Used 2020 GMC Sierra 3500HD for Sale near Connecticut

How much does the 2020 GMC Sierra 3500HD cost?

Prices have softened 8.87% compared to this time last year, making it a favorable time to shop this model year.

There are 545 listings available, which gives you a meaningful amount of inventory to compare.

Is the 2020 GMC Sierra 3500HD a good car?

Yes — the 2020 GMC Sierra 3500HD earns a 5/5 user rating, which points to strong owner satisfaction.

Owners consistently praise its impressive performance when pulling heavy loads, along with a comfortable, well-built feel. The review summary also highlights that many owners view it as having a strong track record compared with competitors, which supports its appeal if you want a serious tow rig that still feels modern and well equipped. The overview also fits that use case: you’re looking at a heavy-duty truck with broad configuration choices and strong towing capability.

With 33.2% of listings marked as good or great deals, you have a decent chance of finding a competitive price if you shop carefully.

Is the 2020 GMC Sierra 3500HD reliable?

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

The review summary points to a truck that owners see as dependable and well built, with many describing it as a strong performer over time. That kind of feedback matters for a heavy-duty truck, where buyers often expect consistent capability and trouble-free ownership under demanding use.

For used buyers, the main long-term risk is less about the truck’s core appeal and more about how hard it was worked, so condition and maintenance history should carry extra weight.

What should I look for when buying a used 2020 GMC Sierra 3500HD?

At 73.9% accident-free, a meaningful share of listings has prior incidents — history verification is especially important.

You should start with a vehicle history report so you can separate clean trucks from those with prior damage or repeated claims. After that, prioritize a thorough inspection of the body, frame, suspension, and towing-related hardware, since this model is often bought for demanding work. You should also focus on overall condition and signs of heavy use, because a truck like this can vary widely depending on how it was driven and maintained.

Is now a good time to buy a used 2020 GMC Sierra 3500HD?

This looks like a moderate, selective buyer’s market, so you can shop patiently but should move quickly on the right truck.

• Deal availability: 33.2% of listings are priced as good or great deals.
• Inventory: There are 545 listings available.
• Price trend: Prices have softened 8.87% compared with last year.
• Clean inventory: 73.9% of listings are accident-free.

If you find a listing below $49,286, that's toward the low end of the year-round range and worth acting on quickly.

What is the 2020 GMC Sierra 3500HD's resale value?

The current average of $49,286 sits slightly below last year's $54,083.

That price movement suggests the market has cooled, which can help you buy more selectively now but may also mean future resale gains are harder to count on in the near term. If you plan to sell later, the best protection is buying a well-kept truck with strong documentation and avoiding examples with accident history or visible wear.

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

Should I buy a 2020 GMC Sierra 3500HD 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:

• 33.2% of listings are priced as good or great deals.
• At 73.9% accident-free, a meaningful share of listings has prior incidents — history verification is especially important.
• Price trend: Prices have softened 8.87% compared with last year.
• Owners rate it 5/5 — a strong satisfaction signal.

The bottom line: You should lean toward the 2020 if you want the redesigned truck and are comfortable shopping carefully for condition and history. If your priority is stretching your budget, a nearby year may offer a lower entry price, but the 2020 remains the better pick when you want the newer design and strong owner approval.

How does the 2020 GMC Sierra 3500HD compare to the 2020 Ford F-350 Super Duty?

These recommendations are based on CarGurus' proprietary market data from October 27, 2026, CarGurus experts' opinions, and generative AI.