Photos By: Evan Williams

The 2018 Chevrolet Equinox, Buick Envision, and GMC Terrain all share a common platform.

But unlike past offerings from General Motors--like the six vehicles that used to share the GMT360 platform---the relationship between these latest three isn't all that obvious.

Sure there are some shared parts, but there are also some surprising differences, with each brand sporting a few unshared party tricks.

So which of GM's three compact crossovers wears the D2XX platform the best, and which one do you want?

First off, a look at some of the similarities. Like their dimensions.

The trio are all quite close in size, the Chevy and GMC share a wheelbase, but the Envision is the biggest at 108.2-inches long, 0.9-inches longer the other two. Surprisingly, that doesn't translate into interior space. Legroom up front is identical for all three, while the Buick is 2.2-inches more cramped for rear-seat riders.

The Buick has the least amount of cargo space too, at 57.3 cubic feet with the seats folded. A surprising six feet less than the other two, so bigger isn't always better, per se. 

Buick gives the Envision more gas, too. Its gas tank holds 17.3 gallons, while the other two hold 15.6 for all-wheel-drive versions and 14.9 for front drivers.

The larger tank is necessitated by the Envision's thirstier base engine. Sure, with 197 hp, the Envision's naturally aspirated 2.5-liter four-cylinder makes more power than the 170 hp 1.5-liter turbo in the Equinox and Terrain. But its 192 lb-ft of twist is less than the turbo's 203 lb-ft, which is accessible over a wide range of engine speeds.

The front-drive Buick is rated for 25 mpg combined, compared with 28 for the Equinox. The Terrain's standard nine-speed automatic doesn't help at the pumps, returning the same 28 mpg as the Equinox manages with a six-speed auto, but somehow manages 2 mpg worse than the Equinox on the highway.

Jump up to the top engine, and all three get the same thing, a 2.0-liter turbo that puts out 252 hp and 260 lb-ft of torque. It uses a little more fuel and demands premium gas, but it really is a great engine. The Chevy and GMC both get a nine-speed in this application, but the Envision keeps its original six-speed. Combined economy is 22, 23, 24 for Envision, Terrain, and Equinox, respectively.

Buick gets a different version of the all-wheel-drive system too, using an Active Twin Clutch system to vector torque and send power where necessary in slippery conditions. Buick says it helps handling too, with a capability to send 100 percent of power either front or rearward.

If you want the real fuel-sipping engine, Chevrolet and GMC both offer a 1.6-liter diesel engine that the Buick doesn't get. That engine's 240 lb-ft of torque is nothing to sneeze at, but it is louder than the gas engines, despite more insulation, making it untenable in the Buick.

That's because the Envision is far and away the quiet one. All three have active noise cancellation, but the Buick has more quiet stuff.

Acoustic glass, extra sound shields in the doors, and better sound absorbing materials under the hood. The other two aren't exactly noisy, but the Buick is so silent that you don't actually realize how quiet it is--until you open a window and remember how noisy it is outside. The Terrain felt slightly quieter than the Equinox, but not enough to say so definitively. If you want silence, get the Buick.

The interiors of all three more unique than you'd expect. From small differences, like the inspired in-dash cell-phone holder in the Terrain and Envision, to the "where did that come from" push-button shifter in the Terrain. The Buick and Chevrolet share a console-shift, although the Buick's wider console intrudes on hip room, the Terrain's push-button shifter frees up space for American staples like sports drinks, cell phones, and chewing tobacco.

You might be thinking that the button-shifter is silly, but it actually works well in practice. The Envision has a more upscale looking dash and steering wheel, but the Terrain wins for the shifter, extra space, and phone holder.

It also wins because it has the best infotainment. GM's Intellilink and MyLink are mostly the same systems, but the Terrain gets the newest version. And it's that much faster, smoother, and easier to use.

When the roads get twisty, the Terrain and Equinox pull away from the Envision. The Envision won't roll over in turns, but the other two are clearly stiffer and sportier. For a highway cruiser, the silent, cushy Buick is the winner. If you want to drive more quickly, get one of the other two.

If you're looking at price, the Equinox will tax your chequebook the least. It starts about $1,000 less than the Terrain, and the Envision is about $10,000 more. But the Envision comes with more standard stuff, like leather-trimmed seats, rear park assist, a bigger display screen, and the color info screen on the dashboard.

When it comes to styling, looks are subjective. But the Envision's exterior is undeniably boring. Inside, though, it looks more upscale than the other two. The Equinox's styling carries the Chevrolet language, but parts of the nose can look awkward, the chrome mirrors too.

The Terrain is probably the best looking of all of them, and it's available in Denali trim. The other two don't have their own brand's High Country or Avenir trims to compete. That gives the Terrain the nod if you want the absolute fanciest of affordable, premium crossovers.

So which one do we recommend? The Terrain with the 2.0-liter engine. It has power, better exterior styling, the newer infotainment system, and the phone holder slot. 

But as always, your mileage may vary.