2008 GMC Sierra 1500 Tow Specifications

GMC offered a selection of four engines in the 2008 Sierra 1500: the Vortec 4.3-liter V-6, the Vortec 4.8-liter V-8, the Vortec 5.3-liter V-8 and the range-topping Vortec 6.0-liter V-8. The V-6 was standard on entry-level Work Truck models. The 4.8-liter V-8 was standard on SL and SLE1 trim-level Sierras. The 5.3-liter V-8 came standard on SLE2 and SLT trucks.

Three transmissions were offered: the 4L60 Hydra-Matic four-speed automatic and the heavy-duty 4L70 Hydra-Matic four-speed automatic. The 4L60 was the standard offering on all models. The 4L70 was optional on SLE1, SLE2 and SLT models. Like essentially all full-size pickups, the Sierra was available with either rear- or part-time four-wheel drive.

Equipped with the base V-6, the regular cab could be had with either a 3.23 or 3.73 rear axle. The two-wheel-drive, standard-box truck with the 3.23 axle could haul up to 4,800 pounds. With the 3.73 axle, that figure increased to 5,400 pounds. The four-wheel-drive, standard-box model came only with the 3.73 axle and had a maximum towing capacity of 5,100 pounds. The two-wheel-drive regular-cab version with the long box could haul 4,700 pounds with the 3.23 axle and 5,200 pounds with the 3.73. The four-wheel-drive model could tow a maximum of 4,900 pounds with its 3.73 rear axle.

With the 4.8-liter V-8 under its hood, the two-wheel-drive regular-cab truck with the standard box could haul 4,700 pounds with the 3.23 axle and a much improved 7,200 pounds with the 3.73 axle. The four-wheel-drive regular-cab model with the standard box had a maximum towing capacity of 6,000 pounds with its 3.42 axle. The two-wheel-drive regular-cab truck with long box could tow 5,100 pounds with the 3.23 rear axle or 7,100 pounds with the 3.73 rear axle. Finally, the four-wheel-drive regular-cab version with long box could haul 5,800 pounds with its 3.42 axle.

When outfitted with the 5.3-liter engine, the rear-wheel-drive regular-cab model with the standard box came with a 3.73 rear axle and had a maximum towing capacity of 8,200 pounds. The four-wheel-drive version featured a 4.10 rear axle and could tow up to 8,900 pounds. The rear-wheel-drive regular-cab truck with the long box had the same rear axle as the short-box model but could tow 200 pounds less. The four-wheel-drive, long-bed model had the same towing capacity as its short-bed equivalent.

The 5.3-liter V-8-powered, rear-wheel-drive extended-cab truck with the standard box was configured with a 3.73 rear axle. Its maximum towing capacity was 8,800 pounds. The four-wheel-drive version, which used the same rear axle, could haul up to 8,500 pounds. Outfitted with the optional Enhanced Trailering package, the two-wheel-drive truck could tow up to 10,300 pounds, and the four-wheel-drive model could manage an impressive 10,500 pounds. Finally, the extended-cab version with the long box could haul up to 7,500 pounds in rear-wheel-drive form with the 3.73 rear axle and 8,300 pounds with four-wheel drive and the 4.10 rear axle.

The crew cab Sierra had a maximum towing capacity of 8,700 pounds with rear-wheel drive and the 3.73 rear axle and 8,500 pounds with four-wheel drive and the same rear axle. Equipped with the optional Enhanced Trailering package, the rear-wheel-drive truck could haul up to 10,200 pounds. The enhanced four-wheel-drive model could tow an impressive maximum of 10,500 pounds, thanks largely to its 4.10 rear axle.