General Motors released the third generation of the Sierra pickup 2500 HD series in 2007 as a 2008 model year and offered it with a choice of three cabins.
It was already common to see the large, heavy-duty pickups used for weekends in the mountains or pulling trailers with boats or motorhomes on the highway. Most of them were crew-cabs, with four doors and a full house inside. The single-cab mainly was a work truck, while the Extended Cab was somewhere in between. It was still good to carry a family to the mountains, as long as it was a family with small children on board. For the 2500 HD (heavy-duty), the American carmaker used a new platform, the T900, which replaced the T800 and offered better solutions and more powerful engines than its predecessor.
Like its predecessor, the Sierra was available in a few body versions, starting with a chassis-cab and going up to the big crew-cab version. Its raked windshield at 57 degrees decreased the wind noise and the aerodynamic resistance, increasing the fuel efficiency. To add a more dynamic appearance, the Sierra featured flared wheel-arches. The Extended Cab version featured two doors for the front passengers and another pair of rear-hinged doors behind them.
Inside, the GMC Sierra offered two or three seating positions, depending on the trim level and options. Like most of the pickups on the market, it provided a big dashboard with a steering-column mounted gear-selector for the automatic transmission. The rear seats were surprisingly good as long as the occupants were not very tall.
GMC offered the Sierra with a choice of two engines paired as standard to a 4-speed automatic gearbox. It was available either as a 2WD or 4WD.
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