My current daily driver truck averages 20-22 arround town, and 24-26 on the highway, and that is in stock form. I use it as a truck about 2 times a month. To tow a trailer that has the same cargo rating of my truck a car capable of doing so would not do much better in the FE department, nor do they tend to handle it as well. I am upgrading my class II hitch bumper to a class III reciever because it isn't handling what I use it for so well. The bed has been used as an example of what a truck bed should look like. (scraped, scratched, dented)
Edit: added from here
http://en.wikipedia.org/wiki/Socorro_County,_New_Mexico
Area 6,649mi^2
Population almost 18,000
Population density 3/mi^2
The population of my town just over 9000 with a density of 630/mi^2
So public transit - None
The local lumber company has 1 delivery truck, which also doubles as their supply truck so you might have to wait a day to get your stuff. If they don't have what you need the next closest is 50 miles away and they charge $150 to deliver with up to a 5 day wait that you have to take off of work to recieve.
When you guys were talking about rural I was snickering. I know of places that are worse, like areas of Nevada.