How much does the 2018 Mercedes-Benz GLS cost?

Prices have softened 13.10% compared to this time last year, making it a favorable time to shop this model year.

There are 970 listings available, which suggests you have a workable amount of inventory to compare.

If you find a listing below $21,549.99, that's toward the low end of the year-round range and worth acting on quickly.

Is the 2018 Mercedes-Benz GLS a good car?

Yes — the 4.8/5 user rating points to strong owner satisfaction. Owners consistently praise the GLS for its luxurious features, comfort, and performance, and they also like the power it delivers along with the electronic features that improve the driving experience. For you, that makes it a strong fit if you want a large luxury three-row SUV that prioritizes comfort, space, and a premium feel over a more modern or more spacious alternative. With 27.3% of listings marked as good or great deals, there is still some room to shop selectively.

Is the 2018 Mercedes-Benz GLS reliable?

Owners rate it 4.8/5, a strong signal of long-term satisfaction.

The owner feedback also points to a dependable, trouble-free ownership experience centered on comfort, power, and electronic features that continue to satisfy over time. That said, used luxury SUVs can carry higher long-term ownership risk if maintenance history is incomplete, so you should be especially careful about service records and overall condition.

What should I look for when buying a used 2018 Mercedes-Benz GLS?

At 64.5% accident-free, a meaningful share of listings has prior incidents — history verification is especially important.

You should start with a vehicle history report and confirm whether any prior damage was cosmetic or structural. A pre-purchase inspection should focus on suspension behavior, electronics, and signs of uneven wear, since those areas matter most on a luxury SUV like this. Pay close attention to how the cabin, third row, and cargo area have held up, because condition can vary a lot from one used example to another.

Is now a good time to buy a used 2018 Mercedes-Benz GLS?

This is a moderate buyer’s market, so you can shop selectively without expecting every listing to be a bargain.

• Deal availability: 27.3% of listings are priced as good or great deals.
• Inventory: There are 970 listings available.
• Price trend: Prices have softened 13.10% compared with last year.
• Clean inventory: 64.5% of listings are accident-free.

If you find a listing below $21,549.99, that's toward the low end of the year-round range and worth acting on quickly.

What is the 2018 Mercedes-Benz GLS's resale value?

The current average of $21,529 sits slightly below last year's $24,773.

That price movement suggests the market has already absorbed a meaningful amount of depreciation, which can help future sellers if they buy at the right price. If you plan to resell later, your best protection is choosing a well-kept example with strong documentation and avoiding vehicles with questionable history or visible wear. Vehicles with strong owner satisfaction ratings, like this model year's 4.8/5, tend to retain buyer demand, which supports resale value over time.

Should I buy a 2018 Mercedes-Benz GLS or consider a different year?

If you're weighing the 2018 against nearby model years, here's how to think about it:

Choose the 2018 if:

• 27.3% of listings are priced as good or great deals.
• At 64.5% accident-free, a meaningful share of listings has prior incidents — history verification is especially important.
• Price trend: Prices have softened 13.10% compared with last year.
• Owners rate it 4.8/5 — a strong satisfaction signal.

The bottom line: You should lean toward the 2018 if you want a luxury three-row SUV with strong owner approval and a softer price environment than last year. If your priority is maximizing value, the 2018 is the better primary target; if you want to widen your search for potentially different pricing or condition combinations, a nearby model year can be a smart secondary path.

These recommendations are based on CarGurus' proprietary market data from August 28, 2026, CarGurus experts' opinions, and generative AI.