The rule that Obamas administration adopted in 2012 would have required automakers to achieve an average fuel economy of 54.5 miles per gallon by 2025 for vehicles sold in the U.S. Even before then, automakers had been seeking fuel economy improvements from every corner of their cars, including engine oils. The oil industry responded by contributing savings of several percentage points, mostly by reducing oil viscosity grades. In 2000, SAE 10W-30 was the most popular grade in the U.S. passenger car market. Today 5W-30 and 5W-20 dominate, and demand is shifting to 0W oils.

EPA Administrator Scott Pruitt announced Monday that the agency will withdraw the 2012 and replace it with something more appropriate. He offered no details about what that might be, but several lubricant industry insiders said yesterday that engine oils probably will not be affected, even if rule ends up significantly rolled back.

Stephen B. Ames, principal of SBA Consulting in Pepper Pike, Ohio, said it is unlikely U.S. automakers would backtrack on any of the fuel economy contributions they have demanded from engine oils in recent years – largely because it costs OEMs nothing now to retain those benefits.

I dont see them going backwards on fuel economy, he said. I see them just tapering the slope to reflect the change in product mix of more sport utility vehicles and pickups and less sedans.

Holly Alfano, CEO of the Independent Lubricant Manufacturers Association, predicted automakers will be compelled to keep seeking better fuel economy because their marketplace values it.

I would think that in order to remain competitive OEMs will continue to push for efficiency and fuel economy, and engine oils are a part of that equation, she said. She also noted that the state government in California has vowed to stick to its own tough fuel economy mandates. Pruitt suggested Washington could try to force the state to accept the national rule.

Theres the question of California and whether it will be able to continue to have its own, more stringent standard, Alfano said.Its the largest vehicle market, and most likely, the courts will have to resolve the question of whether the state can maintain their own standard.

Not everyone was willing to concede that engine oils will not be affected. Valvoline Chief Technology Officer Fran Lockwood said its conceivable that U.S. automakers would attempt to slow the shift to 0W oils.

From what Ive read, automakers are having mixed reaction, so we will be watching the situation carefully, she said.

Several sources agreed that a less ambitious mandate would recognize that the U.S. car fleet has changed since 2012. Lower fuel prices helped revive demand for SUVs and pickups. The Auto Alliance says it would now cost the industry $200 billion to reach the 54 mpg target.

Ames said the change in U.S. policy wont affect foreign automakers, who still face requirements elsewhere that are due to continue tightening. Japanese automakers have pioneered the push toward ultra-low-viscosity passenger car motor oils, such as SAE 0W-16, 0W-12 and 0W-8 oils, which are also making their way into other regions.

The Japanese will keep pursuing that because they have their own standards that they have to meet, as do the Europeans, as do the Chinese, Ames said. So it doesnt matter to them what this administration does. Theyre going to go for the formulations that are best for them.

Such an approach is reinforced, he said, by a desire on the part of OEMs for global platforms that keep their vehicles uniform regardless of where they are sold. The same sentiment will further spur U.S. automakers to keep improving fuel economy since more than half of their sales are now in foreign countries.

The 2012 rule provided for an interim review of the fuel economy target, and Trumps administration undertook a review last year at the request of automakers who argued that the original target was unreasonably burdensome and that Obamas administration cut short a required analysis.

Pruitt said EPA will set a new standard that allows auto manufacturers to make cars that people both want and can afford – while still expanding environmental and safety benefits of newer cars.