I knew it, I was recently saying that with all the modern trailers and multiple slides that someone would pop the top. . and here it is. . WOW. . . . also realized that it is very low like a moving truck. . that is how he was able to get a double-decker height. .
That trailer might not be as heavy as you think. . and with a good modern rig, you could get as high as 8-10 mpg with say a 600hp Cummins. . (ISX)