"Hypercar" has become a fashionable term to describe automobiles which are more efficient. I have been advocating these since 1988. Indeed, a letter of mine on the subject appeared in Popular Mechanics. The issue clearly continues to become more pressing, and should have been given proper consideration.
I came up with some suggested research at about this time. I sent it to Ford, General Motors, and Chrysler. They replied more or less identically; Ford for example "returned my drawings".
My suggestion was to reduce the horsepower of automobiles to 25, and make use of well-known "avalanche effects" to achieve high mileage, perhaps as high as 150 miles per gallon. I also had a specific design outline:
A typical excuse for the ongoing delay in deployment of higher efficiency automobiles is that higher cost materials are required. This is not true. The above design can be implemented with currently used materials and manufacturing methods. Modern safety methods can be used; since the vehicle has a top speed of 60 mph safety is improved already. Some extra weight may be required for safety given the existing fleet of bloated turkeys.
I put this desgn on a usenet thread. One respondent called it "a car that nobody would buy". Mayor Tom Bradley of the City of Los Angeles found the idea attractive for alleviating the city's traffic problems.