Backspacing and Offset : WTF?

It’s not an uncommon situation when you jump into the aftermarket wheel game for folks to not understand the difference between backspacing and wheel offset.

In a nutshell, they different measurements but help to reach the same conclusion.

1. Backspacing: This is the distance from the back edge (the side that faces the suspension) of the wheel to the mounting surface (where the wheel attaches to the hub). It determines how far the wheel is positioned inward or outward from the vehicle's suspension. A larger backspacing means the wheel will sit further inward, while smaller backspacing pushes the wheel outward.

o Measured from: The back edge of the wheel to the mounting surface.

o Impact: Affects clearance between the wheel and suspension components, such as brakes and shocks, as well as how the wheel fits within the wheel well.

2. Offset: Offset refers to the position of the wheel’s mounting surface relative to the centerline of the wheel. It’s the distance between the center of the wheel and the mounting surface. Offset can be positive, negative, or zero:

o Positive offset: The mounting surface is toward the front (or outside) of the wheel, making the wheel sit further inside the wheel well.

o Negative offset: The mounting surface is toward the back (or inside) of the wheel, pushing the wheel outward.

o Zero offset: The mounting surface is exactly at the center of the wheel.

o Measured from: The centerline of the wheel to the mounting surface.

o Impact: Determines how the wheel aligns with the fender and affects vehicle handling, clearance, and aesthetics.

Key Difference:

• Backspacing measures how far the wheel sits inward or outward, starting from the back edge of the wheel.

• Offset measures the position of the wheel's mounting surface relative to the wheel's centerline.