When I got my license, my dad gave me his 1992 Mazda 929 to drive. It sucked. I never looked at gas then, but I bet the POS got 10mpg, it was a heap. It broke down and my parents bought me a new Civic (love my parents btw). I loved the car, I was in college then, and did a lot of commuting from school and home.
Well, all my friends had some sort of sporty car (camaro, mustang), truck with V8, or SUV. I had the econo box with no mods to it. Even though they were joking, I would get teased because I had the slow car.
Sometimes I thought about it, and even looked into getting a quicker car, but I didn't need it. The car wasn't going to win me any races, but I don't race. I need to get to school, back home, to work, and where ever else, safely, and efficiently.
Then my friends all started complaining. Gas cost me this much, I'm spending X amount on gas a month, why is gas so high? They asked me, what kind of mileage do you get? I didn't know, I never looked into it. I really had no idea what my friends payed for gas. So I started calculating mileage. Next time my friends asked, I had an answer. I was averaging 32mpg in my 01 Civic EX coupe auto. The look on their faces was priceless, its like I told them I was Batman. I asked them what they got, I got answers in the low 20's, and mostly in the teens. I was shocked, I never realized that I got "great" mileage. I was sold on the Civic at that point (also had a little fun with my friends, "hey, how much did that last tank cost you? hehehe").
I now have a 2005 Accord EX sedan 4cyl auto (was my parents, they took the Civic and traded it for an Odyssey and gave me the Accord, I love my parents). I took a road trip in 06, drove 4200 miles in 8 days. Only had to fill up the tank 10 times (not counting the initial full tank I started the trip with). Most of the miles were highway, I was say a 70 highway/30 city split. I averaged $35 a tank or so, maybe a little less.
Point I'm trying to make is, if you don't need the truck or SUV or V8 sedan or whatever, think about something more economical next time. Why waste money on gas if you don't have to?