---
id: what-is-the-gmc-sierra-heavy-duty-and-what-is-its-towing-capacity
title: "What is the GMC Sierra Heavy Duty and what is its towing capacity?"
category: faq
subtopic: gmc-sierra-hd-towing
page_type: faq
source_url: "https://www.markquartmotors.com/new-vehicles/gmc/trucks.htm"
tags: ["Sierra HD", "heavy duty", "towing", "diesel", "Duramax"]
questions:
  - "What is the heaviest-duty GMC truck?"
  - "How much can a Sierra Heavy Duty tow?"
  - "What engine does the Sierra HD have?"
  - "What are Sierra Heavy Duty features?"
related: [gmc-trucks-overview, gmc-sierra-1500-features]
dealer: Markquart Motors
---

The 2026 GMC Sierra Heavy Duty is built for serious work with an available Duramax 6.6L Turbo-Diesel V8 delivering 470 horsepower and 975 lb-ft of torque. It offers maximum towing up to 36,000 pounds and features two-speed transfer cases, skid plates, and trail hardware on Z71, AT4, and AT4X variants. The upscale cabin includes authentic wood and patterned aluminum on Denali models, massaging front seats on AT4X and Denali Ultimate, and up to 14 camera views. Advanced trailering systems simplify hookups and monitoring. Call Markquart Motors at (715) 833-0444 to discuss Sierra HD specs and availability.