Idahoktm
Spends too much time on here
It's the easiest rolling trailer I have ever seen. I can roll it all the way across the yard by hand. It's wind resistance. I bet if I attached a flag to the back bumper and drove around it would lose 3 mpg.
I'm going to bow out to your superior understanding of aerodynamics. 7 MPG loss with a small utility trailer and 3 MPG with a flag.