2018 GMC Sierra 1500 Wheel Interchange

2018 GMC Sierra 1500 Wheel Fitment Guide

Known OEM Fitment For 2018 GMC Sierra 1500

The information below includes only the known fitment values supplied for the 2018 GMC Sierra 1500. Factory wheel specifications can vary by cab configuration, trim, package, drivetrain, and original tire option, so confirm the complete specification for your truck before ordering wheels or tires.

The 6x139.7 bolt pattern, 78.1 mm center bore, and M14 x 1.5 thread size are useful starting points, but they do not by themselves prove that a donor wheel will fit. Offset, wheel width, brake clearance, lug-seat design, tire size, and suspension clearance must also be checked.

How To Use The Wheel Interchange Calculator

Use the calculator to compare a donor vehicle's wheel and tire dimensions with the wheels and tires installed on your 2018 GMC Sierra 1500. Enter the donor vehicle under “Wheels from” and enter your truck under “Installed on.” Use the exact dimensions shown on the wheel, tire sidewall, vehicle label, or reliable OEM documentation.

• Compare the donor bolt pattern, center bore, wheel width, diameter, and offset with the known GMC specifications and the values you have confirmed for your truck.
• Use “Custom wheel size” when the donor wheel is not listed or when you want to test a proposed diameter, width, or offset.
• Use “Custom tire size” to enter section width and aspect ratio. Confirm the tire's rim diameter separately because it must match the wheel diameter.
• Review the displayed diameter and clearance differences rather than relying on a vehicle name alone.
• When you change rim diameter, the calculator updates the tire diameter comparison. Recheck overall diameter, sidewall height, speedometer effect, suspension clearance, and body clearance after every change.

The calculator is a comparison and planning tool, not a substitute for a physical test fit or the vehicle manufacturer's requirements. If any dimension is unknown, verify it before making a purchase.

Fitment Checklist Before You Buy

• Confirm the wheel uses the exact 6x139.7 bolt pattern.
• Confirm the wheel center bore is at least 78.1 mm. A smaller bore will not fit over the hub. A larger bore may require correctly sized hub-centric rings when appropriate.
• Confirm the wheel offset and width. These determine inner suspension clearance, outer fender position, and tire sidewall location.
• Check brake caliper and rotor clearance. A wheel can have the correct bolt pattern but still contact the brake assembly.
• Confirm the wheel's lug-seat type and the required lug-nut design. Do not assume the original lug nuts are compatible with aftermarket wheels.
• Check the wheel's load rating against the truck's axle and vehicle requirements.
• Match the tire's approved rim-width range to the selected wheel width.
• Compare the proposed tire diameter and load capacity with the original equipment requirements.
• Inspect for clearance at full steering lock, full suspension compression, and full suspension extension.
• Verify that the tire does not contact the fender liner, control arms, brake hoses, shocks, or other suspension components.

Use the driver-door certification label, owner's manual, original wheel markings, tire sidewall, and a GMC dealer or parts source that can check the VIN to confirm specifications that vary by configuration.

Plus Sizing And Common Upgrades

Plus sizing generally means fitting a larger wheel diameter with a lower-profile tire while keeping the overall tire diameter near the original specification. Because the factory rim diameter, width, offset, and tire size for this truck have not been provided, no specific plus-size combination can be confirmed here.

Enter the confirmed original wheel and tire dimensions into the calculator first, then test the proposed custom wheel and tire size. Compare overall diameter, width, offset, and clearance. A larger wheel may reduce sidewall cushioning and increase the risk of wheel or tire damage on rough roads. A wider tire may also increase contact with suspension or body components.

Do not choose a tire solely by diameter. Confirm load capacity, speed rating, approved wheel width, seasonal suitability, and clearance. Any change that affects tire diameter can influence speedometer readings, traction-control behavior, gearing, and spare-tire compatibility.

Installation Tips

• Inspect every wheel for cracks, bends, corrosion, damaged mounting faces, and questionable repairs before installation.
• Clean the hub and wheel mounting surfaces. Do not install wheels against rust, dirt, or loose debris.
• Use the correct M14 x 1.5 lug nuts with the correct seat style for the wheel.
• Start every lug nut by hand to avoid cross-threading.
• Snug the lug nuts in a star pattern, then torque them to the vehicle or wheel manufacturer's specified value using a calibrated torque wrench.
• Do not use impact tools for final tightening unless the tool is specifically controlled and followed by a torque-wrench check.
• After installation, rotate each wheel by hand and check for obvious interference before lowering the vehicle completely.
• Recheck lug torque after the first short drive and again according to the wheel manufacturer's instructions.
• Check tire pressure with the tires cold and complete the required tire-pressure monitoring system relearn procedure if applicable.

Tools And Helpful Supplies

Useful equipment includes a floor jack and properly rated jack stands, wheel chocks, a socket set, a calibrated torque wrench, a tire-pressure gauge, a tread-depth gauge, and a flashlight for inspecting clearance. A hub measurement tool or precise caliper can help confirm center-bore dimensions, while a straightedge and measuring tools can assist with wheel-width and backspacing checks.

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Always support the truck with jack stands on approved lifting points. Never work under a vehicle supported only by a jack.

FAQs

What is the bolt pattern for the 2018 GMC Sierra 1500?
The known bolt pattern is 6x139.7. Confirm the complete wheel fitment because bolt pattern alone does not establish compatibility.

What is the center bore for the 2018 GMC Sierra 1500?
The known center bore is 78.1 mm. A replacement wheel with a smaller center bore will not fit over the hub. A larger bore may need suitable hub-centric rings when required by the wheel design.

What lug thread size does this truck use?
The known thread size is M14 x 1.5. The lug-nut seat must also match the replacement wheel, so thread size alone is not enough to select lug nuts.

What wheel diameter and width came on the 2018 GMC Sierra 1500?
The supplied information does not identify a single factory diameter or width. These values may vary by trim, configuration, and equipment. Check the original wheel stamp, tire sidewall, door-jamb label, owner's manual, or a VIN-specific OEM source.

Can I use any 6x139.7 wheel on a 2018 GMC Sierra 1500?
No. The wheel must also provide adequate center-bore, brake, suspension, fender, load-rating, offset, width, and lug-seat compatibility. Use the calculator for a dimensional comparison and verify the result with a physical inspection.

How do I check whether a larger wheel will fit?
Enter the confirmed original dimensions, then use the calculator's custom wheel and tire fields to compare the proposed setup. Check inner and outer clearance at full steering lock and through the suspension's operating range. Confirm tire load capacity and the tire manufacturer's approved rim-width range.

Will changing wheel diameter change tire diameter?
The calculator updates the tire diameter comparison when rim diameter changes. The final tire must still be selected by its complete size, load rating, approved rim width, and vehicle clearance requirements.

Do aftermarket wheels require different lug nuts?
They may. Aftermarket wheels can use a different lug-seat style or require a different shank or washer design. Match the lug nuts to the wheel manufacturer’s instructions and the known M14 x 1.5 thread size.