Mercedes: New Downsized Engine Specs in the Works

STUTTGART, Germany — Mercedes-Benz is deciding whether a downsized 1.5-/1.6-liter engine it is planning will have three cylinders or four. The new engine is slated for production within two years and will appear in the next-generation C-Class. Before that, it will be fitted to the smaller A- and B-Class series.

The engine will be developed for both north-south and east-west installations and will feature direct injection and turbochargers.

According to Thomas Weber, Mercedes' head of research and passenger-car development, the decision hinges on the cost of refining the more efficient but vibratory three-cylinder versus a smoother, less economical four. Weber believes that the three would require electronic engine mounts and possibly noise cancellation hardware to meet the refinement standards expected of a Mercedes. This engine is also being prepared in diesotto homogeneous charge compression ignition format. This, however, is five years away because more work is needed to refine the necessary variable compression ratio.

Besides this engine, Mercedes is also planning a new modular four-cylinder balance-shaft 2.0-liter for a downsized role in the E-Class, the next-generation S-Class and assorted SUVs. Like the smaller engine, it will feature direct injection and turbocharging and will also be prepared for diesotto operation.

Inside Line says: Mercedes has been slow to direct inject and downsize, but it is clearly catching up and well placed with new diesotto technology. — Richard Bremner, Correspondent