DEF requirement

I never would have thought that. Then again the EPA gets mad when anyone can circumvent them.

 

They have been experimenting with EGR free engines using SCR/DEF to eliminate the NOX in the exhaust. The added benefit of no EGR is that the higher initial NOX levels in the exhaust allow for more efficient passive DPF regeneration. Plus non EGR engines are less "sooty" to begin with. Seems the tradeoff of increased DEF consumption for higher mpg (little to no active regeneration) and lower maintenance costs (less DPF wear, no EGR valves to replace) might not be a bad thing.

Volvo has shown that reduced EGR cycles and SCR leading to more passive regeneration can work.

If the EPA would allow EGR free engines I think it could work out nicely.

 

That would be the beauty of a aftermarket ECM code change that just shuts down the EGR function. There would be no evidence of any emissions tampering, as no codes set, and everything could just remain in place. The EGR just would not be activated by the ECM, just remain closed. Did that to a couple of smaller diesels and it worked great. Simple ECM tune and problem solved.

 

Here in Australia Cummins have been selling ISX/Signatures that have No EGR or DFP. Instead have a Common rail Injection system with SCR, & they're going great guns..
http://cummins.com.au/all-products/isxe5/?portfolioID=5270

http://cummins.com.au/wp-content/uploads/2014/02/ISXe5-brochure.pdf

 

@haycarter
The Cummins that is sold in Australia isn't allowed in the USA because it is EURO5.The be on the same level as EPA10 it should be EURO6.

 

Thought the progression was dpf first then dpf + scr. .. never heard of scr only engines. Maybe the aussies have it figured out that the environmental problem lies in the nox, not the soot.

 

Here's the rundown on DEF and DPF.
'06 EU comes out with EURO 5, most trucks being DEF only. (some brands off a EGR with DPF alternative with they later abbandon as the DEF only engines prove to be much better)
'07 EPA 07 comes into play which is a EGR and DPF setup.(the thinking was then, the USA preferred non DEF engines)
'10 EPA 10 arrives.All brands except International with the Maxxforce go to DEF/EGR/DPF engines.
The Maxxforce engines try the MEGR+DPF approach(so no DEF) but that ,as we all know,was a little disaster.
'14 EU goes to EURO 6 which very close to EPA10.Which means that trucks on both sides off the big pond now have basicly the same engines,setup nearly the same.DEF+EGR+DPF.

Australia is lagging behind both the USA/Canada and the EU by several years.

 

They figured out how it should have been done here in the first place.

We started with EGR, which generated more soot. Then we had to have DPF's to capture the soot. Then we moved to SCR to control NOx, which the EGR was supposed to do, Now we still have all three systems as once gooberment mandates something, regardless of whether it works or not, they never rescind it. If we had just started out with SCR, we could have avoided all the nonsense that goes on with emissions now. I was wondering why they didn't go this route back when EGR first showed up.

 

That's correct,We're at least a generation behind the rest of the World with our emission regulations..



I think Cummins didn't start selling the ISXe5 here until sometime in 2013. (But happy to be corrected.)
i do know they're very popular & dealers yards are FULL of.2009-2012 trucks

 

I think DEF/SCR was in the experimental stage in 2003 but EGR was "proven" in automotive applications.