2025–2026 Factory-verified internal

SUV guide wording: Emissions override, California (lets a dealer in a California-emissions state order Federal emissions for a vehicle registered in a Federal state). the state list in GM's text changed between the 2025 and 2026 guides. 2025: O in 1SF, 1SG; 2026: O in 3VL, 1SF, 1SG.

GM factory document — 2025 gmc hummer ev suv fleet order guide, p.24.
GM factory document — 2026 gmc hummer ev suv fleet order guide, p.28.

Jimmy — second generation (1995–2001)

1999–2001 Factory-verified internal

GM factory document — 1999 gmc jimmy 4wd rpo code list, p.1.
GM factory document — 2000 gmc jimmy 4wd rpo code list, p.1.
GM factory document — 2001 gmc jimmy 4wd rpo code list, p.1.

Safari — Second generation (1995–2005)

1998 Factory-verified internal

GM factory document — 1998 gmc safari 2wd rpo code list, p.1.

Savana — GMT610 (2003–2027)

2006–2010, 2014–2016, 2025–2027 Factory-verified internal

; the 2006–2009 lists read Emission Override - California System; O: Cargo 1WT, Cutaway 1WT, Cutaway 2WT (2025–2026), Passenger 1LS, Passenger 1LT

GM factory document — 2006 gmc savana rpo code list, p.1.
GM factory document — 2008 gmc savana rpo code list, p.1.
GM factory document — 2008 chevrolet ld electricalfullsizevans, p.17.
GM factory document — 2009 gmc savana rpo code list, p.1.
GM factory document — 2009 chevrolet ld electricalfullsizevans 100813, p.15.
GM factory document — 2010 chevrolet gh van elec 1 7 d1 100813, p.15.
GM factory document — 2014 chevrolet gh van elec bbm si brief, p.7.
GM factory document — 2016 chevrolet express savana electrical body builders manual service manual 2016 en us, p.8.
GM factory document — 2025 gmc savana cargo fleet order guide, p.31.
GM factory document — 2025 gmc savana cutaway fleet order guide, p.38.
GM factory document — 2025 gmc savana passenger fleet order guide, p.22.
GM factory document — 2026 gmc savana cargo fleet order guide, p.33.
GM factory document — 2026 gmc savana cutaway fleet order guide, p.41.
GM factory document — 2026 gmc savana passenger fleet order guide, p.24.
GM factory document — 2027 gmc savana cargo fleet order guide, p.30.
GM factory document — 2027 gmc savana cutaway fleet order guide, p.20.
GM factory document — 2027 gmc savana passenger fleet order guide, p.22.

Sierra EV — BT1 (2024–2027)

2025–2027 Factory-verified internal

GM factory document — 2025 gmc sierra ev denali fleet order guide rpo codes, p.1.
GM factory document — 2025 gmc sierra ev denali fleet order guide, p.10.
GM factory document — 2027 gmc sierra ev fleet order guide rpo codes, p.1.
GM factory document — 2027 gmc sierra ev fleet order guide, p.20.

Sierra 1500 — Next-Generation (2027)

2027 Factory-verified internal

; lets a dealer in states that require California emissions order California emissions

GM factory document — 2027 gmc next generation sierra 1500 retail and fleet fleet order guide, p.44.
GM factory document — 2027 gmc next generation sierra 1500 retail and fleet fleet order guide rpo codes, p.1.

Sierra — GMT400 (1988–2000)

1998 Factory-verified internal

GM factory document — 1998 gmc gmc c pickup 2wd rpo code list, p.1.

Sierra — GMT800 (1999–2007)

2005–2007 Factory-verified internal

GM factory document — 2005 gmc gmc c sierra 2wd rpo code list, p.1.
GM factory document — 2007 gmc sierra classic 2wd rpo code list, p.1.

Sierra HD — GMT900 (2007–2014)

2014 Factory-verified internal

lets a dealer in a California-emissions state order federal emissions

GM factory document — 2014 gmc sierra 2500hd fleet order guide wayback, p.4.
GM factory document — 2014 gmc sierra 3500hd fleet order guide wayback, p.4.

Sierra HD — K2XX (2015–2019)

2015, 2018–2019 Factory-verified internal

lets dealers in California-emission states order federal emissions; not in Maine or Vermont; 2018: GM's 2018 Sierra 2500HD order guide; 2019: GM's 2019 Sierra 3500HD order guide

GM factory document — 2015 gmc sierra 2500hd fleet order guide wayback, p.4.
GM factory document — 2018 gmc sierra 2500hd order guide copy gm authority, p.25.
GM factory document — 2019 gmc sierra 3500hd order guide copy gm authority, p.23.

Sierra HD — T1XX (2020–2027)

2025–2027 Factory-verified internal

GM factory document — 2025 gmc sierra 2500 hd retail and fleet fleet order guide rpo codes, p.1.
GM factory document — 2026 gmc sierra 2500 hd retail and fleet fleet order guide rpo codes, p.1.
GM factory document — 2027 gmc sierra 2500 hd retail and fleet fleet order guide rpo codes, p.1.

Sierra — K2XX (2014–2019)

2014, 2016, 2018–2019 Factory-verified internal

GM factory document — 2014 gmc sierra 1500 fleet order guide wayback, p.4.
GM factory document — 2016 gmc sierra 1500 fleet order guide wayback, p.4.
GM factory document — 2018 gmc sierra 1500 order guide copy gm authority, p.89.
GM factory document — 2019 gmc sierra 1500 limited double cab k2xx order guide copy gm authority, p.40.

Sierra — T1XX (2019–2026)

2025–2026 Factory-verified internal

GM factory document — 2025 gmc sierra 1500 retail and fleet fleet order guide rpo codes, p.1.
GM factory document — 2026 gmc sierra 1500 retail and fleet fleet order guide rpo codes, p.1.

Sonoma — second generation (1994–2004)

1999–2002 Factory-verified internal

GM factory document — 1999 gmc sonoma pickup 4wd rpo code list, p.1.
GM factory document — 2000 gmc sonoma pickup 4wd rpo code list, p.1.
GM factory document — 2001 gmc sonoma pickup 4wd rpo code list, p.1.
GM factory document — 2002 gmc sonoma pickup 4wd rpo code list, p.1.

Suburban — GMT400 (1992–1999)

1998 Factory-verified internal

GM factory document — 1998 gmc gmc suburban 2wd rpo code list, p.1.

Terrain — First generation (2010–2017)

2016–2017 Factory-verified internal

lets a dealer in a California-emission state order Federal emissions for a vehicle registered in a Federal-emission state; requires FE9; not in Maine or Vermont

GM factory document — 2016 gmc terrain fleet order guide wayback, p.4.
GM factory document — 2017 gmc terrain fleet order guide wayback, p.4.

Terrain — Second generation (D2XX) (2018–2024)

2019 Factory-verified internal

GM factory document — 2019 gmc terrain order guide copy gm authority, p.44.

Terrain — Third generation (2025–2027)

2025–2027 Factory-verified internal

; O on all trims; requires FE9; the 2025 guide adds not available in Maine or Vermont

GM factory document — 2025 gmc next generation terrain fleet order guide, p.9.
GM factory document — 2026 gmc next generation terrain fleet order guide, p.13.
GM factory document — 2027 gmc terrain fleet order guide, p.13.

Yukon — GMT400 (1992–1999)

1998 Factory-verified internal

GM factory document — 1998 gmc yukon 2wd rpo code list, p.1.

Yukon — K2XX (2015–2020)

2015–2016, 2018 Factory-verified internal

; requires FE9; 2018 from GM's 2018 Yukon order guide

GM factory document — 2015 gmc yukon denali fleet order guide wayback, p.4.
GM factory document — 2016 gmc yukon denali fleet order guide wayback, p.4.
GM factory document — 2018 gmc yukon order guide copy gm authority, p.32.

Yukon — T1XX (2021–2027)

2025–2027 Factory-verified internal

2027: O on all trims

GM factory document — 2025 gmc new yukon denali fleet order guide, p.36.
GM factory document — 2026 gmc yukon denali fleet order guide, p.38.
GM factory document — 2027 gmc yukon fleet order guide, p.34.

Yukon XL — K2XX (2015–2020)

2015–2016 Factory-verified internal

requires FE9; not in Maine or Vermont

GM factory document — 2015 gmc yukon xl denali fleet order guide wayback, p.4.
GM factory document — 2016 gmc yukon xl denali fleet order guide wayback, p.4.

Yukon XL — T1XX (2021–2027)

2025–2027 Factory-verified internal

2027: O on all trims

GM factory document — 2025 gmc new yukon xl denali fleet order guide, p.39.
GM factory document — 2026 gmc yukon xl denali fleet order guide, p.40.
GM factory document — 2027 gmc yukon xl fleet order guide, p.35.

This page aggregates every documented appearance of NB8 in the GMC reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.