudes outward relative to the median axis of the rim) and negative (the hub is recessed inward relative to the axis).

A clear difference between zero, positive and negative departures.

Disks with a larger departure than prescribed in the technical documentation for the car will be located deeper inside the wheel arch, with a smaller one — protrude outside the car body. Wheel rims with incorrectly selected overhang increase or decrease the track and can cause accelerated wear of suspension units or hub bearings due to uneven load distribution.

Shape and dimensions of mounting bolts

Usually, the working part of bolts and nuts for wheels of stamped "rock" has a conical plane shape. Bolts of increased length (due to the greater thickness of the disc) and fasteners of various shapes (with a conical, hemispherical or flat "head") are used for "casting". In order for the disks to become as expected, this point must be taken into account.

It is best to select wheels by car brand — virtual selection on the sites of large Internet resources is guaranteed to find suitable wheels. Also, there will definitely be parameters recommended by the vehicle manufacturer in the detailed operating manual of a particular car.