1、 the size of the wheel: In fact, the diameter of the hub, we can often hear people say the 15-inch wheel, 16-inch wheel, such as 15, 16 inch refers to the size (diameter) of the hub.
Generally, in a car, if the size of the wheel is large and the flatness of the tire is high, it can visually exert a good tension effect, and the stability of the vehicle handling will also increase, but the fuel consumption increases accordingly. Such additional problems.
2、Hub Width: The hub width is also known as the J value. The width of the hub directly affects the choice of the tire. For the same size of the tire, the J value is different, and the selected tire flat ratio and width are different.
3、PCD and hole position: The professional name of PCD is called the pitch circle diameter, which refers to the diameter between the fixing bolts in the center of the hub. Generally, the large porous position of the hub is 5 bolts and 4 bolts, and the distances of the bolts are different. So we can often hear the name 4X103, 5X114.3, 5X112, 5X114.3 as an example, the PCD representing this wheel is 114.3mm, and the hole is 5 bolts.
PCD is one of the most important parameters when selecting a hub. For safety and stability reasons, it is best to choose the same PCD as the original car for upgrade.
4、Hub offset: English is Offset, commonly known as ET value, the distance between the wheel bolt fixing surface and the geometric center line (the centerline of the hub cross section) is simply the difference between the center screw seat of the hub and the center point of the entire wheel. The value, popular point of view, is whether the wheel is retracted inward or outward after the wheel modification.
For a typical car, the ET is positive and negative for a few vehicles and some jeep. For example, the offset value of a car is 40. If it is replaced by the wheel of the ET45, it will be visually smaller than the original wheel hub.
The ET value not only affects the visual change, but also has a relationship with the steering characteristics of the vehicle and the angle of the wheel. The excessive offset value may cause the tire to wear abnormally, the bearing is easy to wear, or even cannot be installed normally.
In most cases, the same type of wheel of the same brand will provide different ET values to choose from. The comprehensive factor should be considered before the modification. The most safe condition is to maintain the ET value of the modified wheel without modifying the brake system. The original ET value is the same.
5、Hub center hole: The center hole is the part used to fix the connection with the vehicle. It is the position of the hub center and the hub concentric circle. The diameter size here affects whether we can ensure that the wheel center can match the geometric center of the hub.