There was an encouraging report last month from the University of Michigan's Transportation Research Institute about fuel economy.
We hit a record high in February in terms of gas mileage for new vehicles sold in the U.S.: 25.2 miles per gallon. It's the fifth-straight month gas mileage for new vehicles has topped 25 mpg.
That got us wondering how we're faring in the quest to squeeze out better mileage from our cars and trucks, and in the quest to create electric, hybrid, natural gas and fuel-cell vehicles and technologies.
Charles Griffith is the climate and energy program director at the Ecology Center in Ann Arbor, and he joined us today.
Listen to the full interview above.