Thanks for your interest. We have a 20 foot Sunline Solaris travel trailer and began towing at about 1000 odometer. Followed the manual on speeds, etc. Have accumulated about 2000 miles of towing at odometer 5000 miles. We are very pleased with the pair. The Outlook replaced an extended Chevrolet TrailBlazer. The Outlook is smoother, quieter,and seems to be getting about 1 MPG better than the Chevy. We have towed the Solaris around western Michigan and to the Lake of the Ozarks area in Missouri. Economy for the car going solo is 19.86 MPG over 3000 miles, while towing it has averaged 9.97 MPG for the 2000 miles. My wife tells me I am a compulsive record keeper and I guess she is right. There are so many variables affecting fuel economy that I am comfortable in quoting only long-term averages.
The combination seems very sensitive to terrain and wind conditions (no surprise there) and has varied from 8.4 MPG to as high as 12.1. I sometimes think (perhaps wrongly) that I am smarter than the transmission and tend to "play" the Tow Haul button as we drive. That's because I can see the road ahead and the tranny can't. It seems reluctant to up-shift when I can see that a high gear would be appropriate, so I disengage the Tow Haul and let the engine run at a lower speed.
The trailer weighs 3978 pounds with propane, but no water. We travel light and I doubt that we have more than 200 to 250 pounds of food, clothes, toys, etc. This being well within the 4500 Lb towing limit.
Have I told you more than you wanted to hear? My credentials are that I am a retired automotve engineer with 35-pus years of experience with a well-known automoble manufacturer (your guess).