Used 2020 GMC Sierra 2500HD for Sale near Connecticut

How much does the 2020 GMC Sierra 2500HD cost?

Prices have softened 5.38% compared to this time last year, making it a favorable time to shop this model year.

There are 1,285 listings available, which gives you a solid pool of trucks to compare.

Is the 2020 GMC Sierra 2500HD a good car?

Yes — the 2020 GMC Sierra 2500HD earns a 4.9/5 user rating and an 8.2/10 expert rating. The standout strength is Form and function at 10/10.

Owners consistently praise its performance, comfort, towing capabilities, and power, and they also highlight its appealing features. The truck’s Denali identity gives it a more upscale feel, and it’s described as one of the most capable and upscale trucks in General Motors’ lineup.

The trade-offs are clear: it’s called poor value for money, and the interior materials feel cheap. It’s best suited to you if you want heavy-duty capability with premium touches, especially if you need a work-ready truck that still aims for a more upscale experience.

31.0% of listings are priced as good or great deals, so there are still some attractive opportunities if you shop carefully.

Is the 2020 GMC Sierra 2500HD reliable?

Owners rate it 4.9/5, a strong signal of long-term satisfaction.

The owner feedback points to a truck that feels dependable in daily use, with praise centered on performance, comfort, towing capability, and power. That kind of feedback suggests you can count on it for demanding work and long-term ownership if it has been maintained properly.

The expert review also emphasizes its strong capability and the confidence that comes from its heavy-duty hardware. The cost-effectiveness discussion notes that the diesel engine is a pricey option, which matters if you’re planning for long-term ownership costs.

For used buyers, the main risk is paying a premium for a truck that may still need careful inspection to confirm it has been treated as well as its reputation suggests.

What should I look for when buying a used 2020 GMC Sierra 2500HD?

At 73.4% accident-free, a meaningful share of listings has prior incidents — history verification is especially important.

You should start with a vehicle history report and then prioritize a thorough inspection of the body, frame, and any signs of prior repair. Because this is a large heavy-duty truck, you’ll also want to focus on how well the truck has been used and whether its condition matches its asking price.

Key things to evaluate:

• Trim level: The base truck comes with a V8 engine and a 7-inch touchscreen with Apple CarPlay and Android Auto, but frills are minimal. The SLE adds 17-inch aluminum wheels, two-tier trailering mirrors, body-color door handles, tinted glass, stainless steel belt-line moldings, an EZ lift-and-lower tailgate, a 4.2-inch driver-information screen, a 4G LTE WiFi hotspot, cruise control, carpeted floor covering, remote keyless entry, and a leather-wrapped steering wheel. The SLT adds 18-inch aluminum wheels with black accents, LED bed lighting, LED fog lights, chrome door handles and mirror caps, a power-release tailgate, Multi-Pro six-way tailgate, 10-way power-adjustable front seats, wall-style power outlets, and an 8-inch infotainment touchscreen. The Denali adds a full leather interior with wood-grain inserts, chrome adornments, navigation, wireless device charging, and a Bose premium sound system.
• Powertrain: You get two 6.6-liter V8 options: a gas engine with 401 horsepower and 464 pound-feet of torque, or a Duramax diesel V8 with 445 hp and 910 lb-ft. The gas engine uses a 6-speed automatic, while the diesel uses a 10-speed Allison transmission. The diesel delivers massive low-speed grunt, while the gas engine is the simpler path.
• Safety package: Standard safety features include front- and side-impact airbags, traction control, a reversing camera, and a tire pressure monitoring system. The Driver Alert Package I adds front and rear parking sensors, blind-spot monitoring, and rear cross-traffic alert. The Driver Alert Package II adds forward-collision avoidance, lane-departure warning, and automatic high beams.
• Infotainment: The standard setup is a 7-inch touchscreen running GMC Infotainment 3 with Apple CarPlay and Android Auto through USB. The SLT and Denali move to an 8-inch screen, and both are available with navigation. The Denali also adds an 8-inch color driver-information screen.
• Fuel efficiency: In mixed driving, the truck returned an observed average of 16.5 miles per gallon.

Which 2020 GMC Sierra 2500HD trim should I buy?

The 2020 GMC Sierra 2500HD is offered in 4 trim levels: Sierra, SLE, SLT, Denali.

Here's the short version:

• Sierra: This is the entry point, and it gives you the core heavy-duty hardware plus the 7-inch touchscreen with Apple CarPlay and Android Auto. It makes sense if you want the lowest starting point, but the content is sparse compared with the higher trims.
• SLE: This is the best-value trim for many shoppers because it adds useful everyday upgrades like trailering mirrors, remote keyless entry, cruise control, a WiFi hotspot, and a better driver-information display without jumping all the way to luxury pricing.
• SLT: This is the sweet spot if you want a more upscale truck without going full Denali. You get the 8-inch touchscreen, power-adjustable front seats, LED bed lighting, LED fog lights, and the Multi-Pro six-way tailgate.
• Denali: This is the luxury-focused choice, with full leather, wood-grain trim, navigation, wireless charging, and a Bose sound system. It suits you best if you want the most premium cabin and are willing to pay for it.

The safety-package trims add meaningful protection, especially the Driver Alert Package I and Driver Alert Package II features.

Is now a good time to buy a used 2020 GMC Sierra 2500HD?

This looks like a moderate, selective buyer’s market, so you can shop with some leverage if you’re patient and compare listings carefully.

• Deal availability: 31.0% of listings are priced as good or great deals.
• Inventory: There are 1,285 listings available.
• Price trend: Prices have softened 5.38% compared with last year.
• Clean inventory: 73.4% of listings are accident-free.

If you find a listing below $48,344, that's toward the low end of the year-round range and worth acting on quickly.

What is the 2020 GMC Sierra 2500HD's resale value?

The current average of $48,344 sits slightly below last year's $51,095.

That price movement suggests the market has cooled a bit, which can work against you if you’re selling soon. If you own one, you may need to price competitively to stand out, especially if your truck lacks the higher-end equipment that helps justify a stronger asking price.

On the other hand, the truck’s strong capability and premium Denali appeal help support demand among buyers who want heavy-duty strength with upscale features. If your truck is well equipped and in clean condition, it should still hold appeal better than a more ordinary work truck.

Vehicles with strong owner satisfaction ratings, like this model year's 4.9/5, tend to retain buyer demand, which supports resale value over time.

Is the 2020 GMC Sierra 2500HD safe?

The 2020 GMC Sierra 2500HD earns an 8/10 safety score from our experts.

Standard safety features include a full array of front- and side-impact airbags, traction control, a reversing camera, and a tire pressure monitoring system. The Driver Alert Package I adds front and rear parking sensors, blind-spot monitoring, and rear cross-traffic alert, while Driver Alert Package II adds forward-collision avoidance, lane-departure warning, and automatic high beams.

Because this truck is large and can be difficult to maneuver, the available camera coverage and trailering aids matter a lot in real-world use. If you’re shopping used, pay close attention to whether the truck has the driver-assistance packages you want, since they make a meaningful difference in day-to-day confidence.

Should I buy a 2020 GMC Sierra 2500HD or consider a different year?

If you're weighing the 2020 against nearby model years, here's how to think about it:

Choose the 2020 if:

• 31.0% of listings are priced as good or great deals.
• At 73.4% accident-free, a meaningful share of listings has prior incidents — history verification is especially important.
• Price trend: Prices have softened 5.38% compared with last year.
• Owners rate it 4.9/5 — a strong satisfaction signal.
• The 2020 stands out for its Denali appeal, strong capability, and upscale feature set.

The bottom line: If you want a heavy-duty truck with premium touches and strong owner satisfaction, the 2020 is a solid year to target. If you’re more price-sensitive, you may want to compare nearby years and focus on the best-equipped truck in the cleanest condition rather than chasing the newest badge.

How does the 2020 GMC Sierra 2500HD compare to the 2020 Ford F-250 Super Duty?

Expert Pros & Cons (per CarGurus review team)

2020 GMC Sierra 2500HD:

• Pros: Multiple powertrain options, Plenty of cargo space.
• Cons: Poor value for money, Interior materials feel cheap.

2020 Ford F-250 Super Duty:

• Pros: Powerful engine, Spacious.
• Cons: Interior materials feel cheap, Advanced safety features are not standard.

Our experts score the 2020 GMC Sierra 2500HD 8.2/10 and the 2020 Ford F-250 Super Duty 7.7/10. The GMC has the edge in overall expert scoring, while the Ford counters with a lower average used price and more listings available. If you want the stronger value proposition on paper, the Ford may be easier to shop; if you want the better-rated truck with more premium appeal, the GMC is the stronger pick.

Read our full side-by-side expert comparison here.

These recommendations are based on CarGurus' proprietary market data from October 21, 2026, CarGurus experts' opinions, and generative AI.