The 2014 Subaru Legacy does better in fuel economy than earlier models, before last year's all-new 2.5-liter four-cylinder engine--which gets its best gas mileage ratings paired to the Lineartronic continuously variable transmission (CVT).
All trim levels with the 2.5i engine and CVT are rated at either 27 mpg combined (24 mpg city, 32 mpg highway). That's a good numbers for an all-wheel-drive mid-size sedan; the Ford Fusion, the only other model even to offer all-wheel drive as an option, is rated at 25 mpg. Choosing the six-speed manual gearbox instead, offered only on the base Legacy model, cuts efficiency to 24 mpg combined (21 mpg city, 28 mpg highway).
The more powerful flat-six 3.6R engine, on the other hand, is one of the thirstiest mid-size sedans even among six-cylinder models. It's rated at just 20 mpg combined (18 mpg city, 25 mpg highway) with the only transmission choice, a five-speed automatic.