NOVI, MI – The U.S. EPA hopes to take a closer look at what impact additional emerging automotive technologies could have on fuel-economy and vehicle costs as it re-examines its 54.5 mpg (4.3 L/100 km) CAFE target for 2025, an official says.

The agency is conducting a second midterm review of the carbon-dioxide-emissions standard, following the one completed late last year by the outgoing Obama Admin. that automakers contend was rushed through and didn’t give them an opportunity to weigh in.

“I know for a fact that we were not called in (to the late-2016 review),” Fiat Chrysler Automobiles CEO Sergio Marchionne said in March, following the Trump Admin.’s decision to re-examine the standard. “To me it was like somebody reneged on a deal. I don’t like it.”

Under that initial review last year, the EPA estimated the 2025 regulations would cost $875 per vehicle to achieve, while fuel saved over the life of the vehicle would total $1,650.

But speaking here to CTI Symposium USA, a conference on automotive powertrain technology, Kevin Bolon of the EPA’s Office of Transportation and Air Quality says those numbers don’t fully take into account such emerging technologies as electric superchargers and 48V mild-hybrid systems, so the cost and savings estimates could change again with the latest CAFE review.

There’s no concrete timetable for completing the new review, other than an April 2018 deadline that was set when the standard originally was finalized in 2012.

Bolon says each automaker has a different recipe as it engineers vehicles toward the 2025 regulations, and there is no single technology that is dominating as a solution to better fuel economy.

However, he says gasoline-direct-injection technology is now running at a 50% penetration rate, up from 3% in the ’08 model year. Mazda uses GDI across the board, and six other automakers show a 75% penetration rate, he says.

More advanced transmission technology is another popular ingredient, he says, with multispeed automatics (7+ speeds) at about 20% penetration and CVTs now found in more than one in five vehicles sold in the U.S.

In this latest review, the EPA hopes to take a look at what variable-compression-ratio technology – Nissan is about to offer the industry’s first engine with such capability, other lean-burn technologies, electric superchargers and additional friction-reduction measures could do to help automakers meet the 2025 goals and how much it will cost.

Bolon tells WardsAuto the EPA did examine the potential impact of first-generation 48V mild- hybrids in the last review, but the agency may expand its research into more sophisticated phase-2 systems that couple stop/start technology with electrically powered launch assist.

In his presentation here, Bolon indicates automakers appear to be on track to meeting the 2025 bogey, pointing out the targets automatically adjust based on shifts in market demands.

The 54.5 mpg CAFE translates to a real-world value of 36 mpg (L/100 km), the EPA says, based on assumptions of gasoline prices of $2.97 per gallon and a car/truck mix of 53%/47%. But if those assumptions change, so will the real-world fuel economy. Year-to-date, trucks account for 63% of U.S. sales and gasoline averages $2.34.

Bolon also points out automakers have outperformed the standards so far and have built up considerable credits that can be applied to future shortfalls in meeting the standard.

The goal of the latest review will be to make sure the “curves are not too flat or too steep,” he says, meaning automakers should be challenged aggressively but not tasked with trying to reach unrealistic targets.

Auto executives here say they are not terribly concerned about whether the midterm review will provide any relief, because they face stiff emissions and fuel-economy standards in other markets around the world.

“The U.S. could relax (standards) a little,” says Robert J. Fascetti, vice president-Global Powertrain Engineering for Ford, but he notes the rest of the world isn’t likely to follow suit.

“Emissions targets are very aggressive, no matter what market you’re looking at,” he says, pointing to annual-reduction goals of 3.5 % in Brazil and 5.5% in China as evidence. “As a major OEM, we have no choice but to continue our (technology) development, because global markets are not backing down.”

Asked what’s to come after 2025, Bolon demurs, saying the EPA is focused on the current regulations. But he notes California and other global markets already are beginning to look beyond 2025.

“The industry wants consistency, so we will consider these other standards when addressing (post-2025),” he says.

dzoia@wardsauto.com @DavidZoia