A new study by Kelley Blue Book Marketing Research showed that only six percent of new-car shoppers in the United States think that diesel can succeed in becoming a mainstream powertrain for the future. This number pales in comparison to the 40% of consumers who have confidence in hybrids, 20% for hydrogen fuel cell vehicles, and 17% in favor of flexible-fuel systems. The study, above all, proves that perception is king, as nearly half of the shoppers identify diesels as being dirty, noisy, and altogether unrefined. Consumers are also under the false impression that diesel fuel economy is worse than that of conventional gasoline engines.

More than half the vehicles in Europe run on diesel, but consumer interest for the fuel has lagged in the United States, according to the Kelly Blue Book study. On the other hand, the popularity of hybrid technology appears to be growing. The gap in public perception between the two drive systems has widened from 9 points to 17 points in the last month alone. The public sees hybrid technology as a means to a cleaner, greener future, while diesel comes across as backwards and outdated. In fact, today’s hybrids are much cleaner in terms of emissions, but so-called “clean diesel” is in the works.

Mercedes Benz, Audi, Volkswagen, and Jeep will be making a strong push into the market in the coming years. Benz, in particular, is leading this charge with its Bluetec technology. “Many automakers are looking toward diesels as a very workable solution for the future,” said Jack R. Nerad, executive editorial director and executive market analyst for Kelley Blue Book. “But the results of this study should give them pause and make them realize they need to do a better, more thorough job of winning over the American consumer.” A more ambitious campaign to educate consumers could put diesel in a new light, and allow eco-conscious car buyers to overcome negative perceptions of diesel.

In the meantime, hybrids continue to grow in popularity, with 61% of survey respondents saying they are interested in purchasing a gas-electric vehicle. In addition, shoppers considering a hybrid say they are willing to pay an average premium of $3,135 over a gas-powered version of the same vehicle—an increase from $2,645 just one month ago.