RE:RE:RE:RE:BobcatEfficiencies are a good discussion as you can turn over any number of rocks and come up with something.... I'll even point to the type of fuel. Ex. Ethanol has less BTU.
Look at the application of these other devices and their impact.(maybe not bobcats). Indoor or underground mining with batteries don't require as much fresh air exchanges which is huge in energy consumption. KLG has been using these for awhile I think. SO