[BillK]

It can certainly get out of it's own way. http://www.autocar.co.uk/News/NewsArticle.aspx?AR=245954 and http://green.autoblog.com/2009/12/21/report-mercedes-to-add-four-cylinder-diesel-to-s-class/

The current Mercedes S-class will receive an eco boost with the arrival of a four-cylinder diesel version next year.

Called the 300 CDI, the new model is expected to be powered by the E250 CDI’s 201bhp turbodiesel, pushing out 384lb ft of torque.

Mercedes' R&D boss Thomas Weber admitted that downsizing the S-class diesel was an engineering challenge.

"The issue is NVH [noise, vibration and harshness]," he said. "Getting refinement to S-class levels was difficult and we had to change engine mounts and add body stiffness".

If Autocar is correct, Mercedes-Benz will impose some serious downsizing in the engine compartment of the S-class next year. Six cylinder engines are nothing new in European-spec versions of the big Merc. However, Daimler is now set to install its latest 2.2-liter four cylinder diesel in the S.

In dual turbocharged form, the little oil burner produces 201 hp and an ample 384 pound-feet of torque. The new model is expected to be badged as the S300 CDI and equipped with Mercedes' 7-speed automatic. It should perform reasonably well thanks to its ample torque. The biggest problem is apparently ensuring the smooth operation that S-class drivers expect. Don't count on ever seeing this version come to the U.S., though.