If it is like the original big dog then it doesn't use electric motors/actuators it uses hydraulics that are driven by the gas engine.[0] Supposedly it gets ~0.

If it is like the original big dog then it doesn't use electric motors/actuators it uses hydraulics that are driven by the gas engine.[0] Supposedly it gets ~0.5 miles per gallon. [0] http://www.bostondynamics.com/img/BigDog_Overview.pdf http://www.bostondynamics.com/img/BigDog_Overview.pdf