Used 2018 Mercedes-Benz GLS for Sale near Illinois

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 984 listings available, which gives you a solid amount of inventory to compare before you buy.

Is the 2018 Mercedes-Benz GLS a good car?

Yes — the 4.8/5 user rating points to strong owner satisfaction. Owners consistently praise its luxurious features, comfort, power, and the electronic features that improve the driving experience. That fits well if you want a large, premium three-row SUV with space for six or seven people and a cabin that leans into comfort and upscale character. With 36.1% of listings marked as good or great deals, you have a decent chance of finding a compelling offer.

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 vehicle that feels dependable in daily use, with praise centered on comfort, power, and features that make ownership feel easy and trouble-free. That said, used luxury SUVs can carry higher long-term ownership risk if maintenance history is incomplete, so you should pay close attention to service records and overall condition before you commit.

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

At 64.6% 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 confirm accident records, title status, and service history before you go any further. After that, prioritize a thorough pre-purchase inspection, especially for signs of wear in the suspension, electronics, and interior controls. Because this model is a luxury three-row SUV, you should also focus on how well the cabin, seating, and convenience features have held up over time.

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 value if you compare listings carefully.

• Deal availability: 36.1% of listings are priced as good or great deals.
• Inventory: There are 984 listings available.
• Price trend: Prices have softened 13.00% compared with last year.
• Clean inventory: 64.6% of listings are accident-free.

If you find a listing below $21,181, 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 $21,181 sits slightly below last year's $24,345.

That price movement suggests the market has cooled, which can make the GLS more attractive to used buyers today but may also limit upside for a future seller if prices continue to soften. If you buy at the right number and keep the vehicle in strong condition, you can help protect your resale position. Strong demand for a well-reviewed luxury SUV can still support value, especially when the vehicle presents cleanly and has a solid history.

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:

• 36.1% of listings are priced as good or great deals.
• At 64.6% 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 is a strong choice if you want a well-equipped, comfort-focused luxury SUV and you can verify a clean history and good maintenance. If you are especially price-sensitive, you may want to compare nearby years and focus on whichever one gives you the best combination of condition, history, and asking price rather than choosing by model year alone.

These recommendations are based on CarGurus' proprietary market data from September 22, 2026, CarGurus experts' opinions, and generative AI.