Requirement for DEF

[ChasA]

My ISB 6.7 340 HP gets 9.5 to 11 MPG. It's a 2009 with DPF only. I'm happy with it.

[NevadaNick]

The fluid is not introduced to clean the dpf. It is to lower nox emissions. I have had all forms of dsl powered vehicles and will take a dpf/def vehicle anyday over the others because they dont smoke or stink. I have had minor problems with def systems but none on my motorhome. Also you can get Supertech which is Walmart brand def for less Than $8 for 2 1/2 gal jug.

[montyhp]

As someone who just finished an exhaustive search and bought a DP within the last month, here is my perception:

1. Pre emission control (pre DPF) probably pre 2007, are reliable engines. Most of the available engines, both cat and cummins, had long track records.
2. About the time emission controls became required, there were some reported problems with the systems. I received some advice to stay away from year 2007-2009 for that reason, but it wouldn't have stopped me had I found a coach I liked.
3. The most modern engines, say 2013 and newer, do run cleaner and get better fuel economy. Sound like most of the bugs have been worked out.

I ended up with a 2005 simply because it was very clean, well cared for, and had the floor plan we liked. (and we could afford it).

[Dutch Star Don]

The reality is......as time marches on, you'll eventually have to buy a DPF or DEF motor. You can only buy non DPF or DEF engines for so long. DEF isn't any different than when we went to unleaded and were told the sky was falling.

[byoslandry]

Originally Posted by JohnH12

In my quest to get educated about diesel pushers I've been told that a coach made prior to the DEF requirement would be best.
What year did the requirement for DEF start?
Also, any other thoughts from those who have a newer coach requiring DEF would be helpful. I have a 2015 F-350 that requires DEF. It's not a huge issue but it definitely uses more when under a load.
Thanks.

I have a 2004 Newmar Mtn Aire DP 4016 400 HP Cummings ISL Turbo that is pre-DEF and no DFP. The engine is solid at 89,000+ miles, runs great and I get a solid 8 miles per gallon over 30,000 miles traveling 62 mph on cruise. We travel fully loaded and towing a Jeep Liberty with no problems. I do not see any black smoke while accelerating nor do I have any soot on the Jeep.
To me, that DEF is just more money you have to put out to go down the road.
I figure I'll get flamed on this, but hey, I have no problems with my system. I don't always follow the beating drum :-)
Drive safely
Byron

[alpha99]

I love my Cummins DEF 2011 engine. Clean and efficient. 10-11 mpg without a toad, great torque. Wouldn't even consider buying yesterday's technology.

Cheers!