Rim offset is the distance between the mounting surface of a wheel and the centerline of the wheel. It is typically measured in millimeters, and it can be either positive or negative. Positive rim offset means that the mounting surface is closer to the outside of the wheel, while negative rim offset means that the mounting surface is closer to the inside of the wheel.
Rim offset is important because it affects the handling and stability of a vehicle. A wheel with a positive rim offset will make the vehicle more stable, while a wheel with a negative rim offset will make the vehicle more agile. Rim offset can also affect the appearance of a vehicle, with a positive rim offset making the wheels appear to be “tucked in” under the vehicle, while a negative rim offset will make the wheels appear to be “pushed out” from the vehicle.