DETROIT – The push by governments for electrified vehicles, the promise of hydrogen fuel-cell cars and the abundance of natural gas won’t be enough to push the internal-combustion engine from its position of dominance any time soon, automotive engineers say.

Representatives from General Motors, Ford, Chrysler and Toyota participate in a panel discussion on “2018 and Beyond Powertrains” at the 2012 SAE World Congress here.

Members agree the ICE will continue to be refined in an effort to squeeze out every ounce of efficiency. Other than that, little will change in the coming years.

“Unless there is a significant breakthrough in (electrified-vehicle) cost and range, ICEs will dominate for the next 20 years,” says Chris Cowland, Chrysler’s director of advanced and SRT powertrain.

The biggest challenge for the industry will be reducing carbon-dioxide emissions without raising costs. ICEs “have been a very cost-effective solution,” accounting for only 10% of the total cost of a $30,000 vehicle, he says.

While hybrids and EVs hold promise, they currently are expensive and unlikely to be embraced widely by consumers. Developing future powertrains is a pricey proposition and only makes sense if the technology is forecast to have 15% or higher market penetration.

Chrysler is working to improve the efficiency of ICEs, while at the same time developing more efficient automatic transmissions. “Transmissions with multi-speeds have changed the operating conditions of engines, which now run at 1,400 rpm instead of 2,000 rpm,” Cowland says. “That has changed how we develop engines.”

Key to increasing the efficiency of ICEs is reducing parasitic losses and delivering more of the power produced by a gallon of gasoline to the road. Diesels are more efficient than gasoline engines, but legislation has made oil-burners “less efficient,” he says. “We have to restore the efficiency for (diesels) to be viable.”

Joe Bakaj, vice president-powertrain engineering at Ford, says one of the auto maker’s top priorities is reducing CO2 emissions, warning failure to do so will result in “catastrophic global warming.”

Global warming is being addressed by many of the world’s governments, and the resulting regulations are difficult to address because of their varying nature, Bakaj says. However, he sees these rules coming together by 2020.

He cautions the solidified regulations will be stringent, warning the “pace of change will be far more challenging in the next decade” than it has been over the past 10 years.

Bakaj agrees that ICEs will remain the powertrain of choice, particularly because carbon-based liquid fuels have superior energy density and a storage advantage over most alternative fuels. However, diesels, while efficient, will continue to be restrained by costly exhaust aftertreatment technology.

The Ford powertrain executive is bullish on electrification but says electrified vehicles in 2018 only will represent a fraction of the world’s car parc unless costs are significantly reduced.

Ford’s solution is to offer the “power of choice” by making available a wide array of solutions, he says. The auto maker recently launched the Focus Electric and in the coming months will roll out Fusion and all-new C-Max hybrids, as well as the C-Max plug-in hybrid.

“All technologies will be present (in 2018), but at different penetration rates,” Bakaj says. “Will ICEs lose dominance post 2018? No.”

Sam Winegarden, executive director-powertrain engine engineering at General Motors, says CO2 reduction will continue to be the industry’s dominant goal, noting even emerging markets are adopting strict regulations. “In 2018, (they) will be headed toward the rest of the world.”

GM’s strategy is to continue to refine the ICE to increase fuel economy and reduce emissions, while also planning for energy diversification. For example, he says, a C-segment car with a 4-cyl. engine mated to an automatic transmission is 23% fuel efficient, but “only 17% of that energy gets to the ground. We have to get more efficient.”

Cutting mass and improving aerodynamics are two more ways to improve efficiency. Other methods include increasing thermal efficiency, reducing friction, vehicle downsizing, variable-valve technology and advanced combustion.

Regarding other powertrain technologies, Winegarden says battery optimization is expected going forward, but hydrogen has significantly higher energy density than today’s batteries.

As such, hydrogen fuel-cell vehicles are promising, but there are hurdles to overcome before they become economically available, particularly the lack of refueling infrastructure and high costs.

GM will continue to work on electrified vehicles and other alternative solutions, Winegarden says, but the dominant powertrain in 2018 will be smaller-displacement, forced-induction ICEs.