Mazda has been named the top automaker for best fuel efficiency and lowest greenhouse gas emissions per mile by the EPA for the fifth straight year. It was a year of overall improvements across the board, but Mazda kept ahead by making cars with sound designs, rather than trying to adopt new technologies.
Only direct injection was employed by Mazda to reduce fuel usage. Mazda has no hybrids, sells no diesels, and does not use CVT transmissions. Only one new model, the CX-9 uses turbocharging. The rest of Mazda's vehicles are all normally aspirated (non-turbo).
The EPA reports that Mazda’s overall average fuel economy was 29.6 miles per gallon, improved 0.4 mpg over the previous year. The numbers being reported are for model year 2016 vehicles. Mazda currently ranks number two behind Honda by a fraction of an MPG for 2017 in the preliminary reporting.
Mazda also has the lowest greenhouse gas emissions of any U.S. market automaker. As the chart above shows, Mazda isn't just the leader, but also beats the EPA's standard for the vehicles Mazda produces.
Going forward, Mazda looks like the brand is in a good position to maintain this lead. Toyota and Mazda are now partnering on green vehicles and also partnering on U.S.-based manufacturing.