Hi, stumbled upon the site looking for aerodynamic information, and I though I'd register.
We have a 2001 Ford Focus ZTS which has gotten 34MPG on longer trips in warm weather and a 2000 Ford Taurus SES which has disappointed me in that it's usually below 30MPG where my 1990 Mercury Sable was able to over 30MPG. Both had 3.0 V6 motors, but the 2000 model is a 24 valve motor where the 1990 was a 12 valve motor.
Additionally, I have a 1996 E350 dually shuttle bus that has a Power Stroke diesel engine, they are detuned for vans, and I now pull a 24 foot enclosed trailer with it. Best mileage I've got pulling the trailer has been 15MPG, and that came in three fulls, and the worst is around 10MPG. Regularly, it's at probably close to five.
I use the trailers to carry motorcycles that I use to teach schools and race. My current race bikes are Suzuki's, a GSXR750 and an SV1000S.