General Motors GMT platform

GMT (General Motors Truck) is a nomenclature used by General Motors to designate multiple vehicle platforms. In use since the early 1980s, the GMT nomenclature is used for light trucks, full-size SUVs, and vans, along with several medium-duty trucks. With only a few exceptions, nearly all GMT vehicles use body-on-frame construction, along with rear-wheel drive (or all-wheel drive) powertrain configurations.

Primary applications

Primary applications of the platform – those that are equivalent in basic RWD/frame structure to each other – existed from 1981 to 1989, and again since 2018.

Light trucks and SUVs

Pickups and SUVs have been the main vehicles underpinned by GMT platforms, being involved for the entirety of the platform's existence.

Fullsize

GMT400 – Chevrolet C/K and variants, 1988 – 2002
GMT800 – Chevrolet Silverado and variants, 1999 – 2007
GMT900 – Chevrolet Silverado and variants, 2007 – 2014
GMTK2XX – Chevrolet Silverado and variants, 2014 – 2019
GMTT1XX – Chevrolet Silverado and variants, 2019–present

Midsize

GMT325 – Chevrolet S-10 and truck rebadgings, 1982 – 2012
GMT330 – Chevrolet S-10 Blazer and SUV rebadgings, 1983 – 2012
GMT355 – First-gen. Chevrolet Colorado and truck rebadgings, 2004 – 2012
GMT360 – Chevrolet TrailBlazer and rebadgings, 2002 – 2009
GMT700, later GMT31XX – Second-gen. Chevrolet Colorado, 2012–present
GMT700, later GMT31XX – Second-gen. Chevrolet TrailBlazer SUV, 2012–present

Hummer

In contrast to the Hummer H1–designed and assembled by AM General, the Hummer H2 and Hummer H3 were developed by GM, receiving their own platform designations. Designated the GMT825, the H2 was derived from the GMT820 (Chevrolet Tahoe/GMC Yukon), with its own midsection frame design and a rear frame shared with the 2500-series GMT800 pickup trucks.^[1]

The H3 SUV was designated the GMT345, a close variant of the GMT355 (Chevrolet Colorado/GMC Canyon). The 2009-2010 H3T pickup truck was designated as the GMT745, adopting a nomenclature closer in line with the GMT700 used by the later second-generation Colorado/Canyon.

Vans

The 1996 Chevrolet Express/GMC Savana replaced the previous G-series Van/Vandura, adopting the GMT600 designation. As part of a model update and revision for 2003, GM changed the Express/Savana to GMT610, which remains in use, the model line competes with the Ford Transit, and Ford E-Series (dependent on configuration), Mercedes-Benz/Freightliner Sprinter, Dodge Ram Wagon, and the Ram ProMaster (cargo van only).

Medium trucks

For 1990, the Chevrolet Kodiak/GMC TopKick medium-duty trucks adopted the GMT530 designation (sharing the cab of the GMT400 trucks). For 2003, the line was redesigned, becoming the GMT560 platform (sharing a version of the GMT610 cab). After the 2009 model year, General Motors ended medium-duty truck production.

Since 2018, a medium-duty version of the GMTK2XX has been produced in a joint venture with Navistar International.

Other applications

While the aforementioned platforms are the ones model commonly referred to as GMT platforms, there have been other instances of the name being applied which are not for RWD and/or body-on-frame vehicles.

MPVs

For 1990, GM unveiled its first minivans, all of which were underpinned by the first generation of the U platform. This platform was given the alternate name of GMT199 shortly thereafter, beginning the pattern of expanded use for the GMT platform name. This pattern was kept for the 1996 second-generation and 2005 third-generation GM minivans, called the GMT200 and GMT201 platforms, respectively. With the 2010 introduction of the fourth-generation U platform, the designation GMT510 was planned for use. However, all of the GM minivans (save for the China-exclusive Buick GL8) were dropped, ergo the name went unused.

For its production from 2006 to 2011, the compact wagon-bodied Chevrolet HHR rode on the Delta platform. Despite this, it was internally given the designation of GMT001.

Crossovers

In 2001 and 2002, the Pontiac Aztek and Buick Rendezvous were introduced, respectively. These were built upon a shortened version of the U platform which underpinned GM's minivans. As such, they were given the GMT 250 and GMT 257 names respectively. For 2003, Cadillac released their first crossover, the Sigma-based first-generation SRX. Being a luxury model, it was given the alternate platform code of GMT265. The successive generation SRX, on an entirely different platform, was called GMT166. The related Saab 9-4X was called GMT168.

In 2004, with the release of the first-generation Chevrolet Equinox, the GMT 191 name was internally used to refer to it. Consequently, the GMT190 name was retroactively applied to the second-generation Chevrolet Tracker, which could be considered one of the Equinox's predecessors. GMT192 was used to refer to the Pontiac Torrent, which was released a year later. The next application of this platform was called GMT193, used exclusively for the second-generation Suzuki XL7, which was discontinued in 2009. The 2010 second-generation Chevrolet Equinox, was called GMT172. The related GMC Terrain was called GMT177. In 2017, the third-generation Equinox went on sale, though it did not use an alternate GMT designation for its platform, and simply used the latest Delta platform variant D2XX. This decision, along with the equivalent shifts for the Enclave and Traverse models in the same year, made for the end of the use of GMT-platform designations for models that are not RWD and body-on-frame.

For 2007, the release of the new Saturn Outlook and GMC Acadia, as well as the Lambda platform, occurred. Lambda itself was called the GMT960 series, with each individual vehicle it underpinned getting an alternate GMT-designation as well. The Outlook was given GMT966, and the Acadia GMT968. The next year, the Buick Enclave and Chevrolet Traverse were introduced, and given GMT967 and GMT561, respectively. Despite numerical similarity in nomenclature of these platforms to the GMT900/GMT560 platforms, there was no further relation, as these models were actually more similar to the other GM crossover platforms.

*GM GMT platform application timeline*
				1	2	3	8	0	1	2	4	5	6	7	9	0	1	2	3	4	5	6	7	8	9	0	1	4	5	9	0	3
				1980s				1990s								2000s										2010s					2020s
truck	medium-duty							530											560
	medium-duty								455
	light-duty	fullsize	SUT															805/806					941/946
		fullsize	pickup				400/480								800/880								900/910					K2XX		T1XX
		roadster pickup																	368
		midsize	pickup																						745
					325 (Gen 1)						325 (Gen 2)
																				355									700/31XX			31XX-2
SUV	body-on-frame		standard																	305		345
						330 (Gen 1)						330 (Gen 2)
																		360
			extended															370
		fullsize	extended							410/425						830							931/932						K2YC/K2YG		T1YC/T1YG
			extended luxury																830				936						K2YL		T1YL
			standard size							415/420/430						820							921/922						K2UC/K2UG		T1UC/T1UG
			standard size luxury												435			820					926						K2UL		T1UL
			off-road																825
		compact													190
	crossover	compact	standard															315						319
		compact																			191/192					172/177
		midsize																					193
																	250
																		257
			luxury																	265						166
			luxury																								168
		fullsize																					968
																							966
																								967
																									561
van	cargo												600						610
	MPV							199						200
																					201
		compact																				001

References

^ Clavey, William (July 12, 2017). "The Hummer H2 Is A Grand And Opulent Bad Idea". Jalopnik. Retrieved September 25, 2017.

[1] Clavey, William (July 12, 2017). "The Hummer H2 Is A Grand And Opulent Bad Idea". Jalopnik. Retrieved September 25, 2017.

[1]