I agree you just need to change you driving habits, I have and added 3 to 4 more MPG, but simple staying off the gas and let the car coast more in daily stop and go traffic.
Not a fun filled day of driving that is for sure but is save on the pocket book at the end of the week.
The same problem exist with a prius as well, if can get better mileage by changing how you drive but most people have no clue. Most people drive with the gas or brakes all the way to the floor. But here is how you get 80MPG form a prius it is called hypemiling
Just face it any vehicle you drive has huge impact on the environment, if it is not the gas it is all the other nasty chemicals need to fabricate a car. Making AL is really nasty stuff.
I use to love giving tree hugger grief about their Chromollay bikes they road around on. I would ask them did they realize how nasty Chromium is to the environment, needless to say they did not want to talk about it.