2012 Nissan Altima 2.5 S 6M/T · Fuel economyCity: 23 MPG · Highway: 31 MPGFull specs Fuel Economy of 2012 Nissan Altima Fuel economy of the 2012 Nissan Altima. 1984 to present Buyer's Guide to Fuel Efficient Cars and Trucks. Estimates of gas mileage, greenhouse gas emissions, safety ratings, and air pollution ratings for new and used cars and trucks. Gas Mileage of 2012 Nissan Altima - Fuel Economy Find a fuel efficient vehicle that meets your needs. Used Car Label; Selling your car? We can help you advertise its mpg. Save Money & Fuel. 2012 Nissan Altima Coupe 4 cyl, 2.5 L, Automatic (AV-S6) Regular Gasoline: View Estimates How can I share my MPG? Combined MPG: 26. combined. city/highway. MPG. City MPG: 23. city.