1. Determine whether the aluminum alloy wheel will exceed the fender: ET value

The ET value is the Off-set value, that is, the offset (commonly known as the offset value), the unit is MM, and there are three types: positive, zero, and negative. In layman's terms: the higher the ET value, the closer the aluminum alloy wheel is to the inner side, the more embedded; on the contrary, the smaller the ET value, the more the aluminum alloy wheel is squeezed out.

2. The J value determines how thick and wide the aluminum alloy wheel is

We usually say that the width of the aluminum alloy wheel hub is 7J, 8J. In fact, the number here represents the width of the aluminum alloy wheel hub, and the J value represents the shape and height of the aluminum alloy wheel hub flange.

3. The aluminum alloy wheels are fixed on the car, and the PCD hole distance is determined

The pitch circle diameter of the aluminum alloy wheel hub bolt hole is usually called the "rim pitch". The general expression is: 4*100 (for example: Fit, Swift), 5*120 (for example: most BMW models), etc. 4/5 means that there are 4 or 5 bolt holes, and 100/120 means that the pitch circle diameter of the bolt holes is 100mm or 120mm.

4. Will the aluminum alloy wheel block the axle head, depending on the center hole distance

The center hole is also called the middle ring of the aluminum alloy wheel. It refers to the ring that is sleeved on the axle head of the axle shaft when the aluminum alloy wheel is installed. The original data of Japanese and American cars is generally 50-60mm, German and European It is more common between 60-70mm. Therefore, generally modified aluminum alloy wheels like to make the center hole very large (over 65mm) to adapt to different car types.

5. The J value matches the width of the tire

The width of the aluminum alloy wheels determines the width of the tires. To get wider tires, first of all, the aluminum alloy wheels must reach a certain width. The width of aluminum alloy wheels that can be installed with different J values ​​is also standard.

Each J value has a recommended tire width, such as 7J aluminum alloy wheels, the standard tire width is 215, of course, you can also install a small 205, or a larger 225 tire, but they are not standard. Match. With large-width tires, the visual experience is that the tires are thrown outside the aluminum alloy wheels; if the small-width tires are installed, the aluminum alloy wheels seem to be more prominent.

6. Tire aspect ratio

The aspect ratio is a data of the tire, which refers to the percentage of the tire's cross-sectional height to its maximum width, which is simply the tire's aspect ratio. Let¡¯s take a tire with a specification of 195/55 R15 as an example. It shows that the maximum cross-sectional width is 195 mm, the aspect ratio is 55%, and the inner diameter is 15 inches.

Tires with high aspect ratios have long sidewalls and strong cushioning capacity, which are relatively comfortable, but have poor road feeling and weak lateral resistance when cornering;

High aspect ratio tire

Conversely, low-profile tires have a shorter sidewall and a relatively wider tread. Because of the large ground contact area, the tire can withstand greater pressure, respond more sensitively to the road, and have strong lateral resistance when cornering, and excellent handling. .

One more thing to note is: the tire flatness ratio should not be too thin. Too-thin tires will not only reduce the comfort and driving texture, but also cause greater vibrations transmitted to the aluminum alloy wheels due to the reduction of the rubber part, which will sharply reduce their life. At the same time, the tires are more likely to cause bulging.