2025 GMC Sierra — 1500 AT4
The 2025 GMC Sierra 1500 AT4 shipped with 3 different factory tire sizes, depending on the wheel package it left the factory with (this can also reflect a staggered front/rear setup). Check your tire sidewall or door placard to confirm which one applies to your vehicle.
This trim shipped with more than one tire size (staggered fitment, front/rear, or optional wheel package). Confirm which one matches your vehicle by checking your tire sidewall or door placard.
275/65R18
| Section width | 275 mm |
|---|---|
| Aspect ratio (sidewall height) | 65% (178.8 mm) |
| Rim diameter | 18" |
| Overall tire diameter | ~32.1" |
| Revolutions per mile | ~629 |
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265/60R20
| Section width | 265 mm |
|---|---|
| Aspect ratio (sidewall height) | 60% (159 mm) |
| Rim diameter | 20" |
| Overall tire diameter | ~32.5" |
| Revolutions per mile | ~620 |
Compare prices at:
275/60R20
| Section width | 275 mm |
|---|---|
| Aspect ratio (sidewall height) | 60% (165 mm) |
| Rim diameter | 20" |
| Overall tire diameter | ~33" |
| Revolutions per mile | ~611 |
Compare prices at:
What this size means for your GMC Sierra
On the 2025 GMC Sierra 1500 AT4, the factory 275/65R18 measures about 32.1″ in overall diameter with a 178.8 mm (7″) sidewall, and completes roughly 629 revolutions per mile. Its 65-series aspect ratio gives a taller, comfort-biased sidewall that favors ride quality and shrugs off rough pavement. In tire terms it is a passenger (P-metric / Euro-metric) size.
The 275/65R18 and 265/60R20 differ in both width and overall diameter (0.4″, 1.2%), which usually means a staggered front/rear setup — the two sizes are not interchangeable side to side, so match each to its correct axle.
Other 2025 GMC Sierra trims
- 1500 AT4X 275/70R18
- 1500 Denali 275/60R20 / 275/50R22
- 1500 Denali Ultimate 275/50R22
- 1500 Elevation 275/60R20
- 1500 Pro 255/70R17 / 265/70R17 / 275/60R20
- 1500 SLE 255/70R17 / 265/70R17 / 265/65R18 / 275/60R20
- 1500 SLT 265/65R18 / 275/60R20 / 275/50R22
- 2500 HD AT4 275/70R18 / 275/65R20
- 2500 HD AT4X 305/70R18
- 2500 HD Denali 275/65R20
- 2500 HD Denali Ultimate 275/65R20 / 265/60R22
- 2500 HD Pro 245/75R17 / 265/70R17 / 275/70R18
- 2500 HD SLE 245/75R17 / 265/70R17 / 275/70R18 / 275/65R20
- 2500 HD SLT 275/70R18 / 275/65R20
- 3500 HD 275/70R18 / 275/65R20
- 3500 HD Dually 235/80R17 / 235/80R18
GMC Sierra tire sizes by year
- 2026 GMC Sierra 275/65R18 / 265/60R20 / 275/60R20
- 2024 GMC Sierra 275/65R18 / 265/60R20 / 275/60R20
- 2023 GMC Sierra 275/65R18 / 265/60R20 / 275/60R20
- 2022 GMC Sierra 275/65R18 / 265/60R20 / 275/60R20
- 2021 GMC Sierra 265/65R18 / 275/65R18 / 265/60R20 / 275/60R20
- 2020 GMC Sierra 255/70R17 / 265/70R17 / 265/65R18 / 275/60R20 / 275/50R22
- 2019 GMC Sierra 255/70R17 / 265/70R17 / 265/65R18 / 275/60R20 / 275/50R22
- 2018 GMC Sierra 255/70R17 / 265/70R17 / 265/65R18 / 275/55R20 / 285/45R22
- 2017 GMC Sierra 255/70R17 / 265/70R17 / 265/65R18 / 275/55R20 / 285/45R22
- 2016 GMC Sierra 255/70R17 / 265/70R17 / 265/65R18 / 275/55R20 / 285/45R22
How to read a tire size
A tire size like 225/45R17 breaks down into three parts:
the first number is the section width in millimeters
(the tire's width from sidewall to sidewall), the second is the
aspect ratio — the sidewall's height as a percentage of
that width — and the number after the "R" is the rim
diameter in inches. A letter prefix (P or LT) indicates
Passenger or Light Truck construction; its absence usually means
Euro-metric sizing.
Some trucks and off-road tires instead use "flotation" sizing, like
37X12.50R17 — here the numbers are the tire's overall
diameter and width in inches directly, with the rim diameter last.
Always verify against the tire information placard on your driver's-side door jamb or your owner's manual before purchasing — tire size can vary by factory option package even within the same trim.