GMC Sierra

The Sierra at a glance: GMC's version of the GM pickup

GMC has used the Sierra name since the late 1960s, first as trim levels on its C/K trucks (Sierra, Sierra Classic, Sierra Grande and High Sierra). With the GMT400 trucks of 1988 the Sierra became the model name, while Chevrolet kept the C/K name until the Silverado arrived. The two trucks share their frames, engines and most of their bodies; the GMC has its own front end, interior details and, at the top of the range, the Denali luxury trim. GM's history is told in the history of General Motors, and the GMC range is in the GMC catalogue.

GMC Sierra generations since 1988

GMT400 to GMT900 (1988–2013)

The first Sierra of 1988 was about 194 in (4.93 m) long on a 117.5 in (2,985 mm) wheelbase. Engines ran from a 4.3-litre V6 of 112 kW (150 hp) through V8s to a 6.2-litre V8 diesel. The GMT800 trucks arrived in August 1998 as 1999 models, with heavy-duty versions from 2000–2001; the older trucks carried on as "Classic" models. The GMT900 followed in late 2006 for the 2007 model year. Each generation grew a little, and the standard length went from 194 to more than 205 in. By our count, today's shortest Sierra 1500 is about 430 mm longer than the 1988 truck.

K2XX (2014–2018)

The K2XX was introduced on 13 December 2012, and the 1500 went on sale in May 2013 as a 2014 model. It brought the EcoTec3 engine family: a 4.3-litre V6 with 213 kW (285 hp), a 5.3-litre V8 with 265 kW (355 hp) and a 6.2-litre V8 with 313 kW (420 hp). The body was more aerodynamic and the front end and lamps were new. According to the old 1cars text, the front brake discs grew from 325 to 356 mm, with 13 % more pad area. An 8-inch touchscreen, a reversing camera, heated and cooled seats and a Bose audio system were available, and a Z71 off-road package was offered.

T1XX (2019–2026)

The fifth generation was unveiled in January 2018 and went on sale in August 2018 as a 2019 model. It added a 2.7-litre turbo four, renamed TurboMax for 2024, whose torque rose from 472 to 569 Nm (348 to 420 lb-ft) for 2022, and a 3.0-litre Duramax in-line six diesel. The 2022 update brought a new front end, a new interior with a 13.4-inch screen on upper trims, Super Cruise hands-free driver assistance and the AT4X and Denali Ultimate trims. GMC also offers the battery-electric Sierra EV, a separate model related to the Silverado EV.

Sixth generation (from 2026)

GM unveiled the next Silverado on 16 June 2026 and the new Sierra on 25 June 2026, with production starting in 2026 and sales from around the end of the year. It uses only ten-speed automatic gearboxes. Full technical details were still emerging at the time of writing.

TurboMax, EcoTec3 V8s and the Duramax diesel

At launch in 2020 the Duramax diesel gave 207 kW (277 hp); it was raised to 227 kW (305 hp) for 2023. Gearboxes have included six-, eight- and ten-speed automatics. Rear-wheel drive is standard, with four-wheel drive optional.

Regular, double and crew cabs and bed lengths

The current Sierra 1500 is about 211 in (5.36 m) long in its shortest form, and long-bed crew cabs exceed 241 in (6.12 m). Three cabs are offered: regular (two or three seats), double and crew (up to six seats). The old 1cars text gives bed lengths of about 2 metres for the standard bed and 2.44 metres for the long bed. Such a truck needs a big space, so the garage fit tool is worth a check before buying.

Which engine uses least fuel

Full-size pickups are thirsty. The 2.7 TurboMax and the Duramax diesel are the most economical choices, while the 6.2 V8 uses the most fuel. In Europe, where these trucks are imported only privately, large engines also mean high registration taxes in many countries. To estimate fuel costs in l/100 km or mpg, use the fuel cost calculator.

From Pro to Denali Ultimate

The current 1500 comes in Pro, SLE, SLT, AT4, AT4X, Denali and Denali Ultimate trims, with Elevation added on the new generation. AT4 and AT4X are off-road versions, while Denali and Denali Ultimate are luxury trucks with premium leather, large screens and Super Cruise. GMC does not sell the Sierra through dealers in the European Union, so there is no official euro price.

IIHS results and the missing Euro NCAP test

Euro NCAP has not tested the Sierra, because GM does not sell it in Europe. In IIHS tests of its Silverado twin (2022 crew cab), the small-overlap driver-side and moderate-overlap results were rated Good and the small-overlap passenger side Marginal.

Rivals: how the Sierra compares

The Sierra shares its hardware with the Silverado but positions itself as the more upmarket choice, especially as a Denali. Its traditional rivals are the Ram 1500 and the Ford F-150. For a GMC with a fully electric drivetrain, see the GMC Hummer EV, and for the SUV built on the same family of frames, the GMC Yukon Denali.