What is Wheel Offset, And How Do You Choose Offset for New Rims?

When you're looking to upgrade the wheels on your vehicle, there are many factors in your decision. The first thing you need to understand is the difference between wheels and rims.

Although you'll hear people use "wheel" and "rim" synonymously, they are not technically interchangeable. Don't worry. We can help with that: Check out our article that defines wheels, rims, and tires.

When you shop for after market wheels online with Tire Agent, one of the ways you can filter our recommendations is by wheel offset. We'll ask you to confirm your wheel size, and then we'll recommend wheels that are compatible with your vehicle. Wheel offset measurement is vital to ensure your wheels and tires fit correctly. Let's look at what wheel offset actually means and how to choose the right size.

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Defining Wheel Offset and Why It Matters

When you replace your wheels or rims, you want to carefully measure to ensure your tires fit properly in the wheel well without rubbing against the fender, frame, suspension, or other vehicle components. That's where offset and backspacing come into play.

To understand what wheel offset is, it might help to define offset as it's used in other ways. The definition of offset is to place something over or against something or to counterbalance it. So, wheel offset is the distance between the wheel's mounting surface and the centerline, measured in millimeters.

This illustration shows what wheel offset looks like:

Offset and backspacing are two crucial measurements that indicate a wheel's proper location.

Backspacing is the distance between the wheel's mounting surface and the innermost lip, measured in inches.

If you opt to install aftermarket wheels, you'll need to know these measurements because they help identify which wheels are compatible with your vehicle.

How to find wheel offset

If you're a hands-on type of person, you can find the wheel offset of your current wheels relatively easily. It's typically stamped into the back of your vehicle's OEM or factory wheels, next to the letters ET.

Understanding Wheel Offset Better

The offset of a wheel is determined by measuring the distance between the wheel's centerline and the mounting surface. The standard unit for describing offset is millimeters, which can be positive, zero, or negative.

Rim offset meaning:

• Zero offset: The wheel's mounting surface must line up with the centerline to be considered zero offset.
• Negative offset: A mounting surface closer to the back of the wheel is referred to as a negative offset.
• Positive offset: A mounting surface that extends over the centerline and closer to the face of the wheel is referred to as positive offset. Many factory rims have this offset type.

Positive vs negative wheel offsets

Each vehicle has its own offset. The difference between positive offset and negative offset is: A positive offset is common in modern front-wheel-drive automobiles, while a negative offset is common in older or customized vehicles. The precise offset data is imprinted on the mounting surface, or a spoke on most wheels.

What about backspacing? This is an older method of determining the depth of the mounting pad within the wheel. Correct backspacing gives the suspension, braking, and steering systems ample room to operate without interference from the wheel.

Backspacing is increased when the offset is positive, while it is reduced when the offset is negative. The suitable backspacing of each wheel, like offset, is determined by the vehicle's size and design.

Photo credit: ID 11754971  © Calyx22 | Dreamstime.com

Wheel offset illustration: By Matterhorny - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=116077723 no changes were made