For the 2009 model year Toyota had the lowest fleetwide adjusted composite CO2 emissions – and highest fuel economy – performance, followed by Hyundai and Honda, according to the U.S. Environmental Protection Agency.
All but one of the 14 highest-selling manufacturers increased fuel economy, which also reduced CO2 g/mi emission rates since they are inversely related, from MY2008 to MY2009, the last two years for which EPA has definitive data.
Seven manufacturers increased fuel economy by 1 mpg or more.
Chrysler, the one manufacturer that did not improve in MY2009, had the highest CO2 emissions and lowest fuel economy, followed by Daimler and Ford. Both Chrysler and Ford remain heavily dependent on truck and SUV sales, but on average they comply with CAFE law.
Daimler largely sells heavy, powerful luxury cars and simply lets it buyers pays the “gas guzzler” fines that accrue.
Toyota had the biggest improvement in adjusted CO2 and fuel economy performance from MY2008 to MY2009, with a 40 g/mi reduction in fleetwide CO2 emissions (and 2.6 mpg fuel economy improvement), followed by Nissan (29 g/mi reduction in CO2 emissions) and Ford (22 g/mi reduction in CO2 emissions).
EPA says that weight and performance are two of the most important parameters determining a vehicle’s CO2 emissions and fuel economy. All other factors being equal, higher vehicle weight (new options and mandated safety equipment) and faster acceleration both increase a vehicle’s CO2 emissions and decrease fuel economy.
From MY1987 through MY2004, on a fleetwide basis, technology innovation was used “exclusively to support market-driven attributes” other than CO2 emissions and fuel economy, such as vehicle weight, performance, and utility.
Beginning in MY2005, technology has been used to increase both fuel economy, reducing CO2 emissions, and performance, while keeping vehicle weight relatively constant.
