2017 Mercedes-Benz GLS450 Test Drive

Words John Clark | August 18, 2016
If you need a practical and well-rounded luxury SUV, the GLS450’s 7500-pound tow rating and ability to actually fit seven the best in its class
Words John Clark August 18, 2016

Normally, stating that a new or updated car is just like its predecessor kind of saps the life out of its “newness.” Take the 2017 Mercedes-Benz GLS450, for example. Its close kinship with last year’s GL450 may not be exciting, but it is a good thing, as that model represented the ideal intersection of price, performance, and fuel economy in the four-model GL-class lineup. For 2017, that family stays the same aside from a minor name change to GLS-class and subtle cosmetic updates inside and out.

Sharing its 362-hp 3.0-liter twin-turbocharged V-6 with the pre-refresh, S-less GL450, the GLS450 again slots into the lineup above the diesel-powered GLS350d and below the high-powered, high-priced, eight-cylinder GLS550 and GLS63 AMG variants. Make that way, way below the V-8-powered GLS550 and GLS63 AMG, which start at $94,775 and $125,025. They play in a different arena than the $69,625 GLS450.

2017 Mercedes-Benz GLS450

2017 Mercedes-Benz GLS450

The GLS450 comes in $1650 over a GLS350d, and for that extra scratch you get 107 more horsepower at the expense of a few mpg. (The EPA, however, has yet to certify the ’17 GLS350d—likely the result of a federal investigation into possible emissions-test irregularities—making the GLS450 look like an even better proposition.) We have yet to test the 2017-model GLS350d or GLS550, but against the (slightly less powerful, pre-refresh) GL350 diesel and the GL550, the GLS450 compares favorably. The GL350 BlueTec reached 60 mph in 7.5 seconds and returned 22 mpg, while the GL550 accelerated to 60 mph in 5.4 seconds but delivered a dismal 14 mpg. Aside from their new nine-speed automatic transmission shared with the GLS450, the ’17 GLS350d and GLS550 aren’t expected to perform much differently. For its part, the new GLS450 smoked to 60 mph in 5.7 seconds—just a tick behind the 550—while its observed 18 mpg was much closer to the diesel than to the V-8. Those in slightly less of a hurry could argue a strong case for the diesel, as well.

Receiving Transmission!

The GLS450’s new transmission is dubbed 9G-Tronic. Its first seven gears sport shorter ratios than all seven speeds in the old transmission. Compared with a 2015 GL450 we tested last year, the GLS450’s spicier gearing enabled it to reach 60 mph 0.2 second quicker and post snappier 30-to-50-mph and 50-to-70-mph passing times. Some credit for this specific GLS450’s extra zip could be attributed to its lack of optional extras, which made it weigh 207 pounds less than that 2015 GL450.

A straighter line can be drawn between the new transmission and the GLS450’s enhanced fuel economy. The two extra gears, both of which are taller than seventh gear in the old transmission, are responsible for nudging the GLS450’s EPA highway fuel-economy estimate northward by 1 mpg, to 22 mpg. (The city estimate remains 17 mpg.) We saw a bigger improvement, as the 18 mpg our GLS450 notched over a few hundred miles topped the 2015 version by 2 mpg. Better still, the 9G-Tronic’s tall gearing keeps engine revs low at highway speeds, and it behaves nearly flawlessly in the default Comfort mode, save for a tendency to select too high a gear when downshifting unless the throttle is really booted. There is a Sport mode, but it’s slightly too eager, waking up the transmission as though one of those jitter-inducing energy drinks often found at minimarts were poured into the electronics. Lower gears are feverishly held, even at a steady cruise, and first gear is used when accelerating from a stop (second is used in Comfort mode in the interest of smoothness). If you absolutely have to make it to soccer practice on time, use this setting.

The only other new feature vying for attention is a touchpad controller for the updated COMAND infotainment display. The touchpad, which operates via finger swipes and taps like a smartphone’s screen, works as well here as it does in other Benz products. But mostly it presents yet another choice for manipulating the COMAND menus in addition to a knob, steering-wheel controls, and voice commands.

2017 Mercedes-Benz GLS450

2017 Mercedes-Benz GLS450

The Dynamic Story

All else being pretty much equal to the GL450, it’s little wonder that this model’s core competencies carry over. The interior seats up to seven in comfort, and although adults will fit in the third row, those chairs will seem most accommodating to children or teenagers. Air springs are standard, and while this suspension dulls the SUV’s initial responses—there is some body roll in corners—it also makes any road surface feel as if it’s made of memory foam. And despite the body lean, the GLS posted 0.79 g of cornering grip on our skidpad, which is above average for something 72.8 inches tall and weighing nearly 5400 pounds.

The rest of the big Benz’s dynamic qualities are to be expected, with the steering tracking well on the highway but otherwise being numb and with slow, vague responses to driver inputs. The brakes earn similar marks; the pedal feels reassuring after you pass through a brief squishy zone at the top of its travel, but the GLS450’s 186-foot stop from 70 mph is merely okay for this class. Really, though, the only dynamics that matter are the GLS450’s highway manners. We took it on a half-day trip from Ann Arbor to the west side of Michigan and back, and the most grueling part of the journey was the sunburn we got at the beach. Fill the GLS450 with people, cargo (up to 94 cubic feet with the second- and third-row seats folded), or both and you can schlep them far and wide in soft-riding quietude.

It’s particularly telling that this fairly sparsely optioned GLS450 seemed so luxurious and relaxing to drive. Outside of a few individual bits such as a trailer hitch ($575), temperature-controlled cupholders ($180), illuminated running boards ($670), a heated steering wheel ($250), and power-flipping second-row seats ($400), our test car’s biggest addition was the $3830 Premium package that brought SiriusXM satellite radio, Apple CarPlay, a proximity key, lane-keeping assist, ambient interior lighting, and a power passenger seat. A $1290 Parking Assist package (a self-parking system and a surround-view camera) and the rather droll combination of Iridium Silver paint ($720) and dark Anthracite Poplar wood trim ($160) that barely stood out in the all-black M-B Tex pseudo-leather cabin brought the total to $78,550.

Nearly $80,000 is slightly richer than a base, four-wheel-drive Cadillac Escalade—a rig that’s closer to the GLS450 in size and general SUV-ness than the more carlike Audi Q7 and Volvo XC90. The body-on-frame Escalade also happens to be slower, worse to drive, less fuel-efficient, and less roomy for people and cargo, which sets up an opportunity for the GLS450. In our current editorial rankings, the GLS-class (the whole family) trails the Audi and the Volvo, mostly because those tall wagons are more athletic and exquisitely appointed across the breadth of their ranges, but neither can tow more than 5000 pounds or fit adults in their third-row seats. If you need a practical and well-rounded luxury SUV, the GLS450’s 7500-pound tow rating and ability to actually fit seven humans in its boxy body mark it as not only the sweet spot in the GLS lineup, but in its class.

Via: Car and Driver