What does EGR stand for in the context of engine emissions?

EGR stands for Exhaust Gas Recirculation, and this term refers to a technique used in internal combustion engines to reduce nitrogen oxide (NOx) emissions. The EGR system works by recirculating a portion of the engine's exhaust gas back into the intake manifold, which lowers the combustion temperature. Since NOx emissions are formed at high temperatures, this reduction helps mitigate the formation of these pollutants.

In many modern diesel and gasoline engines, EGR is an important technology that contributes to compliance with environmental regulations by improving overall engine efficiency and emissions performance. The effectiveness of EGR systems depends on careful design and tuning to ensure that the engine maintains appropriate performance while reducing harmful emissions.