Diesel Tuner's Blog

5 Q&A's about Diesel Emissions Equipment

Posted by Paul Wilson on Jun 17, 2016 3:42:39 PM


Diesel Emissions Equipment has changed drastically through out the years and it can be very hard to keep up with what the equipment is and how it works. The EGR was introduced in 2004.5, then the DPF in 2007.5, and our current system rolled out in 2011 which includes DEF. This lack of understanding has lead to many myths, half-truths, and misunderstandings of how emissions equipment impacts your diesel pickup.

Here we hope to provide what emissions equipment is, how it works and what do you need to know about it. 

1. What is a DPF? EGR? DEF? DOC? SCR?

  • DPF: Diesel Particulate Filter
    • A filter in the exhaust that captures soot
  • EGR: Exhaust Gas Recirculation
    • Converts exhaust into inert gas used to lower combustion temperatures
  • DEF: Diesel Exhaust Fluid
    • A fluid sprayed in the exhaust to reduce NOx
  • DOC: Diesel Oxidation Catalyst
    • Absorbs hydrocarbon and during regen turns unburnt fuel into heat for DPF
  • SCR: Selective Catalytic Reduction
    • The system in which DEF is sprayed, overall treat NOx emissions

2. Why do we have emissions on diesel pickups?

  • The Clean Air Act was major legislation passed to control air pollution in the United States and grant authority to the EPA
  • According the the EPA, the amount of soot and NOx that diesel trucks produce in normal operation has been categorized as dangerous the environment.

3. How do emissions restrict power and performance?

  • It really depends on your power goals.  Reaching around 500 RWHP with the emissions intact is not a problem. Some have even pushed up into the 600 RWHP range. Going beyond that may be possible in the future, but more technology and custom control will be required.
  • DuramaxTuner.com has produced a recipe for 600+ HP LML Duramax trucks with all emissions intact and CalibratedPower.com has everything you need to make 500+ HP with your 2010 - 2016 Cummins. 
  • With the advances in the size and function of the DPF and regen system there is no longer any reason to install a "free flowing" exhaust. When trucks were all mechanical it made sense to "help them breath", but now so much is electronically controlled that is not a requirement. 

Visit DuramaxTuner.com

4. Does the DPF cost you MPG?

  • No. The fraction of fuel used to raise exhaust gas temperatures during regen is almost not enough to measure. At most a truck may see a 1/2 a mile per gallon change during regen. 
  • The newest generation of trucks are heavier, this is a larger impact on fuel consumption than the DPF. 
  • With the proper tuning, as high as 23 MPG can be achieved with a 2011 + Duramax. 

5. How can you make power with emissions intact?

  • Tuning provides the best bang-for-your-buck!
    • Duramax
    • Cummins
    • Powerstroke
  • Drop in turbo replacement. Shy away from just a wheel change and find an upgraded replacement unit.
  • Lift pump. Help out your high pressure injection pump with a Fass 150 or comparable lift pump.

When emissions first came out on diesel pickups everyone thought the sky was falling. The early generations were unreliable, ineffective, and overall problematic. As the technology has improved so has the functionality and control. Once you better understand how emissions equipment works you can better understand how to work with it.