The Mercedes-Benz name has long been associated with diesel power in the United States, so the concept of an oil-burning E Class is nothing new. What is new-ish, however, is the planned diesel engine downsizing from six cylinders to four.

Mercedes-Benz has previously sold four-cylinder diesels in the U.S. market, namely in cars like the 240D, but that was decades back when a 0 - 60 mph time of ten seconds was considered quick. In recent years, Mercedes has relied on six-cylinder turbodiesels to supply the amount of thrust that U.S. buyers expect.

As Car and Driver reports, that changes for the 2014 model year, when the 3.0-liter turbodiesel V-6 currently used in the E Class is replaced by a 2.1-liter turbodiesel four-cylinder. Output will drop from 210 horsepower and 400 pound feet of torque in current E350 BlueTec models to 190 horsepower and 369 pound feet of torque in upcoming E250 diesel models.

That’s in the ballpark, at least, but the new sedans will surely be slower than the models they’ll replace. The E250 will come only in 4MATIC all-wheel-drive form, which should make it popular in snow belt states regardless of its performance potential; besides, the loss of two cylinders will aid fuel economy, even with AWD thrown into the mix.

Expect to see the same 2.1-liter turbodiesel debut in an M Class SUV, too, although it isn’t clear if such a model will replace the ML350 BlueTec or add to the ML product offerings.

With the introduction of the turbodiesel four, Mercedes is taking a different approach than rivals Audi and BMW, who will continue to offer six-cylinder diesels in mid-size and full-size cars. Only BMW’s 3-Series, which falls into the compact range, will be fitted with a four-cylinder diesel.