Used 2020 GMC Sierra 3500HD for SaleNationwide

How much does the 2020 GMC Sierra 3500HD cost?

Prices have softened 5.94% compared to this time last year, making it a favourable time to shop this model year.

There are 65 listings available, which suggests a modest amount of inventory for this heavy-duty truck.

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, its comfortable and well-built feel, and its strong track record compared with competitors like Ford and Ram. For you, that makes it a compelling fit if you want a heavy-duty truck that can handle serious towing while still feeling more polished than a basic work rig. With 26.2% of listings marked as good or great deals, there is also a decent amount of market opportunity if you shop carefully.

Is the 2020 GMC Sierra 3500HD reliable?

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

The owner feedback also points to a truck that feels dependable and well-built, with many shoppers trusting it for heavy-duty work and long-term use. That said, some owners mention missing convenience features and wish for better lumbar support adjustments, so you should still check the specific truck’s condition and equipment closely before buying. For used buyers, the main long-term ownership risk is less about broad owner dissatisfaction and more about finding a well-maintained example that has been used hard.

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 with some leverage if you are patient and focused.

• Deal availability: 26.2% of listings are priced as good or great deals.
• Inventory: There are 65 listings available.
• Price trend: Prices have softened 5.94% compared with last year.

If you find a listing below $57,144 CAD, 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 $60,949 CAD sits slightly below last year's $64,800 CAD.

That price movement suggests the market has eased a bit, which can make the truck more attractive to buyers today but may also mean future sellers need to be realistic on asking price. If you buy well and keep the truck in strong condition, you may be better positioned when it is time to sell. Heavy-duty trucks with broad appeal and strong owner satisfaction can still hold demand well, especially when they are configured for towing and work use.

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:

• 26.2% of listings are priced as good or great deals.
• Price trend: Prices have softened 5.94% compared with last year.
• Owners rate it 5/5 — a strong satisfaction signal.

The bottom line: If you want the strongest mix of capability, comfort, and current market value, the 2020 is the year to focus on. It makes the most sense if you need serious towing and hauling ability and want a truck that owners rate highly. If you are especially price-sensitive, you can also compare nearby years, but the 2020 offers a solid balance of demand, satisfaction, and softened pricing.

These recommendations are based on CarGurus' proprietary market data from October 6, 2026, CarGurus experts' opinions, and generative AI.