Germany's strongest premium brands in the U.S. sell cars at home that wouldn't fit their image abroad, including tiny city cars and any number of diesels. Nevertheless, the rise of fuel efficiency as a primary buying criterion has reportedly driven the company to consider introducing a four-cylinder diesel engine to North America.

Speaking in front of journalists at the automaker’s local headquarters in New Jersey, Tom Baloga, vice president of engineering for BMW of North America, revealed that a four-cylinder diesel will show up in a range of models in American showrooms in coming years.

"You're going to see it of course in the 3-Series," he said, "and the 5-Series is a good possibility. If the performance [of such an engine] is sufficient in the X3, U.S. customers would likely accept it in the X5 as well."

The engine Baloga was talking about is a 2.0-liter turbodiesel currently sold overseas. However, there will be a number of changes implemented to make it suitable for American tastes. The engine will need to match the “acoustic qualities” of BMW’s six-cylinder engines but perform better in terms of fuel economy and emissions.

Rival Mercedes-Benz has already considered bringing four-cylinder cars, including its new diesels, to the U.S. and Canada in 2010, proving even luxury and premium brands aren't entirely immune from the more mundane considerations of efficiency.

[Edmunds]