The only way to wring more mileage out of the cars is to make them lighter, less safe, and less powerful.
And those mandated lighter weights, more plastic, less collision “crash space” (smaller crumple zones) kill about 5,000 - 8,000 PER YEAR.
But “Washington” and its EPA-liberal cheerleaders) don’t care. Fewer people = less “pollution” and “less environmental impact” don’t you see. (By the way, the pope agrees: But does not notice/care about the increased deaths coming from his enviro papers.)