EGR Rate for Tier III Compliance

Approximate Exhaust Gas Recirculation rate required to reduce engine-out NOx to Tier III limit without urea.

EmissionsEGR

Engine-out NOx (no EGR)g/kWhTarget NOx (Tier III)g/kWh

Required NOx reduction: 0.8%

Estimated EGR rate: 30.5%

Changing the inputs requires JavaScript. The calculator above shows its default inputs and result. The formula, symbols, and regulatory sources are shown in the Formula section below.

Formula, assumptions, and limits

\text{EGR}\% \approx 35 \cdot \sqrt{1 - \text{NO}_x^\text{target} / \text{NO}_x^\text{base}}

Symbol	Meaning	Unit
$\text{NO}_x^\text{base}$	Engine-out NOx at 0 % EGR	g/kWh
$\text{NO}_x^\text{target}$	Tier III limit	g/kWh

Source: MAN ES - EGR Technical Paper

In short

Approximate Exhaust Gas Recirculation rate required to reduce engine-out NOx to Tier III limit without urea.

Learn the theory Engine Performance Monitoring: PMI Systems