Starting next year, all new Volvos will offer some form of powertrain electrification. In the US, Volvo currently offers its T8 Twin Engine setup, combining a supercharged and turbocharged 2.0-liter engine with a rear axle-mounted electric motor. A less powerful version of this powertrain, called the T6 Twin Engine, debuted earlier this year on the V60 wagon. But according to Volvo North America CEO Anders Gustafsson, that T6 plug-in hybrid option won't be coming to the States.

"One thing the customers don't want -- and I would say our partners, retailers, they don't want it either -- they don't want too many versions," Gustafsson told Roadshow during the Volvo S60 media launch last week.

Gustafsson notes Volvo has a "long lead time" on the US-spec T8 plug-in hybrid models, and that "production capacity is really, really stretched."

"If you have too many versions, [customers] always want the car that is parked somewhere else," Gustafsson says. So if Volvo has to choose which plug-in powertrain to import to the US, "Why go for the cheap one when you can sell the big one?"

Volvo's plug-in hybrid T6 Twin Engine system is essentially the same as the more powerful T8, just with reduced output. "The electric motor is the same," Lex Kerssemakers, Volvo's senior vice president, told us earlier this year. "We just play with the engine."

According to preliminary data released at the V60 launch earlier this year, the T6 Twin Engine powertrain produces a total system output of 340 horsepower and 435 pound-feet of torque. The T8, meanwhile, makes 400 horsepower and 472 pound-feet, using the exact same hardware, according to 2019 S60 sedan specifications.

Kerssemakers said the T6 plug-in will expand to other global Volvo models in the near future.

Volvo expects plug-in hybrids to account for a "quarter of our sales ... within the next two years," according to the company's president and CEO, Håkan Samuelsson. Currently, the T8 Twin Engine makes up about 15 percent of all Volvo sales.

Should demand change, or Volvo brass decide the T6 Twin Engine might be a good fit for the US, Gustafsson is 100 percent on board.

"If the team has decided it, I support it," he said. "If we want, it's a decision, and we just do it." But for now, Gustafsson "would like to really to simplify the offer structure."