2012 GMC Sierra 1500 Wheel Offset

Quick specs

Wheel size: 7.5x17 · 8x18 · 8.5x20
Offset: ET31
Backspacing: 4.97 in · 5.22 in · 5.47 in
Bolt pattern: 6x139.7
Center bore: 78.1 mm
Thread: M14 x 1.5
Tire size: 245/70R17 · 265/70R17 · 265/65R18 · 275/55R20

OEM configurations

Configuration	Front	Rear	Offset	Backspacing	Tire	Bolt pattern	Center bore	Thread
4.3i · 4.3L, LU3, V6, Petrol	7.5x17	—	ET31	4.97 in	245/70R17	6x139.7	78.1 mm	M14 x 1.5
4.3i · 4.3L, LU3, V6, Petrol	7.5x17	—	ET31	4.97 in	265/70R17	6x139.7	78.1 mm	M14 x 1.5
4.3i · 4.3L, LU3, V6, Petrol	8x18	—	ET31	5.22 in	265/65R18	6x139.7	78.1 mm	M14 x 1.5
4.3i · 4.3L, LU3, V6, Petrol	8.5x20	10.5x20	ET31 / ET35	5.47 in	275/55R20	6x139.7	78.1 mm	M14 x 1.5
4.8i · 4.8L, L20, V8, Petrol	7.5x17	—	ET31	4.97 in	245/70R17	6x139.7	78.1 mm	M14 x 1.5
4.8i · 4.8L, L20, V8, Petrol	7.5x17	—	ET31	4.97 in	265/70R17	6x139.7	78.1 mm	M14 x 1.5
4.8i · 4.8L, L20, V8, Petrol	8x18	—	ET31	5.22 in	265/65R18	6x139.7	78.1 mm	M14 x 1.5
4.8i · 4.8L, L20, V8, Petrol	8.5x20	10.5x20	ET31 / ET35	5.47 in	275/55R20	6x139.7	78.1 mm	M14 x 1.5
5.3i · 5.3L, LMG/LC9, V8, Flex-Fuel	7.5x17	—	ET31	4.97 in	245/70R17	6x139.7	78.1 mm	M14 x 1.5
5.3i · 5.3L, LMG/LC9, V8, Flex-Fuel	7.5x17	—	ET31	4.97 in	265/70R17	6x139.7	78.1 mm	M14 x 1.5
5.3i · 5.3L, LMG/LC9, V8, Flex-Fuel	8x18	—	ET31	5.22 in	265/65R18	6x139.7	78.1 mm	M14 x 1.5
5.3i · 5.3L, LMG/LC9, V8, Flex-Fuel	8.5x20	10.5x20	ET31 / ET35	5.47 in	275/55R20	6x139.7	78.1 mm	M14 x 1.5
6.2i · 6.2L, L9H, V8, Flex-Fuel	7.5x17	—	ET31	4.97 in	245/70R17	6x139.7	78.1 mm	M14 x 1.5
6.2i · 6.2L, L9H, V8, Flex-Fuel	7.5x17	—	ET31	4.97 in	265/70R17	6x139.7	78.1 mm	M14 x 1.5
6.2i · 6.2L, L9H, V8, Flex-Fuel	8x18	—	ET31	5.22 in	265/65R18	6x139.7	78.1 mm	M14 x 1.5
6.2i · 6.2L, L9H, V8, Flex-Fuel	8.5x20	10.5x20	ET31 / ET35	5.47 in	275/55R20	6x139.7	78.1 mm	M14 x 1.5

Lug hardware

Real-World 2012 GMC Sierra 1500 Wheel Setups

Observed aftermarket setups from documented Modified1 builds. These are individual build records — not OEM specifications and not clearance guarantees for every vehicle.

Common custom wheel sizes

Among builds in our database for this model year:

20-inch — 2 documented builds
26-inch — 1 documented build

3 documented builds.

20×10 ET-18

Documented on a 2012 GMC Sierra 1500 build — observed custom fitment, not a universal fit guarantee.

Tires: 35/12.5R20

Compared with OEM

Compared with the 20×8.5 ET31 OEM configuration. Calculated geometry only — not fit confirmation.

Outer edge 68.1 mm farther toward fender (more outward poke)
Inner edge 29.9 mm farther from suspension (more inner clearance)
Width +1.5" vs OEM

View full build on Modified1

20×10 ET-18

Documented on a 2012 GMC Sierra 1500 build — observed custom fitment, not a universal fit guarantee.

Tires: 35/12.5R20

Compared with OEM

Compared with the 20×8.5 ET31 OEM configuration. Calculated geometry only — not fit confirmation.

Outer edge 68.1 mm farther toward fender (more outward poke)
Inner edge 29.9 mm farther from suspension (more inner clearance)
Width +1.5" vs OEM

View full build on Modified1

Staggered · 26×10 / Rear unknown

Documented on a 2012 GMC Sierra 1500 build — observed custom fitment, not a universal fit guarantee.

Wheel: Velocity VW 12

Front: 26×10 · 275/25R26
Rear: —

Compared with OEM

Compared with the 20×8.5 ET31 OEM configuration. Calculated geometry only — not fit confirmation.

Diameter +6" vs OEM

View full build on Modified1

More specs for the 2012 GMC Sierra 1500

Each OEM row is a catalog configuration. Offset ranges are not collapsed when the database has exact setups. Documented aftermarket builds are observed setups only — not universal fit or clearance confirmation.