Still very tempting to buy my totaled TT back

protel wrote:
One inseresting thing I found is when I towing slower, I actually get better MPG like 13, it used to be a bit more than 10MPG.

This is absolutely true. When pulling a heavy load on a flatbed trailer, when you get to speed, inertia helps keep up that speed, and there is no appreciable increased wind resistance. When pulling a TT, you are actually pulling a large open parachute behind you. When you get to speed, the air resistance against the front of the trailer is trying to slow you down and it takes additional pressure on the gas pedal to overcome that. Hence, your decreased fuel mileage.

Your most fuel efficient speed is about 5 or 10 mph above the speed where you hit top gear. Top gear is your most fuel efficient gear. If you barely hit top gear, any small rise you have to cross will make it downshift. A little faster and you can top a small rise without that downshift taking you out of top gear. Of course, a large rise will downshift no matter what.

My experiments, with both a Class C MH and my Airstream, show that somewhere around 60 mph is the sweet spot. (I actually set the cruise control at 62. I have found that most folks drive on a 5 mph division, 55 or 60 or 65 or 70. By setting my speed 2 or 3 mph off of that division, I don't get caught up in the traffic wolfpacks. Everyone is either slowly passing me, or slowly being passed by me.)

MH - 60 mph gets 12 mpg while 70 mph gets 8 mpg. That is about a 16% increase in speed with a 33% decrease in fuel mileage. (That translated into refueling every 300 miles or every 200 miles.)

Airstream - the numbers are about 14 mpg and 9 mpg.

The tests were run over the same 1,000ish mile stretch of road. Of course, weather conditions were uncontrollable. This was tested while driving from my home in TN to my sister's home in CO.