Comment Log Display

The definition of "minimum useful life" defines when a vehicle must
be eliminated from a fleet and is one of the most critical
definitions in the ACF regulation.  It is found in Article 3.4,
Section 2015(b), under paragraphs (A) and (B).

Existing text is confusing and lacks clarity.  Fortunately, there
is a simple fix.   

Replace this text given both paragraphs A and B:  "...model year
that the engine and emissions control system in a vehicle was first
certified for use by CARB or United States Environmental Protection
Agency (U.S.EPA)."

With this text: "...model year of the vehicle's engine, provided
the original engine is still in the vehicle, with the model year as
specified by the family number give on the engine's Emission
Control Label." 

The term "... first certified for use by CARB..." creates all sorts
of confusion.  For example, ARB approves virtually all engine
emission certifications the year before an engine model year for
obvious reasons.  One could construe "first certified" to the year
on CARB EO for a given engine family, which would make all engines
one year older that the actual model year.

Then you have carryover certification where an emission
certification can be used for subsequent model years where an
engine and emission standard do not change.  Does "first certified"
mean the current engine family model year or the year that engine
family was first certified?  This again is really confusing and
could also accelerate the rate at which trucks must be eliminated.

Fortunately, there is super simple solution.  All engines are
required to have a readable Emission Control Label on the engine
that gives the engine's emission family, and the the first
character of the family number specifies the model year of that
engine. 
 
The proposed corrected text replaces highly confusing "first
certified" year with the engine model year as given by the engine's
family number.

I confirmed that the engine family number is the basis for
determining model year with ARB staff (email communication of
8/21/23 with Chris Franceschi, ARB).

Finally, more minor, the use of text "...certified for use by CARB
or United States Environmental Protection Agency (U.S. EPA)" is
unnecessary.  Existing regulations prohibit the use of engines in
vehicles that have not been certified by ARB/EPA.  This text only
serves to make the regulation longer.