It's only taken a decade, but auto manufacturers have realized that diesel vehicles can compete head to head with hybrids in fuel economy in the U.S. market. Diesels were put on hold for the past few years as engineers regrouped to deal with the new "ultra low sulfur diesel" fuel regulations in the U.S., but cleaner diesels are coming back in force.

Popular Mechanics has a video sneak peek at the 2008 Volkswagen Diesel Jetta. The sedan will get more than 50 miles per gallon on the highway (where diesels shine) and 40+ mpg in the city. VW also has a diesel version of its SUV in the works for 2009-10.

Nissan is readying a diesel model of its Titan pickup truck for 2009, and a diesel Maxima sedan by 2010.

Diesels will be as clean or cleaner than some hybrids, and will be a viable option as diesel fuel is cheaper than gasoline in much of the country. Their arrival should spell more competitive pricing as well, which is good news for consumers.