Mercedes-Benz to Offer S-Class Model Fitted With Four-Cylinder Turbodiesel Engine

Mercedes-Benz to Offer S-Class Model Fitted With Four-Cylinder Turbodiesel Engine

By Scott Doggett December 16, 2009

The current Mercedes-Benz S-class will receive an eco boost with the arrival of a four-cylinder diesel version next year, Mercedes' R&D boss Thomas Weber said today.

The news comes one day after Daimler told Edmunds.com that a new family of engines will emerge from Mercedes-Benz starting late next year that will rely heavily on turbocharging and direct injection to deliver gains in power, efficiency and CO2 reduction. However, no mention was made of the S-class receiving a four-banger.

Called the 300 CDI, the new model is expected to be powered by the E250 CDI's 201-horsepower turbodiesel engine (left), which generates 384 pound-feet of torque.

Weber said that downsizing the S-class diesel proved to be an engineering challenge, due to the NVH (noise, vibration and harshness) issues. Customers don't accept much NVH in Mercedes' top-of-the-line automobiles.

Mercedes engineers met the challenge by changing engine mounts and adding body stiffness, Weber said.

Daimler decision to put a four-cylinder engine in Mercedes' flagship sedan offers further evidence that the trend for downsizing powertrains includes heavy, premium passenger cars. Audi is also planning to launch a four-cylinder version of its A8 flagship sedan.

Both automakers are no doubt responding in part to stringent upcoming fleet-wide emissions regulations that will be adopted by the European Union.

The new four-cylinder S-Class is likely to prove popular with large fleet operators such as luxury hotels and upscale airport-shuttle businesses due to the model's lower running costs.

Scott Doggett:  is an AutoObserver.com Associate Editor.