I have a 15 foot bass boat with a 20 gallon tank and the edge towed it just fine. I did get the larger 2in reciever. got 16 or 17 mpg. 2.5hours each way from Hagerstown, Md to Wye river, Md. Mountains to flat towing did very well.
I used my wife's edge last week to pull a 15 foot bass boat. Got about 16 mpg. I went with a 2inch receiver instead of the 1 1/4. mainly becuase I already had a but of 2" hitches.