A slimmer, more capable GMC Acadia arrives for 2017 with a significant improvement in fuel economy that may make it a more desirable choice for fleet selector lists.

For its second generation, GMC has reduced the Acadia's wheelbase by 7.2 inches and overall length by 7.2 inches. Curb weight falls to 3,956 pounds from 4,656 pounds.

As a result, the mid-size SUV with a powertrain combination of a 3.6L V-6, 6-speed automatic transmission, and all-wheel drive delivers a significant improvement in fuel economy with a 20% increase in economy in city driving to 18 mpg from 15 mpg. Highway driving improves more than 13% to 25 mpg from 22 mpg.

The 3.6L V-6 replaces a 3.3L V-6 and increases power to 310 hp. A new 2.5L four-cylinder makes 194 hp. Front-wheel drive is standard.

The Acadia also adds stop-start technology to reduce idling for further fuel savings.

We tested the Acadia SLT-1 All Terrain with all-wheel drive in the environs of California's Death Valley National Park. The vehicle ably navigated the gravel and dirt road leading to the Mosaic Canyon trail, as well as the undulating Artist's Drive road that snakes through volcanic rock formations.

The 2017 Acadia gives buyers more choices for configuring the seating area with two- and three-row options for five, six or seven occupants. The Acadia adds the All Terrain model that's aimed at off-road adventure seekers. The vehicle uses an all-wheel-drive system that includes an active twin clutch for greater hill-climbing capability.

Other Acadia models also offer a rear sear reminder feature that activates when either rear door is opened or closed within 10 minutes of the vehicle being started. It displays the alert on the instrument panel.

For fleets seeking a mid-size SUV with cargo capability, the Acadia offers a solid choice with a maximum cargo area of 79 cubic feet. With the third row installed, the vehicle provides 12.8 cubic feet. And if trailering is needed, the Acadia can tow 4,000 pounds.