GMT400

An all-new range of Sierra full-size pickups on a new GMT400 architecture arrived for 1988 with nicer interiors, ABS, Insta-Trac shift-on-the-fly 4WD, and improved ride, handling, and fuel efficiency. The car-based Caballero pickup was dropped, as was GMC's last remaining heavy truck, the Brigadier. The following year brought anti-lock rear brakes to S-15 pickups and Jimmys and upgrades to TopKick medium-duty conventional cabs.

For 1990, extended and AWD versions of the Safari van were offered, along with an extended G3500 one-ton van. A 150-hp 4.3-liter V-6 became standard in S-15 Jimmys and Safari vans, with a 170-hp high-output version optional, a new five-speed manual gearbox replaced the old Isuzu four-speed in S-15 pickups, and electronic fuel injection improved performance and fuel efficiency of the 6.0- and 7.0-liter V-8s used in TopKick trucks. For 1991, the compact pickup (now called Sonoma) was redesigned to look more like its Sierra big brothers, a limited-production high-performance Sonoma Syclone model was offered with a 280-hp turbocharged 4.3-liter V-6, a longer-wheelbase four-door Jimmy was added, and a new heavy-duty Hydra-Matic four-speed replaced the old three-speed automatic in HD light trucks.

All-new GMT400 Suburban and Yukon SUVs arrived for 1992, the latter replacing the full-size Jimmy, and a 280-hp Typhoon version of the compact Jimmy joined its high-performance Syclone pickup cousin. In 1993, a new GM North American Truck Platforms organization took over production of medium-duty truck, school bus, and motorhome chassis, and the safety of all GM vans was improved thanks to standard four-wheel anti-lock brakes. In 1994, GM's 6.5-liter V-8 diesel family grew to include a 155-hp naturally aspirated version to replace the less powerful 6.2-liter V-8.

In 1995, the Volvo/GM joint venture WHITEGMC nameplate was discontinued, marking a temporary end to GMC-branded heavy trucks, as light-truck production struggled to keep up with demand. A new compact Jimmy was introduced, along with a longer-wheelbase four-door Yukon. Driver-side airbags were added to all vehicles under 8600-pound GVWR, visibility-enhancing Daytime Running Lights became standard on most truck models, and a third door became available on extended-cab Sierra pickups, historian Meyer reports.

Merger and move

In 1996, the GMC Truck Division merged with Pontiac Motor Division to form Pontiac-GMC Division, and a new family of Vortec gas engines (4.3-liter V-6, 5.0-liter V-8, 5.7-liter V-8, and 7.4-liter V-8, rated at 200-290 hp) with sequential electronic fuel injection improved light-truck power, drivability, and fuel economy. Pontiac-GMC headquarters moved to GM's Detroit Renaissance Center the following year, Volvo bought GM's remaining interest in Volvo GM Heavy Truck Corp., and commercial truck production was consolidated into the Flint plant. An all-new series of Savana full-size G vans replaced the old Rally/Vandura models, an upgraded C series of conventional-cab medium-duty models replaced the TopKicks, and bi-fuel (gasoline/CNG) Sierra 3500 pickups became available.

GMC's next-gen (GMT800) Sierra pickups arrived in 1999 with all-new bodies and chassis and significant improvements throughout. A passenger-side third door became standard on extended cabs, a tow/haul mode was added to automatic transmissions, and upgraded Vortec V-8s ranged from a 255-hp, 4.8-liter through a 270-hp, 5.3-liter to a 300-hp, 6.0-liter. All-new GMT800 Yukon and Yukon XL (formerly Suburban) SUVs followed for 2000, as did an upscale Envoy version of the compact Jimmy SUV. New 200- and 230-hp, 7.8-liter L-6 Duramax diesel engines (from GM partner Isuzu) became available in T-Series trucks.

New GMT800 2500 and 3500 HD models arrived for 2001 with standard, extended, and four-door crew cabs, new 340-hp, 8.1-liter Vortec gas and 300-hp, 6.6-liter Duramax turbodiesel engines, new six-speed manual (ZF) and five-speed automatic (Allison) transmissions, and GVWRs ranging from 6100 to 12,000 pounds. Luxury Denali versions of the Yukon and Yukon XL were added, while compact Sonoma pickups offered three-door extended and four-door crew cabs.

In 2002, an all-new midsize Envoy SUV was launched with a new DOHC, 24-valve, 270-hp I-6, and Motor Trend named it Sport/Utility of the year. Also new were a luxury Sierra Denali pickup, Quadrasteer four-wheel steering (effective but too expensive), and W-Series medium-duty tilt-cab models. The next year brought new conventional-cab TopKick models. A range of Canyon midsize pickups was launched for 2004, powered by a standard 175-hp, 2.8-liter four or optional 220-hp, 3.5-liter five-cylinder, both of which were smaller versions of the Envoy's DOHC inline-six. An Envoy XUV model was also introduced, with a power-sliding rear roof section to accommodate tall loads. Not well accepted, the XUV was cancelled in 2005. The 2006 Sierra 3500 pickup was J.D. Power's best in class for initial quality as a new Allison six-speed automatic with tap-shift electronic control became available with its largest gas and diesel engines.

The big news for 2007 was another all-new line of Sierra light-duty pickups and Yukon SUVs on a vastly improved GMT900 architecture. The Yukon's upscale interior graced topline models, most available engines offered more power, and the slow-selling five-speed manual gearbox was dropped. Also hugely important that year was a new FWD (or AWD) Acadia three-row crossover that would eventually replace the aging Envoy. Powered by a 3.6-liter V-6, it was smaller and more fuel-efficient than a Yukon but offered a carlike cabin with more interior room. An AWD version of the Savana G-Series van was another new 2007 offering.

GMC launched a new Professional Grade ad theme for 2008, along with a pair of important new engineering features. Active Fuel Management, GM's cylinder deactivation system that smoothly shut down half of a (5.3- or 6.0-liter) V-8's cylinders to save fuel under light loads. There was also GM's costly but very effective two-mode gas/electric hybrid system, available on the 2008 Yukon Hybrid model, which substantially improved fuel economy, especially in stop-and-go city driving. Also new was the 403-hp 6.2-liter V-8, the most powerful in the half-ton class, available in topline Sierras and Yukon Denalis.

When the U.S. economy collapsed in late 2008, the resulting sales meltdown led to a 2009 government-guided GM bankruptcy that forced cancellation of four of its eight U.S. brands and closings of thousands of dealerships. But the company has returned to profitability with excellent new Chevrolet, Buick, Cadillac, and GMC products, the latter including strong-selling Sierra pickups, Yukon SUVs, Acadia three-row crossovers, and very popular Terrain compact crossovers. And with a line of state-of-the-art next-generation Sierras on the horizon for 2014, things are looking good again for GMC.