Sierra HD (4th)
Engine Reliability Ratings
L8T - SIDI, VVT, CAST IRON
6.6L 8-cylView details
Complaint Breakdown
Known Issues
L5P
6.6L 8-cyl TurboView details
Complaint Breakdown
Known Issues
1 additional engine variant with fewer than 10 complaints not shown.
Vehicle-Level Issues
These issues affect the GMC Sierra HD regardless of engine variant.
All Generations
Alternatives in Heavy-Duty Truck
Frequently Asked Questions
What are the most common 2020-2025 GMC Sierra HD problems?
The 2020-2025 GMC Sierra HD has accumulated 442 NHTSA complaints. The most frequently reported problem areas are Transmission, Electrical System, Brakes. As with any used vehicle, a pre-purchase inspection and vehicle history report are recommended.
Which GMC Sierra HD engine is most reliable?
The 2020-2025 GMC Sierra HD was offered with 3 engine options. Based on NHTSA complaint data, the 6.6L 8-cyl has the lowest complaint density and is considered the most reliable choice for buyers.
Is the 2020-2025 GMC Sierra HD a good used car?
The 2020-2025 GMC Sierra HD can be a solid used car purchase depending on trim, mileage, and maintenance history. With 442 total NHTSA complaints on record, prospective buyers should review the known problem areas and check for open recalls before buying.
How many NHTSA complaints does the 2020-2025 GMC Sierra HD have?
The 2020-2025 GMC Sierra HD has 442 complaints filed with NHTSA as of our latest data pull. Complaint counts reflect owner-reported issues and do not necessarily indicate defects or safety risks on their own.
What recalls affect the 2020-2025 GMC Sierra HD?
There are 0 NHTSA recalls affecting some 2020-2025 GMC Sierra HD vehicles. Recall status varies by VIN โ check the NHTSA recall database at recalls.nhtsa.dot.gov with your specific VIN to confirm which campaigns apply.
What should I check before buying a used GMC Sierra HD?
Before buying a used GMC Sierra HD, verify all open recalls are completed via the NHTSA VIN lookup tool. Pay particular attention to Transmission, Electrical System, Brakes, which are the most commonly reported problem areas. Request maintenance records, have an independent mechanic inspect the vehicle, and run a vehicle history report to check for prior accidents or title issues.
Does the Sierra HD have NHTSA crash test ratings?
NHTSA has not published crash test ratings for the 2020-2025 GMC Sierra HD. Not all vehicles are tested each year. For the latest NHTSA safety information, visit nhtsa.gov/ratings.
Data from NHTSA federal complaints database. 442 complaints analyzed. Data confidence: high. Last updated: 2026-04-07.