The evironmental movement doesn't always think things through.
The ban on R12 (freon) was foolish.
No connection to the hole in the ozone was found, and the replacements are much less thermodynamically efficient, resulting in greater energy use.
The latest idea of going for greater nominal mileage for big rigs/delivery trucks is downright idiotic.
Fuel burned per ton hauled has been consistently improving over time.
It doesn't matter what type of mileage the vehicle gets, it matters how much fuel is burned per unit transported.
Fuel is the second biggest cost in the transportation industry, they don't need mandates to induce fuel efficiency.
The facts don't matter.
All that matters is whether activists feel good about themselves.