Diesel engine combustion occurs with excess oxygen that produce major pollutants like nitrogen exhaust gas (NOx). NOx is produced when nitrogen and oxygen from air are reacted together in high temperatures during combustion. Therefore lowering the combustion temperature to an optimum level would significantly reduce the amount of NOx. Furthermore, the EGR cooler optimizes the combustion process by lowering the combustion temperature to reduce NOx by recirculating exhaust gas back into the gas intake.

• The EGR cooler was developed to reduce emissions and meet emission regulations. The EGR cooler cools the exhaust gas and recirculates back to gas intake to reduce NOx and particulate matters (PM).