Have we all been backing the wrong horse in devoting so much attention and effort to new vehicle technologies, is it effort that should be spent elsewhere?

Vehicle efficiency is capable of providing large, low-cost CO2 reductions and fuel savings.  It is a very good horse to back. In fact we often overlook vehicle efficiency and “back the wrong horse” in other areas (biofuels comes to mind, though some kinds of biofuels may be very useful in a low CO2, sustainable future).