 | Positives: Handsomely styled exterior, roomy even in row three, big-screen infotainment dazzles, drives smaller than it actually is. |
 | Negatives: Not as noticeable as the BMW X7 or Caddy Escalade, overly fussy and complex infotainment, so-so gas mileage. |
 | Bottom Line: The GLS is one of our favorite big luxury SUVs. It offers handsome styling, an excellent driving experience for something this big, and a roomy interior in all three rows. It's too bad the infotainment system doesn't work as well as it looks. |
Driving Experience
It's hard to believe that something this big and heavy is quite good to drive. Not only is the inline-six gas engine + 48-volt hybrid system powerful and smooth, but the handling is much better than we expected. Despite its size, the GLS is also really good with brakes, and the ride is great even without the optional E-Active Body Control feature.
Ride Quality: Every GLS comes standard with Merc's air suspension, and it's impressively smooth over virtually all road surfaces. The E-Active Body Control tech uses a camera to scan road imperfections and adjust the ride accordingly. It's pricey and unnecessary. The GLS is smooth all on its own.
Acceleration: 0 to 60 mph comes in a quick 5.5 seconds. It's not nearly as quick as the BMW X7 M60i *(3.8 seconds!), but it's still moves with verve. The 9-speed automatic makes quick work of gearshifts and doesn't hesitate when downshifts are called upon.
Braking: The brakes are powerful and bring the 5,467-lb GLS to a stop very quickly and without drama. Pedal progression is smooth, and there was no nose dive that we experienced.
Steering: The steering has some nice heftiness to it, and we appreciated the effort. There's actually some feedback coming through the steering wheel. It remained easy to place in the lane at high speeds and nicely maneuverable in tight spaces.
Handling: The GLS experienced very little body roll in the turns, and it felt very balanced even when we came in fairly hot.
Technology
There's a lot of electronic real estate going on inside the GLS in the form of two giant 12.3-inch digital displays in a single frame that occupies about 2/3rds of the dash. The first is a reconfigurable instrument cluster, and the second manages the infotainment system. It also comes with a virtual assistant, Apple CarPlay, Android Auto, in-dash navigation, and a Wi-Fi hotspot as standard equipment.
Infotainment System: The screens look gorgeous with their blended blue and black hues, but scrolling through the long-linear menu is frustrating, and what could be a single menu screen results in multiple ones. It's tough to navigate menus and make selections, and the system is just too convoluted for our liking. BMW, Genesis, Cadillac, and Lexus make better systems.
Controls: The touchpad controls for the infotainment system are way too finicky. It's actually easier to use the little touch control button on the steering wheel. The gearshift lever is also ridiculous, as it is on essentially all Mercs. It's a stalk on the steering column that we almost always think is the windshield wiper stalk, and we found ourselves shifting into neutral more often than we'd like to admit.
Styling
When you put the GLS next to something as dramatic as the new BMW X7 M60i or even the Cadillac Escalade, it looks conservative. We think it's attractive, and its styling will hold up much better over the span of many years than some of the competition. The body is nicely shaped, and it's peppered with great details like the grille, hood creases, and the handsomely detailed taillights. Inside, it's also well sorted out ergonomically and nicely appointed, if a bit too dark.
Front: The two-bar grille looks great here, especially with the dark mesh behind it and the tri-star logo. The headlights are tastefully done, and the large vents in the lower fascia provide some nice aggression.
Rear: We love the taillights that have just the right amount of inner detail. The chrome bar across the liftgate and the crease at its bottom help reduce visual height. The ovular twin exhaust outlets are also a nice touch.
Profile: The body is so well done from the side view thanks to great fender and door creases, excellent proportions, dark window trim, and big wheels that fill the wells properly.
Cabin: The quad HVAC vents in the center stack look great, as do the grab bars that flank the touchpad. Matte wood, fancy leather, and brushed metal round things out nicely. It's too bad they didn't use red stitching in the upholstery to match the exterior and sport things up.
Comfort
There's a lot to love about the interior of the GLS. Seats are big and accommodating, and the climate control works very well a ton of big vents. Space is plentiful in the first two rows, and the the third row is much better for adults than much of the competition. It's also a quiet place to be, making it great for long road trips.
Front Seats: The front seats have great adjustability, good cushioning, and excellent levels of bolstering that compete with BMW.
Rear Seats: Our tester had Captain's Chairs which provided good support and cushioning. 41.9 inches of legroom means there's ample space to get in, out, and to stretch. 34.6 inches of third-row legroom is pretty good and adults won't feel cramped. It's more than the X7's.
NVH (noise/vibration/harshness): The cabin of the GLS is quiet and enjoyable place to be. Sound deadening is very good, and there's hardly any road noise even with the large tires.
Visibility: The GLS has big glass all around, which provide great views out the front, sides, and back. Pillar size is good, too, which means few obstructions when managing traffic.
Climate: The GLS's climate system works incredibly well with a preponderance of vents and climate control in four zones which provide ideal comfort for all occupants. Heated and ventilated seats also work quickly to get to temp.
Safety
The GLS hasn't been tested by either body, but it does come with a ton of standard and optional safety features.
IIHS Rating: Not tested.
NHTSA Rating: Not tested.
Standard Tech: The GLS 450 comes with a Surround View Camera, Active Brake Assist Crosswind Assist, ATTENTION ASSIST, PRE-SAFE Predictive Occupant-Protection System, Adaptive Hlghbeam Assist, and Blind Spot Assist.
Optional Tech: Our tester came with the optional Driver Assistance Package Plus that inclued Active Distance Assist DISTRONIC, Active Steering Assist, Active Lane Change Assist, Active Emergency Stop Assist, Active Speed Limit Assist, Active Brake Assist w/ Cross-Traffic Function, Evasive Steering Assist, Active Lane Keeping Assist, Active Blind Spot Assist, PRE-SAFE PLUS (Rear-End Collision Protection), Route-Based Speed Adaptation, Active Stop-and-Go Assist,and Traffic Sign Assist.
Storage/Cargo
The GLS is plenty capacious inside with some great small storage options in the cabin and a large cargo section that can swallow a lot of gear. It's not as big for luggage and gear as the Escalade, QX80, or the the X7, but it beats the LX 600 and the GV80.
Storage Space: The front binnacle with the retractable door, door pockets, and the split-top armrest are good for small items.
Cargo Room: The GLS provides 18.4 cubic feet behind row three, 48.7 behind row two, and 84.7 with all the seats folded flat.
Fuel Economy
There's pretty much no expectation for the GLS to be miserly. It's heavy, powerful, and it begs to be driven hastily (we say this for almost any car), so it wasn't surprising to see average numbers in our combined highway and local driving. That said, it should have no problem meeting its EPA estimates if driven conservatively.
Observed: 21.4 mpg.
Distance Driven: 163 miles.
Audio
The GLS gets the awesome Burmester Surround Sound System as standard equipment. It's powerful, clear, and delivers top-notch sound quality without any distortion regardless of volume. The beautiful speaker grilles are commensurate with the quality of the system.
