Wheel Bolt Pattern & Center Cap Fitment Guide
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Wheel Bolt Pattern & Center Cap Fitment Guide
One of the most common questions we get is: "Does my bolt pattern affect which center cap I need?" The short answer is yes — but it's not the only factor. This guide explains how bolt patterns, bore sizes, and lug counts all work together to determine center cap fitment.
What Is a Bolt Pattern?
A bolt pattern (also called a bolt circle or PCD — Pitch Circle Diameter) describes the number of lug holes and the diameter of the circle they form. It's written as two numbers, like 5x5.5 or 6x135:
- The first number = number of lug holes (e.g., 5, 6, or 8)
- The second number = diameter of the bolt circle in inches or millimeters (e.g., 5.5" or 135mm)
Common Bolt Patterns by Vehicle Type
| Bolt Pattern | Common Vehicles |
|---|---|
| 5x4.5 (5x114.3mm) | Ford Mustang, Honda, Toyota cars |
| 5x5 (5x127mm) | Jeep Wrangler, older GM trucks |
| 5x5.5 (5x139.7mm) | Ram 1500, older Dodge trucks |
| 6x5.5 (6x139.7mm) | Chevy/GMC 1500, Toyota Tundra, Nissan Titan |
| 8x6.5 (8x165.1mm) | Ford F-250/350, Ram 2500/3500, GM 2500/3500 |
| 6x135mm | Ford F-150 (2004+), Ford Expedition |
How Bolt Pattern Relates to Center Cap Fitment
Your bolt pattern determines your lug count (5, 6, or 8 lugs), and lug count directly affects which center caps fit your wheel. Here's why:
- 5-lug wheels — Typically use smaller center bore caps. The cap only needs to cover the center hub area.
- 6-lug wheels — Common on half-ton trucks. Caps are sized to match the larger hub diameter typical of these applications.
- 8-lug wheels — Found on heavy-duty trucks (F-250, Ram 2500, etc.). These use the largest caps due to the bigger hub and bearing assembly.
Important: Bolt pattern alone doesn't determine cap fitment. You also need to match the center bore diameter (the opening in the wheel face) and the cap's retention style.
Center Bore vs. Bolt Pattern
The center bore is the circular opening in the middle of the wheel face where the cap sits. It's measured in millimeters and is separate from the bolt pattern. Two wheels can share the same bolt pattern but have different center bore sizes — meaning their caps won't interchange.
Common center bore sizes:
- 78mm — Common on many passenger car and light truck wheels
- 83mm — Common on KMC, Moto Metal, and similar off-road wheels
- 108mm — Common on larger truck and SUV wheels
- 133mm — Found on some heavy-duty off-road wheels
How to Measure Your Center Bore
- Remove the existing cap (or look at the empty bore if the cap is missing).
- Use a caliper or ruler to measure the inner diameter of the circular opening in millimeters.
- Match that measurement to the cap's listed bore size when ordering.