Summary
Navistar has petitioned a Federal court to overturn EPA certification of competitors' SCR systems for 2010 NOx compliance. This could signal issues with Navistar's EGR only strategy as they seek to postpone the 2010 deadline.
Analysis
Navistar remains the sole holdout against SCR solutions for 2010 NOx compliance. Major competitors including Volvo, Cummins, and Daimler have all committed to SCR systems, with some including Volvo aggressively marketing the fuel economy advantages vs. EGR. Navistar's petition claims that the EPA improperly allowed SCR systems to incorporate 'ramped shutdown' procedures if the Urea additive tank runs dry. [This controlled ramp down was a key issue that EPA insisted on before agreeing to embrace SCR; the alternative rejected by OEMs was an instantaneous engine shut down upon SCR system failure or Urea outages.]
While Navistar's true motives remain unknown, it appears that they may be uncomfortable with the state of their EGR-only system development this late in the game. If the end game is to win postponement of the 2010 NOx deadline then all OEMs will likely remain on an even keel; if the court [improbably] agrees to reject current SCR certifications then Navistar would trump all with the only viable alternative.
