2023 Mercedes-Benz GLS450

Full-Size SUV · 3.0L Twin-Turbo I6 Hybrid · AWD

84/100

AutoVault's overall score, weighted for what a full-size suv is actually for — performance, technology, comfort, reliability, safety and value.

Specifications

Engine	3.0L Twin-Turbo I6 Hybrid
Horsepower	362 hp
Torque	369 lb-ft
0–60 mph	6 sec
Top speed	130 mph
Drivetrain	AWD
Seats	7
Combined MPG	31 mpg (30 city / 33 hwy)
Range	471 miles
MSRP	$81,800
Body style	Full-Size SUV

The verdict

What's good

Limo-quiet, genuine three-row space
Smooth inline-six with mild-hybrid help
First-class adult third-row seating
Comfortable, road-trip-ready ride

What's not

Massive and hard to park
Loaded versions get very expensive
Touchscreen menus can frustrate
Heavy feel through tight corners

The engine

M256

Turbo Inline-6 Mild-Hybrid

A silky turbocharged straight-six that revives Mercedes' classic inline-six layout, blending creamy, vibration-free power with a 48-volt electric boost that erases turbo lag.

Introduced in 2017 on the W222 S 450 as part of Mercedes' Modular Powertrain Architecture, it marked the return of the inline-six after years of V6 engines, succeeding the M276.

It pairs a conventional turbocharger with a 48-volt electric auxiliary compressor that spins up to around 70,000 rpm in about 300 milliseconds to fill in low-end boost.
A belt-free design integrates the starter-generator, water pump, and air-conditioning compressor electrically, allowing a slim package.
The inline-six layout is inherently balanced, eliminating the need for balance shafts and giving exceptional smoothness.

See the rest in AutoVault

The six sub-scores behind the 84 — performance, tech, comfort, reliability, safety and value
Market value today and year-by-year value history
All 3 trims with pricing
Studio photography — exterior, rear and interior
Side-by-side comparison with up to four cars

Open in AutoVault