Made a trip from Austin to Houston and back last weekend. Pulled a double axle, 18ft trailer with me. I took the trailer empty, and brought it back with a 24ft long BMX racing starting gate on it.
Here was the trailer, empty.
Here is how it looked after the gate was on it.
380 mile round trip. Interesting fuel consumption results... I reset my trip computer before I left. On the trip out, I stayed around 70 mph. My mpg was 17.4.
It was a slightly unstable load coming back since the gate hung off the back so much. Depending on the road conditions, I had to slow down to about 65 mph. My mpg increased to 18. I did not reset the trip computer on my way back, so it got UP to 18, from the 17.4.