Offset refers to the distance in millimeters from the wheel’s centerline to the mounting plate of the wheel. Since that the mounting plate can be either in front of, coincide or behind the centerline, the offset can be either positive, neutral, or negative.
A positive offset is when the mounting plate is in front of the centerline of the wheel. The mounting plate will be closer to the outside. Neutral offset is when the wheel’s mounting plate is exactly in line with the centerline. They are often referred to as “ET0” wheels. Wheels with negative offset have the mounting plate located behind the centerline of the wheel. The mounting plate will be closer to the inside.