We are all curious about what Navistar will do with motor homes.  Here is information about one of the engines that may be available, and how they will meet the 2010 emissions requirements without using the SCR Urea system.   On their website are three videos that look at the two different approaches.  

http://maxxforce.com/2010

As we understand it the MaxxForce 13 Big Bore engine is currently in the testing stage.  You can find out more about this engine here.

http://maxxforce.com/Application/on-highway/Engine/MaxxForce_13_Big_Bore