Summary

• With 153 currently listed for sale near Saint Louis, MO and an average price of $36,590.00, 28.1% of 2020 Mercedes-Benz GLSs for sale on CarGurus are rated as good or great deals.

• Favorably reviewed: Owners rated the 2020 Mercedes-Benz GLS 5 / 5 stars.

• 77.1% of 2020 GLS models on CarGurus are accident free.

Why it stands out

The 2020 Mercedes-Benz GLS stands out as the roomiest vehicle in the Mercedes-Benz lineup, with three rows of seating for six or seven people and up to 94 cubic feet of cargo space. It is also positioned as a midsize SUV that blends the comfort and space of the S-Class luxury sedan with some off-road capability, which gives it a broader appeal than a typical family hauler. For 2020, Mercedes moved the GLS into its second generation with a curvier exterior, a wide-screened cabin, a stretched wheelbase, and a body that was just over 2.5 inches longer.

That redesign brought meaningful gains in technology and refinement. The 2020 GLS450 used a new 3.0-liter inline-six with 362 horsepower and 369 pound-feet of torque, paired with a 48-volt mild hybrid system called EQ Boost. Mercedes said that setup improved fuel economy to an EPA-estimated 21 mpg combined, up from 18 mpg in the 2019 model. Standard equipment was generous, including dual 12.3-inch displays with MBUX, navigation, a Burmester surround sound stereo, wireless charging, nine USB-C ports, power-folding third-row seats, power-adjustable second-row seats, and 19-inch wheels. Safety and convenience features were also a highlight, with blind spot assist, 360-degree cameras, adaptive headlamps, auto high beams, parking assist, Car-to-X communication, and Exit Warning Assist all included.

The GLS also has a practical side that helps explain its appeal. Mercedes built in a seating function that automatically adjusts the seat in front when part of the second or third row is folded, making it easier to load passengers or cargo without repeated seat shuffling. At the same time, the 2020 model is not without compromises: front headroom decreased, total cargo space shrank significantly compared with the previous generation, and the AMG Line Package could impede entry and exit. Even so, the 2020 GLS remains distinctive for buyers who want a large, luxurious three-row SUV with strong standard technology and a cabin designed around comfort and flexibility.

Other model years to consider

• 2024 Mercedes-Benz GLS

  • Average price: $66,899.00
  • Good/great deal percentage: 25.1%
  • User rating: 5 / 5
  • Total listings: 195

• 2018 Mercedes-Benz GLS

  • Average price: $22,022.00
  • Good/great deal percentage: 35.6%
  • User rating: 4.8 / 5
  • Total listings: 180

• 2025 Mercedes-Benz GLS

  • Average price: $63,481.00
  • Good/great deal percentage: 25.1%
  • Total listings: 187

This analysis is based on CarGurus' proprietary market data from August 11, 2026, CarGurus experts' opinions, and generative AI.