2021 GMC Sierra Tire Size Factory tire sizes, bolt pattern & tire pressure
Tire Sizes
265/70R17, 275/60R20
Bolt Pattern
6x139.7
Offset
24-34
Tire Pressure
35/35 PSI
Tire Sizes by Trim
| Trim | Tire Size | Bolt Pattern | Pressure (F/R) |
|---|---|---|---|
| Base | 265/70R17 | 6x139.7 | 35/35 PSI |
| SLE/Elevation | 275/60R20 | 6x139.7 | 35/35 PSI |
| SLT/AT4/Denali | 275/60R20 | 6x139.7 | 35/35 PSI |
Alternative Tire Sizes
These sizes are within 3% diameter of the factory 265/70R17 and may fit the 2021 GMC Sierra.
265/65R18 Safe
0.1% · same width · +1" rim 285/55R19 Safe
0.8% · +20mm · +2" rim 255/70R18 Safe
1.4% · -10mm · +1" rim 275/65R18 Safe
1.5% · +10mm · +1" rim 255/70R17 Caution
1.7% · -10mm · same rim 255/65R18 Caution
1.8% · -10mm · +1" rim 275/60R18 Caution
1.9% · +10mm · +1" rim 275/55R19 Caution
2.2% · +10mm · +2" rim
Related Comparisons
265/70R17 vs 275/70R17 Common truck width upgrade 265/70R17 vs 285/70R17 Popular truck tire upsizing 265/70R17 vs 265/65R17 Same width, shorter sidewall 245/75R16 vs 265/70R17 Classic truck rim and tire upgrade 275/55R20 vs 275/60R20 Taller sidewall same width 275/60R20 vs 285/60R20 Full-size SUV tire comparison 235/75R15 vs 265/70R17 Classic to modern off-road upgrade 255/70R18 vs 265/70R17 Rim downsize comparison 265/65R17 vs 265/70R17 Taller sidewall same width 235/70R16 vs 265/70R17 Off-road rim and size upgrade 305/55R20 vs 275/60R20 Wide vs tall truck tire 265/70R16 vs 265/70R17 Truck rim upgrade same tire 275/60R20 vs 275/55R20 Profile height comparison 245/70R17 vs 265/70R17 Truck width upgrade 17s
Tire Maintenance Tips for the GMC Sierra
Proper tire maintenance extends tire life and keeps your 2021 GMC Sierra safe on the road. Follow these guidelines from NHTSA:
- Check tire pressure monthly — the GMC Sierra requires 35/35 PSI (front/rear). Check when tires are cold, before driving.
- Rotate tires every 5,000–7,500 miles — this ensures even wear across all four tires, especially important for vehicles with staggered setups.
- Inspect tread depth regularly — the legal minimum is 2/32", but most experts recommend replacing tires at 4/32" for adequate wet traction.
- Check the DOT date code — tires older than 6 years should be inspected by a professional, regardless of tread depth. The 4-digit DOT code on the sidewall shows the week and year of manufacture.
Choosing Alternative Tires
When replacing tires on your 2021 GMC Sierra, stay within 3% of the factory tire's overall diameter to avoid affecting your speedometer accuracy, ABS calibration, and traction control. The factory bolt pattern (6x139.7) and offset (24-34) must also match.
Always verify any alternative size with a qualified tire professional before purchase. For more information on tire safety, see the NHTSA Tire Ratings Search.