The Honda Civic has always been one of the most fuel-efficient vehicles in its class, and the latest 2012 Civic is no exception. With EPA city ratings of 28 or 29 in the city and up to 41 on the highway, the Civic actually gets better mileage than the smaller Honda Fit.
Actually, there is one exception in the lineup: The Civic Si, with its larger 2.4-liter engine and lower gear ratios, doesn't do much better on gas than a mid-size V-6 sedan. If gas mileage is a priority, you might want to reconsider.
For maximum gas mileage, though, there's the Civic Hybrid model, now in its third generation and reworked to be even more fuel-efficient than before. Its EPA ratings are 44 mpg on both city and highway cycles, and for 2012, it provides more boost from a larger 15-kilowatt (20-hp) electric motor.
Nearly all Civics come with an 'Econ' button on the left side of the instrument panel; the mode, when engaged, provides a gentler throttle setting, along with more conservative transmission behavior and accessory operation. It even softens cruise-control responsiveness to save fuel.
In real-world driving, from our observations, the Civic Hybrid is very impressive. Over nearly 400 miles of driving—leaving the car mostly in 'Econ' mode—we averaged more than 45 mpg. As for the other models, we managed to about match the EPA city number in mostly city driving.