What Does Negative Wheel Offset Mean?
1 Answers
Negative wheel offset refers to the numerical value of the wheel's center offset, representing the deviation distance from the wheel's centerline to the wheel's mounting surface. Therefore, the larger the negative ET value, the more the wheel will protrude outward when installed on the vehicle. The term 'offset' can be seen in the middle position. Offset plays a crucial role in the performance of tires and wheels, as well as the overall performance of the vehicle. This is because offset affects the wheel track, which in turn influences the vehicle's stability and tire grip to some extent. Offset is defined as the difference between the wheel's center reference plane and the wheel's load-bearing surface (mounting surface), measured in millimeters. When the wheel's load-bearing surface is outside the center reference plane (from the perspective after installation), the wheel is a positive-offset wheel (most factory-installed wheels are positive-offset). The advantages of positive-offset wheels include safety, stability, and reduced additional air resistance since they are tucked inside the vehicle body. Conversely, when the load-bearing surface is inside the center reference plane, the wheel is a negative-offset wheel. The benefits of negative-offset wheels include widening the wheel track, providing better vehicle stability, and enhancing the lateral support capability of high-performance tires. However, negative-offset wheels typically protrude outside the vehicle body, creating additional air resistance and increasing the risk of scraping against external objects. Simply put, the advantage of negative-offset wheels lies in offering greater support during cornering. Wheel offset is often denoted as ETxx. For example, ET+30 means an offset of +3 cm, while ET-30 indicates an offset of -3 cm. Generally, the maximum positive offset is +50, and the maximum negative offset is -44. Most SUVs come with positive-offset wheels from the factory. Switching to negative-offset wheels widens the wheel track, improving vehicle stability.
