Diesel and Hybrids Don't Mix

Abstract

Hybrid gasoline–electric and fuel-efficient, low-emission diesels are becoming more popular as these technologies improve and fuel prices increase. In Europe, light-duty diesels are the technology of choice for many consumers (“good, clean, green fun”), while in the United States, diesels face significant regulatory certification hurdles. Moreover, U.S. consumers are more interested in hybrids as a solution for improving fuel efficiency and reducing CO2 emissions. The objective of this paper is to assess U.S. attitudes about hybrid and diesel technologies and behavior of those who purchase these technologies. With survey research, the attitudes of likely diesel and hybrid new car buyers are compared, and the actual driving behavior of new owners of diesels and hybrids is examined. Significant differences were found in both cases. Significant attitudinal differences exist across 20 questions spanning regulatory and environmental issues, with likely hybrid buyers being more environmentally concerned and willing to accept tougher regulatory standards. Hybrid drivers logged fewer annual miles and had a higher percentage of in-city driving. Hybrid buyers generally traded in vehicles that were newer, had better fuel economy, and had smaller engines than did diesel buyers. Both hybrid and diesel drivers saw significant fuel savings with their new vehicles. Because of the bigger improvement from their previous cars and the greater number of miles per year that they drove, however, diesel owners saved more fuel than did new hybrid owners (420 gal per year compared with 275 gal). Acknowledging these differences in public attitudes and behavior is a necessary first step in the development of strategies to reduce mobile source greenhouse gas emissions.