This is basically how CAFE works, and it's part of the problem. Trucks are necessary for commerce and utility, and we allow people to drive them on the road. So we now have a road filled with vehicles that are technically "trucks" carrying families instead of "cars".
You could. Whether or not you’d get a desirable outcome is up to the particulars of the implementation.
It’s worth remembering that the current state of things is an unintended consequence. Describing the problem generally is easy. Defining it specifically enough so that there isn’t a workaround is the tough part
This is basically how CAFE works, and it's part of the problem. Trucks are necessary for commerce and utility, and we allow people to drive them on the road. So we now have a road filled with vehicles that are technically "trucks" carrying families instead of "cars".