First, Amory wants us to become more efficient in the ways we already know: shed vehicle weight; use hybrids; Plug in hybrids; no idling when stopped, etc. He believes we can double our overall vehicle efficiency that way! For our remaining transportation energy needs we have natural gas (?) and biofuels. He sees Boeing's new jet, the Dreamliner, as an example. New materials, less weight for its size, 20 percent more MPGs even with its conventional jet engines.
Weight is the enemy of efficiency, so Lovins wants to see the Dreamliner approach applied to cars. Use new materials, or old materials in new ways, to save weight and improve function. That will allow engine downsizing without performance downsizing.
Instead of CAFE (Corporate Average Fuel Economy) or CT (Carbon Tax), he suggests a "feebate": buy a low-efficiency car and pay extra - the fee - to do it. Example: Buy an Acura MDX in place of another crossover SUV that has better mileage numbers. But if you buy that more efficient model, you get a rebate. That should have the OEMs squeezing weight out of their vehicles as Boeing did with the Dreamliner. Note: Compromises in safety will not be allowed. Say a vehicle drops from 3500 lbs (1600 kg) to 3000 (1360 kg). You'll see it in your mileage and 3,000 lbs is still a substantial amount of weight.
I would also like to see the vehicle footprint reduced - length and width. Now that we are up around 240 million on-road vehicles, there is less road space to drive them and less parking space to park them. Smaller vehicles help reduce congestion, not just emissions.
For more on the Rocky Mountain Institute and RMI's Hypercar, check out the ABG Q&A with Michael Brylawski.