Used 2020 GMC Sierra 3500HD for SaleNationwide

How much does the 2020 GMC Sierra 3500HD cost?

Prices have softened 9.01% compared to this time last year, making it a favorable time to shop this model year.

There are 550 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, especially when pulling heavy loads, along with its comfortable, well-built feel. The review summary also highlights that many owners view it as having a strong track record compared with competitors, which matters if you want a heavy-duty truck that feels dependable in real-world use. In the context of its work-focused design and broad configuration range, that makes it a strong fit if you need serious towing capability without giving up a more refined upper-trim experience.

With 30.4% of listings marked as good or great deals, you have some room to shop selectively.

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 reliable, dependable, and trouble-free enough to trust for heavy-duty use. It also suggests that buyers value its long-term durability and the confidence it inspires compared with competitors. For used buyers, that kind of feedback lowers—but does not eliminate—the risk of expensive ownership surprises, so condition and maintenance history still matter.

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

At 74.5% 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 examples from trucks with prior damage or repeated claims. After that, prioritize a thorough pre-purchase inspection, especially if the truck has been used for towing or jobsite duty. Focus on overall condition, signs of wear from heavy use, and whether the truck’s equipment and trim level match the way you plan to use it.

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 carefully and still find worthwhile options.

• Deal availability: 30.4% of listings are priced as good or great deals.
• Inventory: There are 550 listings available.
• Price trend: Prices have softened 9.01% compared with last year.
• Clean inventory: 74.5% of listings are accident-free.

If you find a listing below $49,295, 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 $49,357 sits slightly below last year's $54,242.

That decline suggests the market has become a bit more favorable for buyers, but it also means future sellers may need to price more competitively than owners did a year ago. If you buy well now, you may have a better chance of limiting depreciation pressure later. Strong demand for capable heavy-duty trucks can help, but resale will still depend on mileage, condition, and how well the truck has been maintained.

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:

• 30.4% of listings are priced as good or great deals.
• At 74.5% accident-free, a meaningful share of listings has prior incidents — history verification is especially important.
• Price trend: Prices have softened 9.01% 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 you find a clean, well-priced example with the equipment you need. If your priority is maximizing savings, a nearby year may be worth considering, especially if you can find a lower-mileage truck with a cleaner history and a better asking price.

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 21, 2026, CarGurus experts' opinions, and generative AI.