Used 2020 GMC Sierra 3500HD for SaleNationwide

How much does the 2020 GMC Sierra 3500HD cost?

Prices have softened 8.29% compared to this time last year, making it a favorable time to shop this model year.

There are 456 listings available, which gives you a meaningful pool to compare prices and equipment.

If you find a listing below $50,330.28, that's toward the low end of the year-round range and worth acting on quickly.

Is the 2020 GMC Sierra 3500HD a good car?

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

Owners consistently praise its impressive performance when pulling heavy loads, along with a comfortable and well-built feel. The review summary also highlights that many owners view it favorably versus competitors like Ford and Ram, which reinforces its appeal if you want a heavy-duty truck with serious capability and a strong reputation among buyers.

Given its role as a truck built for demanding work, that combination makes it especially appealing if you need real towing and hauling strength with a broad range of trims and configurations. With 28.1% of listings marked as good or great deals, you still have room to shop selectively.

Is the 2020 GMC Sierra 3500HD reliable?

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

The owner summary points to a truck that feels well-built and dependable, with praise centered on its strong performance and confidence when handling heavy loads. That kind of feedback matters for a heavy-duty pickup, because buyers in this segment often care as much about consistency and durability as they do about features.

For used buyers, the main long-term ownership risk is less about the truck’s core appeal and more about finding one that has been maintained properly and not overworked beyond its condition.

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

At 74.3% 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 inspection of the truck’s condition, especially if it has been used for towing or hauling, since heavy-duty use can leave wear that is not obvious at first glance.

Focus on how the truck presents overall rather than just the odometer reading. A careful walkaround, a test drive, and a close look at maintenance records can help you avoid paying strong money for a truck that has been worked harder than it looks.

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

This is a moderate, selective buyer’s market, so you can shop with some leverage if you stay disciplined.

• Deal availability: 28.1% of listings are priced as good or great deals.
• Inventory: There are 456 listings available.
• Price trend: Prices have softened 8.29% compared with last year.
• Clean inventory: 74.3% of listings are accident-free.

If you find a listing below $50,330.28, 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 $50,653 sits slightly below last year's $55,230.

That price movement suggests the market has cooled enough to give you a better entry point now, but it also means future sellers may not see the same pricing strength if values continue to soften. If you buy well and keep the truck in strong condition, you can help protect your exit value later.

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:

• 28.1% of listings are priced as good or great deals.
• At 74.3% accident-free, a meaningful share of listings has prior incidents — history verification is especially important.
• Price trend: Prices have softened 8.29% compared with last year.
• Owners rate it 5/5 — a strong satisfaction signal.

The bottom line: If you want the redesigned heavy-duty Sierra with strong owner approval and a market that has eased from last year, the 2020 is a sensible primary choice. If you are especially price-sensitive, you may want to compare it with nearby years to see whether a lower-priced example offers similar capability with a better deal on paper.

These recommendations are based on CarGurus' proprietary market data from September 4, 2026, CarGurus experts' opinions, and generative AI.