Why Tata Motors is offering both EGR and SCR in BS IV trucks and buses?

Tata Motors, the country’s largest truck and bus manufacturer, announced readiness of SCR (Selective Catalytic Reduction) and EGR (Exhaust Gas Recirculation) technologies for BSIV compliant engines, powering its range of Commercial Vehicles. Exhaust Gas Recirculation (EGR) technology adopted by Tata Motors in 2010 will continue to power small-to-medium category of commercial vehicles with engine power