What is Chevrolet 6 bolt pattern?
Chevrolet six-lug wheel patterns refer to wheels that mount with six lug studs arranged on a circular bolt circle. The exact bolt circle diameter varies by model and generation, but two patterns are commonly encountered in Chevrolet vehicles: 6x139.7 mm (6 on 5.5 inches) and 6x120.65 mm (6 on 4.75 inches).
Understanding the concept
A wheel bolt pattern describes how many lug holes a wheel uses and the diameter of the circle that passes through the centers of those lug holes. For six-lug patterns, the number of holes is six, and the bolt circle diameter (also called the pitch circle diameter) is the key measurement that determines compatibility with a given hub and brake setup.
Bolt circle diameter explained
The bolt circle diameter is measured from the center of one lug hole to the center of the opposite lug hole across the wheel. For Chevrolet six-lug setups, the two most commonly seen diameters are 139.7 mm (5.5 inches) and 120.65 mm (4.75 inches). Other variations exist for specific models or earlier generations, so always confirm the exact pattern for your vehicle.
Common Chevrolet six-lug patterns
Chevrolet wheels with six lug holes can use different bolt-circle sizes depending on the vehicle’s era and trim. The patterns listed below are among the patterns you may encounter in the wild. Always verify with your vehicle’s manual or a trusted spec sheet before buying wheels.
- 6x139.7 mm (6 on 5.5 inches)
- 6x120.65 mm (6 on 4.75 inches)
In addition to these two, some older or specialty models may use other six-lug configurations. If you’re unsure, check the owner’s manual, the vehicle’s door sticker, or contact a dealership or wheel professional to confirm the exact bolt pattern for your specific Chevrolet model and year.
How to determine your vehicle’s bolt pattern
To ensure you buy wheels that fit, you need to identify the exact six-lug bolt pattern on your Chevrolet. The steps below help you verify pattern, center bore, and fitment considerations.
- Count the lug holes: confirm there are six lug studs or holes on the wheel hub.
- Measure the bolt circle diameter: measure straight across the hub from the center of one lug hole to the center of the opposite lug hole. Convert the measurement to millimeters if needed to compare with standards (for example, 139.7 mm or 120.65 mm).
- Check the center bore size: measure the hole in the wheel center that fits over the hub. It must be at least as large as the hub bore; if it’s smaller, the wheel won’t center properly.
- Verify compatibility with brake components and offset: ensure the wheel clears calipers and that the wheel’s offset and backspacing work with your suspension and fender clearance.
- Consult official sources: if in doubt, consult the vehicle’s manual, VIN-based spec sheets, or a professional to confirm the exact pattern for your specific model and year.
Understanding these details helps prevent fitment issues such as clearance problems or wheels that sit too far in or out from the fenders.
Practical considerations for wheel swaps
When swapping wheels on a Chevrolet with a six-lug pattern, several practical points matter beyond just matching lug count and bolt circle. These factors influence safety, performance, and alignment with the vehicle’s design.
- Center bore and hub-centric vs lug-centric fitment: a wheel with a center bore larger than the hub can be used with hub-centric rings for proper centering; a mismatch can cause vibration or improper seating.
- Offset and backspacing: the wheel’s offset affects track width, brake clearance, and fender clearance; incorrect offset can rub on suspension or body components.
- Brake caliper clearance: some wheels may not clear certain brake caliper shapes or sizes; verify clearance, especially with aftermarket wheels.
- Lug nut type and seat style: ensure the lug nuts match the wheel’s seat type (conical, ball, or radius) and thread pitch; mismatches can lead to improper seating.
- Torque specs and lug tightening pattern: follow the manufacturer’s recommended torque and star-pattern sequence to avoid warping rotors or damaging studs.
If you’re considering adapters or conversions to a different bolt pattern, consult a wheel and tire professional. In many cases, using the correct six-lug pattern and properly centering components is safer and more reliable than attempting an incompatible setup.
Summary
A Chevrolet six-lug wheel pattern means there are six lug studs arranged on a circle, and the critical specification is the bolt circle diameter. The two most common patterns you’ll encounter are 6x139.7 mm (5.5 inches) and 6x120.65 mm (4.75 inches), though other variations exist for certain models and years. To ensure a safe and proper fit, verify lug count, bolt circle diameter, center bore, offset, and brake clearance for your specific vehicle, and consult manuals or professionals if you’re unsure. Proper matching is essential for safety, performance, and wheel longevity.
