Diesel-fueled cars are making a comeback, but they are not for everyone. 

Three months ago New Jersey motorist Guy Anello bought a new car. Along with a small but growing number of Americans, he bought a diesel. He says the gas mileage on his diesel Volkswagen Passat is “phenomenal.” He cites an average of 32 miles per gallon for city driving and expects about 46 mpg on the highway.

According to recent sales figures, about 2 percent of all new car sales in the U.S. are diesel. Although diesel fuel costs an average of $4.07 per gallon, about 7 percent  more per gallon than gasoline, diesel vehicles are about 30 percent more efficient. 

Diesel fuel, which was once cheaper than gasoline, is more costly due to federal requirements to produce a cleaner low sulfur fuel, higher taxes, but mainly increased demand. According to oil analyst Tom Kloza of the Oil Price Information Service, “Diesel is more expensive because global demand is a little bit closer to global supply.”  

Nearly half of all cars driven in Europe are powered by diesel. While heavy trucks run almost exclusively on the fuel, most U.S. motorists are not interested in diesel cars. After a brief spike in sales in the 1970s, most Americans rejected diesels as too loud and emitting a bad smell. 

Diesel fans say the current generation of vehicles, although a few thousand dollars more expensive than their gasoline-fueled counterparts, are much more quiet and don't produce foul odors. Foreign car companies importing diesel cars to the United Sates report a dramatic increase in demand. Volkswagen cites a 35 percent sales increase in the last year.

American automakers don't sell diesel cars in the United States, but that will change in 2013 when General Motors plans to offer a diesel version of the Chevy Cruze. Auto analyst Joe Philippi says if the trend continues, diesel sales could have “an impact on, say, hybrid cars to some extent."

Analysts say it's highly unlikely American diesel car sales will ever catch up to Europe. But even if sales triple, diesel fuel prices probably won't be significantly affected. The U.S. currently produces more diesel than it uses, exporting more than a million gallons a day. Is diesel economical right for you? Auto analyst Philippi said potential purchasers should do the math, “Sit down with a calculator and a pad of paper and a pencil.”

Read: Couple squeezes 84 mpg out of diesel Volkswagen Passat