Reply #69: Doing so would shut down all of the auto plants in the US

[Xithras]

You can't just slap a smaller engine in an existing car to make it more fuel efficient, so this will require the redesign of every car and truck in their portfolio. It takes time (years) to design, test, and make the molds and stamps for a new car model.

Requiring that the regs go into force next year would simply shit down the auto industry once and for all. They couldn't retool in time.