Cool car but the fuel mileage claims are BS, or well if you drive like Brian does maybe. Brabus is just acting Italian now and lying about their MPG.
Their is a Youtube video online of a CL63 AMG with some Brabus mods doing pulls on the Autobahn and you can actually watch the fuel gauge drop in the 7 minutes it lasts.
I'm guessing real world if you drive normally 12 maybe, if you hot rod it single digits.
But really who cares anyway.
