Fitch believes part of the reason for NAV's decision to source away from CMI was due to CMI's decision to use Selective Catalytic Reduction (SCR) technology to comply with 2010 emissions standards (0.2 NOx [g/hp-hr] down from 1.2 in 2007) versus NAV's strategy of relying on Exhaust Gas Recirculation (EGR) technology.