I spoke with my dealer's diesel mechanic about how to break in and maintain my ED and he gave me a lot of good pointers and advice. One thing he did say was to be careful not to let the engine idle for long periods of time. The way I understood it was that the engine needed a lot of heat to burn off the carbon with the new emission standards now required for diesel engines. At idle there is not enough heat to burn these carbon deposits off and they can build up in the emission system in the truck and cause issues. I was reading the manual and it stated that after towing or hauling heavy loads that you should idle the engine for up to 5 minutes. Does anybody have any input on this and can help clarify?