What do the Chevrolet Cruze, Jeep Grand Cherokee and Mazda6 have in common? Generally, not much.
But this year all three vehicles will be offered with optional diesel engines, an unprecedented proliferation of a technology traditionally offered by German automakers.
"There's no shortage of manufacturers investing in [diesel engines]," says Jeremy Acevedo, an industry analyst with Edmunds.com. "They just need to resolve [diesel's] image. For a lot of consumers here in America, they think of loud, gurgling cars pluming smoke."
Making diesel 'clean'
Today's diesel is a far cry from Grandpa's. Billed as "clean" or, as Jeep calls it, "eco," modern diesel fuel is an ultra-low-sulfur formulation with dramatically lower emissions than previous-generation diesels. It also offers a peppier driving experience and up to 35 percent better fuel economy compared with gasoline. The downside: Diesel costs more, for both the vehicle and the fuel.
While diesel cars account for about half of the European market, just 3 percent of new passenger-vehicle sales in the U.S. are diesel, according to Dave Cavano, car buying service manager for the Automobile Club of Southern California in Los Angeles. More than 500 models of gasoline-powered passenger vehicles are available in the U.S. market, he says, compared with 31 diesel vehicles, more than half of which are trucks and vans.
That is changing. This year, Audi, BMW, Chevrolet, Jeep, Mazda, Mercedes-Benz, Porsche and Ram are each introducing new diesel passenger vehicles.
Traditionally, Volkswagen has dominated the market with diesel versions of its Beetle, Jetta and Passat. Audi, which has offered its A3 hatchback and Q7 SUV as diesels, this year is expanding its portfolio to the A6, A7, A8 and Q5.
BMW will offer its 328 and 7-series sedans as diesels. And Porsche, which last year added a diesel version of its Cayenne SUV, will introduce its smaller Cajun SUV as a diesel for the 2014 model year.
The biggest news, however, is that after years of sitting on the sidelines, Japanese and American automakers are introducing small diesel vehicles.
"All the manufacturers in the U.S. are scrambling for ways to improve their [miles per gallon]," Cavano says. "The Germans like diesel. Japanese like hybrids. Chevy's got the Volt. Nissan's got the Leaf. So they're shuffling technology to get to the 54.5-mpg average they need to meet by 2025" under the new fuel economy standard set by the U.S. government last year.
The question is whether U.S. consumers are ready to buy into a technology that costs more.
The price premium for a diesel version of an ordinarily gas-powered car varies by make and model. While the new Mercedes-Benz GLK250 BlueTEC that came on the market in May costs less than a comparable gas model, many diesels come with a $2,000 to $3,000 price premium, according to Edmunds' Acevedo.
The diesel 2013 Jetta costs $2,680 more than a comparably equipped gas Jetta. The price premium for a hybrid version of a gas-powered car is roughly similar.
The Chevrolet Cruze Clean Turbo Diesel, which came out in select U.S. cities in May, will yield the best fuel economy of any non-hybrid car for sale in the U.S., General Motors says, with an EPA-estimated 46 mpg highway. On a single tank of fuel, drivers could travel up to 700 miles.
"The Cruze is the vehicle all eyes are going to be on for the future of this segment, because it's a volume seller from one of the biggest automakers," Acevedo says. The car has a starting price of $24,885, while the gas-powered Cruze, which gets up to 38 mpg, comes with a starting price of $17,130.
"When Audi first came out with the clean diesels, sales were a little tough," says Matt Crandall, general manager of Commonwealth Audi in Santa Ana, Calif., which now sells half of its Q7 SUVs in diesel and half in gasoline. "The more we educate the customer, the more diesels are coming back."
A 'dirty' history
The compression-ignition system used in diesel engines was invented by German engineer Rudolf Diesel in 1893, but it wasn't until the 1930s that automakers Citroen in France and Mercedes-Benz in Germany introduced diesel-powered passenger vehicles.
By the '70s, diesel cars were beginning to make their way to the U.S. market, with Mercedes being the main player. But they fell out of favor, in part because the engines were loud and their emissions sooty. They began to make a comeback in the '90s, when Volkswagen offered its Beetle with a turbocharged direct-injection diesel engine that helped meet U.S. emissions standards.
In 2007, the EPA mandated that 80 percent of diesel fuel refined or imported to the U.S. be ultra-low sulfur, which allows vehicles' catalytic converters and particulate traps to catch the most harmful emissions that result from burning diesel — namely, fine particulate and oxides of nitrogen. Since 2010, all of the diesel available in the U.S. is ultra-low sulfur — a development that has helped prompt the current U.S. diesel resurgence.
"Seven or eight years ago, diesel was a dirty word," says Sean Holman, editor in chief of Diesel Power magazine in El Segundo, Calif. "Nobody wanted to touch it, and then trucks came out with next-generation diesel that was high horsepower, high torque with good fuel economy. Trucks have carried the diesel torch over the past few years, and now you're starting to see a proliferation in the passenger-car market."