Even to the untrained eye, the Mercedes GLS 63 AMG is clearly something out of the ordinary. There are subtle design cues everywhere and when combined they let everyone know that this is no ordinary GLS.
The front grill and bumper are a little more aggressive, the rims are massive and wrapped in sporty tires, and even at idle the sound from the dual exhaust is noticeably different from the standard GLS. Everything about this vehicle says something great is hiding under that large voluptuous body, yet somehow it appears understated.
Overall, the AMG GLS looks very similar to a regular GLS, but all the extra little bits and pieces throughout the exterior give it an entirely different feel. This vehicle has presence with its large stature, and it doesn’t go unnoticed.
The Mercedes S Class is widely perceived as the most luxurious vehicle outside of the ultra-luxurious British cars, and the GLS 63 can be thought of as an S Class SUV. Beyond the normal levels of luxury in this vehicle, our tester was equipped with a $4,500 sound system, additional sound deadening and a comfort package that includes heated door panels and arm rests. Who knew that heated door panels and arm rests would be something worth having? We enjoyed those features and now we wish more vehicles had them.
The seating position is adjustable enough to be comfortable for almost anyone. The side bolsters can be moved to be comfortable when cruising or to hold the driver and front passenger in place when hitting the track. Lumbar support can be adjusted both vertically and horizontally meaning that it can be positioned exactly where the driver needs it to be.
For the middle row our tester had the Executive Rear Seat Package Plus which pretty much gives the middle row all the features of the front row. There is an included Samsung tablet that allows anyone in the GLS to adjust the interior lighting, radio, climate control, and massaging seats. Yes, the middle row does have heated, ventilated, and massaging outboard seats.
As part of the executive package the driver and passenger side middle row can control the front row passenger seat. This allows for a chauffeur to adjust the seat to for the comfort of the person they are driving around.
The third row is a little cramped and hauling adults in all three rows will be a challenge. There are four USB ports in the third row. Also, the middle and rear rows are power folding and lifting. To get into the third row a button is pushed and once in the third row you can return the second row seat to it’s position with the push of another button.
It’s hard to accurately describe how the GLS 63 feels when driving on pavement. Weighing in at 3 tons it somehow manages ridiculous levels of handling, acceleration, and braking. It doesn’t feel like a sports car, the weight and size are felt, but it can put down very impressive sports car fighting numbers.
The 0-60mph time is rated at 4.3 seconds, and we nearly achieved that number in our testing at 5,000 feet above sea level. There is a little bit of turbo lag down low, when we say turbo lag take that with a grain of salt as the torque curve is pretty much flat from 1800 rpm to 5200 rpm. Once the GLS gets to about 4000 rpm the power is absurd and really pins the passengers into their seats.
In comfort mode the ride is firm, but the driving characteristics are slightly subdued. The throttle and steering are dampened for smooth luxurious driving. Switching to sport+ mode changes the suspension damping, ride height, transmission shift points, throttle sensitivity, and steering stiffness all of which give the driver a more confident and sporty driving experience.
While cruising on the highway at normal speeds the GLS 63 actually returned a respectable 19 mpg. On the other end we had days where we averaged closer to 10 mpg. It’s hard not to play with the 600 hp available from the skinny pedal.
The massive 23-inch rims are wrapped in very low-profile Michelin Pilot Sport 4s tires. Up front they are 285/40ZR23 and out back they are a nearly 13-inch wide 325/35ZR23. This makes for a stiffer ride, but great handling chacteristics.
Thanks to the Acoustic Comfort Package the inside of the GLS was very quiet and composed. That of course changes when the exhaust baffles are opened and the sound of the glorious V8 is set free. The pops and crackles from the turbos and exhaust give the drive wonderful feelings of glee while potentially upsetting the neighbors.
With such a high performance on road vehicle the off-road capabilities are slightly limited. We didn’t attempt our usual steep hill climb with this vehicle for fear of damaging a 23-inch rim or a low hanging running board on the GLS 63 was a real possibility.
Instead of doing the typical off-road test we headed to a sandy beach on the edge of a lake. The high-performance tires are well suited for sand duty as the lugs are shallow. This provides for good floatation on top of the sand. However, with little sidewall there isn’t much room to air down and increase the tire footprint.
Another feature that makes sand driving easy is having a high horsepower high torque engine. Sand can sap power quickly, but with 600 hp, and even more torque, the GLS was a blast to drive in the sand. The sand was quite wet during our testing, so traction and floatation were higher than normal.
The base price for a 2021 Mercedes AMG GLS 63 is $132,100. Nearly $20,000 in upgrades were added to our test vehicle. The options were:
- Metal Weave (trim) $440
- Carbon Fiber Engine Cover $1,500
- AMG Performance Steering Wheel $600
- 23” AMG Multi-Spoke Forged Wheel $4,950
- Augmented Video $350
- Burmester High-End Surround Sound $4,550
- Magic Vision Control $350
- Warmth and Comfort Package $1,100
- Executive Rear Seat Package Plus $3,700
- ENERGIZING Package Plus $550
- Night Package $750
- Acoustic Comfort Package $1,100
Including destination charges this brought the total to $153,035. This is one of the most expensive vehicles we’ve tested. It’s also one of the fastest, most luxurious, and craziest SUV’s we’ve ever driven.
If you’re in the market for a family SUV that can tow your speed boat to the lake, then the GLS 63 AMG might be the vehicle for you. It’s very luxurious inside, has ridiculous power, and great handling, all while being able to tow 7,500 pounds. Other vehicles this absurd worth comparing to the GLS 63 are the Dodge Durango Hellcat, Audi SQ7, and BMW Alpina XB7.
Matthew Barnes is an experienced towing expert. He works as a mechanical engineer and his day job involves testing a variety of vehicles while towing trailers of all types and sizes. Matt shares his knowledge by writing for automotive news outlets in the evenings. When he’s not working he can be found spending time in the great outdoors with his family. He enjoys camping, hiking, canyoneering, and backpacking. Whenever possible he spends time riding in or on any power sports vehicle he can find and claims he can drive anything with a motor, which probably isn’t true.