I shudder and cringe when I hear someone who's thinking about upgrading their car because the new one gets better gas mileage.
I don't often yell, but please indulge me for a moment. YOU SHOULD NOT UPGRADE YOUR CAR IN ORDER TO GET BETTER GAS MILEAGE!
And, I'll prove it to you.
Listen to this show. And then, download the free calculator I built years ago and plug in your own numbers to see whether you should upgrade or not.
I think you'll be glad you did.
Joshua
Radical Personal Finance