I have a 2004 Mustang Cobra. It's got a Supercharged V8 six speed manual engine, and does 0-60 in four seconds. I did a quick look up for stats and I see it gets 24 mph highway, and 17 mph city.
However, I work from home and rarely leave the house. I couldn't tell you the last time I drove my car, and when I did it was just to make sure it still runs. I can't remember the last time I filled it up with gas. It was months ago.
My wife has a 2004 Ford Explorer with a V6 in it. She doesn't work, and we use it for running around town. We fill it up once every other month and it costs $70. I don't stress too much because I can live with $70 every other month. Everything here is within walking distance - including a Target - so we rarely drive.