ANN ARBOR, MI – Like other auto makers, Mercedes is turning its eye to smaller engines to meet rigid worldwide fuel economy standards, particularly in the U.S.

The German auto maker also believes it can win over more American customers with diesel powerplants, a senior executive tells WardsAuto here. The biggest challenge is making Americans aware of clean-diesel technology.

Mercedes adds a 4-cyl., 2.2L diesel engine to its ’13 GLK250 cross/utility vehicle, which went on sale last month. A diesel version already sells in Europe.

“The base engine was already fixed, but we had some new applications for the U.S. market,” says Peter Lueckert, director-diesel powertrain development. While there are specific aftertreatments and controllers added to the U.S. engine, “we get very close to the architecture (of) the engine in Europe. There’s nothing special for the U.S. application that we don’t have in Europe.”

The GLK250 diesel makes 200 hp and 360 lb.-ft. (488 Nm) of torque. It features a 2-stage turbocharger comprising a small, high-pressure component and a larger, low-pressure component.

The diesel mates with Mercedes’ 7 G-Tronic automatic transmission, which also debuts in the ’14 Sprinter van later this year. Other diesel-powered Mercedes models already on sale in the U.S. include the M-Class SUV and E350 sedan.

It took about two years to revamp the Euro-spec diesel engine for the U.S. market. Typically, engine development takes up to three years, Lueckert says.

“We see the advantages for the diesel in the U.S. market,” he says. “We know that fuel prices are a little bit higher, but on the other hand I think with the truck range we have…we think it will be a good package for the future.”

Mercedes has long sold diesels in the U.S., but as rival auto makers bring more models to market, customers know the luxury marque’s “tradition” behind the powerplant. Lueckert says the next challenge is more widely compressing engine size with turbocharging technology across Mercedes’ lineup.

“We see the trend going to smaller displacement and smaller cylinder numbers, so the trend from six to four cylinders” is growing, he says. “And I think (downsizing) from eight to six cylinders, that depends a little bit also on the portfolio. I think in the upper class and the very high upper class, they will stay in the 8-cyl. market.

“But in the middle, I think there is a change coming from six to four cylinders, from naturally aspirated to 4-cyl. turbocharged, and especially for the European market,” he says. “We see diesel (expanding) for future (fuel-efficiency) regulation in the U.S. market.

“I think we have the advantage for the future, especially for the higher class.”

afoley@wardsauto.com