Chevrolet chose to introduce the 2018 Equinox last night, the evening of the autumn equinox, and it came with a surprise — a 1.6-liter turbo diesel that Chevy estimates will achieve and estimated 40 mpg in highway driving.

The compact crossover SUV segment is now the industry’s single-largest segment, and the Equinox crossover is Chevrolet’s second-best selling vehicle, with more than 2 million finding homes since its launch as 2005 model.

Only the Silverado pickup attracts more buyers.

The 2018 Equinox’s turbo diesel is a class exclusive in the U.S., but expect other automakers to follow in the next year or two.

A six-speed automatic transmission will direct the turbo diesel’s 136-horsepower output to either the front or all four wheels when equipped with all-wheel drive.

It’s not known if the estimated 40-mpg highway includes all-wheel drive models.

Typical of some carmakers looking to sell the sizzle, Chevrolet did not give estimated city or combined fuel economy numbers beyond the “40 mpg” highway figure.

Combined fuel economy is more reflective of real world driving, but the 40-mpg highway grabs more attention, at least for now.

For some idea of what the new diesel Equinox fuel economy might be, the 2015 Chevy Cruze turbo diesel has an EPA rating of 33-mpg combined, 27-mpg city and 46-mpg highway.

SEE ALSO: 2014 Chevrolet Cruze Turbo Diesel – Video

As for the new Equinox, its gas and diesel engine line up is all turbocharged.

The entry-level offering is a 1.5-liter gasoline turbo with 170 horsepower, an estimated fuel economy of 31-mpg highway and a six speed automatic.

Then there’s the more powerful gas 2.0-liter turbo, which has 252 horsepower and 28-highway mpg with a nine-speed automatic.

Built on a new platform, the 2018 Equinox contains only eight parts from the old model, is four inches shorter in length and 400 pounds lighter than the outgoing model.

“It is an all-new SUV from the ground up and one that takes on the industry’s biggest competitors with a stronger architecture, greater efficiency and more technology,” said Rick Spina, executive chief engineer.

Styling is lean and muscular, with design cues and shapes from the Chevy Volt, Malibu and Cruze.

The design features chrome trim on all models, projector-beam headlamps drawn from the Malibu are standard, along with LED daytime running lamps.

At the rear, horizontal tail lamps emphasize the Equinox’s wide stance, while up level models feature LED tail lamps.

SEE ALSO: 5 Cool Things About the 2017 Chevy Bolt EV

The new architecture lets the crossover’s instrument panel be positioned down and away, and a low windshield panel allows a good forward view.

It also has a rear “kneeling” seat: The bottom cushions tilt forward when seatbacks are lowered, allowing a flat load floor.

There’s a full suite of infotainment and connectivity features available including a 7.0- and 8.0-inch MyLink infotainment systems designed to accommodate Apple CarPlay and Android Auto; an OnStar 4G LTE Wi-Fi hotspot is also availabl

New parents will be attracted to the rear seat alert, which reminds them not to leave tots in the back seat, and those with teen drivers can keep track of their driving habits with Teen Driver.

On the safety front, the 2018 Equinox offers the optional forward-collision warning with a following-distance indicator and low-speed automatic braking; also available are lane-departure warning, lane-keeping assist, blind-spot monitoring, and rear cross-traffic alert.

The 2018 Chevrolet Equinox will reach dealer show rooms in the first quarter of 2017.