Used 2018 Mercedes-Benz GLS for SaleNationwide

How much does the 2018 Mercedes-Benz GLS cost?

Prices have softened 13.00% compared to this time last year, making it a favorable time to shop this model year.

There are 980 listings available, which suggests a healthy amount of inventory to compare.

Is the 2018 Mercedes-Benz GLS a good car?

Yes — 4.8/5 is a strong user rating, and owners consistently praise the GLS for its luxurious features, comfort, and performance. The review summary also points to strong power delivery and electronic features that improve the driving experience, while the overview shows why it fits buyers who want a large, family-focused luxury SUV with three rows and a premium cabin. With 34.8% of listings marked as good or great deals, you have a meaningful number of opportunities to shop selectively.

Is the 2018 Mercedes-Benz GLS reliable?

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

The review summary highlights a dependable-feeling ownership experience through its comfort, luxury, and performance, with owners especially appreciating the way it delivers power and the electronic features that enhance daily use. For used buyers, that kind of satisfaction can reduce long-term ownership risk, though you should still verify condition carefully before committing.

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

At 65.4% 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 those with prior damage. After that, prioritize a pre-purchase inspection that focuses on body condition, interior wear, and how well the technology and comfort features are functioning. Because this is a large luxury SUV, you should also pay close attention to signs of heavy family use and whether the cabin still feels well cared for.

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

This looks like a moderate, selective buyer’s market, so you can shop patiently and still find worthwhile listings.

• Deal availability: 34.8% of listings are priced as good or great deals.
• Inventory: There are 980 listings available.
• Price trend: Prices have softened 13.00% compared with last year.
• Clean inventory: 65.4% of listings are accident-free.

If you find a listing below $21,419, 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 $21,419 sits slightly below last year's $24,620.

That price movement suggests the market has already adjusted downward, which can help you buy at a more favorable entry point today. For a future seller, it also means resale value may depend more heavily on condition, mileage, and how well the vehicle has been maintained. Well-kept examples should stand out more clearly if the broader market remains soft.

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:

• 34.8% of listings are priced as good or great deals.
• At 65.4% accident-free, a meaningful share of listings has prior incidents — history verification is especially important.
• Price trend: Prices have softened 13.00% compared with last year.
• Owners rate it 4.8/5 — a strong satisfaction signal.

The bottom line: The 2018 GLS makes the most sense if you want a spacious, upscale three-row SUV and you value current pricing that has moved lower than last year. If you are especially price-sensitive, you can also use the softer market to compare carefully against nearby model years and focus on the cleanest, best-maintained example rather than rushing into the first attractive listing.

These recommendations are based on CarGurus' proprietary market data from September 15, 2026, CarGurus experts' opinions, and generative AI.