Hmm, maybe a little bit of a couple of those. I like the brag and wow factor when people ask me what mpg I get. Also, I'm all about saving a little money on gas, considering I commute 64 miles a day. Hell, if I could fill my Civic up for $10 like I could back in the '90's, I'd still be driving it like I stole it! They still get great mileage even then.
Not really concerned with the environment all that much and definitely not into hugging trees. It was here before us and it will be here long after we're gone.