How does egr valve reduce combustion temperatures?

The Exhaust Gas Recirculation (EGR) valve reduces combustion temperatures by recirculating a portion of the engine's exhaust gases back into the intake manifold. This process dilutes the air-fuel mixture, lowering the overall oxygen concentration in the combustion chamber. As a result, the peak combustion temperatures decrease, which helps reduce the formation of nitrogen oxides (NOx) and improves overall engine efficiency. By controlling combustion temperatures, the EGR system contributes to lower emissions and enhanced engine performance.