Jeffersonville, OH | JAnderson - 1/31/2026 09:54
DEF helps with visible emissions (smoke) since you can run more advanced timing. However the by product of a more efficient hotter burn is increased nox. That’s where the def comes into play, taking care of the nox created by that better/hotter burn.
Yes, this exactly. DEF does nothing for visible emissions, but does allow the engine tuning to be more relaxed to help "tune" out the visible smoke, and clean it up outside of the engine. EGR can also be eliminated, at the expense of using much more DEF...see CNH a few years ago went away from EGR from my understanding, but now guzzles the DEF. I'm not sure that's a bad thing, but AGCO has always tried to keep DEF usage around 5-8% of fuel burn...CNH can be up to like 17% now if memory serves?
I'd rather keep the exhaust gasses OUT of my engine, and the soot out of my oil.
Here's another part of emissions...ALL Engine and Combustion gasses are regulated...so, we have multi-hundred dollar systems to clean the oil vapors out of the blowby so it can be recycled back into the engines...either via a changeable crankcase filter, or a centrifugal type separator that is mostly maintenance free. And a plugged Crankcase filter can cause some SIGNIFICANT oil consumption issues.
So, lots of ways to skin the cat, all effective in some ways, but with trade offs. Each manufacturer finds a way they like to "sell" as the best, and it's up to the end user to decide which approach is best. I actually like DEF within the constraints of emissions standards as the least invasive to engine performance and longevity. Sure there's a few more sensors, but your engine is injecting cleaner air, and using cleaner oil so potentially could last longer before a major component failure....of course on Ag Talk that means it gets spun to costing you MORE to replace sensors over the life of the engine....
Chris |
How modern Diesel Emissions work, paging Silverluv75 and others
