Forest River Sunseeker E450 2300 MPG

Thanks all. I have a much better idea of what to expect. 8-10 looks about right. For what its worth, I have a hybrid at present to drive as a car and use that like a "milk float" - one of those electric vehicles that used to "float" around slowly delivering milk, so 55mph should be easy enough to keep to... after all its a vacation.. As a newbie, do you guys reckon that I could tow a RAV4 or Kia Optima Hybrid with an E450 or E350? Looks like a case to buy the E450 I suppose...