Both backspace and offset relate to how the wheel "tucks" or "pokes" on the vehicle. They represent where the wheel is positioned compared to the fender.
With regards to truck and Jeep applications, a general rule of thumb for selecting the proper offset is:
Stock height: Use a higher offset option (18mm +)
Leveled: Use zero to mid offset (0mm to 20mm) | 0mm is more aggressive with more "poke" than the higher offset.
Lifted: Use negative to zero offset. Negative offset options vary based on wheel width and the proper choice is determined by the vehicle height. Negative offset wheels require vehicle modification and fitment depends on the amount of lift. Wider wheels with lower offsets require more vehicle height. These are aggressive fitments with the most "poke".
Your local dealer is a great source for more information. To find a dealer near you, click here: Dealer Locator
Still have questions? Contact our Customer Support Team at 1-800-260-2522.
WHAT'S THE DIFFERNCE BETWEEN BACKSPACE & OFFSET?
BACKSPACE
Backspace is the distance in inches from the edge of the rear flange to the mounting surface.
To measure the backspace, lay a straight edge across the back of the wheel and measure the distance from that edge to the mounting surface.
Measuring the vehicle may be required to determine the backspace needed for custom wheels. For more on measuring your vehicle check out this video: How Do I Measure A Vehicle For Custom Wheels
OFFSET
Offset is the distance in millimeters from the wheel’s imaginary centerline to the mounting pad and cannot be physically measured.
The higher the offset the more the wheel tucks under the fender. As the offset gets lower, the wheel moves closer to the fender's edge. The offset usually impacts the depth of the wheel and always affects the stance of the wheel package.
Some wheel designs may be offered with multiple offset options. These options can be generalized into three main categories: Positive, Mid & Negative.
Notice how the offset impacted both the depth of the wheel and the stance on the vehicle?
Here's a side-by-side look at offsets showing the position of the wheel mounting surface compared to the centerline.