Large

The new 2014 Chevrolet Impala is a big five-passenger family sedan, the largest one Chevy sells. While it was launched earlier this year with a 303-horsepower 3.6-liter V-6 engine, it can now also be ordered with a 196-hp, 2.5-liter four-cylinder Ecotec engine that produces 186 lb-ft of torque. That would seem to be a small engine in a big car, but it’s in the service of—naturally—fuel economy. The four-cylinder Impala is rated at 25 mpg (21 mpg city, 31 mpg highway) by the EPA, better than the 22-mpg combined rating of the V-6 version. We got a chance for a quick 20-minute...