3
Federal Emission NOx Standards for New Engines
lTier 1 – 3, compliance
met with engine design (mostly)
lTier 4, further 90+%
reduction over Tier 1 – 3
2.6
2011+
hp
> 750
(except
gensets > 900 kW)
0.50
2011+
Gensets
> 900 kW (1207 hp)
0.30
2011+
75
< hp < 750
Emission
Limit, g/bhp-hr
Model
Year
Category
Tier 4 NOx Emission Standards
*Districts in
nonattainment areas (CA, Northeast, ATL) may impose more stringent
standards for new and existing engines.