The experienced reviewers at TheCarConnection.com picked the best, most useful information to share regarding the 2009 Chevrolet Cobalt. TheCarConnection.com's editors have also driven the Cobalt and pass along their observations and advice.The Cobalt is Chevrolet’s family of compact coupes and sedans, and it returns for 2009 with only minimal changes. Last year, the big news was the expansion of the high-performance SS to the sedan body style, rather than just the coupe, and mid-year, new more fuel-efficient XFE models joined the lineup.Three trim levels are offered on the 2009 Chevrolet Cobalt: LS, LT, and SS. The first two feature a 2.2-liter four-cylinder engine that produces 155 horsepower, which is up by 7 horsepower compared to 2008. Chevrolet Cobalt SS models are powered by a 2.0-liter turbocharged engine.Chevrolet has applied the efficiency gains of the XFE model to the entire non-SS Cobalt lineup, which means that all models will get a significant fuel economy boost compared to last year's model. Thanks to a taller drive ratio and variable valve timing, the EPA estimates that the 2009 Chevrolet Cobalt will get 37 mpg on the highway and a respectable 25 mpg in the city.