Buick has been spotted testing a new crossover SUV set to fill the wide gap between the Envision and Enclave.

The new crossover, which is rumored to adopt GMC's Envoy name, thus in keeping with Buick's practice of starting its crossover names with “En,” will boast three rows of seats. It's to provide big families with a more affordable alternative to the larger Enclave, which has become a tad more upmarket with its latest redesign.

Our spy shots show a prototype for the new crossover wearing the production lights and grille, suggesting that the debut can't be far. A reveal late this year or early next is possible. Sales will likely follow next summer, which would make this a 2021 model year arrival.

2021 Buick 3-row crossover spy shots - Image via S. Baldauf/SB-Medien

2021 Buick 3-row crossover spy shots - Image via S. Baldauf/SB-Medien

The new crossover is based on the mid-length version of General Motors C1XX platform found in the GMC Acadia and Cadillac XT6. This means we're likely looking at an overall length of about 199 inches, which is six inches shorter than the Enclave.

It also means powertrains should match units used in the Acadia and XT6, thus buyers will be looking at either a turbocharged inline-4 or a naturally aspirated V-6. The latter, if equipped, will offer 310 horsepower. Front-wheel drive will likely be standard and all-wheel drive available.

As for the design, you'll notice that the headlights are much slimmer than we're used to seeing on a Buick, and the rear takes on a much more angular look than the brand's current offerings. Such a design was previewed last year by Buick's Enspire concept. The handsome concept is expected to spawn a smaller crossover for Buick that will likely end up replacing the Chinese-made Envision in the next year or two.