The automakers all seem to be in favor of this new rule...I assume because it's apparently a bit 'smarter' in the designation between trucks and cars...and even credits gas-saving technologies like EV or ethanol...
I think, though, they're mostly in favor of it because it's a clearly-defined "do this". Versus a dozen competing standards that need to be decoded.
I hate it. I think it's completely stupid, frankly...in every way. But if the automakers have a hand in writing it, maybe it won't be as awful as it could be. Wishful thinking, perhaps...