Well, try to give you some idea on what to expect. Here is what we experienced towing a 17 ft Casita
with a 2002 Ford Ranger, 4.0 liter engine, 4X4. Without the trailer highway mileage was about 20. With trailer in tow driving no more than 65 mph, we got about 13 to 14 mpg.
The engine size makes a big difference in towing with these little Rangers. The 4.0 engine pulls very well and frankly, I would discourage anyone from an engine of lesser size in the Ranger. If I remember correctly, three different engine sizes are available.
As a rule of thumb, when selecting a car or a truck, I check for acceleration specs. I find that a vehicle which can go 0 to 60 mph in ten seconds or less, to be adequate for pulling a trailer, given the trailer weight
does not exceed the manufacturers weight