If you are considering a wheel customization for your vehicle or simply need to replace older, rusted out wheels on your vehicle, you will need to take offset and backspacing into consideration before making your purchase. Knowing the difference, how they are measured and how they affect proper vehicle operation are important. 

What is offset?

The offset of a wheel describes its ideal position in relation to the fender or the brakes. It is established by technicians by measuring between the centerline of the wheel and the wheel mounting surface and is typically designated in millimeters. Offset is described in zero, positive or negative according to the relative position of the centerline to the mounting surface. 

  • Zero Offset. The mounting surface and the centerline of the wheel.
  • Positive Offset. The mounting surface extends beyond the centerline and is closer to the wheel face by a variable distance in mm.
  • Negative Offset. The mounting surface is nearer to the back of the wheel by a variable distance in mm. 

Every wheel has a specified offset. It is common for later model, front wheel drive vehicles to have a positive offset, but older models and customized vehicles tend to have a negative offset. 

What is backspacing?

An older system of measurement for determining the depth of the mounting pad in relation to the wheel is backspacing. Suspension, brake and steering systems require clearance in order to operate without interference in the space at the back of the wheel. Backspace is related to offset in the following way: 

  • Positive offset tends to create more backspace.
  • Negative offset reduces the amount of available backspace. 

Determining the proper backspacing requires measuring the distance between the wheel's mounting surface and the innermost point where it will allow for proper operation of the wheel and the vehicle's systems. 

Why you should know the difference?

Offset and backspacing clearance are necessary for determining whether or not a particular custom or replacement wheel will fit on a particular vehicle without rubbing on the fender or interfering with the proper functioning of brakes, steering and suspension systems. 

There are plenty of custom wheels available to choose from once you know the proper offset and backspacing required for your vehicle. Get more help understanding these terms or customizing your vehicle by visiting TireGet.