With the GMC Acadia coming off its strongest sales year (96,393 units in 2015) in its nearly decade-long lifetime, the automaker is resizing the full-size, three-row crossover for the 2017 model year as a midsize crossover with an available third-row bench. GMC says the new midsize 2017 GMC Acadia slots between the compact Terrain crossover and full-size Yukon SUV.

While the outgoing GMC Acadia is based on GM's Lambda platform (shared with the Buick Enclave, Chevrolet Traverse, and discontinued Saturn Outlook), the 2017 model will ride on an all-new -- and smaller and lighter -- platform. Although GM hasn't revealed what chassis the new 2017 Acadia rides on, we suspect it's the new scalable Chi architecture that will underpin the upcoming Cadillac XT5 as well as replace the other Lambda-based crossovers.

The 2017 GMC Acadia rides on a 112.5-inch-long wheelbase and is 193.6 inches long overall. For comparison, the compact, two-row-only GMC Terrain rides on a 112.5-inch wheelbase and is 185.5 inches overall.

Compared to the outgoing model, the new Acadia's dimensions are downsized as such: wheelbase by 6.4 inches, length by 7.2 inches, width by 3.5 inches, and height by 3.9 inches. Turning radius improves from 40.4 feet to 38.7 feet.

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Along with its smaller dimensions, the 2017 GMC Acadia is now 700 pounds lighter than the outgoing model. The original Acadia came standard with three rows of seating, but the 2017 model will be available with two rows for five-passenger seating or with three rows with six- or seven-passenger seating.

The Acadia's sizable weight savings was also made possible through use of more high-strength steel throughout the platform. Crash safety has improved thanks to new splayed front frame rails that flare outward during small overlap frontal crashes.

The smaller and lighter new Acadia now features a new 2.5-liter, direct-injected inline-four engine as standard. The engine features the division's first use of stop/start technology. Power for the 2.5-liter is SAE certified at 194 hp at 6,300 rpm and 190 lb-ft of torque at 4,400 rpm. GMC estimates the front-drive model with new four-cylinder will achieve 22/28 mpg city/highway. Official EPA ratings are still pending.

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The outgoing model's standard 288-hp, 3.6-liter V-6 has been replaced by a new 3.6-liter V-6. Power for the engine is estimated at 310 hp at 6,600 rpm and 271 lb-ft at 5,000 rpm, while fuel mileage is estimated at 17/25 mpg for a front-drive model. (The outgoing V-6 is EPA-rated 17/24 mpg with front-drive and 16/23 mpg with all-wheel-drive.) Official power and fuel economy ratings for the new Acadia are pending. With the V-6 engine, the Acadia is estimated to tow up to 4,000 pounds with the available towing package.

Both engines are mated to a six-speed automatic transmission. Front-wheel drive is standard, and all-wheel-drive is available. The transmission features a new drive mode selector that varies chassis and powertrain settings depending on driving conditions. Front-drive models feature Normal, Snow, Sport, and Trailer/Tow modes, and the available all-wheel-drive system features 2x4 (AWD disconnect), 4x4, Sport, Off Road, and Trailer/Tow modes. The 4x4 mode is an on-demand all-wheel-drive mode.

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Inside, the Smart Slide second-row seat now features a split-folding feature that is said to offer greater flexibility and easier access to the optional third-row seats. That available 50/50 split third-row bench folds flat with the cargo area. The 2017 Acadia features 12.8 cubic-feet of space behind the third row, 41.7 cubic feet behind the second row with the third row folded, and 79 cubic-feet of cargo space with the second row folded.

Other new interior features include a storage drawer on the rear of the center console for second-row passengers as well as a standard rear seat alert that notifies the driver if an item has been left on the second- or third-row seats. GMC also added USB charge ports for all three rows.

Along with the new chassis, the 2017 Acadia receives new, more refined styling. Up front, the Acadia features a chrome-trimmed grille with wraparound headlights. Halogen projector headlights are standard, while Denali models get HID headlights. All models feature LED running lights. Squared-off and flared wheel arches dominate the side profile, while wraparound side windows with dark D-pillars and C-shape lighting accentuate the rear of the crossover.

Denali models feature a "dimensional chrome grille," chrome side trim, chrome door handles, chrome lower rear fascia, and unique six-spoke wheels.

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In addition to the automaker's current active safety tech (forward collision alert, lane keep assist with lane departure warning, lane change alert with blind spot alert, front and rear parking assist), the 2017 GMC Acadia gains new safety tech. The new features include front pedestrian braking, low-speed forward automatic braking (standard on SLT-2 and Denali), forward automatic braking (available on Denali), following-distance indicator, IntelliBeam automatic headlamp high-beam control, Surround Vision camera system, and Safety Alert Seat, which vibrates the left or right seat bolster when a hazard is detected.

The new Acadia is available with a new Tow Vision Trailering system that uses a camera with guidelines to assist when hitching up to a trailer. The camera also allows the driver to keep an eye on the trailer while driving.

Connectivity features include Apple CarPlay and Android Auto integration with the available GMC IntelliLink system as well as available OnStar 4G LTE Wi-Fi hotspot.

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For 2017, the Acadia is available with a new off-road-oriented All Terrain model that features an all-wheel-drive system with an Active Twin Clutch, which GMC says optimizes traction for the conditions. The AWD system also provides enhanced hill-climb capability. Cosmetic upgrades include body-color grille surround, black chrome trim, and unique wheels, five-passenger seating, unique interior trim, and covered storage bins in lieu of the third-row seat.

The automaker hopes the all-new 2017 GMC Acadia will make a huge impact in the midsize crossover segment. Only time will tell if a smaller, nimbler, lighter, more fuel-efficient, and more powerful midsize crossover will sell as well as GMC's full-size sales success.