SOUTHFIELD, MI – General Motors Co. anticipates a 60:40 take rate in favor of its 2.4L Ecotec I-4 when the all-new Buick Regal sports sedan arrives in U.S. showrooms next quarter.

It is a milestone launch, considering there is no available 6-cyl. engine and the conventional Buick customer has long preferred larger powerplants. The Regal’s optional mill is a 2.0L turbocharged I-4 that generates 220 hp, 38 more ponies than the direct-injected Ecotec.

But GM is confident. Says Craig Bierley, Buick marketing manager: “I don’t think we’re going to have a backlash.”

Dealers, Bierley tells Ward’s during an exclusive preview of the car, are not shy about expressing displeasure with a product. “And not one of them said we need a V-6,” he says.

George Fowler, general manager of Superior Buick GMC in Dearborn, MI, is among the Regal fans in GM’s dealer network.

“If you look at the old-time, old-fashioned (Buick) buyer, the 72-year-old guy, this isn’t the car that’s going to appeal to that kind of guy,” he admits. But Buick’s demographic has been skewing steadily younger. Entering 2010, the average customer was 65 – down from 70.

From the traffic Fowler has seen, cost of ownership is the No.1 deal-breaker. “(Consumers) all want cheap lease payments,” he tells Ward’s. “If they can get the car for under $350 (a month), we’re going to sell a ton.”

Fowler says this with confidence, even in the shadow of Ford Motor Co.’s world headquarters, where his dealership is located. “The engine is not going to be a problem.”

Against a backdrop of rising gasoline prices, American car buyers are enthusiastically embracing thriftier 4-cyl. powerplants. Nearly 62% of all ’09 cars produced for the U.S. market featured 4-cyl. engines, up from 51.7% in ’08, according to Ward’s data.

Regals equipped the 2.4L Ecotec, chosen one of Ward’s 10 Best Engines for 2010, start at $26,995. Units with the turbocharged 2.0L engine start at $29,495.