Despite increases in the price of gas in the last few months, it appears that fewer and fewer consumers are putting vehicles with hybrid powertrains on their shopping list. According to industry experts J.D. Power, consumers with interested in hybrids dropped from 57 percent in 2006 to 50 percent for the early summer months in '07, a significant figure for such a short period of time.

The study, which was conducted during May and June '06 and again in the same period of '07, found that, despite gas still hovering around $3.00 U.S. per gallon, consumer interest in hybrids has dropped.

The study did find that more and more consumers are putting diesel cars on their lists, however. In '06, just 12 percent of buyers were looking at diesels; now, nearly twice as many, 23 percent, have diesels on their shopping lists. Interestingly, the number of diesel cars on the new car market has dropped since then. The Volkswagen Jetta TDI, one of the biggest volume diesel cars in the U.S., didn't meet 2007 regulations. Volkswagen will be introducing a 50-state diesel car shortly. Jeep offered a diesel Liberty in '06; it didn't meet the '07 regulations, but a diesel Grand Cherokee with a Mercedes-Benz-developed engine was released in Spring '07.

Are diesels more fuel efficient that petrol engines? yes. So why can't they be used for hybrid technology as well? I don't understand why more people aren't talking about and pushing the idea of diesel hybrids. IMO, you would get the best of both worlds - excellent fuel efficiency & massive amounts of torque.