By Tara Weingarten
Despite what automakers would have you believe, fuel efficiency just doesn't come in big packages. Sure, they've overrun the market with big, powerful hybrids that promise to sip rather than guzzle gas. Don't believe the marketing of such "hype-brid" vehicles. The truth: the most fuel-efficient cars are sub-compacts and mid-size vehicles. Here's a look at the 10 most fuel-efficient cars of 2009, plus a look back at the top 10 of 2008.
