Automaker Rankings 2007

The Environmental Performance of Car Companies

Published Jul 15, 2007


The product planning decisions of a handful of powerful companies have an immense influence on the environmental health of the United States and the world. Automaker Rankings 2007: The Environmental Performance of Car Companies analyzes the bottom-line environmental performance of eight companies, which together account for 96 percent of cars and trucks sold in the United States—the world's largest vehicle market. The analysis uses sales and emissions data from the U.S. Environmental Protection Agency and Department of Transportation for model year 2005. Overall scores are based on a 50/50 weighting of average per-mile emissions of smog-forming and global warming pollutants from each manufacturer's vehicles. The average across all eight automakers is defined as a score of 100 and lower scores indicate less pollution.

All automakers need to do better.

Even the leaders in these rankings should be doing more, especially when it comes to global warming. Conventional technologies can cut global warming emissions by 40 percent; hybrids can reduce emissions even further.

The next time you purchase a car or truck, choose one with the lowest emissions and highest fuel economy that meets your needs and budget. Automakers need a strong signal that consumers care about the environmental impact of their vehicle choices. When all else is equal, use these rankings to reward the best overall automaker.

Key Findings, by Automaker:

Honda retains its title as the Greenest Automaker. Honda has the best smog performance in four out of the five classes of vehicles it produced, and better-than-average global warming scores in every class.

Toyota is nipping at Honda's bumper. Toyota is the only major automaker to consistently improve global warming performance since 2001, thanks to hybrids and better conventional technology.

Hyundai-Kia wins bronze in its debut appearance. Hyundai-Kia's vehicles have better-than-average performance on both smog and global warming pollution.

Nissan slips from its second-place finish in our last ranking. Nissan could have made the top three had it not taken advantage of a loophole that artificially inflates fuel economy ratings for dual-fuel (gasoline/ethanol) vehicles.

Volkswagen's vehicles disappoint. VW cars are some of the dirtiest, when compared with others in the same classes. Cleaner diesel and gasoline vehicles are a key to future success.

Ford is the best of the worst. Ford could have tied for third place on global warming performance if it had matched the reductions in global warming pollutants it has achieved in its European fleet since 1997.

General Motors crawls out of the basement—barely. GM is the top peddler of vehicles rated at 15 mpg or worse in city driving.

DaimlerChrysler is Public Polluter #1, with the worst global warming performance in half the classes in which it produces vehicles. Its small pickup trucks produce more smog than any class of vehicles from any other automaker.

Important lessons

  • Size is no excuse for a dirty fleet. Toyota is a full-line manufacturer, producing vehicles in every class evaluated, yet it nearly ties Honda's global warming score—despite the fact that Honda did not make pickups, large cars, or large SUVs in 2005.
  • Consistency is key. The top two finishers, Honda and Toyota, are the only two automakers with consistently better-than-average performance in both the smog and global warming categories in nearly every vehicle class. In contrast, GM undermines its leadership in some vehicle classes with poor performance elsewhere.
  • Many greener choices are hot sellers. Nearly one of every two vehicles Toyota sold in model year 2005 was the best model in its class in one or more environmental categories. Similarly, one in four of Honda's vehicles and one in five of Hyundai-Kia's were the best models in their classes.

*Scores are proportional to average per-mile emissions of smog and global warming pollution. Lower scores indicate less pollution.

Related resources