1
MEMORANDUM
DATE:
June
2,
2004
SUBJECT:
Lubricity
of
Ultra
Low
Sulfur
Diesel
Fuel
FROM:
Melanie
Taylor
and
Brad
Nelson,
Alpha­
Gamma
Technologies,
Inc.

TO:
Sims
Roy,
EPA
OAQPS
ESD
Combustion
Group
The
purpose
of
this
memorandum
is
to
document
information
on
the
issue
of
the
lubricity
of
ultra
low
sulfur
diesel
(
ULSD)
fuel.
Information
in
the
May
2004
EPA
final
rule
for
nonroad
diesel
engines
indicates
that
sulfur
is
a
natural
lubricant
and
when
it
is
removed
from
the
diesel
fuel,
the
fuel
loses
some
of
its
lubricity.
This
will
have
an
effect
on
rotary
and
distributor
type
pumps
used
in
light
and
medium
duty
diesel
engines
because
they
are
completely
fuel
lubricated
(
no
crankcase
oil).
Here
is
an
excerpt
from
the
Regulatory
Impact
Analysis
for
the
final
nonroad
diesel
engine
rule:

"
Engine
manufacturers
depend
on
diesel
fuel
lubricity
properties
to
lubricate
and
protect
moving
parts
within
fuel
pumps
and
injection
systems
for
reliable
performance.
Unit
injector
systems
and
in­
line
pumps,
commonly
used
in
diesel
engines,
are
actuated
by
cams
lubricated
with
crankcase
oil,
and
have
minimal
sensitivity
to
fuel
lubricity.
However,
rotary
and
distributor
type
pumps,
commonly
used
in
light
and
medium­
duty
diesel
engines,
are
completely
fuel
lubricated,
resulting
in
high
sensitivity
to
fuel
lubricity."

There
were
a
few
comments
on
the
proposed
nonroad
diesel
engine
rule
regarding
the
need
for
EPA
to
regulate
the
lubricity
of
ULSD.
However,
many
of
the
oil
companies
do
not
want
this
regulated.
For
now
EPA
is
letting
the
marketplace
designate
what
the
lubricity
of
the
fuel
should
be.
The
Engine
Manufacturers
Association
has
set
some
performance
requirements
for
the
lubricity
of
ULSD
(
3100
g
­
ASTM
D
6078,
450
um
­
ASTM
6079).
Several
oil
companies
are
advertising
the
3100
ULSD
fuel;
the
companies
that
are
meeting
this
lubricity
requirement
are
adding
additives
to
the
fuel
to
achieve
that
lubricity,
such
biodiesel
additives.

For
the
final
nonroad
diesel
engine
rule,
EPA
estimated
that
all
diesel
fuel
meeting
a
15
ppm
sulfur
standard
will
use
lubricity
additives
at
a
cost
of
0.2
cents
per
gallon.
They
estimated
that
the
cost
of
additional
lubricity
additives
for
the
affected
500
ppm
diesel
2
fuel
is
0.01
cents
per
gallon.
The
cost
is
lower
for
500
ppm
fuel
because
the
vast
majority
of
500
ppm
diesel
fuel
does
not
require
the
use
of
lubricity
additives.

It
was
also
estimated
for
the
final
nonroad
diesel
engine
rule
that
reducing
the
sulfur
in
diesel
fuel
would
reduce
engine
wear
and
oil
degradation.
The
largest
impact
will
be
increasing
the
interval
between
oil
changes.
The
savings
per
gallon
is
calculated
to
be
about
3
cents.
Therefore
the
positive
impact
on
engine
wear
would
outweigh
the
cost
for
lubricity
additives.
