Interesting video and clearly aimed at marketing the Airstream product.
How they are doing (numerically) would obviously be beneficial in the telling of their progress, similar to the quoted "25%" improvement over a box type structure/trailer. Twisting an adage, "what are you doing now, not 20 years ago".
No doubt the cost of doing this research is hidden in the cost of their trailers, and subsequently, the total cost and value of the tweaks and changes, following further experiments...
...not cheap.
Kinda like the addition of another solar panel on the front edge of the 21 Escapes.
Assumed performance can often lead to failures resulting in unexpected costs and repairs to the manufacturer and/or owner. ETI did respond fairly quickly when incidents were reported and developed a remedy after some viability study at their end. Perhaps the "stick on solar panels" may prove more viable in the long term, but at present, rigid panels seem to be the option of choice by most manufacturers.
I'd suggest at this point, cleaning up the airflow over the accessories/appliances on the roof would show considerable improvement on our Escapes (and others). But that's on the suppliers and consistency across the industry.
Yes...it'd be kind of nice to recover 10% of fuel costs (or range) with some minor add ons to our rigs, but it takes money to do that, and the competition isn't helping other manufacturers to that end.
But I'd rather an Escape than some square stick built...which are far more comfortable than a Red River Cart or Conestoga Wagon.