Many engine manufacturers have chosen to adopt/implement Selective Catalytic Reduction (SCR) technology, which does an adequate job of treating NOx as an exhaust after treatment system. However, they are expensive, plagued with many moving parts, making them susceptible to breaking/failure and requiring parts be fixed or outright replaced. Furthermore the expensive additive Diesel Exhaust Fluid (DEF) is regularly required with SCR systems. An SCR equipped engine can NOT operate without DEF, directly affecting your fleet’s bottom line.
Likewise, In-Cylinder EGR systems often involve additional components not used with SCR technology including: vehicle cooling, air handling systems, coupled with the need for additional turbocharging, decreased engine life, greater fuel consumption and considerably increased costs.