 According to Consumer Reports in December 2011 , the Chevrolet Volt fuel cost in electric mode was 3 @.@ 8 ¢ / mile , while the Nissan Leaf had a cost of 3 @.@ 5 ¢ / mi . The Volt 's higher cost per mile was attributed to its heavier weight . Their estimates used the U.S. national average electricity rate of 11 ¢ / ( kWh ) and energy consumption rates as measured on their own , unofficial tests . When comparing the Volt in range @-@ extended mode with the four most fuel efficient gasoline @-@ powered cars as tested by the magazine , the plug @-@ in hybrid had a cost of 12 @.@ 5 ¢ / mi ( using premium gasoline ) while the Toyota Prius had a cost of 8 @.@ 6 ¢ / mi . , the Honda Civic Hybrid 9 @.@ 5 ¢ / mi . , the Toyota Corolla 11 @.@ 9 ¢ / mi . , and the Hyundai Elantra 13 @.@ 1 ¢ / mi . The analysis also found that , on trips up to 100 mi ( 160 km ) , the Volt was cheaper to drive than the other four cars because the Volt was able to drive 35 mi ( 56 km ) using less expensive electric power . Consumer Reports found that , using their proprietary testing , the Volt overall fuel efficiency was 99 mpg @-@ US ( 2 @.@ 4 L / 100 km ; 119 mpg @-@ imp ) equivalent ( MPG @-@ e ) , and using only range @-@ extended mode the overall fuel economy was 32 mpg @-@ US ( 7 @.@ 4 L / 100 km ; 38 mpg @-@ imp ) and equivalent to the Toyota Corolla . The report noted that , as of 2011 , plug @-@ in electric cars are more expensive to buy , and the previous operating costs do not include maintenance , depreciation or other costs . 
