Know the Terms PCD and Offset on Car Rims
Car wheel modification is a simple modification that can enhance the appearance of the car. However, before doing so, car owners must understand two important terms, namely PCD and Offset. This is because the compatibility of wheels on a car is determined by these two factors.
What is PCD?
PCD (Pitch Circle Diameter) is a term used to define the diameter of the bolt pattern on a car wheel. Simply put, PCD can be interpreted as the diameter of the bolt holes in the center of the car wheel. For some people, PCD is also known as stud pattern or bolt pattern. PCD itself uses military units for its measurement.
The size of PCD refers to the power and load on the car. For those of you who want to measure PCD, you need to draw a straight line from each wheel bolt hole. The size of PCD varies widely, with examples like 4 x 100, 8 x 100, 5 x 114.3, and others. If PCD is written as 8 x 100, then the wheel has 8 bolts and the bolt diameter distance is 100 mm. Understanding PCD is very important because if you incorrectly determine the PCD, the wheel cannot be installed because it won't fit properly.
Read Also: List of Car Wheel PCDs and How to See Them, Let's Find Out!
What is Offset?
Meanwhile, the term Offset (ET) on wheels is used to define the distance from the centerline (the center point of the wheel) to the mounting surface (the inner fastening part of the wheel). Offset has a significant impact on tire position, car appearance, and balance.
Simply put, Offset can determine how much the center surface of the wheel is recessed in or out. To determine the size of Offset, it is usually marked with the ET code followed by a plus sign. Example: ET25, ET 35, ET 45, and so on.
The larger the number indicated, the more the wheel position is recessed into the car's fender. This type of offset is usually known as Positive Offset. Conversely, the smaller the number indicated on the Offset code, the more the wheel position extends out from the car's fender. This type of offset is usually known as Negative Offset. Additionally, there is Zero Offset where the wheel hole position aligns with the centerline of the wheel.
In the installation of new wheels, offset is one of the important factors that determine driving comfort and car appearance. Incorrectly determining the offset size can cause damage to the car's suspension components. It can even lead to tire blowouts.
If you intend to replace your wheels for aesthetic purposes only, you can use wheels with a relatively high Negative Offset. However, for style and good wheel performance, you can use wheels with Negative or Zero Offset.
The Relationship Between PCD and Offset
Although both have different meanings and functions, they are interrelated. To ensure perfect wheel compatibility with the car, car owners who plan to modify their wheels must pay attention to the correct selection of PCD and Offset sizes. Choosing the right PCD and Offset can enhance wheel performance so that the wheels can easily bear the car's load and, of course, improve the car's performance when maneuvering.
Read Also: Meaning and Code of Car Wheel Sizes
Thus, this is a review of the terms PCD and Offset. If you intend to replace your wheels with new ones, make sure to consult first with a competent mechanic in the field to avoid mistakes. Or take your car to an official Daihatsu workshop for the wheel replacement.
