Simply put, a wheel spacer is (hopefully) an aluminum ring that sits between the hub and the wheel of a vehicle, effectively widening the track (distance between the wheels) of the vehicle in question. There are a host of reasons why wheel spacers can make sense as well as a host of spacer options on the market. We’ll break down the basics of wheel spacers with this handy wheel spacer buyer’s guide.

Wheel Spacer Vocab

Before getting too deep into you wheel spacer shopping, there are some suspension terms that you should be familiar with:

• Bolt Pattern- The bolt pattern of a wheel or vehicle indicates how many lug studs or holes are present and how far apart they are. For example, the 2013 Ford F-150 has a bolt pattern of 6x135mm. This indicates that there are six wheel studs with 135mm (5.31”) between the studs when measured across the hub. Bolt patterns are well documented and easy to look up for most makes and models.

• Center Bore- The center bore of a wheel refers to the diameter of the hole in the center of a wheel that typically fits over the center of the hub. This is another measurement that is typically well-documented. For example, the 2013 Ford F-150 has a center bore of 87mm, meaning that the hole in the center of its wheel is 87mm across.

• Wheel Offset (Backspacing)- A wheel’s offset refers to where its mating surface (the point at which it physically contacts the vehicle’s hub) is in relation to the center of the wheel. If you were to look at the cross section of a wheel, an offset of zero would indicate that the hub mating surface is exactly at the center point of the wheel. A positive offset indicates that the mating surface sits to the outside (away from the axle) of the wheel’s center while a negative offset indicates that the mating surface sits to the inside of the wheel’s center. Generally speaking, adding a wheel spacer will create the effect of a more positive offset.

• Hub Centric vs. Lug Centric- These terms refer to how a wheel or wheel spacer is centered on the vehicle’s hub. A hub centric design is centered by the center of the vehicle’s hub. Lug centric designs center the wheel or spacer with the lug nuts themselves. There is a lot of debate regarding these two designs but a properly designed and installed lug centric spacer can be just as safe and reliable as a hub centric one. More on this later.

Why Wheel Spacers?

Installing wheel spacers can be a cost-effective solution for a number of situations when modifying your vehicle.  Here are a few common applications:

• Aesthetics- Many vehicles, especially older models, are designed with the wheels tucked under the bodywork. This can give the truck a “big kid with little feet” appearance that is even more apparent when the vehicle is lifted. The installation of wheel spacers allow those wheels to be flush with the side of the truck, lending a much more modern and rugged look without having to replace expensive axle components.

• Handling- Basic physics dictates that the farther apart the wheels are, the more difficult it is for the vehicle to sway from side to side. Adding a set of wheel spacers increases the track of the vehicle and thus, makes it more stable in cornering. In off-road applications, widening the track can also help you straddle rutted trails and reduce the chances of getting stuck.

• Fitting Larger Tires- Probably the single most effective upgrade to an off-road vehicle is a set of aggressive tires. In many cases, especially when re-using the factory wheels, wider tires can rub on the inside of the fender well. Wheel spacers can be the difference between chewing up your expensive, new rubber on a frame rail and smooth, worry-free driving.

• Fitting Custom Wheels- Once in a while, a great deal on the perfect set of wheels can appear except the bolt pattern ends up being incorrect. While these situations are somewhat rare, there are wheel spacers available that act as bolt pattern adapters. They are designed to be installed on one bolt pattern but accept a wheel of a different one.

Wheel Spacer Dos and Don’ts

In certain circles, there is a stigma associated with wheel spacer installation, and for good reason. Many folks are concerned about putting additional wear on suspension components. While installing larger tires on a vehicle can put some additional strain on ball joints and wheel bearings, installing wheel spacers won’t put any more strain on the suspension than a set of aftermarket wheels that have a slightly more positive offset. Bear in mind that many folks have been running wheel spacers in both highway and extreme off-roading applications without experiencing premature suspension component wear.

Another wheel spacer worry is the durability of the spacer itself. There are cheaply made spacers out there that have cracked for some people but the way to avoid this is by paying attention to the material used to construct the spacers. By selecting a spacer machined from solid billet aluminum, you’re insuring that the spacer is made from a material that is at least as strong as the wheel that’s bolted to it and can be counted on for years of hassle-free duty.

There also have been reports of wheel spacers leading to unwanted vibrations and, in extreme cases, leading to damaged wheel studs. The roots of these complaints can be linked to both the design of the spacer as well as its installation procedure. There are many thin and inexpensive wheel spacers on the market that simply slide over the factory wheel studs and rely on the wheel to hold them in place. This style spacer can be dangerous since it does not allow the lug nut to seat completely on the stud and, especially if improperly torqued, can lead to vibrations, loose lug nuts, and catastrophic damage. A quality wheel spacer will be installed to the factory wheel studs with a thread sealant. The wheel will then be installed onto the studs that are built into the wheel spacer.

A properly designed wheel spacer will feature a set of bolt holes, as well as its own set of wheel studs. To install, the spacer is fitted over the vehicle’s factory wheel studs and it is held in place by torqueing the supplied nuts to spec. It is good practice to apply a thread locker to the studs prior to installing the lug nuts. The spacer should be thick enough that the factory wheel studs do not protrude from its front (outside) surface to ensure that the wheel can mount flush to the spacer. The wheel is then installed onto the spacer’s wheel studs and the original lug nuts are torqued to spec. This design allows for the spacer to be secured separately from the wheel and, when properly installed, prevents opportunities for vibrations to occur.

As previously mentioned, there is some debate regarding hub centric vs. lug centric wheel spacers. While hub centric spacers are certainly the most fail-safe design, properly engineered and installed lug centric spacers can be just as worry-free as hub centric spacers. If you choose to go with a lug centric spacer, make sure that they include wheel studs that are properly splined and pressed into the spacer bodies. With a lug centric spacer, it is absolutely critical that you follow the proper torqueing sequence as outlines in the accompanying diagram. This allows the spacer to be properly centered and free from vibrations and balance issues. Just like when installing a set of wheels, be sure to re-check your wheel spacer torque after 100 miles of driving.

The installation of wheel spacers can be an effective solution to improving the handling and appearance of your vehicle. While there is some risk involved with wheel spacers, selecting a properly designed product and carefully following the installation procedures will eliminate any worries involved.