A new study released this month from the University of Michigan's Transportation Research Institute found that the average fuel efficiency of America's fleet has only risen by 3.6 miles per gallon in the last 92 years.
Audi was disappointed with its diesel-powered racing prototype at Le Mans this year, but it did manage to clock two other records: taking the lap record at the Sachsenring, and cruising 1,158.9 miles on a single tank of diesel.
Momentary changes to the spec site for the 2016 Chevrolet Volt suggest that it might get 43 miles per gallon and 106 mpge, rather than the original rating of 41 mpg and 102 mpge. There have been other tweaks, as well.
Subaru is making a major investment in its powertrains to comply with the latest fuel economy regulations, and to comply in California, a plug-in hybrid is likely on the way. This might mean more expensive models from the company in the future.