 The EPA rating for the model year 2011 Volt's tailpipe emissions is 84 grams of CO2 per mile, (52.5 CO2 g / km). Tailpipe emissions for the improved model year 2014 / 15 Volt fell to 81 grams of CO2 per mile, (50.6 CO2 g / km). CO2 emissions are produced by the internal combustion engine in extended-range mode, and only after the Volt's primary battery charge has been depleted. In the other air pollutants category, the Volt rates six out of ten, with ten being best.
