I wondered the same thing. My fuel economy hasn't decreased at all. I actually got the best fuel economy I've ever gotten back in October- 13 mpg on a trip to Texas.
I got the lowest priced gas in 9-10 years in Southaven, MS Sunday- $2.299 for E85 Ethanol.
You do have to be more careful when backing into a parking space to keep from squashing the flaps against the curb. I can see them in my rear-view camera. If they hit the curb, I put it in park. I get "Big Bubba" or "redneck" comments, but the front of my trailer is clean!
2013 Classic 30 Limited
2007 Silver Toyota Tundra Crew Max Limited 5.7 iForce
2006 Vivid Black Harley-Davidson Road King Classic
1999 Black Nissan Pathfinder LE
WBCCI #1811, Region 6, Unit 56