Emissions Durability Period and Air
Index Information On Your Engine
Emissions Label
Engines that are certified to meet the California Air
Resources Board (CARB) Tier 2 Emission Standards must
display information regarding the Emissions Durability Period
and Air Index.The engine manufacturer makes this
information available to the consumer on emission labels.
The Emissions Durability Period describes the number of
hours of actual running time for which the engine is certified
to be emissions compliant, assuming proper maintenance in
accordance with the Operating & Maintenance Instructions.
The following categories are used:
Moderate: Engine is certified to be emission compliant for
125 hours of actual engine running time.
Intermediate: Engine is certified to be emission compliant
for 250 hours of actual engine running time.
Extended: Engine is certified to be emission compliant for
500 hours of actual engine running time.
For example, a typical walk-behind lawn mower is used 20 to
25 hours per year.Therefore, the Emissions Durability
Period of an engine with an intermediate rating would
equate to 10 to 12 years.
The Air Index is a calculated number describing the relative
level of emissions for a specific engine family.The lower the
Air Index, the cleaner the engine.This information is
displayed in graphical form on the emissions label.
Emissions Compliance Period On
Engine Emissions Compliance
Label
After July 1, 2000 certain Briggs & Stratton engines will be
certified to meet the United States Environmental Protection
Agency (USEPA) Phase 2 emission standards. For phase 2
certified engines, the Emissions Compliance Period referred to
on the Emissions Compliance label indicates the number of
operating hours for which the engine has been shown to meet
Federal emission requirements. For engines less than 225 cc
displacement, Category C = 125 hours, B = 250 hours and A =
500 hours. For engines of 225 cc or more, Category C = 250
hours, B = 500 hours and A = 1000 hours.
This engine has an intermediate rating with and Air Index of
2.The EPA Emissions compliance period is Category B.The
displacement of these engines is 206 cc.
Below is a generic representation of the emission label
typically found on a certified engine.
EMISSIONS
25