|Average new car and light truck CO2 emissions rate. The sharp drop corresponds with the initiation of CAFE. Click to enlarge. Source: Environmental Defense|
While the average CO2 emissions rate from new vehicles sold in the US fell 3% from 2004 to 2005, it remained up a net 1.5% since 1990, according to a study by Environmental Defense. The report examines the automakers’ overall carbon burden, reflecting the efficiency of vehicles and the carbon intensity of the fuel they run on, as well as new vehicle sales.
The study, Automakers’ Corporate Carbon Burdens, Update for 1990-2005, found that GM, Ford, and DaimlerChrysler all saw a net worsening of their fleet-average CO2 emissions, while Toyota and BMW, in spite of rising light truck sales, cut their average per-vehicle CO2 emissions rate—the only automakers in the US to do so. Nissan had the largest increase in its average CO2 emissions rate due to the combined effect of rising truck fraction and declining truck fuel economy.
The six largest automakers in the US market—GM, Ford, DaimlerChrysler, Toyota, Honda and Nissan—had a 90% market share and accounted for 90% of new fleet carbon burden in 2005. With the exception of Toyota, the average fuel economy for the Big Six automakers decreased from 1990 to 2005.
This trend is largely explained by each firm’s rising truck fraction, resulting in higher fleet average CO2 emissions rates. All automakers significantly expanded their light truck offerings, with the overall light truck fraction growing 22 points over this 16-year period.
Nissan had the largest increase in its average CO2 emissions rate due to the combined effect of rising truck fraction and declining truck fuel economy. Toyota’s 125% increase in new vehicle carbon burden was the largest among the Big Six. It is, however, the only firm among the Big Six that showed improved fuel economy, despite the company’s growing truck fraction. Its carbon burden increase therefore was solely driven by its sales success. The fleet average CO2 emissions rate of both GM and Ford in 2005 was higher than in 1990 due to their higher reliance on trucks. Nevertheless, their new fleet carbon burdens fell below the 1990 levels as both companies saw nearly 10% drops in sales between 1990 and 2005.
Summary findings for the Big Six include:
General Motors. GM’s new fleet average CO2 emissions rate was 3 percent higher in 2005 than it was in 1990, while market share dropped 10 points. GM’s new car fuel economy steadily increased from 2000 through 2005, reaching a value 6.4% higher in 2005 than it was in 1990, as a result of a general increase in the fuel economy of some high-volume models.
However, rising light truck share and flex-fuel vehicle (FFV) credits more than offset the recent increases in the fuel economy of many GM models. Carbon burden fell 6.5% but remained the largest overall.
Ford. Ford’s market share dropped 7 points from 1990 to 2005, leading to a 5.8% drop in carbon burdens. Heavy use of FFV credits caused a 4.3% increase in fleet average CO2 emissions rate, accounting for most of Ford’s total 4.7% increase in emissions rate.
Ford’s car saw its fuel economy increase 1.2 mpg from 2004 to 200, due to market shifts to more efficient vehicles. Ford’s 2005 new fleet average CO2 emissions rate was down 5% from its 2004 peak as a result of lower sales of the most fuel-consuming models.
DaimlerChrysler. As a result of higher truck share and net lower fuel economy, the company’s CO2 emissions rate was up 4.8 percent from 1990 levels, and the worst among all automakers. Market share increased 3 points. The company’s truck share increased by 22 points to reach 72% in 2005, the highest among all automakers.
Truck fleet fuel economy rose 7% from its lowest levels in 1999 but as of 2005 remained down a net 0.4% from its 1990 level.
Toyota. Toyota’s CO2 emissions rate decreased 3% while its market share rose 7 points from 1990 to 2005. Its carbon burden growth—the highest among the Big Six—was due entirely to increased sales.
Despite a 17 point increase in the truck share of its sales, Toyota’s average new fleet CO2 emissions rate dropped as its CAFE levels improved 13.6% for cars and 5% for trucks. Of the 13.6% improvement in Toyota’s average new car fuel economy, 5.4% came from steady fuel economy improvements and strong sales of the Corolla, and 4.2% came from the introduction and growing sales of the Prius.
Honda. A rapidly growing truck fraction pushed Honda’s CO2 emissions rate up 4.4% while its market share gained 1.6 points from 1990 to 2005. Nevertheless, the company remained the fuel economy leader with a combined car and light truck average of 29 mpg. The company’s average new car CO2 emissions rate dropped by 7.6%, corresponding to an 8.2% fuel economy gain over 1990.
Since entering the light truck market in 1997, Honda’s truck share grew at an average 4.5 points per year, reaching 40% in 2005.
Nissan. Growing truck reliance and declining truck fuel economy pushed Nissan’s CO2 emissions rate up 9.2 percent, the most among the Big Six, while the company gained 2 points of market share from 1990 to 2005.
The truck fraction of Nissan’s sales grew from 27% to 42% while its light truck fuel economy dropped 17% between 1990 and 2005. The car-to-truck shift alone accounted for 3.5% of the 9.2% overall growth in Nissan’s CO2 emissions rate from 1990 to 2005.
Nissan was the first overseas automaker to use FFV credits, which inflated its combined CAFE by 0.5 mpg as of 2005 and pushed its CO2 emissions rate 1.8% higher than if the company had achieved the same fuel economy levels without the credits.