As we suspected back in May based on spy shots, Chevrolet is adding a bi-fuel version of the tenth-generation Chevy Impala that can run on both regular gasoline and compressed natural gas (CNG).

The 3.6-liter V-6 Impala will not feature stop-start. The 2015 Impala comes equipped with Chevrolet's 2.5-liter Ecotec four-cylinder engine, which will also offer 22 mpg in the city, and 31 on the ...