Reading the Wheel Size

Example Wheel Size: 15x7 4-100 40S

15
Wheel Diameter: The size (in inches) of the wheel as measured across its center.
7
Wheel Width: The width (in inches) of the wheel as measured across its barrel from outer face to the inner face.
4-100
Bolt Pattern: The bolt pattern indicates the arrangement of lug holes and consists of two elements: the number of bolts, or lugs (4 in this case), and the distance between them across the center of the wheel (100mm in our example). Some wheels have multiple bolt patterns. For more detailed information, visit our Bolt Pattern page.
40
Offset: The offset of a wheel is what locates the tire and wheel assembly in relation to the suspension. More specifically, it is the measured distance between the hub mounting surface and the centerline of the rim. Our Info Center has more information in the Wheel Offset page.
S
Finish: With hundreds of different wheels there are dozens of different wheel finishes. They are clearly marked at the end of the wheel size (ex. S = silver).