CHICAGO – Cadillac’s new flagship, the fullsize XTS sedan, is powered by a 3.6L 300-hp V-6, with no new V-8 in the works, but there may be a larger model planned.

“We can add a turbo to the V-6, and as we move forward with the XTS there will be what we'll call power enhancements," says Don Butler, vice president-marketing for Cadillac during an interview at the auto show here.

But there is no XTS-V super potent version. "(The) CTS and ATS are performance vehicles,” he says. “The XTS isn't a performance vehicle, so ‘no’ to a V version."

The CTS has a high-performance V version, and the new compact ATS is destined to get one.

Butler says the XTS trunk will hold four sets of golf clubs, and folks traveling in the rear seat can cross their legs without fear of injury. But an even bigger vehicle is possible for the fleet.

"Do I want something larger than XTS? Hope so. We’re exploring something more substantial, larger and grander,” he says.

“We continue to study that territory. We’ve now got the volume segments covered with the compact ATS, midsize CTS, fullsize XTS and SRX crossover. Next would be to add a new halo car with more substance.”

Mark Reuss, president-GM North America, told WardsAuto during an interview late last year that GM was mulling a Cadillac entry in the high-end luxury-car segment.

“Do we need something that is a statement on a sedan basis for Cadillac that competes with some of the biggest and most-expensive cars? Yeah, we probably do in the long run. And so we’re looking at that,” he said at the time.

A bigger, bolder car is something Butler would like as well. “I can't tell you any timing,” he says, “but it's something we are studying."