Sandip Chattaraj
Department of Mechanical Engineering, Dnyandeo Yashwantrao Patil (D Y Patil) International University, Akurdi, 411044, Pune, Maharashtra, India ADM Group, Montreal Business Center, Baner, 411045, Pune, Maharashtra, India.

Swapnil Bhurat
Department of Mechanical Engineering, Dnyandeo Yashwantrao Patil (D Y Patil) International University, Akurdi, 411044, Pune, Maharashtra, India.

Sangeeta Pant
Symbiosis Institute of Technology Pune, Symbiosis International (Deemed University), 412115, Pune, Maharashtra, India.

DOI https://doi.org/10.33889/IJMEMS.2026.11.3.054

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Abstract

Sustainable transportation has led to a surge in zero-carbon engine technologies. The environmental impact of internal combustion (IC) engines has become a crucial concern. To meet Euro 7 emission norms and fuel economy, the Exhaust Gas Recirculation (EGR) system technology has emerged as a promising technology for enhancing engine efficiency and reducing nitrogen oxide (NOx) emissions. This paper covers the following essential aspects. The Euro 7 emission norms are more stringent than Euro 6, by 35-56 percent for NOx and 13-27 percent for particulate matter (PM). EGR rate can vary between 10 percent and 60 percent, depending on the emission-reduction strategy adopted by the engine manufacturer. Almost 70 percent of diesel vehicles adopted EGR technology over other technologies. The market trend is shifting toward hybrid EGR-plus-SCR and EGR-plus-LNT technologies. Cooled EGR technology appears to be a standard adaptation for gasoline engines rather than an optional technology for fuel economy, with 2-10 percent fuel economy gains depending on the engine manufacturer's adaptation. Based on comprehensive technological advances over the past two decades in diesel engines, the study proposed that cooled EGR is a promising technology for NOx reduction up to 80 percent, hinting at the future of automotive technology to meet Euro7 emission norms.

Keywords- Exhaust gas recirculation cooler, Euro 7, Emission, Nitrogen oxide emission, Green hydrogen, Hybrid, Bharat stage 7, Gasoline direct injection, Particulate matter.

Citation

Chattaraj, S., Bhurat, S., & Pant, S. (2026). EGR Cooler Technology for Euro 7 Compliance and Fuel Economy: A Review from SI Engines to Hybrid and Hydrogen Powertrains. International Journal of Mathematical, Engineering and Management Sciences, 11(3), 1314-1345. https://doi.org/10.33889/IJMEMS.2026.11.3.054.