Wheel Spacer Buyer's Guide

• Slip-On: Thin, plate-style spacers that slide over the existing studs. Best for small adjustments of roughly 3-15 mm. Because they reduce the available stud length for your lug nuts, thread engagement must be verified before using a slip-on spacer.

• Bolt-On: Thicker spacers that bolt to the hub and include their own set of studs for the wheel to mount onto. Required for larger adjustments where a slip-on spacer would create unsafe thread engagement. The safer choice for anything beyond a modest adjustment.

Determining the Right Thickness

Your target fitment determines the thickness you need:

• Tucked: The wheel and tire sit well inside the fender.

• Flush: The outer face of the wheel sits even with the fender edge. This is the most popular target for enthusiasts.

• Poke: The wheel extends beyond the fender. Common in stance and show builds, but may require fender rolling or trimming.

To find the thickness you need, measure the gap between your current wheel and the inside of your fender. Align a straight edge with the face of your wheel, point it up, and use a ruler to measure the distance to the inner lip of your fender. Always check clearances with the suspension compressed for the most accurate measurement.

Center Bore

Match your wheel spacer's center bore to your vehicle's hub diameter to ensure hub-centric fitment. Hub-centric spacers prevent vibration. You can find your vehicle's center bore measurement by searching online or using calipers for a precise measurement. See our hub-centric ring guide for more information about hub-centric fitment.

Wheel Bolt Pattern

Your wheel spacer must also match your vehicle's bolt pattern, both the number of lugs and the bolt circle diameter. A mismatched bolt pattern will prevent installation entirely. You can find your vehicle's bolt pattern by searching online or measuring using the diagram below.

Cautions & Tradeoffs

Wheel spacers are a popular and widely used modification, but there are tradeoffs to understand before installing them.

• Thread Engagement: Slip-on spacers reduce the available stud length for your lug nuts, which can compromise thread engagement. The minimum thread engagement for lug nuts/bolts is equal to the diameter of the stud/bolt. For example, a 12 mm stud requires at least 12 mm of thread engagement. If your remaining stud length doesn't meet this threshold after adding a slip-on spacer, switch to a bolt-on spacer with longer studs or install extended studs.

• Fender Rubbing: Spacers push the wheel outward, increasing the risk of fender rubbing and damage - especially on lowered vehicles or with aggressive fitments. Check for rubbing at full steering lock and over bumps after installation.

• Increased Bearing Stress: Spacers increase the lever arm acting on the wheel bearings, accelerating wear over time. The thicker the spacer, the more pronounced the effect. This is generally a minor concern for street-driven vehicles using modest spacer thicknesses, but is worth noting for track use or large spacers.

• Altered Scrub Radius: Moving the wheel outboard changes your vehicle's scrub radius, which can affect steering feel and stability. More relevant for thick spacers.

Conclusion

Wheel spacers are an effective and affordable way to fine-tune wheel fitment, clear brake calipers, or resolve rubbing issues. Choose your target fitment, confirm your hub's center bore and bolt pattern, and select the appropriate spacer type and thickness. When in doubt, a bolt-on spacer is the safer choice for anything beyond modest adjustments. You can find all the parts to plan your build on RideBuilder.

Additional Resources

• Wheel Buyer's Guide

• Tire Buyer's Guide

• Brake Caliper Buyer's Guide

• Hub-Centric Ring Buyer's Guide