January
31,
2003
Greg
H.
Guinther
Senior
Advisor
Ethyl
Corporation
Ethyl
Petroleum
Additives,
Inc.
P.
O.
Box
2158
Richmond,
VA
23218­
2158
Dear
Mr.
Guinther,

On
January
10,
2003,
you
submitted
to
Joe
Sopata
of
my
staff
a
request
for
an
amendment
to
the
study
protocol
entitled,
"
Fleet
Testing
and
Vehicle
Service
Protocol
for
Ethyl
Corporation's
Alternative
Tier
2
Emission
Characterization
Program".
As
you
know,
the
MMT
Alternative
Tier
2
Health
Effects
Testing
Requirements
require
Agency
approval
of
amendments
to
a
previously
approved
protocol.
This
study
protocol
was
approved
by
the
Agency
on
December
19,
2002.

With
this
amendment,
Ethyl
is
proposing
several
changes
to
the
modified
Standard
Mileage
Accumulation
(
SMA)
vehicle
driving
cycle,
which
was
specified
in
the
May
11,
2000,
MMT
notification
letter
to
Ethyl
to
be
used
for
mileage
accumulation
in
the
emission
characterization
study.
According
to
your
letter,
the
requested
changes
to
cruise
speeds,
number
of
stops,
time
per
stop,
and
acceleration
rates
will
allow
Ethyl's
contractor,
Southwest
Research
Institute
(
SwRI),
to
operate
the
test
vehicles
on
public
roads
in
a
legal
and
safe
manner.

The
SMA
cycle,
which
was
originally
proposed
by
EPA
for
the
mileage
accumulation
requirements
and
which
ultimately
became
the
modified
SMA
through
negotiations
with
Ethyl,
was
designed
to
be
conducted
on
test
tracks,
not
on
public
roads.
We
believe
the
80
mph
speeds
and
wide
open
throttle
(
WOT)
accelerations
simulate
real­
world
driving
and
are
requirements
that
should
be
maintained.
Moreover,
by
following
the
modified
SMA
on
a
test
track,
Ethyl
and
SwRI
will
ensure
that
the
test
vehicles
are
driven
over
the
prescribed
mileage
accumulation
period
in
the
exact
manner
specified
in
the
requirements,
thus
reducing
the
variability
associated
with
driving
on
public
roads.
Therefore,
EPA
is
not
approving
your
request
for
this
amendment.
­
2­

If
you
have
any
questions,
please
contact
Joe
Sopata
of
my
staff
at
(
202)
564­
9034.

Sincerely,

/
s/

Suzanne
Rudzinski
Director
Transportation
and
Regional
Programs
Division
cc:
Monica
Alvarez,
ORD/
OSP
Tim
Backstrom,
OGC
Kevin
Fast,
Hunton
&
Williams
