 A 2014 analysis conducted by the Idaho National Laboratory using a sample of 21 @,@ 600 all @-@ electric cars and plug @-@ in hybrids , found that Volt owners traveled on average 9 @,@ 112 miles in all @-@ electric mode ( e @-@ miles ) per year , while Leaf owners traveled 9 @,@ 697 e @-@ miles per year , despite the Volt 's shorter all @-@ electric range , about half of the Leaf 's . The 2015 edition of the EPA 's annual report " Light @-@ Duty Automotive Technology , Carbon Dioxide Emissions , and Fuel Economy Trends " estimates the following utility factors for 2015 model year plug @-@ in hybrids to represent the percentage of miles that will be driven using electricity by an average driver , whether in electric only or blended modes , The Volt has a utility factor of 66 % , compared with 83 % for the BMW i3 REx , 45 % for the Ford Energi models , 43 % for the McLaren P1 , 37 % for the BMW i8 , and 29 % for the Toyota Prius PHV . 
