Current EPA emissions regulations required further reduction of NOx from diesel engine exhaust. Volvo eliminates NOx with the proven and highly efficient process of SCR: Selective Catalytic Reduction. Volvo engines with SCR technology have near-zero emissions with less fuel consumption.
Volvo further reduces NOx through the aftertreatment of engine exhaust. If NOx gases are selectively eliminated in a downstream aftertreatment chamber, the level of NOx produced by the engine can be significantly higher. This approach allows the engine to be retuned for maximum fuel efficiency.
SCR requires a catalytic converter into which is injected Diesel Exhaust Fluid (DEF). The primary component of DEF is water; the active organic component is urea.