 Second, electric vehicles have become more efficient, as the average model year 2013 all-electric vehicle used 0.325 kWh/mile, representing a 5% improvement over 2011 models.The Nissan Leaf, used as the reference model for the baseline of the 2012 study, was upgraded in model year 2013 to achieve a rating of 0.30 kWh/mile, a 12% improvement over the 2011 model year model rating of 0.34 kWh/mile.Also, some new models are cleaner than the average, such as the BMW i3, which is rated at 0.27 kWh by the EPA.