The Tour X will presumably match the Opel Insignia Sports Tourer available in Europe.
A California Air Resources Board document spotted by Motor1 lists the Regal wagon among several 2018-model-year vehicles that will be powered by General Motors' turbocharged 2.0-liter engine.
The certification suggests the Tour X will be available with either an eight- or nine-speed transmission and standard all-wheel drive.
GM already offers a wagon in Europe based on the Regal's Opel-badged sibling, the Insignia. Rumors have suggested the latest-generation Opel Insignia Sports Tourer will be headed to US showrooms, likely with few aesthetic tweaks aside from a new grille.
If the US-bound wagon's 2.0-liter engine specs match the current Regal Turbo sedan, drivers can expect 259 horsepower and 295 pound-feet of torque.
The Tour X is presumably on track to land in showrooms sometime this year.