Don't be too sure about that. I remember hearing people rationalizing their decision to buy those fancy euro, vespa scooters. They all had to mention how great it was to have a great mileage vehicle. Notice they don't publish the mpg on those things. I dug and found some numbers and it turns out I still get better mpg with my honda insight. And I'm out of the weather and have the air conditioner running.
Next good trick. Figure out the mpg per pound of payload. My honda is ten times less fuel efficient than my old freightliner. Who's green now? I think the truck industry is behind the power curve on advertising this fact. CSX, the rail company, figured it out.
eb