Never mind the tow ratings and space: the 2018 Mercedes-Benz GLS hits the road with sport-wagon finesse.

With its poised ride and its tire-punishing weight, the 2018 Mercedes-Benz GLS might be dismissed as just another big SUV. May we show you something in a GLS 63, then?

It’s at times an astonishing reminder that utility vehicles don’t have to have buckboard rides and dingy acceleration.

Count up the extra points it earns for its powertrain, ride, and off-road ability, and we come to 8.

The GLS draws on three different powertrains. The GLS 450 gets a 362-horsepower, twin-turbo V-6 and a 9-speed automatic. GLS 550s sport a 449-hp twin-turbo 4.7-liter V-8 and the same 9-speed automatic.

At the top of the range, the twin-turbo 5.5-liter V-8 in the GLS 63 AMG pumps out 577 hp. To cope with all that power, it shifts gears via a beefier 7-speed automatic.

In all, the turbo twist doesn’t begin right at idle, so turbo lag is evident. The 9-speed models also have a few ratios to downshift through at times, which can make the powertrain feel busy on freeway entrance ramps and steep corner climbs.

All versions of the 2018 GLS have standard all-wheel drive. A set of drive modes tailors other traction systems to bow to prevailing conditions, while reprogramming the GLS’ adaptive suspension, steering, and drivetrain. Select Comfort and all the vehicle’s reactions relax; select Off-Road+ and the air springs rise to grant a total of 8.5 inches of ground clearance. In Sport mode, the steering weights up and shifts come more quickly, which gives the GLS a hopeful hint of nimbleness in traffic. Select Slippery mode and the GLS clamps down on wheelspin and shifts into higher gears to keep as much traction on tap as is possible.

While it can drive like a smaller SUV, the GLS is immense. The steering feel on versions with the standard wheels isn’t too loose or light, but it's not overly graced with feedback, either. The variable-ratio rack provides different response at low speeds than it does at higher ones.

The smooth ride the GLS generates from its standard air suspension is creamy under most circumstances. There’s an optional Active Curve system that presses down on its anti-sway bars to counteract body lean, but in doing so it removes a layer of natural information that disguises the GLS’ speed through sweeping corners. We prefer the regular setup. We also prefer the standard wheel-and-tire combination, at 19 inches, rather than the larger options with lower-profile tires, which seem to add some jiggle to the ride.