Nissan and Subaru led the way for outperforming the GHG emission standards by 23 grams per mile each, while FCA, Mercedes, and Kia all lagged behind the standard. FCA barely missed out by three grams per mile, Mercedes fell short by 11 grams per mile, and Kia trailed behind by 12 grams per mile, respectively.
In 2015, automakers were expected to average approximately 267 grams of GHG emissions per mile, a sharp decrease of 20 grams per mile since 2012. Average fuel economy figures for automakers rose to 24.8 miles per gallon for the 2015 model year, representing an increase of 0.5 mpg from 2014.
While automakers outperforming the EPA and NHTSA's GHG emission standards are a good thing, the margin by which the manufacturers did so decreased. In 2012, automakers beat the standards by 11 grams per mile, while the figure topped out at 13 grams per mile in 2014. With car companies tasked with hitting ever-increasing greenhouse gas requirements, it's only going to get harder for automakers to meet or beat the EPA's standards in the coming years.