How to Read Car Rim Sizes to Avoid Making the Wrong Choice
JAKARTA, KOMPAS.com – Rims are one of the most frequently modified components on a car, used to enhance its appearance and character. However, many car owners replace their rims without paying attention to the appropriate technical specifications.
Kumar from Kickoff Ciputat, a car rim and tyre shop in the Cipayung, Ciputat area, says that rim replacement should not be done haphazardly as it can lead to various risks.
“Rims are not just for aesthetics; they also affect comfort and safety while driving. If the size does not match the car’s specifications, the impact can be felt on the handling, suspension, and the durability of components,” Kumar told Kompas.com on Monday (23/2/2026).
Each rim has an identification code printed on the inside, known as the rim marking. This code contains important information about the rim’s specifications, from size to bolt configuration.
The Marketing Division Head of Auto2000, Nur Imansyah Tara, explains that rim markings are actually quite easy to understand. For example, on a rim, you will usually find codes such as 9x20, 5x112, and ET +20.
The code 9x20 indicates the basic size of the rim. The number 9 indicates the width of the rim in inches, while the number 20 is the diameter of the rim in inches. This means that the rim has a width of 9 inches and a diameter of 20 inches.
The code 5x112, on the other hand, relates to the wheel bolt pattern or Pitch Center Diameter (PCD). The number 5 indicates the number of bolts used, while the number 112 indicates the distance between the bolt holes in millimeters.
Thus, the rim is designed for a five-bolt mounting system with a bolt hole spacing of 112 mm.
In addition to size and bolt pattern, there is also the ET code, which indicates the rim offset value. The offset is the distance between the centre point of the rim and the bolt mounting surface.
“Usually, the offset is marked with a zero, negative, or positive number. If the bolt mounting is exactly in the centre, then the offset is zero,” said Imansyah.
Conversely, a positive offset indicates that the bolt mounting is further inwards, making the wheel position closer to the inside of the fender.
Understanding these codes is an important step before deciding to replace the rims. With the right specifications, the modification will not only enhance the appearance but also maintain comfort, stability, and safety during daily use.
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