Questions about DEF

I think the point of DEF is to neutralize any unburned fuel at the point of exhaust, for lack of a better way to describe it. I have a 2011 Dodge 5500 and it has never had black smoke from the exhaust system, even under a heavy load, and it hasn't ever smelled of burnt diesel. I did have an older diesel pick up that had a real strong burnt diesel smell and that was a few years before DEF was thought up, but I don't know if the DEF or better engine design makes the difference.

 

No the dpf is there to trap the soot every truck since 2007 has to have a dpf to trap the soot. The DEF system (DEF Doser & Catalyst) is injected into the exhaust stream between the dpf and the DEF catalyst. The DEF and the exhaust gas reacts inside the catalyst to reduce the NOx. No 2007 engine or newer is sposed to have soot out the stack. Then you have a cracked dpf.

it smells just like a epa 07 exhaust to me.

International uses heavy egr to reduce the NOx levels inside the engine rather then externally. Trucks with DEF use less egr vs pre 2010 units as they take care of the NOx outside the engine.

 

As much as I hate to say it, your better off with a truck from 2012 onward. Urea injection IS a huge pain, carrying more fluid, BUT, it significantly reduces the amount of exhaust gas the engine has to eat over and over again. I think a engine with urea and a DPF will last substantially longer then a engine from 2008 to 2011 where it is just DPF's.

The engine pays the price, which ultimately translates to the owner! Gotta love this world.

 

You are a year or two off in your statements. 2007 - the end of 2009 Cummins had just a DPF on the aftertreatment. Starting 2010 they use a DPF and SCR (DEF). 2013 will be a 2010 with OBD on it. 2016, guess we will all have to wait to see what happens there.

 

As much as Navistar is touting using "advanced" EGR instead of DEF, they have partnered with a formerly Dutch outfit to create an ammonia based solid cartridge to do what liquid urea does now. They claim that the cartridge would only need to be changed at regular service interval. No spill, no mess. Kinda fits in with their "driver should not worry about the emissions" philosophy. http://www.todaystrucking.com/news.cfm?intDocID=23021

And the saga continues....

 

Came across this Morgan Stanley investor article on the Navistar option. MS is advising investment, so they must think it can compete very well with typical SCR. Kind of a technical read, but worth it.

http://psndealer.com/dealersite/images/tricotruck/morgans4-11.pdf