A reviewer has tested the fuel economy of the 2020 GMC Sierra AT4 with the 6.6-liter Duramax V8 engine on a highway/city test loop. Read the results right here. 1 - 10 of 12 reviews Moved from 2017 2500 Sierra diesel Denali to 2020 by MP MD from Lady Lake, FL on Sun Jan 19 2020 Great new features. Search over 15,900 listings to find the best local deals. You might need something more than a 1500 Series pickup. Have You Driven the 2020 GMC Sierra 2500? Need to pull a large boat, horses, construction equipment or a luxury travel trailer? Overview. We analyze millions of used cars daily. Need to pull a large boat, horses, construction equipment or a luxury travel trailer? The 2020 GMC Sierra HD goes on sale later this year with up to 910 lb-ft of torque and a 30,000-plus-pound max towing capacity. 2020 GMC Sierra 2500 HD Diesel Towing Review: Powerful Hauler, Dull Package 910 pound-feet of torque is an eye-popping number. Step on up to the GMC Sierra 2500 HD… Step on up to the GMC Sierra 2500 HD… The weight of passengers, cargo and options or accessories may reduce the amount you can tow. You might need something more than a 1500 Series pickup. Search over 16,000 listings to find the best local deals. Before you buy a vehicle or use it for trailering, carefully review the trailering section of the Owner’s Manual. Sierra Denali's 9,300-lb rating requires 2wd. Get the full story here! Before you buy a vehicle or use it for trailering, carefully … The 2020 GMC Sierra 2500HD is new from the ground up, utilizing a new, more robust frame and revised powertrain options to tow an impressive 18,510 pounds and haul up to 3,979 pounds of payload. Big jobs require big trucks and the all-new 2020 GMC Sierra HD rises to the challenge with copious features and massive tow ratings. Get the latest in-depth reviews, ratings, pricing and more for the 2020 GMC Sierra 2500HD from Consumer Reports. The weight of passengers, cargo and options or accessories may reduce the amount you can tow. Too bad the rest of the truck isn't. Sierra's 12,500-lb rating requires Sierra Double Cab or Crew Cab Short box 2wd with 6.2L EcoTec3 V8 engine and NHT Max Trailering Package. Save $12,630 on a used GMC Sierra 2500HD near you. Too bad the rest of the truck isn't. Save $9,798 on a 2020 GMC Sierra 2500HD near you. 2020 GMC Sierra 2500 HD Diesel Towing Review: Powerful Hauler, Dull Package 910 pound-feet of torque is an eye-popping number. The 2020 GMC Sierra 2500HD 2dr Regular Cab 4WD LB (6.6L 8cyl 6A) can be purchased for less than the Manufacturer’s Suggested Retail Price (aka MSRP) of $44,470. We analyze millions of used cars daily. Before you buy a vehicle or use it for trailering, carefully review the trailering section of the Owner’s Manual. The 2020 GMC Sierra 2500 and 3500 models are founded on an entirely new, stronger, longer, and taller ladder frame, specifically designed to deliver bigger max towing and payload numbers.