The pressure is on for automakers to offer smaller, more efficient powertrains. In response, Mercedes Benz announced plans for a new four-cylinder diesel engine for the U.S. market. This would be the German automaker’s first four-cylinder offering in the U.S. in several years. Benz says the new engine offers “greater power, greater economy, and greater cleanliness” over virtually all comparably sized gas and diesel-powered systems.

Diesel fans shouldn’t get too excited too soon. Mercedes spokesperson Dan Berilli told that there’s no definitive timeline for bringing the four-cylinder diesel engine to the United States.

The new 2.1-liter engine churns out 204 horsepower and an axle-twisting 368 pound-feet of torque, 25 percent more than its current European-based small diesel. That means a ton of acceleration—roughly on par with six-cylinder high performance cars. Diesels offer a unique combination of performance and efficiency. The new engine could produce fuel economy in the mid-40 mpg range, reducing carbon emissions by more than 10 percent. The smaller engine could also play a role in bringing down other tailpipe emissions that currently prevent diesel vehicles from passing strict standards in California and other states. Mercedes reports that an even smaller, more efficient version of the new engine is in the works, but provided no further details.

Though diesel vehicles continue to suffer from negative perception in the U.S., all indications point to a change of heart in America. J.D. Power, a market research firm, recently predicted that the growth of the diesel vehicle market will outpace U.S. hybrid sales.

Because small, efficient luxury cars are nearly non-existent in the U.S., there is currently no competing vehicle that offers the level of combined performance and fuel economy promised by a four-cylinder Mercedes diesel. The new Mercedes diesel will most probably be implemented in the brand’s entry-point C-Class line—but expect a hefty premium for the diesel powertrain to challenge how much you’re willing to pay for efficiency, performance and style.