 The Opel Ampera official equivalent fuel consumption under the EU @-@ approved UN ECE R101 standard for plug @-@ in hybrids is 1 @.@ 2 L / 100 km ( 196 @.@ 0 mpg @-@ US ; 235 @.@ 4 mpg @-@ imp ) ( 83 @.@ 3 km / L ) . However , a leading Opel engineer prefers saying 169 Wh / km while battery @-@ powered , and then 20 km / L petrol @-@ powered . The ECE R101 standard weights charge @-@ depleting mode as 76 % and gasoline @-@ only driving as 24 % . 
