Summary

• With 60 currently listed for sale near Mobile, AL and an average price of $51,695.00, 31.7% of 2020 GMC Sierra 3500HDs for sale on CarGurus are rated as good or great deals.

• Favorably reviewed: Owners rated the 2020 GMC Sierra 3500HD 5 / 5 stars.

• 56.7% of 2020 Sierra 3500HD models on CarGurus are accident free.

Why it stands out

The 2020 GMC Sierra 3500HD stands out as a heavy-duty truck that was redesigned to be bigger and more capable, with the fifth-generation model debuting as a 2020 model. Compared with the previous generation, it grew as much as 10 inches in length and 2.5 inches in height, and its revised styling brought a larger, blockier grille. More importantly for buyers who need real work capability, it delivered a significant increase in maximum towing capacity, which rose by 53 percent in its most extreme case.

This truck also offers the kind of configuration range that matters in the heavy-duty segment. Buyers could choose regular, extended, or crew cab body styles, pair them with a short or long bed, and select either single- or dual-wheel rear axles. Two engines were available: a 6.6-liter V8 with 401 horsepower and 464 pound-feet of torque, or a 6.6-liter Duramax turbodiesel V8 with 445 hp and 910 lb-ft of torque. Properly equipped, it could haul up to 7,442 pounds of cargo and tow up to 35,500 pounds, though those maximum ratings required the diesel engine, a single cab body, rear-wheel drive, a gooseneck hitch, and dual rear wheels.

Inside, the 2020 Sierra 3500HD was trimmed across five levels, from a basic work-truck setup to the Denali luxury model. Even the base version included a seven-inch infotainment touchscreen plus Apple CarPlay and Android Auto, while higher trims added features such as the MultiPro tailgate, trailering assist technology, off-road hardware, and premium leather appointments. The truck’s appeal is strongest for shoppers who want serious towing and hauling ability with a wide spread of trims and equipment, though its size can make it unwieldy in parking lots and its top trims can be prohibitively expensive.

Other model years to consider

• 2023 GMC Sierra 3500HD

  • Average price: $56,500.00
  • Good/great deal percentage: 30.4%
  • Accident-free percentage: 91.1%
  • Total listings: 135

• 2025 GMC Sierra 3500HD

  • Average price: $77,987.00
  • Good/great deal percentage: 16.4%
  • User rating: 5 / 5
  • Total listings: 165

• 2026 GMC Sierra 3500HD

  • Average price: $63,845.00
  • Good/great deal percentage: 7.8%
  • Accident-free percentage: 96.7%
  • Total listings: 90

This analysis is based on CarGurus' proprietary market data from August 11, 2026, CarGurus experts' opinions, and generative AI.