PONTIAC, MI – General Motors global powertrain chief Dan Nicholson says the automaker’s engine-consolidation plan, a major cost-saving initiative aimed at slashing engine architectures, is on schedule but warns the effort will go only so far.

“We’re on track,” Nicholson tells WardsAuto in an interview at GM’s powertrain R&D headquarters here.

“It’s critical to the business. If we don’t stay on track, we can’t get everything done and meet the (carbon-dioxide emissions) curves.”

Nicholson declines to stake exactly where GM lies in a process to trim global engine architectures to 10 from 15 by 2018. A blurring of engine families, due mostly to new flexible-manufacturing technology, makes it difficult to be too specific.

“Our definition of an (engine) family has evolved a little bit,” says Nicholson, who was appointed vice president-global powertrain at GM one year ago. “The way we are designing engines is different, so it’s a complicated topic. But the short answer is we are on track.”

A consolidation of engine architectures, much like GM’s efforts to shrink its number of vehicle platforms, leads to broader parts and component sharing, as well as common tooling sets, which drives purchasing scale and savings in the billions of dollars.

The first example of GM’s engine-consolidation program began last year with the rollout of a new line of 3- and 4-cyl. Ecotec engines blending three engine families into one.

The engines will make their way into five GM brands and 27 models by the ’17 model year. They should account for roughly 2.5 million engine installations in that time, and output from five global assembly facilities is expected to reach 10,000 units daily.

Dean Guard, executive director-global gasoline engine engineering at GM, says new lean- and flexible-manufacturing techniques have led to a “blurring” of engine families.

“As we get (additional) lean, agile and flexible manufacturing capability, the things we used to say define a family can be opened up a little bit,” he says during a backgrounder for the 2016 Ward’s 10 Best Engines competition. “We can run more variations of engines down the same manufacturing system and gain some efficiency.”

Put simply, Nicholson adds, “It’s not a bore-center world anymore.”

However, GM can consolidate only so far, the executives admit.

Specialty customers, such as buyers of profitable GM luxury and performance vehicles, expect a degree of differentiation in their engines from more mainstream makes. Volume products, where the emphasis tilts more toward fuel economy and affordability, will factor more heavily in GM’s engine-architecture sharing.

“It’s a business reality,” Guard says. “We can’t do as much differentiation as we’d like, so we have to pick wisely. And the wisest place to do it is in the luxury and performance segments.”

Taking it a step further, the performance customer at Chevrolet, for example, wants a different driving experience than a customer at Cadillac.

Nicholson points to the Chevy Camaro SS and Cadillac ATS-V.

The Camaro SS employs a 6.2L LT1 V-8 making 455 hp and 455 lb.-ft. (617 Nm) of torque, while the twin-turbo 3.6L V-6 in the ATS-V cranks out 464 hp and 445 lb.-ft. (601 Nm) of torque.

Product plans would suggest the two engines sit on top of one another, but they come at different price points. Plus, a large-displacement, naturally aspirated engine offers a much different driving experience than a downsized boosted one.

Nicholson says such differentiation comes from the upper reaches of the organization, namely product development chief Mark Reuss, who wants each GM brand to have its own powertrain characteristics. As a result, brand champions are installed at the powertrain level to help execute that strategy.

“That’s an example of the lengths we are going to to get the right powertrains to the right customers,” Nicholson says.

He declines to speculate on the future of passenger-car diesel engines in the wake of the Volkswagen emissions-cheating scandal, but says GM is keen to expand its use of the technology around the world. “We’d like to sell more,” he says.

In the U.S., Nicholson thinks the automaker has found a sweet spot with the upcoming launch of the 2.8L Duramax turbodiesel 4-cyl. in the Chevy Colorado and GMC Canyon.

“It’s going to be the only diesel in the midsize truck segment, which we think is a great segment for the diesel,” he says. “It is going to be a winner. We’re committed to diesel in the U.S., and we’ll keep looking for market opportunities.”

He does admit to a degree of uncertainty presently surrounding U.S. acceptance of diesels. However, Nicholson also considers diesel owners a savvy bunch. “The customer will sort this (scandal) out.”

jamend@wardsauto.com