The call for greener vehicles has resulted to automakers developing cleaner vehicles. Gas electric hybrids like the Toyota Prius are very popular among consumers even if it does not look very cool to many. While Japanese and American automakers are dawdling with these hybrid vehicles, European automakers are tinkering with diesel engines which they claim are much cleaner than diesel engines of the past. In fact, a Volkswagen Polo with a diesel engine is said to be the cleanest car in the United Kingdom - beating the Prius.

In the United States though, Kelley Blue Book's study reported that consumers are still wary about purchasing diesel engined vehicles. Jack Nerad, the executive editorial director for KBB, had this to say according to The Auto Channel: "Many automakers are looking toward diesels as a very workable solution for the future, especially in light of the recently passed energy bill, 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."

"Clearly many Americans still think of the dirty diesels of the past and are not aware of the benefits of new clean-diesel technology. Some manufacturers, such as Volkswagen with its 'Diesolution Tour,' are doing their part to ensure consumers are educated about today's diesels. However, not enough is being done by the auto industry as a whole to help American consumers understand the benefits of modern-day diesel technology," Nerad continued.

Rick Wainschel, vice president of marketing research and brand communications at KBB, added: "As auto manufacturers look toward development of future products and technologies, it's important for them to track, trend and understand current perceptions among in-market new-vehicle shoppers. Knowing where shoppers stand on these issues also can help manufacturers devise successful marketing campaigns to ensure proper education about new technologies and ultimately, success in the sales of their future products."