Backspacing And Offset

In a previous post, "Jeep Wrangler Wheels and Tires", we discussed using 17x9" aftermarket wheels with -12mm offset, which is about 4.5" backspacing on a Jeep Wrangler. That sizing, for many people, is the magic combination to fit 33" or 35" tires on the Jeep JK. I was…

…vehicle and wheel size combinations to confirm which ones work correctly. Our extensive database allows our sales staff to offer you the perfect fit for your vehicle. *Backspacing, similar to offset, is the distance from the hub mounting surface to the inside lip of the wheel (measured in inches).

When you're shopping for aftermarket wheels, you'll see a range of backspacing, offset and width measurements available for your vehicle. When looking at wheels, sometimes we'll have the measurements from your stock wheels, but sometimes we do not. This may lead you to wonder, "How…

…and centerbore, but not offset and backspacing. Offset is the distance between the mounting pad and rim's midpoint. The diagram to the right shows a wheel with a positive offset. Every contemporary Original Equipment wheel has a positive offset, however O.E. offset varies. For example, my old…

…off your lap times. Choosing the right wheel for the vehicle is paramount. There are several pieces to the puzzle, such as bolt pattern, offset and backspacing. Luckily, we've done all the math for you. Prior to recommending a wheel for your vehicle on our website, we bring an example of that…

…mounted on some sportier looking wheels! A perfect fit would be the new KMC XD Series XD300 Pulley in 17x8 with a zero millimeter offset and 4.5 inches of backspacing. As you can see, these wheels fit the stock tires perfectly and push them out to the edge of the fenders where they belong, rather…

…styling and fitments that are generally more aggressive than stock fitments. The Jeep JK (2007-2016) fitments are 17x8.5 with a 0mm offset (4.8" backspacing), which is mild enough to fit on a stock Jeep with the stock 255/75R17 tires, yet can still handle the 35x12.50R17 on a Jeep like mine…

…as well as the geometry of where they put the bend. It seems to give a bit more room for big tires with slightly higher offset wheels. Generally, 4.5" backspacing is an easy number to clear big tires on the JK, but mine are 4.75" which give very little clearance to the upper control…

…you select a wheel diameter that's different than the Original Equipment, you may need a new set of tires. You can shop by size to help you find the tires that are right for your application. For more information on selecting the proper wheel, read "What is Wheel Offset and Backspace?"

…the back edge of the wheel, where offset measures the distance from the mounting plate of the wheel to the center of the wheel barrel. The higher the backspace, the further back into the fender well it will sit. To help you understand offset and backspacing, take a look at the diagram below:…