The fuel economy stakes of Big Auto's emissions fight with Trump

Automotive emissions standards — essentially a proxy for mileage improvements — would rise under an agreement with California by four big automakers, according to an analysis from The Rhodium Group.

What they found: Under the California deal, the group estimates "that fleetwide average rises to 39 to 41 mpg in 2025, and 42 to 45 mpg by 2030." That would be less than Obama-era standards but still higher than under Trump's plan to freeze mileage rules.

• The analysis assumes that Ford, Honda, BMW and VW — which together represent about a third of the U.S. market — sell cars nationwide that comply with the California deal.

By the numbers: It estimates that the California deal "could reduce emissions by 184 to 266 million metric tons (MMTs) cumulatively from 2021 to 2035 relative to Trump's pending rollback."

• If all automakers active in U.S. markets signed on, "cumulative reductions would jump to 557 to 807 MMT over the same timeframe."
• That would be "on par" with the effects of the Obama-era standards.

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