Perhaps it is... in comparison to their... uh... dump truck that they normally drive?
so what's fuel efficient parking all about? are the spaces closer to the shops or something? or is it just for bragging rights effectively?! never come across this idea and seems a bit odd!
I'm guessing the aerodynamic roof storage is what makes it so fuel efficient. Kudos to the owner for going the DIY route on hauling his extra stuff rather than buying an 18-wheeler.