We drove the full GLS lineup through Colorado's red rock canyons and Arches National Park in Utah, cycling through the models in ascending order. The GLS350d 4Matic is the base model, with a 3.0-liter V-6 turbodiesel generating 255 horsepower (up 15) and 457 lb-ft of torque. It is the sleeper鈥擬ercedes never advertises its diesel in the U.S. 鈥 攖o the tune of about 15 percent of GLS sales. All trim levels have standard 4Matic all-wheel drive, and all but the AMG have Mercedes' new 9-speed automatic transmission which improves fuel economy about 5 percent. Also new for the lineup is Dynamic Select, offering up to six transmission modes. Switching to Sport lowers the suspension, tightens the steering, and increases throttle response. Go into the settings on the infotainment screen to mix and match your preferences: want comfort steering but a stiffer sport suspension? Done. And there are graphics to illustrate how the vehicle is set and how it is performing. Move up to the GLS450 4Matic and you get the 3.0-liter V-6 twin-turbo gasoline engine instead of a V-8.

We drove the full GLS lineup through Colorado's red rock canyons and Arches National Park in Utah, cycling through the models in ascending order. The GLS350d 4Matic is the base model, with a 3.0-liter V-6 turbodiesel generating 255 horsepower (up 15) and 457 lb-ft of torque. It is the sleeper鈥擬ercedes never advertises its diesel in the U.S. 鈥攖o the tune of about 15 percent of GLS sales. All trim levels have standard 4Matic all-wheel drive, and all but the AMG have Mercedes' new 9-speed automatic transmission which improves fuel economy about 5 percent. Also new for the lineup is Dynamic Select, offering up to six transmission modes. Switching to Sport lowers the suspension, tightens the steering, and increases throttle response. Go into the settings on the infotainment screen to mix and match your preferences: want comfort steering but a stiffer sport suspension? Done. And there are graphics to illustrate how the vehicle is set and how it is performing. Move up to the GLS450 4Matic and you get the 3.0-liter V-6 twin-turbo gasoline engine instead of a V-8.

There is no compromise here: 362 hp and 369 lb-ft of torque. This is the most popular model, accounting for about half of GLS sales. The beauty of the GLS is that regardless of what is under the hood, this seven-passenger vehicle does not feel big or lumbering even on twisting roads. Part of that is courtesy of the "active curve system" to control body roll. And the new computer-controlled air suspension slurps up any irregularities the pavement has to offer. All choices offer enough power鈥攂ut your definition of "enough" can vary. If you can afford the step up to the GLS550 with a 4.7-liter V-8 twin-turbo gasoline engine, you will appreciate the 449 hp (up 20) and keep grinning with 516 lb-ft of torque at your disposal. The SUV hits 120 mph effortlessly without feeling like it is going fast. If you want to be the big dog on your block, the AMG GLS63 stuffs a 5.5-liter V-8 twin-turbo engine under the hood. It harnesses 577 hp (up 27 hp) and 561 lb-ft of torque through a 7-speed automatic transmission and can hit 60 mph in a claimed 4.5 seconds in a 5,750-pound, seven-passenger SUV. When we track-tested a 2013 GL63 AMG, the 550-hp SUV hit 60 in 4.7 seconds. Downshift for the most delicious burps and burbles. It helps you ignore EPA fuel economy figures of 13/17 mpg city/hwy for a combined 14 mpg. 126,880 with a few extra goodies including second-row sunshades, trailer hitch, and heated/cooled cupholders. Will there be a GLS65 in the future? Still to be determined, Herring says. And at this point there are no plans for a GLS coupe.

Minor: A High Desert package headlines the Silverado鈥檚 changes. The package adds a flexible, lockable storage system with two storage bins and a three-piece tonneau cover. High Country models with the package are offered with GM鈥檚 Magnetic Ride Control suspension, which should help improve its ride comfort and handling. The Silverado鈥檚 engine lineup leaves the diesel to the smaller Colorado and the larger Silverado HD. Look For: Chevrolet to continue its marketers鈥?steel versus aluminum bed debate as long as possible. Sum Up: Conventional good looks in a competent package. Minor: A functional hood scoop and air-intake system are new for the diesel model, adding more curb appeal to what鈥檚 already a huge, imposing heavy-duty truck; at highway speeds, the scoops generate a ram-air effect. Look For: Either natural gas or conventional gas if you go for the bi-fuel system, which has a CNG tank in the front of the bed.

Sum Up: Capable and now with a bit more visual attitude. Unchanged: A new trim called Premier replaces LTZ and includes performated, leather, heated, and ventilated driver and front passenger seats. Also, the Teen Driver monitoring tech is now standard, and a low-speed forward automatic braking system is newly available, as is a new 22-inch wheel option for Premier. Cool Fact: More than 60 percent of Suburban passengers use the available 4G LTE Wi-Fi hot spot, which recently had its price cut in half. Sum Up: Two large and hard to beat SUVs that dominate their segment. Minor: The seven- to eight-passenger Traverse enters 2017 with a new Graphite special edition. The value package is based on the 2LT model and adds black Chevrolet Bow Tie badges, 20-inch wheels with a dark finish, dual exhaust, integrated assist steps, and a choice of black paint or extra-cost shades of red or white.