1: Emissions, a brand new truck that gets 10mpg pollutes exponentially less then an 86 whatever that gets 35mpg.
2: See above (Nuggets Post), 50mpg in Europe = 41.635mpg in the USA. It's amazing how many people don't realize that.
3: It is possible to make a cheap 40mpg shitbox that nobody wants to drive. It's called the FIAT 500. If you've never driven a car in Europe, they're small, slow, and just not suited for the American market. It's been tried, and has failed every time.
I'm all for efficiency over clean, but that's just not the way the world works.