In regards to fuel economy standards, it is now a global market where the US is just another country (5% of the world’s population). Auto manufacturers have to design cars for the world market and governments around the world are getting very strict on Fuel economy and demanding much higher mileage than here in the USA. It is more efficient for auto manufacturers to design and build as few variations and engines as possible in order to keep costs down. This means even though the US might have lower standards the fuel mileage demanded by the rest of the world still puts more fuel efficient cars on the road here. A downside is if US auto makers get lazy and slow down technology development because of low standards in the US and fall far behind foreign car makers in the race for better efficiency. This is not good for our competitiveness and even national security.While there are a few Nachos in the wild, it was never available for order and has been discontinued.
It's just a proposal at this point. The administration wants to freeze the current standards after the 2020 model year.