Who's getting 10 mpg? Towing or empty?
If you get as low as 10 mpg towing, something just ain't right or you are driving too fast.
If you get as much as 15 mpg towing, you have a miracle machine.
I don't think anyone towing a 30' Airstream will see much more than 13 regardless of tow vehicle.
I don't think anyone towing a 30" Airstream with a modern pickup is getting as little as 10.
The comparison needs to be done between the known 15 mpg my Tundra gets and the 17 or 19 other pickups get.
I average 6,000 miles per year.
So, in reality, my sucky fuel economy costs me roughly $400 per year.
It would take me roughly 87 1/2 years to see a savings after spending $35,000 for a more fuel efficient truck.
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