Thinking about Def
I know that this has been proven to be a much more reliable way to manage the emissions systems than on my 09' pre def Cummins for example but what happens in a couple of years when/if the manufacture...
Forum Discussion
Huntindog wrote:BB_TX wrote:I can explain it easy.dreeder wrote:
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which could possibly effect resale of the vehicle down the road due to the additional fuel system. ...........
DEF is not an additional fuel system. The fluid is injected into the exhaust flow at the SCR to reduce pollutants.
DEF explained
There are basically two types of emissions in diesels that are problems.
NoOX, and particlates.
There are two ways to lower the NOX. LOTs of EGR to lower the combustion chamber temps, and lower the NOX formation in the engine (this lowers MPGs, power, and causes things like the EGR cooler and turbo to get choked with soot} or tuning the motor for best performance, then treating the NOX with an after treatment in thje exhaust (SCR). This is what the DEF is for.
Whether DEF is used or not, both systems use a DPF for particulate emissions... The interaction part has to do with THE DEF systems being able to use LESS EGR, so the DPF can go longer between regens.
There is a 3rd way to regulate NOX, and that is to also have a butterfly valve for air and oxygen intake to be cut back or restricted, in conjunction with an EGR. Cut back on the air intake, and you choke the air intake enough to effectively lower the compression ratio and lower the fuel combustion temperatures too, which again reduces NOX production.
A SCR NOX regulated system which treats NOX with diesel exhaust fluid allows the tuners to tune for power and better fuel efficiency, as well as fewer DPF regenerations, which are a huge waste of fuel, and worry about regulating NOX standards further down stream with the Exhaust fluid cleaning things up instead for NOX requirements. Saving a lot more fuel more than offsets cost of DEF, but probably not if the DEF pump and heater system to heat the DEF fluid to the proper operating temps to function,is taken into consideration.
