Volvo's 60-plus years of engine research shows the best way to reduce NOx in diesel exhaust is to reduce combustion temperatures in the engine. High combustion temperatures causes the nitrogen in our air to form NOx. Mixing exhaust gas with intake air reduces the amount of oxygen in the engine's cylinders, and lowers combustion temperatures for a cooler, cleaner burn. This technique is called exhaust gas recirculation (EGR).
Click here to see how HEGR works.
Volvo's High-Efficiency EGR for 2007 evolved from the EGR technology used on Volvo engines in North America since 2002. Fuel consumption remains comparable to current levels, and reliability has been proven over four years of production and on highway experience. Volvo's HEGR technology relies on several simple processes.