1999 GMC Sierra 1500 Regular Cab Bolt Pattern
Checking fitment for your vehicle? Below you will find the factory bolt pattern (also known as the lug pattern) for the 1999 GMC Sierra 1500 Regular Cab, along with offset and center bore data.
| Bolt Pattern (Lug Pattern) | 6x139.7 (6x5.5") |
|---|---|
| Lug Nut / Bolt Size | 14x1.5 |
| Center Bore (CB) | 78.1 mm |
| Offset (ET) | 20-30 |
| Torque Specs | 100 ft-lbs (135 Nm) |
Imperial Match: 6x139.7 is commonly referred to as 6x5.5" in US Standard.
1999 Sierra 1500 Regular Cab — Year-Specific Fitment Context
The 1999 model year marks the beginning of the GMC Sierra 1500 Regular Cab's 6x139.7 bolt pattern era, which continued through 2024 (26 consecutive years). Wheels from any 1999–2024 GMC Sierra 1500 Regular Cab are cross-compatible with the 1999 model.
GMC Sierra 1500 Regular Cab Bolt Pattern by Year
The table below shows how the Sierra 1500 Regular Cab's wheel specifications have changed over the years. The 1999 model year is highlighted.
| Year | Bolt Pattern | Center Bore | Offset |
|---|---|---|---|
| ▸ 1999 | 6x139.7 | 78.1 | 20-30 |
| 2000 | 6x139.7 | 78.1 | 20-30 |
| 2001 | 6x139.7 | 78.1 | 20-30 |
| 2002 | 6x139.7 | 78.1 | 20-30 |
| 2003 | 6x139.7 | 78.1 | 20-30 |
| 2004 | 6x139.7 | 78.1 | 20-30 |
| 2005 | 6x139.7 | 78.1 | 20-30 |
| 2006 | 6x139.7 | 78.1 | 20-30 |
| 2007 | 6x139.7 | 78.1 | 20-30 |
| 2008 | 6x139.7 | 78.1 | 20-30 |
| 2009 | 6x139.7 | 78.1 | 20-30 |
| 2010 | 6x139.7 | 78.1 | 20-30 |
| 2011 | 6x139.7 | 78.1 | 20-30 |
| 2012 | 6x139.7 | 78.1 | 20-30 |
| 2013 | 6x139.7 | 78.1 | 20-30 |
| 2014 | 6x139.7 | 78.1 | 20-30 |
| 2015 | 6x139.7 | 78.1 | 20-30 |
| 2016 | 6x139.7 | 78.1 | 20-30 |
| 2017 | 6x139.7 | 78.1 | 20-30 |
| 2018 | 6x139.7 | 78.1 | 20-30 |
| 2019 | 6x139.7 | 78.1 | 20-30 |
| 2020 | 6x139.7 | 78.1 | 20-30 |
| 2021 | 6x139.7 | 78.1 | 20-30 |
| 2022 | 6x139.7 | 78.1 | 20-30 |
| 2023 | 6x139.7 | 78.1 | 20-30 |
| 2024 | 6x139.7 | 78.1 | 20-30 |
6x139.7 Pattern Context
This bolt pattern appears on 1067 vehicles in our current database and is considered common.
Examples of other vehicles using 6x139.7:
Expert Buying Guide for 1999 GMC Sierra 1500 Regular Cab
For your 1999 GMC Sierra 1500 Regular Cab, the 6x139.7 bolt pattern is shared across 1999-2024 models, ensuring broad wheel compatibility. Critical fitment factors include a 78.1mm center bore; aftermarket wheels with larger bores require hub-centric rings to prevent vibration and ensure load support. Offset must stay within 20-30mm to avoid rubbing or clearance issues. Always use lug nuts with the correct 14x1.5 thread pitch and matching seat type (cone or ball) to prevent loosening or damage. Verify wheel load rating meets or exceeds OEM specifications for safety.
Historical Fitment Data Reference
In our dataset, GMC Sierra 1500 Regular Cab appears from 1999 to 2024 (26 model years). Across recorded model years, this model generally keeps the same bolt pattern.
- Observed bolt-pattern variants for this model: 1
- Observed center-bore variants for this model: 1
- Observed lug-size variants for this model: 1
- Observed total offset span across years: 50.0 mm
Quick Tips & Safety Warnings
- ✅ Re-torque lug nuts after 50-100 miles of driving to maintain proper clamping force.
- ✅ Avoid using universal-fit wheels without hub-centric rings; they can cause steering wheel vibration.
- ✅ Check that aftermarket wheels clear the brake calipers and suspension components, especially with lower offsets.
- ⚠️ This fitment uses a wide offset range. Check brake clearance and fender clearance before buying wheels.
- ⚠️ Torque lugs in a star pattern to 100 ft-lbs (135 Nm), then re-check torque after 50-100 km (30-60 miles).
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1999 GMC Sierra 1500 Regular Cab — Frequently Asked Questions
What is the bolt pattern for a 1999 GMC Sierra 1500 Regular Cab?
The 1999 GMC Sierra 1500 Regular Cab uses a 6x139.7 bolt pattern (also called lug pattern or PCD). The center bore is 78.1mm and the offset is 20-30mm.
What other years of GMC Sierra 1500 Regular Cab have the same bolt pattern as the 1999?
The GMC Sierra 1500 Regular Cab uses the 6x139.7 pattern from 1999 through 2024. Wheels from any of these model years are dimensionally compatible with the 1999, provided the offset and center bore also match.
What is the center bore of a 1999 GMC Sierra 1500 Regular Cab?
The factory center bore (hub bore) for the 1999 GMC Sierra 1500 Regular Cab is 78.1mm. If your aftermarket wheels have a larger hub bore, you will need hub-centric rings to prevent vibration.
Do 1999 GMC Sierra 1500 Regular Cabs use lug bolts or lug nuts?
The 1999 Sierra 1500 Regular Cab requires 14x1.5 hardware. Check your specific trim to ensure you use the correct conical or spherical seating.
How do I measure the bolt pattern on my 1999 GMC?
The 1999 Sierra 1500 Regular Cab uses a 6x139.7 pattern. For 4, 6, or 8-lug wheels, measure center-to-center across opposite holes. For 5-lug, measure from the center of one hole to the back of the opposite hole.
What is the factory wheel offset for a 1999 GMC Sierra 1500 Regular Cab?
The OEM offset for the 1999 Sierra 1500 Regular Cab is typically around 20-30mm. Depending on wheel width, a deviation of ±5mm is usually acceptable, but verify suspension clearance.
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