What is the difference between a 5.9l and 6.7l Cummings engine? What are the pros and cons to the different engines? Also what is the gas mililage for each of the emgines? Thank you.

 

Displacement is the most obvious difference, still pretty much the same engine though. The newer ones are going to have more emissions equipment though... (DEF requirement, etc) I think the older ones actually are better on fuel.......