ON THE

                      ON THE
                   OCTOBER 1980

                          IMPORTANT NOTICE

     EPA has recently decided to delay the implementation of more
stringent low-altitude standards for light-duty trucks (LDTs) from
1983 to 1984.  Since the high-altitude LOT standards are based on
the levels of the applicable low-altitude standards, this decision
also affects the stringency of the 1983 high-altitude standards.
This Summary and Analysis of Comments was completed prior to the
postponement; therefore, the analyses presented here were done
under the assumption that LDTs would comply with more stringent
standards in 1983.   Although the LOT high-altitude standards which
were originally proposed for 1982 will now also be applicable in
1983, the conclusions contained in this document remain valid and
EPA has chosen not  to revise the analyses in order to prevent an
unnecessary delay in promulgating the interim high-altitude stan-

        Commenters and Speakers on the
Proposed High-Altitude Motor Vehicle Standards
       Congressman Alan Simpson
       Congressman Gary Hart
       Recreation Vehicle Industry Association
       Ford Motor Company
       General Motors Corporation
       Motor Vehicle Manufacturers Association
       Chrysler Corporation
       Renault, USA
       Colorado Department of Highways
       Subaru of America, Inc.
       Colorado Open Space Council
       National Automobile Dealers Association
       Welling Ford Sales, Inc.
       Nissan Motor Company
       Jaguar Rover Triumph, Inc.
       U.S. Technical Research Company
       Colorado Department of Health
       Toyota Motor Company
       Mr. B. Jay Welling
       South Dakota Department of Health
       Congressman Timothy Wirth
       Congresswoman Patricia Schroeder
       Volkswagen of America, Inc.
       American Motors Corporation
       International Harvester
       Mr. Steve Schweitzberger
       Mr. Richard Becker
       Utah Department of Health
       Honda Motor Company
       Ray Shellabarger, Chevrolet, Inc.
       Zeiger Enterprises

                         Table of Contents
Issues                                                       Page
Important Notice.
Commenters and Speakers on the
Proposed High-Altitude Motor Vehicle Standards	ii

Table of Contents	iii

A.   Standards	    1

B.   Technical Feasibility	13

C.   Adequacy of Existing High-Altitude Test facilities  ...   35

D.   Selective Enforcement Auditing 	   47

E.   High-Altitude Certification	57

F.   Number of Certification Vehicles 	   73

G.   Economic Impact	78

H.   Environmental Impact 	   91

I.   Leadtime	101

J.   Exemptions	110

K.   Model Availability 	  120

L.   EPA's Legal Authority	123

M.   Parameter Adjustment 	  133

N.   Fuel Economy	137

A.   Issue:  Standards

Summary of Issue

     1.    Light-Duty Vehicle.   EPA derived the light-duty vehicle
standard  (which  called  for  a  maximum 90  percent  reduction from
a 1970 high altitude baseline fleet) from  a limited  sample of
high mileage  vehicles tested by  the  MVMA.   Because  this limited
and older sample  could not be construed  to have equal  results
with  a  true  1970  high-altitude  baseline,  certain"  controversial
mathematical procedures  were used   on  this data  to  obtain  an
estimate  of  the  true baseline  figure.   Also, EPA did not propose
any high-altitude  counterpart  to  the   1982  CO and NOx waivers for
low altitude.

     2.    Light-Duty Truck.   EPA derived the  light-duty  truck
standard  beginning  with  1969 low-altitude fleet  data  and used the
MVMA light-duty vehicle  test data to  estimate the altitude effect.
While  this approach  was  recognized to  be  far  from ideal,  it  seemed
the only  rational method given  the dearth  of  data available  at the

Summary of Comments

     The  industry  collectively  disputed the procedures used  in the
derivation of the LDV and  LDT  standards.   The criticism  of the LDV
derivation involved  the  question of the proper manipulation  of the
data;  the criticism of the LDT derivation  also included a challenge
of the propriety of the assorted data  which were used.

Major  Subissues

     1.    Light-Duty Vehicle.  Most of  the manufacturers who
commented  on  the subject  supported  the position of  the MVMA who
criticized  EPA's  "misapplication" of their  data.    Specifically,
MVMA  argued that  their fleet  was statistically representative
(something about which EPA had earlier doubts), but  that  EPA  should
have multiplied  the  ratio of  the high-to-low altitude  emissions
found  from  the  test data by the low-altitude baseline which  hope-
fully  would  provide  an  estimate of  the  true high-altitude  base-
line.  A 90  percent reduction  then yields  the high-altitude  stan-
dard.   Rather,  EPA "erroneously" added the absolute  difference of
the high-  and low-altitude data to the true .low-altitude baseline.

     MVMA, as well  as several  manufacturers  (AMC, Toyota,  Peugeot,
and Jaguar),  also  pointed  out   that EPA had not proposed  any CO or
NOx waiver  standards to  parallel  those permitted by  the  CAA.  Not
to do  so would contravene the  act.    Peugeot  also  complained that
the evaporative emission standard  was too tough and  that  the MVMA
fleet  itself  was unrepresentative because  it contained no  diesel

     2.    Light-Duty Truck.   Again the industry  as a whole  echoed

the MVMA  criticisms.   MVMA had four major  complaints  with  the  EPA
methodology.   First,  as  with  the LDV,  they felt that EPA should
have used  a ratio approach rather  than  an  absolute difference  in
extrapolating the  low-altitude baseline  to  high  altitude.   Second,
they objected to EPA's use of a 1969 instead of 1970  baseline fleet
which was  not  even representative of  the  LDT sizes.   Third,  they
objected to the use of the LDV data from their study  to extrapolate
the  baseline  from  low altitude  to  high altitude.    Fourth,  they
capped  off their  criticism by  claiming that  EPA's  formula  gave
nonsensical results.

     Ford  and  Chrysler went on to  recommend that EPA  abandon  the
LDT standard until such  time as it had a representative 1970 fleet
from  which to  obtain high- and low-altitude comparison data.
Chrysler  also  questioned if EPA's  use of  LDV data  to derive  the
LDT standard was  legal  in view of the  U.S.  Court of  Appeals ruling
in  International Harvester vs.  Ruckelshaus in which the court
forbad EPA from  treating LDT  the  same as LDV  and  thus giving  them
the same standards.

Analysis of Comments

     1.    Light-Duty Vehicle.  Certain criticisms  can  be  dismissed
at  once;  others  require greater analysis.    First, Peugeot  claimed
that the evaporative emission standard was  "too tough."  Perhaps it
is  for  Peugeot,  but  it  is  nonetheless  correct.   The MVMA study
verified  the EPA theoretical  prediction for  the  evaporative emis-
sion baseline at high altitudel/ and subsequently supported  the  2.6
g/test SHED requirement.  With EPA's  prediction  thus substantiated
by  an experimental  program  conducted  by  industry,  little  attention
need be paid to Peugeot unsupported claim.

     Peugeot also claimed  that  the 1970 baseline  fleet that  was
used was  not  representative because  it  did  not contain a diesel
vehicle.   This  is  wrong.  In  1970,  less  than one-tenth  of  one
percent of the  LDVs  sold were  diesel.   Hence,  they  represent  a
negligible  influence on the baseline and even one vehicle  in  the
MVMA fleet of 25 would grossly over-represent diesels.

     Several manufacturers  and  MVMA pointed out EPA's  failure  to
provide CO and NOx waiver standards  for  1982 to  parallel  those  for
the statutory low-altitude standards.  This  is  an  excellent point.
This final rule will include waiver standards.  The exact levels of
the standards will  be  discussed  along with EPA's rebuttal  to  the
industry  objections  to  EPA's  approach  to   the  derivation  of  the

     For  the LDV standard,  the single remaining complaint  is  that
the EPA applied  an  additive correction for  altitude  to the recog-
nized 1970 fleet baseline  rather than  applying a  multiplicative
factor to get an  estimate of the  1970  high-altitude  baseline which
is  not available from data.   The Clean Air  Act  (202(f))  requires
that  the  high-altitude  emissions reduction from  the 1970 high-

altitude  emission  level be  no  greater than  that  required at  low
altitude.   Inasmuch  as the  corresponding  low-altitude  regulations
for  LDV (202(b))  require  a 90 percent  reduction  from the 1970
baseline,  this  same  reduction (or less) is also required  for high
altitude  LDV  standards.  The basic  information which  is  required
is a high-altitude emissions baseline  from a  certification  fleet
of 1970 vehicles  using the 1975 FTP.   Such information is not

     However,  data do  exist which  allow  the high-altitude  base-
line  to be estimated  and  thus  the  standards  to  be  found.   These
estimates  can  be  obtained  in two ways:   1)  by obtaining a  well-
tuned 1970 vehicle high-altitude baseline  and  applying  a 90 percent
reduction  to  these emissions to  establish the 1982-83  standards,
and  2)  by generating a high-to-low  altitude correlation and  using
this  to adjust  the generally recognized low-altitude baseline to a
high-altitude  equivalent.   The  former approach is most  similar  to
the  ideal  method  if confidence can  be  gained that the  test  fleet
(1)  is  representative,  (2)  is in  compliance with  the  corresponding
1970  low-altitude  standards, (3)  properly accounts  for  deteriora-
tion,  and  (4)   is  tested  with the relevant (1975) FTP.    If  these
conditions cannot be met,  then  the latter  procedure may offer
greater  confidence.

     These alternatives were first discussed by Miriam  Torres in a
memorandum to  R. Maxwell  on July  24,  1978.*   On the basis of  the
data available to her at  the  time, she  recommended  the latter
approach which, as  she saw it,  involved the use of  a ratio of
high-to-low  altitude  emission performance which  would be  applied
to  the   low-altitude baseline to  establish a  high altitude  base-
line.    There  are other  possibilities,  of course,  including  the
procedure  used  by  EPA  in  determining the  proposed standards.  Ms.
Torres'  preference for  the   high-to-low altitude  correlation  rests
largely in the lack of confidence that  the high-altitude data
available  then  was adequate and appropriate (being based  upon  the
obsolete  1970  FTP  and  untuned,  less than  new  condition  vehicles):

     The  most   important  reason  for preferring  the  ratio method
     (i.e., a  high-to-low altitude  correlation)  is that it is not
     necessary  to  determine what   high-altitude  emission  levels
     would  correspond  to the  low-altitude  emissions  that were
     determined  for  the 1970 model  year baseline under  the CVS-CH
     procedure.  This correspondence  would be  necessary  in  order  to
     meet  the   Clean  Air  Act requirement that  the  high-altitude
     emissions   reduction be no greater than  that  required at  low
     altitude.     No study has been conducted  where the  same set of
*    This document was referred to several times  in  the  comments as
evidence that EPA officially  supported a  ratio approach.   However,
a memorandum  from a  branch  member  to the  branch  chief does not
constitute agency policy.

      vehicles was  tested in both high- and low-altitude cities  and,
      therefore,  there is no assurance that a proportional emissions
      reduction would be achieved (emphasis added).

      With the advent of  the  recent MVMA data,  this concern  is
 largely overcome if that  data  can  be accepted (1) as  representa-
 tive,  (2) in compliance with  the corresponding  low-altitude stan-
 dards,  (3)  with deterioration properly accounted  for, and  (4)
 with  the relevant  (1975)  FTP  used.   Indeed  MVMA presents  strong
 arguments  that their  data  are  indeed  valid  and representative.   If
 so,  then a 90 percent reduction would lead to high-altitude stan-
 dards  of 0.3 gm/mile HC and 2.1 gm/mile CO,  which are  far below the
 proposed values.   Hence,  the  proposed standards apparently  repre-
 sent  a  less  severe  criterion  than  the corresponding  low-altitude
 standard.    The  uncertainties   in  the baseline  nonetheless weigh
 against  the imposition  of these  values.   For  instance,  MVMA
 attempted  to validate the  test data by comparing  the  low-altitude
 portion  with the  original  low-altitude  certification  data.    This
 led  to  only marginal agreement  with  HC,  the  two numbers  being about
 one  standard deviation  apart.    Thus, the MVMA  HC result appears
 genuinely low at least at low altitude for which  the comparison was
 made.   But  if  the  high-altitude  data  is considered to  be a roughly
 correct baseline  (but  because of  small  sample size,  partially
 deteriorated or worn condition  of the  vehicles, etc., an  element  of
 uncertainty exists), how then to  adjust  the above  result in a
 reasonable  manner, recognizing  that  excessive  conservation  will
 result  in a standard too lax?

     The MVMA data can  be  utilized  to adjust  the baseline using a
 correlation method (method  2).   The idea here is to find  a correc-
 tion  for altitude (i.e.,   the  correlation)  and apply  it  to  the
 generally accepted  low-altitude  values  which  are  higher than  the
 MVMA values.  This would result in a new baseline for high altitude
 that is above the raw MVMA  value.

     One  correlation method, and the  one that was used by EPA  in
 deriving  the  proposed  standards, applies an  additive  constant  to
 the  generally  recognized  low-altitude  baseline  values  (the  1970
 standards corrected to account  for the effects of the current,  1975
 FTP)  to arrive  at the  high-altitude  baseline.   This  additive
 constant  is  obtained  from  the difference  in  the  high-  and  low-
 altitude data.

     The  other  correlation method is  the use  of ratios  (high-
 altitude data/low-altitude  data) as  advocated  by Miriam Torres  and
MVMA.   MVMA supported  their  position by heavy reference  to  Ms.
 Torres' work.  Ms.  Torres,  in turn,  supported her position with two
 observations:  (1)  ratios  vary less than  the  emissions  themselves
 and (2) deterioration and maladjustment  have less effect on ratios
 than on  emissions.  The  second  of  these  is irrelevant to the MVMA
 data  as  that fleet was carefully  tuned and,  indeed,  partially
 renovated.   The  first proves  incorrect  for the MVMA  data  as  the
 following summary of that data  shows.

  f rejected
     EPA    77.9p
     MVMA   64.4
      EPA   34
                                                                    Characteristic Curve
                                                     Emissions  =  43.9
                                                (Rich)             14.7 (Ideal)

                                                      Air/Fuel Ratio
                *  Necessarily equal to the MVMA emissions consequence (= 64.4 - 20.5 or 43.9 gm/mile) if the
                EPA altitude effect is taken to be equal to the MVMA altitude effect (very nearly true for the
                16 percent change due to altitude over the plausible range of air/fuel ratios).

                                                /Std. Deviationx
       Method                Mean	              Mean
                         HC          CO           HC          CO

1.   Ratio               1.60        3.47          0.19        0.45

2.   High-altitude       4.47       64.45          0.21        0.37
    absolute level

3.   Low-altitude        2.851      20.45          0.24        0.40
    absolute level

     The differences in  the  normalized  standard deviations do not
appear  significant.   The ratio method  operates with a marginally
better  variation in HC, but  worse variation in  CO  than does the
absolute difference method which utilizes the data in rows 2  and  3
in  the  table.   Thus,  while these  two methods  for correlation
obviously result in different  high-altitude baselines and, hence,
standards,   they  cannot  so easily be criticized  on  the  basis of

     Finally, MVMA  submitted  to EPA some  late  data  (having  asked
for an  extension of the comment period) which by the ratio method
again,  they  attempt to demonstrate how  actual, more or less cur-
rently  controlled vehicles  (1976,  1978)  change with  altitude
differently  than the EPA high-altitude  standards  require them to
do.  EPA finds these data unpersuasive.   The  issue is to determine
a  1970  baseline and,  therefore,  it is   necessary  to see how 1970
vehicles vary with  altitude,  since vehicles produced in different
model years  have  different  emission characteristics.    In  fact,
these MVMA  data are also  irrelevant with  regard  to the issue of
technical  ability  to  achieve  the standards  because  the vehicles
tested were under no requirement to reduce  high-altitude emissions.
The 1977 model year was specifically avoided.

     EPA's decision  to  use the  absolute  difference method is  based
upon  a  recognition  that a  multiplicative approach, such  as the
ratio method, tends  to  exaggerate  an otherwise modest error in the
high-to-low  altitude correlation which might appear as a result of
the  use of  a fairly small sample (25   vehicles).   The  additive
approach ought to avoid this  concern.

     A  further  argument, based upon a  consideration of the  chem-
istry involved,  independently supports  the  additive  approach.  The
argument will  be   presented for  CO,  the  pollutant of  greatest
concern  to   the  manufacturers;  it is equally valid  for  HC.   The
slope of CO  vs.  air/fuel ratio is very  linear on the rich side of
stoichiometry,  the  typical  running regime of  weakly   controlled
vehicles (i.e.,  1970).  This  is shown in Figure 1.   The  generally
recognized CO emissions factor  for the   1970  low-altitude fleet is
34  gm/mile.   The MVMA  fleet  obtained 20.5  gm/mile at low altitude
and 64.4 gm/mile at  high altitude.   These  are also  shown  in Figure

1.  The air/fuel ratios between the MVMA data points must differ by
16 percent  due  to the altitude effect  on  air  density.   The actual
low  altitude  air/fuel ratios  for the  general  fleet and  the  MVMA
fleet are not known; however, the MVMA  fleet as seen in Figure 1 is
necessarily  more  lean  than  the  general  fleet  at  each  altitude.

     From the figure, it is apparent that a change in stoichiometry
due  to altitude  leads  to  a nearly constant change in the emissions
regardless  of the  initial  value.   That  is,  for  a  given altitude
effect (i.e., change in air/fuel ratio), there is a constant change
in  the  emissions  consequence,  regardless  of  the  starting  point.
Thus, the emissions effect is clearly additive.

     Criticism that EPA failed to account for the CO and NOx waiver
portions  of the  standards  is well  founded.   Again,  the question
arises how  best  to account  for  this.   At  low altitude  the waiver
granted  under 202(b)(5)  permits  the governing  CO  standard  to  go
from 3.4 gm/mile to 7.0 gm/mile during MY 1981-82.  Once again, the
derivation  of a  high-altitude analogue requires  a decision on the
choice of methodology.   Similar  reasoning to the preceeding  dic-
tates the utilization  of  the absolute  difference approach.   Hence,
the  CO waiver standard  should be  7.8 + (7.0 - 3.4) = 11.4 gm/mile,
or,  rounding to two significant figures, 11  gm/mile.  The NOx
waiver  from 1.0  gm/mile  to  1.5  gm/mile  for  MY  1981-1984  diesel
vehicles which may be  granted under  202(b)(6)  of the Clean Air Act
as  amended  (1977)  will also be  available  for high-altitude vehi-
cles.   Even  though NOx  emissions  for a particular vehicle are
generally lower  at high altitudes,  the  Clean  Air Act prohibits EPA
from  establishing  high-altitude  standards  which are  numerically
lower than  corresponding  low-altitude  standards.    The  diesel NOx
waivers have  been determined on  an  engine family basis,  and  thus
any  engine  family which  is granted  the NOx waiver at low altitude
will also have the waiver at high altitude.

     2.     Light-Duty Truck.   MVMA's complaints  about the proposed
LDT  standard  fall  into two  general categories:   first,  they chal-
lenge the equation, claiming by example that it gives "nonsensical"
results.    Thus, no matter how  excellent the  data may be,  the
standard would be  incorrect,  they insist.  Second,  they point out
several   alleged  deficiencies  in  the data  base  that  results  from
EPA's use of  certain  assumptions  and approximations  they claim are
inappropriate or outright wrong.

     Taking  these  points  one  at  a  time,  EPA rejects MVMA's  con-
tention   that  the  equation  used  to  derive the  standards  is  non-
sensical.  The behavior of the equation demonstrated by MVMA in its
examples  is consistent and rational.   One example:*

     EPA  proposed  the  following  equation  for  calculation  of the
     LDT standard at altitude.
*     From submittal  at  the time of the Public  Hearing,  March 30,


Standard      _    (LDT baseline at   +  Change in LDVv  x  LPT low-altitude  std.
at Altitude       •  low altitude          Emissions       LDT low altitude

     When  this  equation  is used  to  calculate  the  1982 HC  high-
     altitude  standard,  the following  result,  which  was also shown
     in the NPRM,  is  obtained:

     High-Altitude HC Standard = (8 + 1.6) -~j— = 2.0 g/mi

     Now,  consider what happens  if the value of  the  low-altitude
     baseline, (i.e., 8 g/mi  HC)   is,  in  fact,  high  since  it  was
     obtained with  vehicles which  were  both uncontrolled  and
     heavier  than average  for vehicles in the  present  LDT  weight
     class.   EPA  recognized  that  this  was, in  fact,  likely to be
     the case.    Suppose the high-altitude  baseline value  were  5
     g/mi  HC  instead  of  8  g/mi  HC.   Then,  substituting this
     value  in  the  equation  in the EPA methodology gives the follow-
     ing result:

     High-Altitude HC Standard = (5 + 1.6) ^- = 2.24 g/mi

     This is indeed  surprising.   Contrary  to  the EPA reasoning  and
     expectations, a  high value for the low-altitude baseline gives
     a more stringent rather  than a less  stringent high altitude
     emission   standard.    Obviously,  the  methodology contains  a

     Deeper consideration  of this  example  will  corroborate  the
result and  serve  to  support  the  equation.  The  significant point
to  observe is  that  the stringency of  the  standard (i.e.,  the
fractional   reduction from  the  baseline)  changes  as  the  baseline
changes.  Thus,  if the low-altitude baseline is 5 (as in the  second
scenario), then  the standard  (1.7)  represents  something less
stringent  than in the  first  scenario.   Because the standard is  a
proportional  standard  (i.e.,  it requires  the  same percentage
reduction   from  the  appropriate  baseline  at both high and  low
altitude),   this less stringent  low-altitude standard  yields  also  a
proportionally less  strict  high-altitude standard,  too.

     This  does, however, disprove  the  logic  behind EPA's assump-
tion,  namely  that while  the two  pieces  of available data were
not  directly  applicable,   their  errors would be  in  the  opposite
direction  and,  therefore,  would tend  to cancel, hopefully to
large  degree.    It is evident that the use of this  equation shows
that as  the baseline is reduced,  the  standard  increases  slowly to
reflect  the fact  that the  stringency of the standard (low-altitude
standard/low-altitude base) is  lessening  at a slightly faster rate
than the high-altitude baseline  is  dropping.   This is  due  to  the
additive nature  of  the  altitude  correction.  A multiplicative
altitude correction  would not display this behavior, as pointed  out


by MVMA,  but that  cannot  be construed  as  an endorsement of  that
approach.   EPA remains  convinced  that the  additive  nature of
altitude effects is correct  and amply defended its position  in  the
LDV discussion.

     However,  because  the errors  in  the data base  compound  each
other  rather than  cancel,  EPA must  take  care  to  see that these
errors are minimized, if not removed altogether.   A  careful  recon-
sideration of the overall derivation  of  the  standards provides  some
useful insight'  into  the  problem at hand.  The basic  equation  upon
which  the standards are based is:

u- u Ai^-t j  o..  j  j _ /high-altitude..    /1-fractional  reduction     N
High-Altitude Standard = (  ?   , .      )  x  (c    .,   ,    ., .    ,     ,  .)
                            baseline         from  the  baseline demanded

Guidelines  for  the numbers to be used in  the  terms within the
parentheses  are found  in section  202(f)(2) of the CAA(1977):

     "Any  such  future  regulation  applicable  to  high-altitude
     vehicles  or  engines  shall  not require  a percentage of  reduc-
     tion  in the  emissions  of  such vehicles  which is  greater  than
     the  required  percentage of reduction  in emissions  from motor
     vehicles  as set  forth  in  section  202(b)-    This  percentage
     reduction  shall  be  determined by comparing  any  proposed
     high-altitude  emission  standards to  high-altitude   emissions
     from vehicles manufactured during model  year 1970."

     Section  202(b) refers to  the  LDV standards  for  1982 and  1983
among  other  years.  The LDV  standards for these  years  reflect  a 90
percent reduction  from  the baseline  year 1970 which was also  the
basis  for  the high-altitude LDV  standards.   Thus,   the  fractional
reduction  permitted  by  the  CAA to be used  for  the  derivation of
these  LOT standards is  also 90  percent,  not the  various  lesser
reductions  used in the  derivation  of the  proposed standards.
Section 202(f)(2)  also requires  this  90 percent  reduction  to be
taken  from a  1970 baseline.

     The 1970 model year saw the present  LOT  class divided  into  two
groups:   those  up  to  6,000 Ibs. GVW which were  classified as  LDVs
and subject  to those standards and those of 6,000-8,500 Ibs.   GVW
which  were classified as HDTs and  subject to  those standards.   The
lighter weight group constituted 84 percent of sal'es,  the heavier,
16 percent  of sales.   Thus, a  composite baseline of  these  groups
can be expressed by:

Low-Altitude Baseline = 0.16(LDV baseline) +  0.84(HDV baseline)

However,  this is not useful because the  1970  HDV  baseline  cannot be
approximated  by  its standard and converted to an equivalent  number
for the current  test procedure  based  upon the generally  recognized
conversion  factors.2/    Unfortunately,  the  HDV   standard  was   not
based  upon  the LDV cycle  and,  in fact,  is  not  even  expressed in
terms of gm/mi.  Thus,  there  is  no recognized conversion.

     Barring the use  of a  1970  low-altitude baseline, the available
1969 low-altitude baseline must  be  considered.  This will be highly
favorable to the industry  as  the HDVs  (i.e.,  those 6,000-8,500 Ibs.
GVW) are totally uncontrolled and the LDVs (i.e., trucks less than
6,000 Ibs.  GVW)  are  less controlled  than in  1970.   Furthermore,
because 1969 LDV data (or  appropriate  standards)  are not available,
it becomes necessary  to put  this 1969 baseline completely in terms
of  the  6,000-8,500  Ibs.  GVW vehicles,  thus  raising  the baseline
further.  The values  for  this baseline used  in the NPRM were found
to be erroneous and were later  corrected by retesting.  The correct
values are:3_/

     HC     6.46 gm/mi
     CO    76.02 gm/mi

These values are higher by an unknown, but nonetheless, substantial
amount  than  the proper  1970   baseline  fleet  of sales-weighted
0-8,500 Ib. GVW LDTs.

     The correct  low-altitude baseline,  as  referenced above, must
be  corrected  to  a high-altitude baseline, so  to it  must be added
the high-altitude  increment  (following the LDV procedure which was
amply justified in the  earlier  discussion).   For  the LDT increment,
EPA used the LDV increment because  no  proper  LDT  high-altitude data
existed then, nor exists now.  While EPA  recognized that this
value was  probably low, it  concluded  that the value cannot be too
erroneous because the increase  in  emissions  with altitude is
largely due  to  the enriching of the  fuel-air  mixture of the car-
buretor  and  is  not  significantly  affected   by  the  differences in
weight  or  road  load  between  the two categories of vehicles.  What
little  error  there may be (a value too low  and  therefore unfavor-
able  to industry) will have a  smaller effect  than  the advantage
given to industry  by the  use of the uncontrolled 1969 low-altitude
baseline.  Also,  in  its final submittal, MVMA presented additional
data  which  followed,  to  a  degree,  the format of  its earlier LDV
study.  It presented the  results of 5 LDTs (all  GM) tested at both
low  and high altitude  with  which  it  concluded that  EPA grossly
underestimated the degradation  of emissions with altitude by using
the LDV  data  additively.   It did this by comparing those high-to-
low  altitude  ratios  to  that implicit in  the  proposed standards.
EPA  rejects  the data  and,  hence, the  argument.   The data  are
irrelevant because they  come  from vehicles  designed  to  meet  the
1978  California  standards.   The behavior with  altitude  of these
strongly  controlled,  vehicles is  irrelevant  to  the  estimation of
altitude effects  in  a  very  weakly controlled 1970 baseline  fleet:
variation  with  altitude  could  be  vastly different due  to vastly
different control technologies.   Furthermore, EPA has  already
rejected the  use  of  the ratio method and, hence, finds an argument
based upon the  comparison of two computed ratios to be pointless.

     Thus, the high-altitude  baseline  is  taken  to be:

     HC    6.5+1.6=8.1 gm/mi
     CO    76 + 44 =  120 gm/mi


Taking then  10  percent  of this baseline, as permitted by  Sections
202(f)(2) and 202(b)  of the CAA(1977),  yields potential'standards
for  1982-83  of 0.8  gm/mi for  HC and  12 gm/mi for CO.   These
values still  are higher  than  that allowed because of the  generous
baseline used  (the only  supportable  one,  however,  at this  time).
They are, however,  less  than  the 1982 and 1983  standards  proposed
by EPA on January  24,  1980  and debated here.   Unfortunately, while
the  CAA  permits these lower standards,  to  use them at this point
would suggest a reproposal  which would  delay  the truck standards,
at least to  1983.   EPA judges that it would be  preferable  from  an
air-  quality  perspective  to  promulgate the proposed rules,  thereby
obtaining   some control,  although  not  the  maximum,   in 1982.

Recommendat ion

     The standards  are  acceptable as  proposed  except for  the need
to include waiver  standards for  CO and  NOx.   The waiver  standards
should be,  for  qualifying vehicles, CO = 11 gms/mile  and  NOx =1.5
gms/ mile.



I/   Michael  W.  Leifertnan,  "Effect  of  Altitude  on Non-Controlled
~~    Evaporative  Emissions  from  Gasoline-Fueled  Vehicles,"  U.S.
     Environmental Protection  Agency, Emission Control Technology
     Division, Ann Arbor, Michigan, January,  1979.

2/   Thomas  A.  Huls,  "Evolution  of  Federal  Light-Duty Mass  Emis-
~~    sions  Regulations,"  Society of Automotive  Engineers   paper
     730554,  1973.

3/   Larry  Ragsdale,  "Final  1969 LOT Baseline Emission Results,"
~~    U.S. EPA, Memorandum to the  Record, March  21,  1980.

B.   Issue:  Technical Feasibility

Summary of Issue

     In  the NPRM,  EPA predicted  that  it  would  be  technically
feasible for all  light-duty vehicles and light-duty trucks  to
comply with the proposed high-altitude  standards.

Summary of Comments

     Most  of  the manufacturers  commended that  the  proposed  stan-
dards were not  feasible for the 1982 model year, for either light-
duty vehicles or light-duty trucks.

Major Subissues

     1.   Technical Feasibility  for Gasoline-Fueled Light-Duty

     2.   Technical Feasibility  for Gasoline-Fueled Light-Duty

     3.   Technical  Feasibility  for Diesel-Fueled Light-Duty
Vehicles and Trucks Analysis of  Comments.

Analysis of Comments

     1 .    Technical  Feasibility for  Light-Duty  Vehicles.  The
light-duty vehicle  high-altitude standards which EPA proposed, and
which EPA  is promulgating  in the final rule,  are 0.57  g/mi HC, 7.8
g/mi CO,  and  1.0 g/mi NOx.  There are several exceptions  to  these
standards, however.   Several  engine  families  have  received  CO
waivers  for  the  1982  model year at  low altitude.   Accordingly,
these engine  families will only have  to meet  a high-altitude  CO
standard  of  11 g/mi  in  1982  rather  than 7.8 g/mi.   These  engine
families are listed in Table 1.

     In  addition, American Motors must  only  comply to a  2.0  g/mi
low-altitude NOx standard  in  1982;  accordingly, American  Motors
will have  a  2.0 g/mi high-altitude  NOx  standard in 1982  as  well.
Finally,  several  light-duty diesel  engine families have  received
low-altitude NOx waivers for 1982;  these engine families will have
high-altitude  NOx  standards  equivalent  to  the low-altitude NOx
standard  levels  for 1982.    These  engine families  and their  1982
waiver levels are listed in Table 2.

     The analysis of  the  feasibility of the  1982-83 high-altitude
interim  standards has not been an  easy  task.   Many  of the  manu-
facturers  submitted  little or no high-altitude test  data  for the
emission  control  systems   they  plan  to  use  in  the 1982  and  1983
model years.   Many manufacturers  did not even submit relevant
low-altitude data  or  data  which  would be helpful  in determining
appropriate high-altitude/low-altitude  emission  factors.   Due  to


                    Table 1

Engines with CO Waivers for the 1982 Model Year

Manufacturer                      Engine

American Motors                   258 CID

Chrysler                          1.7 L
                                  3.7 L
                                  5.2 L-4V

General Motors                    2.8 L/173 CID-2V
                                  3.8 L/231 CID-2V

Jaguar-Rover-Triumph              215 CID
                                  326 CID

Toyota                            88.6 CID


                              Table 2

                  Diesel Engines with NOx Waivers


General Motors


for the 1982 Model Year
Engine Family
2.4 L
3.0 L-NA
3.0 L-TC
5.7 L
2.3 L-TC-XD2S
1.6 L-NA-2375IW
2.0 L-NA-3250IW
1.6 L-TC-2375IW
1.6 L-TC-2625IW
2.0 L-TC-3250IW
2.4 L-NA
1982 NOx Standard
1.5 •

the  scarcity  of relevant  data,  our technical  evaluation  has not
been based  on  as  broad a data base as EPA  would  prefer  to use in
its technical assessments.

     Nevertheless,  despite  the  limitations imposed by the lack of a
broad  data  base,   EPA's  technical  staff  has performed  a  compre-
hensive  feasibility analysis for all  the manufacturers  which
commented on the  technical  feasibility of the proposed standards.
It  is  entitled "Technical  Feasibility of  the  Proposed  1982-1983
High  Altitude  Standards  for  Light-Duty  Vehicles  and  Light-Duty
Trucks" by  Robert  J. Bruetsch, John  J.  McFadden,  and William M.
Pidgeon,  dated August,  1980.  This Technical Report has been placed
in  the docket and  is  publicly available  as CTAB/TA/80-3.   This
chapter will  only summarize the  methodology and results  of this
analysis,  anyone wishing  further  detail should consult  the  above

     The basic methodology used by EPA's technical staff  to deter-
mine  the  feasibility of  the high-altitude  standards was  to make
pass/fail  judgments  on  the manufacturers'   technical  ability  to
comply with the standards.   The following four methods were used in
making the pass/fail  judgments.

     1.    The  first method used  high-altitude data  for  emission
control systems which  the EPA technical staff  predicted would be
used by  the manufacturers   for the  1982-1983 model years.   These
data were averaged for each  engine  group.   The  averages  were then
multiplied  by  deterioration factors  (dfs)   taken  from 1981  cer-
tification data for that manufacturer.  The calculated results were
then compared to the  standards.

     2.   The  second method utilized  1981  certification  test data
from emission  data vehicles and  deterioration  factors  from 1981
certification durability vehicles.   Factors  were developed to
reflect the  change  in  emissions  based on  tests  at high  and low
altitudes.  These three data sets  were multiplied  to calculate the
predicted high-altitude emissions at 50,000 miles.   These predicted
levels were then compared  to the standards.

     3.   The  third method  is  the same as method 2, but instead of
emission  data  vehicle results,  4,000-mile extrapolated  emis-
sion  results  from the  1981 certification durability vehicles
were  substituted.    Therefore,  the dfs  and 4,000-mile  emissions
were from the same  vehicles.

     4.    The  fourth  method utilized  technical knowledge of the
emission  control  system's  ability to compensate  for altitude.
This was  used  for situations  where data were  unavailable  or  to
specifically address  issues  raised  by  the  particular manufacturer
being evaluated.

     Before  using  any of the four  methods  it was necessary for EPA
to predict the  engine displacements  and emission control technology

to  be used  by  each manufacturer.   In most cases  these  judgments
were  based  on  information  from four  sources;  a)  1981  certification
data,  b)  CO waiver  applications,  c) testimony from  the  1982-1983
high-altitude hearings, and comments on the 1982-1983  high-altitude
NPRM,  and d) written responses to questions  from  the  high-altitude
hearing panel.   Of  these  four  sources,  only  the  1981  certification
data  were   not  yet   publicly available.   While certification  data
were  considered  in  this  analysis,  data which  were unavailable  from
the  other   sources  cannot  be  divulged  in our analysis.   In  such
cases, the  engine displacement was replaced by a  letter  designation
and the emission control  system description was replaced by a
numbe r.

     Where  the  manufacturer  has  historically  grouped  more  than one
engine displacement  in an engine family, or where  the  EPA  technical
staff  judged that several engine  displacements were  equipped with
similar emission control systems, these engines were evaluated as a
group in order  to  expedite the analysis.   Several engine dis-
placements were available  with more  than  one emission control
system.  The prime concern was to evaluate whether the manufacturer
had  the  technology  for each engine group to comply with  the stan-
dards.  It  was  not  possible  for  this analysis  to  determine whether
every combination  of engine  displacement  and emission control
system which the manufacturer  had available could comply with the
standards.  Therefore, in most cases, only one such combination was

     In methods  1 thru 3,  four different  data  sets  were used.  The
1981  certification  dfs comprised  one  of the  data  sets.   The dfs
were  taken  from  the EPA Certification Status Report of  July 11,
1980  and  averaged  for each engine  group.   Deterioration factors
were  only  calculated for vehicles with at least  three,valid tests
and  a 15,000-mile test.    Vehicles  which  were line crossing* were
not  included in the  average.

     Because manufacturers have historically  generated dfs  for more
engine families  than  they  actually market, a  second set of dfs was
also used.   In many cases, a manufacturer will actually market only
those  engine families whose durability vehicles achieved the  lowest
deterioration  factors.   In  order  to reflect these practices,  EPA
selected the durability data within  the engine group  which had the
best  combination of results  when considered with  the  altitude
factors  and the  4,000-mile  data.   The  best combination results
would  give  the engine  group  the  highest probability of passing the
standards.    These  deterioration  factors  are referred  to  as  the
"lowest dfs."    It  should be  noted  that  the  dfs  from  the  single
durability  vehicle  with  the best  combination results was chosen,
*     A  durability  vehicle  is considered to be line crossing when
the results  from one or more  valid  tests are above the  1982-1983
model year  low-altitude  standards,  and either the extrapolated 4K
or  extrapolated  50K  results  are  also above  the  same  standards.

and not  the lowest  dfs from  among all  the  individual  vehicles
within the engine group.  The selected vehicle's  dfs  were  then used
in the calculations.

     The  second  data set  used in methods 1,  2  and 3  were low
mileage test results.  In method 1, low mileage  high-altitude test
results were used along with certification dfs in order to predict
50,000-mile  emissions  at  high  altitude.   Due to  the scarcity of
high-altitude test data, method 1 was  infrequently used.

     In method 2, the  low mileage test results were  the 4,000-mile
certification results  from  1981 emission  data  vehicles  which had
been assigned a  certification  disposition of  passing.  The  cutoff
date for  this data was July 15, 1980 for  light-duty  vehicles, and
July 23, 1980 for light-duty trucks.   These data  were  then averaged
for each engine group.

     Because the  1981  Federal  CO standard for light-duty vehicles
is  more  stringent than  the California  standard,  where   possible,
only emission  data  vehicles  calibrated  for sale  in 49-states or
50-states  were  included in  4,000  test averages.   For light-duty
trucks, the  opposite is true.   The California  standards  are more
stringent.  In this case California  trucks and 50-state trucks were
used in the 4,000-mile test  averages.

     Durability vehicles were  selected  by emission control  system
only.  Sales location  was not  a criterion  in their selection.  All
durability vehicles with at  least three valid tests,  a 15,000-mile
test, and which were not considered to be  line crossing,  were used
for  the df  averages  and  the  extrapolated 4,000-mile  results.

     The  third  data  set  was  used  when  4,000-mile  emission data
vehicle test  results with  a  certification disposition of passing
were not  available.   Instead,  extrapolated 4,000-mile results from
the durability vehicles within  the EPA designated engine group were
averaged and used.   Only  those vehicles  which  met the criteria to
be  included in  the  df average were  included  in the 4,000-mile
average.    These  data were gathered on July  17,  1980, and used in
method 3.

     The fourth  set  of data used in  methods 2  and 3 were factors
reflecting the change in emissions for a vehicle  tested at high and
low altitudes.   The  primary  reason  for emissions problems at high
altitude is  the  fact that as  altitude  increases,  the air density
decreases.   This causes  the air/fuel ratio of  non-altitude com-
pensated  fuel  metering systems  to  enrich  as  altitude increases.
Attendant  with richer mixtures are increases  in HC  and  CO emis-
sions.   Therefore, in order  to  prevent or  limit increases  in  HC and
CO  emissions  with increases  in altitude, the air/fuel  ratio en-
richment  has  to  be  limited,  and/or  the  emission  control   after-
treatment  system  has  to  be  modified to increase  its  effectiveness
in converting the increased  engine-out  emissions.   The methods of
achieving  those  objectives  vary with  the  type  of emission control

system.    Multiplicative high-altitude  to  low-altitude  emission
factors were  developed  for  four generic emission control systems:

     1.    Pulse  or  aspirator type  air  injection systems  (PAIR),
oxidation catalysts (OC), and  exhaust gas  recirculation (EGR)
with altitude compensating carburetors.

     2.   Air  injection  systems  using air  pumps  (AIR), OC,  and EGR
with altitude compensating carburetors.

     3.     Feedback  carburation (FBC),  three-way catalysts (3W),
AIR, OC, and EGR.

     4.    Closed-loop electronic  fuel  injection (CLEFl),  3W,  and

These factors were developed from light-duty vehicle data submitted
by  various  manufacturers.   They  are summarized  in Table  3.

     For  further  detail  on the  calculation of  these  factors,  see
the aforementioned EPA Technical Report  CTAB/TA/80-3.

     With this basic methodology, we will now  briefly  summarize the
analyses for each light-duty vehicle manufacturer.

     American Motors -  In  their final  written  comments,  American
Motors(AMC) did not "dispute  the basic  feasibility of the proposed
standards."   They considered  the  issue  more  one of  leadtime  and
resource prioritization.   Table  4 summarizes EPA's technical
analysis of AMC's position.   Based  on the above quote  from AMC, the
advanced nature  of  the GM  emission  control system  that  AMC uses,
and the dearth of any data  to  the  contrary, EPA  concludes that AMC
will be able to comply with  the high-altitude  standards.

     Chrysler  -  Table  5  summarizes EPA's  technical feasibility
analysis for Chrysler.   Based  on the conclusions  reached in Table 5
and EPA's  latest  discussions  with  Chrysler representatives, it is
clear that Chrysler will  have  no  problems meeting the  high-altitude
standards in 1982-1983.

     Ford - Table 6 summarizes EPA's technical feasibility analysis
for Ford.  As  can be seen  from Table 6, EPA  cannot show that Ford
can comply with the high-altitude standards.   This is  primarily due
to a lack of relevant data.  However, the  following statement from
a letter  from D.A.  Jensen  of Ford  to EPA  (dated April  30, 1980)
clarifies Ford's current  position:

     "The data  in  Table  2 indicates that Ford's  current 'altitude
     compensated electronic  calibrations' are  capable of achieving
     the standards EPA has  proposed  at altitude.   The test  results
     on Vehicle #4  indicate that less costly 'aneroid compensated
     nonelectronic calibrations also comply'."

                                   Table 3

                    High-Altitude to Low-Altitude Emission
                  Factors for Genenic Emission Control Systems
Control System

aneroid carburetor

aneroid carburetor

aneroid carburetor




Data Base
Chrysler, Ford
All Others
All Others


                              Table 4

            Technical Feasibility for American Motors
Engine    Year
         Emission  Control
151 CID  1982-83    FBC/AIR/3W/OC/EGR
258 CID   1982
258 CID
Not Enough

Not Enough
                                  Method  1 Analysis
                                  Using GM Data and
                                  Lowest  DFs.
                              Table 5

                 Technical Feasibility for Chrysler
1.7 L
2.2 L
2.6 L
3.7 L
Emission Control
                                                       Method 2 Analysis

                                                       Method 2 Analysis

                                                       Method 2 Analysis

                                                       Method 2 Analysis

                                      Table 6

                          Technical Feasibility for Ford

Engine        Year      Emission Control System   Conclusion         Basis	

1.3/1.6 L    1982-83    Open-loop/AIR/3W/OC/EGR  Not enough data

2.3 L        1982-83    FBC/AIR/3W/OC/EGR or     Pass             Method 3 analysis
                        Open-loop/AIR/3W/OC/EGR  Not enough data

2.3 L/TC     1982       FBC/AIR/3W/OC/EGR or     Not enough data
                        Open-loop/AIR/3W/OC/EGR  Not enough data
             1983       EFI                      Not enough data

3.3 L        1982-83    FBC/AIR/3W/OC/EGR or     Not enough data
                        Open-loop/AIR/3W/OC/EGR  Not enough data
                                                 Pass             Method 2 analysis

4.2/5.0/     1982-83    Open-loop/AIR/3W/OC/EGR  Not enough data

5.8L                    FBC/AIR/3W/OC/EGR        Fail (NOx)       Method 1 analysis
                        CFI/AIR/3W/OC/EGR        Pass             Method 1 analysis


Thus ,  there seems  to  be  little  question that Ford  can  meet the
high-altitude standards.

     General Motors - Table  7  summarizes  EPA's analysis of General
Motors' technical position.

     GM  did not  make  technical  feasibility an  issue  in  their
comments  on the NPRM.   They provided more extensive  high-altitude
test  data  than any  other manufacturer.   This allowed  EPA to use
method  1  analyses, which  give conclusions  with  higher confidence
than methods 2, 3,  or 4.   As Table 7 shows, we have concluded that
most of  the engine  groups  for  which  GM Provided high-altitude test
data  will  comply  with  the  high-altitude standards.   Two factors
must  be noted  with respect to Table 7.  First,  there  are four
engine groups  for which  we could not show  compliance.  GM did
provide high-altitude data on  these vehicles, and EPA's  technical
analsyis  showed these vehicles to fail  the high-altitude standards.
But  in each of these four instances,  there  have been extenuating
circumstances  that  lead us  to  the  conclusion  that  we do  not have
sufficient  information  to make a  conclusion  (for  example,  in the
case  of  the 4.4-liter  engine  GM  has  expanded  the  feedback car-
buret ion  range  of  authority and  they expect  the  engine  to meet
high-altitude requirements).  Secondly, the technical  staff did not
attempt  to  analyze every  engine displacement  and emission control
system  which GM might use  for the 1982-83 model years.   GM char-
acterized  the  data  they presented as   "representing the  broad
spectrum  of General Motors passenger cars," and EPA concluded that
analyses covering these data would  be representative  of GM's
capabilities in complying with the high-altitude standards,  based
on Table  7, then,  we conclude that GM will be able to comply with
the high—altitude standards.

     Honda  - We have  assumed that Honda  will  market engines A,  B,
and  C  with  emission  control systems 1,  2,  and  3  for model  years
1982 and  1983.   Honda has used an "air  jet controller"  (aneroid)
modification to  the  carburetor assembly for air/fuel ratio control
on high-altitude vehicles  since 1977.  The potential  effectiveness
of this control, as demonstrated on the 1.8-liter, 49-state vehicle
adjusted  for deterioration, is shown in Table  8.

     It can be seen that the high-altitude emissions in Table 8 are
well  under the standards.   The  air  jet control  technology  is
considered to  be  transferable to other Honda  engines  allowing
compliance  with the 1982-83 high-altitude  standards.

     Jaguar-Rover-Triumph - Table  9 summarizes Jaguar-Rover-Triumph
(JTR) technical position.

     JRT  submitted no high-altitude data  for any of their engines.
This has  made  our technical analysis very difficult.   JRT uses  a
Lucas/Bosch  electronically-controlled fuel njection  system on its
vehicles.   It   is  an air  flow sensitive, pulsed,  port   injection
system with one  injector  per engine cylinder.   The air/fuel ratio

Engine     Year

1.6 L     1982-83

2.5 L     1982-83

3.8 L     1982-83

4.3 L     1982-83

4.4 L     1982-83

4.9 L     1982-83

4.9 L     1982-83

4.9 L/TC  1982-83

5.0/5.7L  1982-83

6.0 L     1982-83
                Table 7

Technical Feasibility for General Motors

Emission Control System    Conclusion









Not enough data



Not enough data


Method 1 analysis
using lowest dfs.

Method 1 analysis

Method 1 analysis

Method 1 analysis

Method 1 analysis
Not enough data       —

Pass             Method 1 analysis

Not enough data       —

                              Table  8

            Honda High-Altitude Emission Characteristics
                       Using Air Jet Controller
1.8 L 49-states
1.8 L 49-states
Test Location
Low altitude
High altitude*
Low altitude
High altiude*
     With Air Jet Controller
                              Table 9

           Technical Feasibility for Jaguar-Rover-Triumph


122 CID
215 CID
258 CID
Emission Control
Not enough data
Not enough data
Method 3
                       or CLEFI/3W

326 CID   1982-83      CLEFI/3W/3W     Not enough data

is controlled near  stoichiometry  by the use of  oxygen  sensors in
the exhaust down pipes.   Bosch has  claimed that this control system
is self-compensating up to 8,200  feet.   Thus,  despite the lack of
relevant data, we have  concluded  that JRT will  be  able to comply
with the high-altitude  standards.

     Nissan  - Table  10 summarizes our  technical  analysis  for

     Based on  the  technical analysis,  EPA concludes  that Nissan
will be able to comply  with  the high-altitude standards.

     Peugeot - EPA assumes  that Peugeot will market  engine A with
emission control system 5 in model years 1982 and 1983.   Data
were  not available  to fully  utilize methods  1,  2, and  3.   We
did have some limited data analysis of this along with engineering
judgment led  us  to  predict  the following results  for the Peugeot
engine at high altitude:  0.38 g/mi HC, 7.0 g/mi CO,  and 0.58 g/mi
NOx.    These  results  are  less  than the  high-altitude  standards.

     Toyota - Table  11  summarizes Toyota's position.

     As shown in Table  11,  EPA  concludes  that  Toyota will achieve
compliance with the  high-altitude  standards.

     Volkswagen - Volkswagen  intends to use the Bosch K-Jetronic
fuel injection system.   Although this system is able to compensate
for changes  in  air density, VW  expressed  some  doubt  that it would
compensate sufficiently to meet  the  high-altitude standards.  Bosch
has stated  that the system compensates  for  altitude up  to 8,200
feet.    In addition, Volvo  test data has  shown  that the  same K-
Jetronic  fuel  injection  system produced  emissions   results  well
under  the  high-altitude standards.   In  view  of these  facts,  and
lacking any VW  data  to  prove otherwise,  the  EPA  technical staff's
judgment is  that VW will be able  to comply with the high-altitude
standards.   For a more  complete  discussion of VW, see EPA Technical
Report CTAB-TA/80-3.

     2.   Technical  Feasibility  for Gasoline-Fueled Light-Duty
Trucks.  Light-duty  trucks  have higher  numerical standards at low
altitude than do light-duty  vehicles.  Similarly, light-duty trucks
will have numerically less  stringent standards at high-altitudes as
well.   In 1982,  light-duty  trucks will have high-altitude standards
of 2.0 gpm HC, 2b gpm CO, and 2.3 gpm NOx.  In 1983, the high-alti-
tude  standards  will  be 1.0 gpm HC, 14 gpm  CO,  and  2.3  gpm NOx.

     Basically,  the  methodology used by the EPA technical staff to
determine the technical  feasibility for  light-duty truck manufac-
turers was the  same as that  used in the previous  subissue for
light-duty vehicles.   One issue in  this regard was the validity of
using the high altitude to  low  altitude emission  factors in Table 3
(calculated from light-duty vehicle data) in assessing the techni-

           Table 10

Technical Feasibility for Nissan

 Emission Control System  Conclusion
2.0 L
2.8 L
"Fast Burn"/CLEFI/
Method 3
Method 3
Method 1
                              Table 11

                   Technical Feasibility for Toyota

Engine     Year     Emission Control System  Conclusion

78.7 CID  1982-83   PAIR/OC/EGR                 Pass

88.6 CID  1982-83   PAIR/OC/EGR                 Pass

108 CID   1982-83   Closed Loop AIR/3W/EGR      Pass
134/      1982-83   Closed Loop AIR/3W/EGR      Pass
144.4 CID

156.4/    1982-83   CLEFI/3W/EGR                Pass
168.4 CID

                                               Method 3

                                               Method 3

                                               Method 4

                                               Method 3

                                               Method 3

cal feasibility for light-duty trucks.  This issue is discussed in
some  depth in the EPA Technical  Report CTAB/TA/80-3  discussed
above.  EPA did use the emission factors in Table 3  for  light-duty
trucks, but did so with the  understanding that  there  were questions
about doing so.

     We will  now  summarize  the technical feasibility  of  each
light-duty truck manufacturer  that  commented on the issue.

     American Motors  - The  summary  of AMC's technical position is
listed in Table 12.

     Table  12  indicates  that  AMC  can comply   with the  1982 high-
altitude light-duty truck  standards  but  can not now show  compliance
with  the  1983 standards.  There  will be an  extra full  year of
leadtime for  1983  and EPA believes this to be sufficient for the
development of a  light-duty truck  package  to  meet  the  1983 stan-
dards .

     Chrysler - Table  13 summarizes our analysis  of  Chryslers
light-duty trucks.

     EPA anticipates  that  Chrysler will have  no problems meeting
the high-altitude light-duty truck  standards.

     Ford  -  Our  analysis  of  Ford's  light-duty situation is high-
lighted in Table 14.

     As shown  in Table  14,  the  only engine  groupings which failed
were  engines  A-l  and  B/C/D-1, both for the 1983  model  year.   Two
factors must be noted.  One,  both  of these engines  involved emis-
sion  control systems  which were calibrated  to  meet the 49-state HC
standard of 1.7 gpm,  thus  it  is not surprising  that  these vehicles
would  fail  to  meet the  1983 high-altitude HC  standard of 1.0 gpm.
Given a year of development  time  and the lower  standard it is quite
likely  that  compliance  can be  achieved.   Second, both  the  A and
B/C/D  engines  were able  to  show  compliance  with the  1983  high-
altitude standards with emission control  system 2.   Thus  we con-
clude  that Ford will  be able  to meet  the high-altitude  standards.

     General Motors  - Our  summary  of  GM's  light-duty truck situa-
tion  is given in Table 15.

     As Table 15 shows,  GM should be able to meet  the high-altitude
light-duty truck standards.

     International  Harvester - The  only high-altitude data which IE
provided to EPA  were  two  series of tests of  1977 Scout Travelers
with 345 CID engines.   Both  vehicles showed high-altitude emissions
consistently  below  the 1983  high-altitude standards.    Since  IE
demonstrated ability  to meet  the  1983  standards at  high-altitude
with  a relatively  large vehicle (5000  pounds  inertia weight)  and
large engine (345 CID),  EPA  is confident that the  technology can be

                              Table 12
            LPT Technical Feasibility for American Motors
Engine   Year
           Emission Control

                                                      Method 4 Analysis
                                                      Method 2 Analysis
                                                      Method 2 Analysis
                                                      Method 2 Analysis
                                                      Method 2 Analysis
                                                      Method 2 Analysis
                                                      Method 2 Analysis
                              Table 13

                 LPT Technical Feasibility for Chrysler
Engine   Year
           Emission Control
Method 2 Analysis
Method 3 Analysis
                              Table 14
                  LOT Technical Feasibility for Ford
Engine   Year
           Emission Control

                                                      Method 2 Analysis
                                                      Method 2 Analysis
                                                      Method 2 Analysis
                                                      Method 2 Analysis
                                                      Method 2 Analysis
                                                      Method 2 Analysis

                                   Table 15

                LPT Technical Feasibility for  General Motors

                   Emission Control
Engine   Year

A       1982-83

B       1982-83

C/D     1982-83





Method 4 Analysis

Method 2 Analysis

Method 2 Analysis
                                   Table  16

                LPT Technical  Feasibility for General Motors
Engine   Year

A       1982-83

B       1982-83
Emission Control




Method 4 Analysis

Method 4 Analysis

transferred to  smaller  displacement  engines  and lighter vehicles.
In addition, three years time has elapsed yielding IE much time to
resolve  any possible problems  in transferring the technology.

     Nissan -  Nissan  is  expected  to  market only  one  light-duty
gasoline engine  for light-duty trucks in  1982-83.  The Nissan
A engine  is expected to be  available with emission control system
1.   A method  2 analysis  was performed  which  indicated  that  this
engine easily  complies  with the  1982 and 1983 high-altitude  stan-
dards .

     Toyota -  Table  16 summarizes our analysis  of Toyota's feasi-
bility in meeting the light-duty  truck  standards.

     Based  on  Table  16, Toyota  should be  able  to comply with the
high-altitude light-duty truck standards.

     3.   Technical Feasibility for Diesel-Fueled Light-Duty
Vehicles and Trucks

Light-Duty Vehicles

     General Motors, Peugeot, Volkswagen,  Mercedes  Benz,  Volvo,
Audi, and  International Harvester offer diesel-fueled vehicles in
their  product  mix for  light-duty vehicle  and/or light-duty  truck
applications.    The diesel  combustion process tends  to produce low
HC  and  CO emissions, and the  technical  staff's  judgement  is  that
the  interim high-altitude  standards  should not  pose a problen for
this  category  of  engines.   There  were  not many comments from the
manufacturers  concerning  this  issue.   General  Motors did comment

     "For diesel engines,  adjustments have  a much  smaller effect on
     HC,  CO and NOx compared to  gasoline  engines,  but  can reduce
     exhaust smoke."

     In  order  to   assess the  ability of diesel  engines  to comply
with the standards,  the technical staff  developed  high/low altitude
emission factors  from two sources.  Data from an EPA  report entit-
led  "1977  EPA-Industry Light-Duty  Diesel  Correlation  Program,"
April 1978, showed that HC, CO  and NOx emissions were lower  for a
Mercedes Benz 300D at high  altitude  than at  low altitude.  This is
explainable since this engine  was apparently equipped  with an
intake-air  density  compensator.    The  high-altitude/low-alt itude
emission  factors  were 0.98, 0.94,  and  0.92 for  HC,  CO,  and  NOx,
respectively.   The same report determined altitude factors for a GM
Oldsmobile  diesel  as well.  Its  high-altitude/low-altitude factors
were  1.31, 1.21, and  0.79 for  HC,  CO, and NOx,  respectively.
Comparing  these altitude factors  to factors for the high-to-low
altitude standards (high/low altitude standard)  of 1.89 HC, 2.3 CO,
and  1.0  NOx,  would  indicate that  diesel  LDVs  can comply with the
proposed standards without  the need for  adjustments.

     Other FTP data more  recently  developed,  for five diesel LDVs
(two Oldsmobiles, VW,  Peugeot,  Mercedes) tested at  both  EPA (for
low-altitude environment)  and at the Automotive Testing Laboratory
(ATL) at Auroram  Colorado  (5480 feet),  averaged high/low-altitude
emission  factors of  2.27, 1.87,  and 1.02  for HC, CO,  and N0xs

     These factors show some  upward pressure  on HC and CO emissions
and negligible effect  on NOx emissions.   However, the CO factor of
1.85 is offset by the  higher  standard  of  7.8  g/mi at high altitude,
which is  calculated to be 2.3  times  the low-altitude standard of
3.4 g/mi.   Those  LDV diesels  certifying (low  altitude) at 0.25 g/mi
HC or below should comply  with  the interim HC high-altitude stan-
dard.  Otherwise, aneroids, other fuel limiting devices, fuel rack
adjustments,  or injection  timing modification options are available
to the manufacturers.

     In order to  test  this assumption that  diesel  LDVs  can comply
with  the  interim high-altitude  standards for 1982  and  1983, with
only  minor adjustments,  the technical staff  applied the more
conservative  high/low  altitude  factors   of  2.27 HC,  1.85  CO,  and
1.02  NOx  to  low altitude  1980 4K  certification,  average test
results on the CMC, Mercedes,  Peugeot,  VW, Audi,  and Volvo vehi-
cles.  The predicted results  are listed in Table 17.

     These results confirm  that  there  could be some upward pressure
on HC from diesel  LDVs at  high altitude,  and  that some  minor
injection  timing  or  maximum  fuel  adjustments  may be required  to
meet  the  high-altitude standard of  0.57 g/mi.    The conservative
high/low altitude  factor  of  1.02 NOx indicates  that  the  manufac-
turers that certify at low altitude should  also  conform  to high-
altitude standards.   The  higher NOx  values  shown here are  to be
expected since the NOx standard  for 1980  MY vehicles was 2.0 g/mi.
Although the  1981  statutory  NOx standard is 1.0  g/mi,  wiavers  to
1.5  g/mi  NOx are available for manufacturers  whom fulfull  the
statutory  criteria under Section 202(b)(b)(B) of the Clean Air Act
for model  years  1981 through  1984.

Light-Duty Trucks

     With  respect to the LOT  standards for  1982  and 1983, Nissan,
who has supplied diesel engines  to International Harvester, provi-
ded the following statement:

     "Because  the amount of inlet  air is reduced  at high  altitude
     and excessive air cannor be obtained, an altitude compensator
     (aneroid type compensator) will  be required for  the fuel
     injection system  at WOR  operation.   Furthermore,  our simula-
     tion  test data indicates that HC and  CO emissions  are likely
     to increase  with  altitude even at partial  load  operation.
     (The  HC  and  CO  emissions  during FTP  increases  2.2   and  1.4
     times  respectively.)   Therefore,  in  order to control HC and Co
     emissions at  high  altitude,  it  is considered that using only a

                      Table 17

Predicted High-Altitude Diesel LDV Emissions Using
      Conservative Altitude Factors and 1980
                 Certification Results
CMC (49 states)
(NA) (NA)
0.71 0.72
3.86 1.98
1.68 1.50
                      Table 18

  Predicted High-Altitude Diesel LDT Emissions Using
        Conservative Altitude Factors and 1980
                 Certification Results


     compensator  is not  enough,  and  recalibration  of  injection
     timing and EGR will be necessary."

     International Harvester has used a turbocharged engine for LDT
applications.   This  engine does  have  the  capability to  provide
excess air, and the statement by Nissan that  "excess  air  cannot be
obtained"  does  not apply.   Furthermore,  it  is  currently  accepted
practice  to  install aneroid controls  on turbocharged  engines  for
the  sole  purpose  of  preventing excess  smoke during  acceleration
modes.   This  aneroid  could also automatically correct  the maximum
fuel setting for high-altitude  conditions.

     Nissan,  in  their  submission,  considered emission factors  of
2.2  and  1.4 for HC and  CO,  respectively, for high altitude.   The
EPA  technical staff used  the more  conservative LDV  factors  of 2.27
and  1.85  for HC and CO  in establishing whether this  engine  would
comply with the  high  altitude  standards.    Application  of  these
factors to  1980 MY  certification test  results provided  the results
in Table 18.

     Since  the  1983 high-altitude LDT  standards  are  1.0  g/mi  HC,
14.0 g/mi  CO,  and  2.3  g/mi NOx, both the VW  Diesel and the Nissan
198TC Diesel, as used  by International Harvester,  are  considered by
the  technical  staff  to  be  capable of  meeting  the  high-altitude
standards  for  the 1982  and  1983 model  years.   Because of upward
pressure on HC, the CMC  trucks  will  probably  require  modifications
which may  include adjustments  of  injection  timing  or  the  maximum
fuel setting in order  to comply  with 1983 MY  standards.

     Particulate emissions were  not  considered  in  this determina-
tion, but  there  is no  high-altitude particulate standard  for  the
1982 and  1983  model years.  Thus, it  is  the determination of  the
technical staff that both light-duty vehicles  and  light-duty trucks
powered by  diesel  engines can  comply with the high-altitude  stan-
dards  with minor adjustments or,  effectively,  by addition  of
aneroid type controls.


     The interim high-altitude  standards  appear  to be  technically
feasible  after  a  careful  analysis  of  the  available  information.
Therefore,  the levels  of the standards  should  not  be changed in  the
final rule.

c-   Issue;   Adequacy  of Existing  High-Altitude Test Facilities

Summary of the Issue

     The proposed regulations would necessitate the use of testing
facilities located at high altitude (HA)  or  testing facilities with
the capability of simulating HA conditions.   These HA test facili-
ties would  be needed  for research and  development (R  &  D) work,
certification testing,  and Selective Enforcement Audits as well as
continued EPA in-use surveillance testing.    The proposal assumed
that existing HA test facilities would  be sufficient to develop and
certify the  low-altitude  light-duty  fleet to the proposed 1982 and
1983 HA standard.

Summary of the Comments

     The major comment by the manufacturers was that  existing
commercial HA test facilities  might not have adequate test capacity
to  meet  the  needs  of  the  manufacturers.   MVMA  stated  that they
questioned if HA test  facilities would be adequate but they didn't
give any analysis of this suspicion.  Ford  stated that they prob-
ably would require expansion   of their HA facility.   However,
further details were not given.  AMC claimed  that  HA test facilities
were already scheduled to capacity  and  Fuji/Subaru  was concerned
that the Denver  commercial  labs could  not guarantee  test  time due
to  limited  testing  capacity.   VW claimed that since HA facilities
would be fully utilized for development work,  Selective Enforcement
Audits could not be done.

Analysis of Comments

     The  following  discussion  and  analysis  of high-altitude test
facilities is divided into two parts.  First,   a  review of existing
facilities both  commercial  and  private is presented.   This infor-
mation was  obtained from the  various manufacturers  at the request
of EPA.  EPA1s letter and the  manufacturer's responses can be found
in  the public docket  for this rulemaking.   The two commercial
testing  facilities  also  submitted  information in response  to  an
EPA request and their  letters can be found  in  the public docket as

     After  discussing existing  facilities,  the need for  high-
altitude  test facilities  will  be  presented.    Estimates  of each
manufacturer's research and  development  (R&D), certification, and
Selective Enforcement Audit  (SEA) burdens  are made.   Then the
previously developed information on existing facilities is combined
with the  need for  facilities  to resolve the  issue of whether or
not there  are adequate high-altitude test  facilities  to  implement
the proposed rule.

     la   Existing Facilities.   Currently, there  are two commercial
high-altitude test facilities  in the Denver  area.  EPA is  not aware

of any  other  commercial  facilities  capable of performing HA  test-
ing.   The two  facilities are Automotive Testing Laboratories  (ATL)
and Environmental Testing Corporation (ETC).  Both  facilities have
the capability of performing the full Federal Test  Procedure  (FTP)
for  light-duty  vehicles  (LDVs)  and  light-duty  trucks  (LDTs)  in-
cluding evaporative  emission  testing.   Both  facilities have con-
siderable amounts of  testing  capacity" still available at the time
of this writing  and both facilities doubt  that  the proposed rule
will  necessitate full utilization of their respective testing

     ETC is located  in Aurora, Colorado, a  suburb of Denver.  This
commercial testing  facility  has two  chassis  dynanometers and  one
LDV  evaporative  emission enclosure  or  SHED.   ETC  states that by
running at full  capacity they  could  conduct 252  tests per week if
evaporative testing  is not included  (i.e., 2 test sites x 3 shifts
per  day x 6  tests per test  site per shift x 7 days per week).  If
each  test  included   evaporative  emission  testing,  ETC  could then
conduct 63 tests per week (i.e., 3 tests per  test site  per shift x
1  test  site x 3  shifts per day x 7  days  per  week).  However,  ETC
states that  they could have  another LDV  SHED operational within  six
months should they perceive a need.   This would effectively double
their  evaporative  emission  testing  capability  to  126  tests  per

     The above test  rates are  for non-certification  testing.   These
rates would  be appropriate for  R &  D  testing but  not  for actual
certification  testing.   Tests  conducted  for  R&D purposes  do  not
have  to meet  any EPA  specifications.  For example,  R&D  tests  could
be conducted with an ambient  temperature of  50°F.  This would  still
be a useful  test for R&D purposes  but would not be  acceptable
from  a certification point of view.   Because  there  are a  number of
specifications which must be met in order to have a valid certifi-
cation  test,  a void  rate  should be applied  to  the above testing
rates if  the testing has to be of certification quality.    ETC
estimated their  void rate  as  20 percent  at  maximum.   This  would
reduce  the  above test rates  to 202 tests  per week not  including
evaporative testing  and  101 tests per  week including evaporative
testing (2 SHEDs).

     The other  commercial  high-altitude testing  -laboratory,  Auto-
motive Testing Laboratories,  Inc. (ATL), is  also  located in Aurora,
Colorado.   This  facility currently has  one test  cell in  operation
and  floor  space  for  another.   A second test cell  will be opera-
tional by November  1, 1980,  which is  the  date  that this analysis
will  use  as  the starting point  of  the manufacturers' development
effort.   November 1,  1980  will be used as  the  starting date even
though  we  know  that  significant development effort  has already
occurred.   In  fact,  conversations with  ATL  indicate that a number
of manufacturers have  been  testing  since  the spring  of  this year
and  testing  is  continuing  to  be scheduled  from now  through  the
November 1  starting  point of  this analysis.  ATL does not  expect to
fully utilize  their testing capacity  at  any  time  in  the next 12


month s.   Furthermore,  conversations with Chrysler  (see  the  public
docket  for  this rulemaking)  indicate  that  they have  been  running
4-5 tests/day since February 1, 1980.   It is,  however,  difficult to
quantify the amount of development work that will have  been done by
November 1, because ATL cannot provide the necessary details  due to
the proprietary nature of such information.   Thus, this analysis is
based  on  the very  conservative  assumption  that no  HA development
testing will be done until November 1, 1980.

     The  test cell currently operating at  ATL's  high-altitude
facility  is  staffed to operate  20  hours per  day.   The  other  four
hours  are used  for  calibration  and  maintenance.   ATL  submitted
standard  dynamometer  test times  which show that  112  FTPs  without
SHED could be  conducted per 7-day week.  With  the addition  of the
second  test  cell 224  non-SHED FTPs  could  be conducted per  7-day

     ATL's one  operating  test  cell  includes a SHED for evaporative
emissions  testing.   ATL has another SHED and  the  necessary  auxil-
iary equipment  for  evaporative emissions testing at the Aurora lab,
however,  it  is  not  set up at  the present time.   This  second evap-
orative emission  test  site could be assembled very  quickly  if the
need  presented  itself.   Therefore  this analysis  will  assume  that
the  second SHED  is operational.   It has  not been assembled  yet
because ATL  has no indication that it  will  be needed.  With  two
operating  SHEDs  and two chassis dynos, ATL could  conduct  about 93
FTPs per week including SHED testing.

     ATL  did not   include  a  void  rate  for  certification  quality
testing so ETC' s  void rate  of  20 percent will  be used.  ATL's
capacity  for certification quality testing  is  179  FTPs per  week
excluding  SHED  testing and 74  FTPs  per week  including  SHED  test-

     To summarize the available commercial facilities,  with current
equipment  ETC  can  run  252  non-SHED FTPs per  week and ATL can run
224  non-SHED FTPs  per week  for a total of 476  tests per week.
If evaporative emissions testing capabilities  are included  then ETC
can  run  63 FTP (with  SHED) tests per week  and ATL  can  run  93  FTP
(with  SHED) tests  per week  for a total of 156  tests per week.
Additionally, if necessary ETC could double its capacity within six
months to 126 FTP (with SHED) tests per week bringing the total for
both  facilities  to 219  tests per  week.   Test rates  for  certifi-
cation quality  testing  would  be  the above testing rates  reduced by
20 percent.

     The total  number  of non-SHED tests that  could  be made  avail-
able between  November 1,  1980  and  June 30,  1981  is somewhat  more
than 16,000 of R&D  quality.  EPA expects that  SHED testing  will not
be a limiting factor because it will be relatively easy to  meet the
HA evaporative  emission standards.  Therefore,  the  large  majority
of testing will be  R&D quality, non-SHED test.

     Besides commercial  test  facilities there  are  many manufact-
urers  that  have  facilities  for  high-altitude  testing.   General
Motors, Ford, Honda, Mercedes  Benz,  and Fiat have testing facili-
ties  located at  high  altitude.   Furthermore,  General  Motors,
VW/Audi,  Honda,  Nissan, Mercedes  Benz, Toyota,  BMW,  Mitsubishi,
Mazda,  Subaru, and  Peugeot all  either have  a pressure  chamber
capable of  simulating  high-altitude  conditions  or have contracted
to rent such a facility overseas.  In this section a brief discus-
sion of each manufacturer's  high-altitude  test  facilities will be

     General Motors  has  an emissions laboratory  in  Denver,  Colo-
rado.   It has three  chassis  dynamometers,  two  SHEDs,  and covers
51,750 ft2-  General Motors  also  has a  high-altitude test chamber
at Mil ford, Michigan.  The  chamber has one chassis dynamometer only
and  was  designed  to achieve a pressure reduction of  4 inches of
mercury below ambient atmospheric  pressure.

     Ford  also has an  emissions  laboratory at  Denver,  Colorado.
Ford's facility has  four chassis dynamometers,  one SHED and covers
approximately 25,000 ft2 which  includes a  soak area  for  45  vehi-
cles.  Although Ford  does not have an altitude test chamber at this
time,  the  company  is considering  converting  an engine dynamometer
cell to accomodate  simulated high-altitude conditions.

     Chyrsler has no  facilities  of its own at high altitude nor any
capable of  simulating high-altitude  conditions.   However,  Chrysler
has contracted with ETC to rent two  of  their six testing shifts as
of August, 1980.

     Volkswagenwerk/Audi  has  a  chamber  capable  of simulating
high-altitude conditions which  is located in Germany.  The chamber
is very  close  to being  finished  and some testing has  been  done.
The chamber has one chassis dynamometer  and one SHED plus area for
soaking vehicles.   Another  chamber is planned.

     Nissan  has  a high-altitude simulation chamber located in
Japan.   The chamber has  two  chassis  dynamometers  and one  SHED.
Nissan is currently studying whether or  not to build a test facil-
ity at a high altitude  location  in the USA.

     Toyota has  a pressure  controlled test  room in Japan which has
one chassis dynamometer and one  SHED.

     Mercedes Benz  has both  an  emissions  testing   facility  at  a
high-altitude location (Aurora, Colorado) and a chamber capable of
simulating high-altitude conditions   (in  Germany).   The facility at
high-altitude has  one  chassis  dynamometer,  one SHED,  and covers
10,300 ft2.  The high-altitude  simulation  chamber has  two chassis
dynamometers but  they can't be  used   simultaneously.   It has a SHED
and  particulate measuring equipment  that will  be installed by


     Mitsubishi has neither a facility located  at high-altitude nor
a chamber capable of simulating high-altitude conditions.  However,
they  do rent  time from  a laboratory in Japan  which has high-
altitude simulation capability.   This facility has an  engine
dynamometer but no chassis dynamometer or SHED.

     Toyo  Kogyo/Mazda  has  a high-altitude simulation  chamber  in
Japan.   The chamber has one  chassis  dynamometer, one SHED and area
for soaking vehicles.

     Honda has  a high-altitude emissions test  facility in  Denver,
Colorado.  The  facility has  one  chassis  dynamometer, one SHED, and
covers  approximately  19,000 ft2.   Honda also  has a high-altitude
simulation chamber  located  in  Japan.   This chamber has one engine
dynamometer and covers approximately 2200 ft2.

     Subaru/Fuji has a facility capable of simulating high-altitude
conditions and  is  located  in Japan.   This  facility has one  chassis
dyno but no  SHED.   However,  the company is planning to construct
another  facility  capable of  performing  the full FTP including SHED
in one of their plants.

     Fiat has  a laboratory located  in Sestrier,  Italy which is  at
an  altitude  of  6,691  ft.  this  facility has  one  chassis   dynamo-
meter, no SHED, and covers approximately 2100 ft2.

     Peugeot has  built  a  pressure chamber in  France.   The  chamber
has one  chassis dynamometer but SHED testing cannot be performed  in
accordance with Federal  regulations.

     BMW will  be  using  an environmental chamber  that  is owned and
operated by Industrieanlagen-Betriebsgesellschaft  of West Germany.
This facility has one chassis dynamometer and one  SHED.

     Renault is currently  building  a  chamber for the simulation  of
high-altitude  conditions  in Lardy,  France.    It  will  include one
dynamometer and one  SHED and is  scheduled  to be ready for the 1982
model year.

     AMC, IHC,  Isuzu, Volvo and  Alfa Romeo indicated  they have  no
facilities at  a high-altitude  location nor do  they have a  chamber
capable of simulating high-altitude  conditions.

     EPA did  not obtain  information  from other  companies   such  as
Ferrari, Maserati,  Lotus,  Panther,   Porsche, Jaguar/Rover/Triumph,
Hyundai,  Rolls Royce,   or  Aston Martin.   These  smaller companies
represent  less  than 10 percent  of   the  engine  families  that were
certified in  1980.   For  the  purposes of this  analysis  it   will  be
assumed  that  these  manufacturers have no high-altitude test capa-

     2.   Need  for Facilities.    High-altitude  emissions  test
facilities are  needed  for  four primary reasons.  First, high-

altitude test  facilities  are needed  for  research and development
(R&D) work.   Some  engine  families  will need some recalibration  of
either  the  carburetor  or the  feedback control system.   Once  the
recalibration is made it must be tested to  see  if it meets  the  new
high-altitude standards.  As  discussed later in this section,  R&D
is the  only  area  of facility usage that even comes close to  fully
utilizing  existing commercial  high-altitude test  facility  capa-

     High-altitude test  facilities  will also be  needed  for certifi-
cation  testing.  In order to produce a model the manufacturer must
show to EPA  that  the model  meets the emission"  standards.   He does
this by performing certification tests  in  the late spring and  early
summer before production is  scheduled  to begin  (usually in August).
If the  vehicle representing  the  model passes the test  (and  it
usually does) the manufacturer  is issued a  certificate which allows
him  to  produce  the model.   The  utilization of high-altitude test
facilities   for  certification testing  will be  minor  as  discussed
later in this section.

     The third  and fourth reasons  that high-altitude test  facili-
ties will  be needed relate  to  Selective  Enforcement  Audits  (SEA)
and potential in-use surveillance programs.   SEA is EPA's method  of
checking to  make   sure  that  production  vehicles from the assembly
line  actually meet the  emission standards.   In-use surveillance
testing  is  used by EPA to  help determine  the  level  of emissions
of vehicles  that  have  been  owned  and operated by  the public  for
various  lengths  of time.   Both  SEA  and  in-use  surveillance  are
expected to utilize  relatively minor amounts of high-altitude
testing facilities as  discussed later  in this section.

     a.    Research and Development Needs.    Of  the  four different
reasons why HA commercial  test facilities are  needed  for  this
proposed regulation (i.e.,   R&D,  certification testing,  SEA,  and
in-use  surveillance),  R&D is the only one  that  could approach full
utilization of existing  commercial  test capacity.  In order  to meet
the  proposed  HA standards some manufacturers will have to  recali-
brate  their  low altitude engine/  emission  control  systems.  Some
manufacturers may add  new components  for HA vehicles that will have
to be  optimized  for  emissions, fuel economy and driveability.
Estimations of  R&D efforts  for  the industry are,  of course,  dif-
ficult  because  each manufacturer's  needs  are  different.    Addi-
tionally,  utilization of  test facilities to meet a  given R&D
need can vary  considerably  depending  on  factors such as the  engi-
neering  experience  and  skill,  the  priority that  the manufacturer
places  on  the  project  and the extent  that  theoretical evaluations
can be  substituted  for  trial and error FTP  testing.  The  following
discussion present  EPA's  estimation of HA  commercial test facility
utilization for R&D in which a "worst  case"  scenario is  evaluated.
The "worst case" is based  on the assumption that manufacturers will
not  begin  development  work until  November  1,  1980,  the projected
date  for  the  final rule (this  conservative  assumption, which
ignores  the  development  work  done prior  to November 1,  will   be
discussed later.


     It  is convenient to  divide LDVs and  LDTs into  two groups
according  to'expected engine/emission control strategies.  Feedback
control  strategies  are  those  where  an oxygen sensor electronically
communicates  with  the air/fuel metering system through a  computer
to  provide a  constant stoichiometric  A:F ratio during most driving
modes.  This  allows optimization among emissions,  fuel economy, and
driveability.    The  feedback  control system was  relatively rare
prior  to  1981  but  with the  stricter  low-altitude NOx,  HC and CO
standards  for 1981  this type of system is now in the majority and
is  expected  to be  the predominant  type  of system for  1982 and
1983.   The other  group of engine control  systems are  known as
non-feedback.    This  group has  air/fuel  metering systems  of the
conventional  type such  as  carburetion  or fuel injection but has no
oxygen sensor or associated micro-processor unit.

     The  feedback  systems are  the  easier  of  the two  groups to
modify for compliance with  the proposed HA standards.   When a
feedback  system that  has  been developed  for  low-altitude  use is
operated  at high altitudes,  there will be  some automatic  compensa-
tion  for  the  less  dense  air.  The  oxygen sensor  will  signal the
air/fuel  metering  system  that  the A:F ratio  is too rich.   The
mixture will  be enleaned  to either the correct  mixture  called for
by  the micro-processor unit  (usually close  to  stoichiometric) or
the  leanest  mixture that  the  system  can deliver.   If  the leanest
mixture  is still to  rich,  the system's  range of authority can be
shifted so that proper A:F  mixture  is obtained.   Shifting the
range  of  authority is  probably  the simplest of  the modifications
that will  be  needed to meet the HA standards.

     The  optimization effort  for  non-feedback systems will include
recalibration for cold  start, power enrichment,  and other driving
modes. Proper engine  and  emission control system performance must
be  obtained  at  different  cruising speeds, during accelerations and
decelerations,  and  during  transient  operation.    The  development
effort  for non-feedback systems  is  expected to  be more  than the
development effort  for feedback systems.

     In order to determine if the  capacity  of HA commercial test
facilities  is sufficient,  the number  of  R&D tests which  will  be
needed must be  estimated.   In the chapter entitled Economic Impact
of the 1982-1983 High-Altitude Emission Standards  (Chapter  V)  of
the  "Regulatory Analysis"  of this  rulemaking  the  number  of R&D
tests  required  to  meet these  HA  standards is estimated.   To sum-
marize that discussion, all diesel engine families,  whether car or
truck, are expected  to need 20 R&D tests each.  Also, all gasoline-
fueled LOT families  are  expected to  need  150  tests per famliy.
Gasoline-fueled  LDV engine  families  are divided  into  two groups:
those  which  need so  few R&D  tests as to be considered  already
meeting the standards  (GM's C-4 system and Bosch's Jetronic system)
and those  others which EPA  estimates will each need 150 R&D tests.

     The number of  LDV and LOT engine  families to be certified for
1982 is,  of  course,  unknown  at  this  time.   We have assumed that


approximately the same number of engine families will be .certified
in  1982  as was certified  in 1980.   In  1980 there  were 156 non-
California LDV  and  LDT engine  families certified.   These include
families for sale in either the  49  states, excluding California, or
the  50  states,  including  California.   Engine  families  which are
certified  for  sale  in California  only have  been excluded because
these  proposed regulations do  not  apply  to  those  vehicles.

     Since some manufacturers have their own facilities capable of
performing HA  tests,  a  number of the 156  non-California engine
families will have R&D work done at  these facilities  instead of the
HA commerical facilities.   We estimate  that GM will have 32 LDV and
LDT  engine families  in 1982.  As  discussed  earlier,  GM has a test
facility in the  Denver area which has  3  chassis  dynos.   At a
testing rate of 6 FTPs per  shift per dyno site x 3 dynos x 3 shifts
per  day  x 7 days per week, GM could  perform 378 FTPs  per week.
Testing at this rate  for 8 months  (i.e.,  from the promulgation of
the  final  rule, November 1,  1980  to June  30, 1981)  gives a poten-
tial of about 12,000  HA FTPs.   Since  all  of GM's LDV engine fami-
lies will  have  the  C-4  system,  they will  need minimal R&D testing
to comply with the HA standards.  EPA estimates that GM's remaining
engine  families  (diesels   and  LDTs) will  require less  than 1000
tests total.   Therefore,  GM  should easily  be able  to  handle all
necessary R&D work at their own  HA  facility.

     Ford's  situation  is  similar  to GM's.  Ford  has  a HA test
facility with 4  chassis dynos while GM had  only  3.   Thus,  Ford's
testing capacity  is about  16,000  R&D  tests.   EPA  estimates that
Ford will need  about 3000 R&D tests.  Therefore, Ford should easily
be able to handle all of their R&D  testing in-house.

     Mercedes Benz  has  both  a  facility  at  HA  (Denver)  and  a HA
chamber in Germany.   Each  facility has one  chassis  dyno.   There-
fore, Mercedes can run about  8000 FTPs  in 8 months.  However,
EPA  estimates Mercedes  will have  to  run  less than  100  tests for
R&D  purposes and, therefore, Mercedes will not have  to use any of
the commercial  HA test facilities.

     Similar analyses for  Honda (2 engine  families),  BMW (3 engine
families), Nissan (6  engine families), Fiat  (2  engine  families),
Subaru/Fuji (3 engine families), Peugeot  (2  engine families), Toyo
Kogyo/Mazda (5  engine families), Toyota  (8 engine families),
VW/Audi (3 engine families), Porsche (3 engine families), and Saab
(2  engine families)  indicate   that these  manufacturers have  the
capacity to  do  all  of their R&D work  in-house either  at HA or in
chambers  capable  of simulating HA conditions.  None of  these
manufacturers should  need  to use the  existing  commercial  HA test
facilities in Denver for R&D  work.

     The above  discussion  shows  that  the  total number of  LDV and
LDT engine families  for which the necessary R&D work can be done at
manufacturers'  facilities is  106.   This leaves 50 LDV and  LDT
engine families  that may have to use the commercial testing labs in


Denver.   If  all of  these  50  engine  families  were gasoline-fueled
LDVs and  LDTs,  which did not  employ either the  C-4  system or the
Bosch^Jetronic,  then  the  required R&D tests  at HA commercial
facilities would  be about 7500.  However,  since  some of  these
engine families are  diesels and some  use the C-4 or Bosch Jetronic
systems, EPA estimates that the number of R&D  tests to be conducted
at HA  commercial  facilities  will be  about  6400.   As discussed
earlier,  EPA  estimates  that  the commercial  HA test  facilities are
capable  of performing  about  476  FTPs  (excluding SHED)  per  week.
This means the  test  capacity  for  8 months  is  approximately 16,000
tests.   Subtracting the tests  needed  for  R&D work  (6400)  leaves
a reserve  capacity  of  9,600  tests.   Therefore,  EPA has determined
that adequate  HA  comercial  testing facilities exist  to handle the
R&D work required for this  rulemaking.

     As mentioned  earlier,  the above  analysis is based  on  a very
conservative  assumption  —  that manufacturers will not  begin
high-altitude  development testing  until November  1, 1980,  the
projected  date  for  promulgation of the  final  rule.   Even assuming
this  to  be  true,  we  showed   that existing  commercial facilities
would  be  able  to provide  the high-altitude  R&D test capacities
necessary for  those manufacturers  which do not have their own
high-altitude test facilities.

     EPA  is  aware,  however,   that many  manufacturers  have  already
begun  their  high-altitude  R&D  test  programs.   Chrysler has  been
running  tests  at ETC since February  of  this  year (telephone
conversation of June 30, 1980).  JRT has also notified EPA that it
has performed testing at high  altitude as well (June 2, 1980 letter
to EPA).   Finally-,  conversations with ATL  and ETC indicate that a
substantial amount of high-altitude development work  has been done
by  several manufacturers.   The  exact  amount  of  testing that  has
been done by each manufacturer is  unknown  since manufacturers did
not  volunteer  such  information in their written  comments  and
because  the  commercial  labs  will not divulge  proprietary informa-
tion.  The point is  that much  development work has been and will be
performed  prior  to November  1, 1980.  Our  above analysis  ignores
this work,  and to  that extent overestimates  the test capacities
needed  after  November  1.   Thus, there  will  actually be  an  even
greater safety  margin  than the near-60 percent hypothesized above.

     In conclusion,  when it is  remembered that:  • 1)  the number of
R&D  tests required  per engine family  was  estimated  on the  high
side, 2)  most  if  not all manufacturers  have  already  done some R&D
testing at the time of this writing (July, 1980) and will certainly
do more between now and November, 1980, 3) the estimate of existing
commercial test  facility capacity includes liberal  estimates  for
maintenance and downtime, and  4) even with this worst  case scenario
there  is   60  percent  reserve  capacity,  EPA's  determination  that
sufficient test capacity exists for high-altitude R&D work  is both
reasonable and conservative.

     b.    Certification Needs.  High-altitude test facilities

needed for certification  testing  appear  to be more than  adequate.
Since each manufacturer will be required to test only one emission
data  vehicle  per non-California  engine family  (see the issue
entitled "Number of Certification Vehicles" in this document), the
total number  of certification  tests  at high-altitude  should ap-
proximate the  number  of non-California engine families certified.
However, the actual number of high-altitude certification  tests may
be somewhat more  or  less  than the number  of non-California  engine
families.   Tending to  decrease the  number of certification  tests
which  may be  needed  is  the fact  that some  low-altitude, non-
California engine  families will not need  to  be tested under  high-
altitude conditions because of the exemption criteria discussed  in
the issue "Exemptions"  in  this  document.   Tending  to increase the
number of certification tests is  the  fact  that some tests will  be
voided due to mechanical problems or human error.  But, as discus-
sed earlier, the void rate is included in  the  testing rates  of the
commercial facilities  and, therefore,  no  further consideration  of
the void rate is required  in  this  discussion of adequate commercial
testing capacity.  Another factor  tending to increase the  number  of
certification tests is  emission test failures.  Some emission-data
vehicles may  not pass  the  emissions  test  the first  time.    Those
vehicles will have to  be  retested if  the  problems  can be resolved
or, possibly,  instead  of  retesting,  new  engine  families (almost
identical to the ones  which failed)  could be created, tested  at low
altitude and then  tested  at  high  altitude.  Emission test  failure
is relatively  rare and  it may well  be that  the  exemptions will
cancel out  the retests leaving  the number  of high-altitude  certi-
fication tests about  equal to the number of engine families  to  be
certified.   However,  since the  exact number of  non-California
engine families in 1982 and 1983 is  unknown and the exact  number  of
exemptions and retests  are unknown, a  safety  factor  of 50 percent
will be used.

     The number  of non-California engine families  to be  certified
in model years 1982 and 1983 will be estimated by using the  number
of non-California  engine  families  that were  certified  in  1980.
Analysis of  certification  data  for  model year 1980 indicates that
156 certificates of conformity were  issued  for  engine families that
could be sold  only in the 49 states excluding California or  could
be sold in all 50 states.   Certification  for California-only  engine
families were not  included.   Applying the  safety factor of  50
percent gives the  estimated number of 234  high-altitude certifica-
tion tests  per  model  year.  As discussed  earlier  under  "Existing
Facilities", the two commercial testing laboratories (ATL and ETC)
in Denver  can perform  175 full  FTPs  (including SHED  tests) per
week.   This  number assumes a void rate  of 20  percent.   The  above
numbers show that the  entire  industry's high-altitude certification
testing could easily be done  in  less than two weeks if only the two
commercial laboratories were used.  However, EPA expects  that most
manufacturers who have high-altitude test  facilities will do  their
own certification  testing.   These manufacturers  include GM,  Ford,
Mercedes Benz, Honda,  VW/Audi, Nissan,  Toyota,  Toyo Kogyo, Fiat and
Renault.   The number of 1980 non-California engine families  repre-

sented by these ten manufacturers is 94, thereby leaving only (156
- 94)  x 1.5 or 93  certification  tests  to  be performed by the two
commercial  laboratories  in  Denver.   Thus, of  the  total amount  of
commercial  facility  test time available between now  and the 1982
model  year,  EPA estimates that less  than  5  days  would have to  be
devoted to  the  actual  certification of  the emission-data vehicles.

     c-    Selective Enforcement Audit (SEA)  Needs.   One commenter
expressed concern that  there would be no test  facilities available
for  SEA testing.    EPA  expects  that  HA commercial  test facility
availability for  SEA testing will be more than adequate.   SEA
testing would  not  begin  until after  the  start of  the 1982 model
year.   Therefore,  development work  needed for the  first  year  of
implementation  will be  finished long  before  SEAs  are required.
While  it is  likely  that  some development work will need  to be done
for  the 1983 model year,  that  effort should be less  than  that
required  for the  first  year  of  implementation  (i.e.,  1982 model
year).  Thus,  there  should  be  ample reserve  testing  capacity
at the time  that SEAs would be done.

     Furthermore,  the  number of  SEAs  that  might  be  required at  HA
is expected  to  be quite  small.  As discussed in the issue entitled
"Selective Enforcement Auditing  (High Altitude)" in this document,
the  number  of  SEAs at HA  should approximate the percent  of  HA
sales.   Since  HA sales  are  about 4  percent  of all  sales, HA SEAs
would be about 4 percent of all SEAs.   This is  a very small number;
maybe  3  at  most.   Three SEAs  might  require 30 tests  which  is  a
liberal  estimate.    Since  EPA believes that excess  HA  commercial
testing capacity will  be many  times  the 30 tests required for the
maximum number of SEAs, the Agency concludes  that existing capacity
for  commercial  HA  testing  will be more than adequate for HA SEAs.

     d.   In-Use Surveillance Needs.  The  fourth area of demand  to
be placed  on existing  commerical  high-altitude  test  facilites  is
the  use  of  those  facilities  for EPA's  In-Use Surveillance (IUS)
program.   EPA  contracts  with  test  facilities  each year  to  test
limited numbers of vehicles in  different  regions  of the country.
The  data from  this testing are  used to  develop EPA's  Emission
Factors which are subsequently used in air quality projections and
analyses.  ATL's Denver  lab will be testing vehicles for EPA's IUS
program  from December,  1980  through  July,  1981.   At  most,  this
testing effort will  require  about  350  tests at  ATL.  Even  if
utilization of the existing  commercial  HA test facilities  ap-
proaches the 40 percent rate  discussed  earlier  (an very unlikely
possibility); the 60 percent reserve capacity represents more than
enough full FTPs  with SHED  (3300) of certification  quality  to
handle the  350  tests needed for  the  IUS  program.   Therefore,  EPA
expects that IUS testing will be absorbed by  existing HA  commerical
test  facilities with  little or  no  impact on  their  capability  to
supply the auto industry with  adequate capacity for R&D and certi-
fication testing.


Reconnnendat ion

     EPA has  determined that  available  high-altitude testing
facilities  are adequate  to meet  the testing requirements imposed  by
the  proposed  regulation.   Therefore,  it  is  recommended that  no
change to the  proposal be made concerning this issue.


D-   Issue;  Selective Enforcement Auditing

Summary of Issue

     In the preamble  to the NPRM,  EPA  stated that, "The Agency may
also require manufacturers to perform assembly-line testing  (Selec-
tive Enforcement Audits) at high-altitude locations." No regulatory
changes to the  current SEA  program were proposed in the NPRM.

Summary of Comments

     EPA received  many comments with respect to the high-altitude
NPRM and Selective Enforcement Audits  (SEA).  Some commenters
stated  that  since  EPA failed  to  explicitly  propose  a regulatory
system  for  implementation  of  SEA at high altitude,  EPA would have
to  repropose  the SEA  portion  of  the  rulemaking.   Many commenters
simply  believed  that  high-altitude SEA testing  would be impossible
due  to  an inadequate  number  of high-altitude  test  facilities (in
view  of developmental  and  certification testing  requirements and
too  little  time to construct new  facilities) and/or the difficul-
ties involved in obtaining a sufficient number of high-altitude SEA
vehicles  in  a  specified  time  period.   A  few  commenters   desired
clarification  of EPA's position,  with respect  to whether  foreign
manufacturers  would be  required  to  construct  high-altitude test
facilities in the U.S., and whether a suspension or revocation of a
certificate would  apply only to vehicles operated at the altitude
at which the  SEA failure occurred, or at  all altitudes.  Finally,
several commenters  recommended  alternate test  procedures for
high-altitude  SEA  and  one  manufacturer expressed concern about the
criteria EPA  would  use  to determine when a  SEA was required.

Major Subissues

     1 .   Adequacy of Proposal.  Ford commented  that EPA had  failed
to  propose  a  responsible regulatory system for the implementation
of SEA  at high  altitude  and,  therefore,  reproposal of this  portion
of  the  NPRM  is required.   Ford  also believed  that the  actual
mechanics  of  the  high-altitude SEA program  were impermissibly
vague.   The  Motor Vehicle Manufacturers Association (MVMA)  stated
that  EPA should withdraw  its  high-altitude SEA  testing  require-
ments.   After  certain problems  (discussed under other  SEA sub-
issues) have been  resolved and  a  specific  need  for a high-altitude
SEA program has  been  identified, MVMA  recommended that the  program
then be reproposed for public comment.

     2.    Facilities.  EPA regulations  require that manufacturers
provide a  testfacility that  would be capable  of performing high-
altitude (HA)  emission  testing  for  SEA.   Some commenters expressed
concern that not enough HA facilities  are  available to conduct SEA
testing, or  to  perform the  testing within the  time constraints
imposed by  the  SEA regulations.   The Motor Vehicle Manufacturers
Association (MVMA)  stated  that  leasing or  renting facilities would
present considerable  problems  to manufacturers  and  EPA because of


the following reasons:   (1)  facilities may not be available quickly
enough to conduct SEA in an expeditious manner due to the require-
ments of HA  development  and certification  testing;  and  2)  schedu-
ling  problems  might  occur  due  to  the unknown number of required
audit tests or the possibility  of  an  audit  failure.   In addition,
MVMA  noted  that  §86.079-30(d)(2)  requires  all  manufacturers  to
provide HA SEA test  facilities and  manpower, but stated that with a
large number  of  manufacturers  competing for  available  facilities
and because of the difficulty  of predicting how many tests would be
required,  scheduling  problems would be encountered.   Chrysler
stated  that  it does not have  a HA  facility, and would have to
purchase cell  time from  a  private  firm.  Therefore,  they would be
competing with other manufacturers and with EPA  itself  for time,
and this would result in extremely  complicated scheduling difficul-
ties.  Chrysler believed that a SEA at a contractor facility would
take up to one month, depending  on  cell availability.  In addition,
Chrysler felt that there was no  guarantee that the minimum require-
ment of four tests per  day could be achieved utilizing a contractor
facility.   Further, Chrysler  commented that  the  development  of
rolls  validation data  prior to  conducting SEAs  would require
several weeks of  contractor  time.   Volkswagen (VW) stated that they
can not contract  for HA testing in the short time frame imposed by
the SEA regulations.  VW also  suggested that test capability at the
HA location,  or the development  and availability  of HA chambers at
manufacturing facilities,  are extremely limited,  and that  the
capacity of  these  facilities  would be  fully  utilized  for develop-
ment  testing.   Subaru   of America  stated  that there  are problems
with  testing in Denver  because  of  scheduling  problems and  lack of
available  facilities.   They  indicated  that  they  are  considering
building a HA  facility  in Japan, and  that  approximately  22  months
of lead  time  is  necessary to develop operating procedures  and do
some  engine design work.   Therefore,  they suggested that  the
effective  date for  these HA  regulations be  extended to  the  1983
model year.  Ford stated that  they  needed to acquire an environmen-
tal chamber.    They claimed  that  it would  take a  "couple of years"
to construct  an operational  facility.

     3.    Impact  on Foreign Manufacturers.    Several  foreign manu-
facturers were concerned  that their HA  test  facilities  might  have
to be  located in the  U.S., thereby  increasing  the cost  of  SEA
testing due to shipping costs.  Nissan stated that a high-altitude
test  facility  for SEA  testing,  e.g.,  a  pressure 'chamber,  would be
required at each  assembly plant, or SEA test vehicles would have to
be sent to Denver, Colorado; in either case,  Nissan believes it is
too expensive  and unreasonable.   Renault stated that high-altitude
SEA  testing  would have to be  conducted in  the  U.S. and  would,
therefore,  be very expensive for an importer.  Jaguar/Rover/Triumph
(JRT) believes that  HA SEA  is  financially  burdensome due  to  the
company's lack of HA testing  facilities and  the  distance to suit-
able  commercially  available  facilities.   (JRT  did  not  indicate
where  they  anticipated these facilities  would be   located.)

     4.     Available  Vehicles.   Some  manufacturers  were  concerned

 that a sufficient number of HA vehicles would  not be  available in a
 specified time period for SEA testing.   American Motors stated that
 there would be  a lack  of  sufficient  HA vehicles for SEA testing.
 International  Harvester  stated that,  based  on their  1979 audit,
 SEAs can not be easily  completed in a  short period of time because
 a sufficient number of HA vehicles may  be difficult, if not impos-
 sible, to find. The Motor  Vehicle Manufacturers Association (MVMA)
 stated that  there may be a lack of HA-equipped vehicles to complete
 the  audit  within  a  reasonable  time  period,  especially  for  low-
 volume manufacturers.   MVMA pointed  to  a possible lack of necessary
 engine,  transmission,  and axle  ratio  categories  at  the  assembly
 plant or on dealer lots,  and  stated  that  pre-sold  vehicles would
 further reduce  the number  of vehicles  available.   Chrysler stated
 that SEA test  vehicles required under the batch sampling plans may
 exceed the  entire sales population of a high-altitude configura-

      5.   Sanctions.   Ford asked for a  clarification of the Selec-
 tive Enforcement  Audit  (SEA)  implications  of  the new regulations.
 Ford inquired  whether  a suspension  or  revocation  of  a certificate
 of conformity  would apply only to vehicles operated at the altitude
 at which the  audit failure  occurred,  or at all  altitudes.   Ford
 contended that  EPA  lacks,authority to  suspend or  revoke  certifi-
 cates based  upon testing at any altitude other than the altitude at
 which  the vehicles in  question are  principally  operated.   Ford
 provided  no  basis  for  this  statement.

      6.   Alternative Test Procedures.   Currently the Federal  Test
 Procedure (FTP)isusedtotestvehicles  during  SEAs.    Several
 manufacturers  suggested  that  EPA  use  an  alternate  test  procedure
 for HA SEAs to ease  the scheduling  and cost problems that  the
 manufacturers  believe  will  occur as a result of the HA SEA program.
 American  Motors  and Ford suggested  that EPA adopt  a test  procedure
 patterned after  the   California  Air Resources  Board (GARB)  test
 procedure for vehicles  that  will  be  operated  at high  altitude.
 Ford  further recommended that  a more  representative  driving cycle
 be developed  for high-altitude testing.  Chrysler  believes  that  HA
 vehicles should  be  tested  at low altitude  and  a  mathematical
 adjustment  should be  used to  determine anticipated  high-altitude
 performance.   Chrysler also recommended  the development of  a  more
 representative  driving  cycle.   Nissan recommended,  for  economic
 reasons,  that  altitude compensator  functional  tests be used  for  HA
 SEAs  instead of  chassis dynamometer tests.

      7.   Test Order Criteria.  Section  206(b)  of the  Clean  Air Act
 authorizes the Administrator to test new motor vehicles to  deter-
mine  whether  they  do   in  fact conform  with  the regulations  with
 respect to which the certificate of  conformity was  issued.   Inter-
national  Harvester (IH)  stated that  EPA should  limit  SEA test
orders only to situations where there is a specific  indication  that
 a  vehicle configuration  is  failing  to conform to  the  regulations
at HA.

Analysis of Comments

     1.    Adequacy  of Proposal.   Section  206(b)  of the Act autho-
rizes EPA  to  test  new production vehicles to determine compliance
with emission  requirements  contained in  regulations  issued under
Section 202 of the Clean Air Act.   The Agency established the
LDV/LDT  SEA  program to accomplish that objective.   As additional
standards  become  applicable  to  these, vehicles,  EPA  may  exercise
its  discretionary  authority to test for compliance with those

     The SEA regulations in Subpart G of Part 86 are  structured to
accommodate new  LDV and/or LDT  emission  standards within the
existing  SEA program.   For  example,  when  particulate  standards
become effective in the 1982 model year, diesel LDVs  and LDTs will
also be tested under SEA for compliance with those standards.  The
only changes that  EPA made to the SEA  regulations because of the
new  particulate  standards  were:    additional information  required
with regard  to  particulate testing results  (a new test  procedure
was  promulgated)  and wording changes to  indicate  that compliance
must be  determined  for  all  "regulated"  pollutants  instead  of just
the  "three"  pollutants presently  tested  for  (i.e.,  HC,  CO,  and
NOx) .   See 45  FR  14524-14525,  March  5,  1980.  The only mention of
SEA  in  the preamble to  the  particulate  rule  was  the  discussion of
the  deletion of  separate  SEA test procedures and  the adoption of
the  test  procedures used  during  certification in  Subpart  B of 40
CFR  86,  including  the  new particulate test  procedure,  for SEA

     For the  proposed  high-altitude  emission standards,  EPA had
determined that no  regulatory changes to  the existing SEA program
were required due to the new standards and,  therefore, no proposed
changes were included  in  the NPRM.  EPA  believes  that any unique
situations which may develop  when testing vehicles under high-alti-
tude conditions can be  dealt with  adequately under the purview of
the existing SEA regulations. Manufacturers viewed their high-alti-
tude SEA testing  responsibilities within the context of  the SEA
program as it presently exists and indentified or alluded to these
unique situations.   As discussed  in other SEA subissues, the Agency
believes that all  of the manufacturers' concerns can be accommodat-
ed under the present  SEA program and  has  therefore made no amend-
ments to Subpart G of Part  86 in  this final rule.

     In summary, EPA does not believe that a reproposal describing
a  program  of high-altitude  vehicle Selective Enforcement Auditing
is necessary because this program is already  covered by the present
SEA  regulations.   The  SEA  regulations  apply  to both  high-altitude
and  low-altitude  vehicles  and are not  "impermissibly vague,"  as
Ford suggested, because the special high-altitude  testing situa-
tions and  problems  anticipated by  both  EPA  and the manufacturers,
and  discussed  under other  SEA  subissues,  can be  handled  by the
flexibility contained in  the  existing  SEA regulations,  e.g.,
very low-volume high-altitude vehicle configurations can be tested

using sampling  plans  A,  B,  or C of Appendix VIII of 40 CFR 86, if
necessary  (see Subissue 4);  additional  time  for shipment to
high  altitude  facilities may  be granted  under §86.608(e)  (see
Subissue  3);  and  the  4-test-per-day  requirement may  be relaxed
under  §86.608(g)  if  a  manufacturer  experiences scheduling diffi-
culties at contractor facilities (see Subissue  2).

     MVMA suggested that a high-altitude SEA program  be  established
only  after  a specific need  for  this  program has been  identified.
Experience  with  the  current SEA program indicates that compliance
by  a  prototype  certification vehicle does not  necessarily indicate
that  the manufacturer's  production  vehicles  will   also  meet  the
standards.   Since the  initiation of  the  program in  1977,  eight
vehicle configurations have been terminated  as  a result  of SEA test
orders, with failure rates varying from 72  to 91 percent.  MVMA did
not  identify any  characteristic of  high-altitude  vehicles  which
indicate  that  they will  comply  with high-altitude  emission stan-
dards  to  a  greater  degree  than that  of  low-altitude  vehicles to
low-altitude standards.

     SEA  provides a  logical means  of ensuring that  production
vehicles comply with  standards at  the time of manufacture by
testing vehicles  at  the completion of  assembly.   In this manner,
SEA  provides a deterrent to the production of noncomplying vehi-
cles,  as experience  with the  program has  illustrated,  and  thus
serves to  prevent  introduction  into  commerce of vehicles  polluting
above the established standards.   Considering the substantial
contribution of mobile source  emissions to ambient  HC and  CO in
high-altitude regions  and  the air quality  benefits  to be obtained
from  adherence  to  the  proposed  standards, EPA  sees a very definite
need  for monitoring compliance of motor  vehicles destined  for
high-altitude use.

     2.    Facilities.  Presently, two of  the  five domestic manu-
facturers (GM and Ford) have test facilities in Denver,  Colorado, a
high-altitude location, which are capable of performing  the Federal
Test Procedure  (FTP).   GM has three chassis  dynamometers;  Ford has
four.I/   Chrysler, American Motors  Corporation  (AMC)  and Inter-
national Harvester (IH) do  not  have  their  own  HA test  facilities.
Of  the seven  Japanese  manufacturers,  only  Honda has  an  emission
test facility capable of performing  the Federal Test  Procedure at a
high-altitude  location.^/    Mercedes-Benz  and  Fiat  are  the  only
European manufacturers which  have test  facilities in high-altitude

     At  the  present  time, only  a small proportion  (approximately
4.0 percent) of total  vehicle sales  are expected to occur at high
altitude.   Once the  Agency  is  satisfied  that  HA vehicles are not
more likely to be in noncompliance with the  emission  standards than
low-altitude vehicles, the proportion of test  orders applicable to
HA  vehicles should  generally  approximate   their  sales  fraction.
Thus   EPA  does not  expect  manufacturers  to construct facilities
solely for HA SEA testing if other options  exist.

     Presently,   there  are  two  independent HA  testing  facilities
(Automotive Testing  Laboratory  (ATL) and  Environmental  Test Cor-
poration (ETC)),  both located in  the  Denver area.  ETC has two test
cells, with the  capacity  to do  a total of 12 tests per  eight-hour
shift, while ATL has  one cell with  the capacity to do 6 tests in an
eight-hour shift.47

     Since  fewer  than  12  tests  would  be  required to  complete a
typical HA  audit,  these  facilities  provide  a substantial testing
capability for manufacturers, even  considering those tests required
for preconditioning,  voided tests,  and normal downtime.   Therefore,
with presently available contractor facilities, the Agency believes
sufficient capacity exists to accommodate HA  SEAs as well as
certification and  emission  calibration  testing.   The  ability of
contractors to operate on more than one  shift and the possibilities
of HA  SEA testing by foreign manufacturers outside of the United
States should supplement high-altitude  test facility availability.
Further, if a manufacturer  which has  no HA facility of  its own is
unable  to  schedule a facility  for SEA testing on  an "as-needed"
basis, sufficient  lead  time may  be provided  before actual testing
must begin so as to  enable  the manufacturer to obtain the use of a
HA  test facility.  EPA  may also  exercise its  authority  under
§86.604 of the regulations  to perform HA SEA testing using its own
mobile  emission  testing  facility  (METFac).    In  this  latter  in-
stance,  the  EPA facility would  be  devoted exclusively  to  SEA
testing,  so  that the manufacturers  should  experience  no facility
availability or scheduling problems.

     The  two  manufacturers  (Ford and Subaru of America) who men-
tioned problems with insufficient  lead time  for building a HA
facility  did  not  provide  any  documentation  to  substantiate  the
amount of  time  they  claim  is  needed  to  build  this  facility-
According to ATL,  a  lead  time of 9 months  is necessary to build a
HA test facility.

     In summary,  the Agency believes  that  there will  be a suffi-
cient  availability of high-altitude facilities to meet SEA testing

     3.     Impact  on Foreign Manufacturers.   The  SEA regulations
require  manufacturers to  provide  the personnel  and  equipment
(facility) needed  to conduct testing.   This facility  (the manu-
facturer's own or a contractor's) could  be located anywhere as long
as  the high-altitude  conditions  are  satisfied  when  the  exhaust
emission tests are conducted under  Subpart  B of 40 CFR 86.  There-
fore,  a  foreign manufacturer has  the  option  of  testing at  a HA
facility  in  the  U.S. or  in its  own country.   If  a foreign manu-
facturer has access  to a HA facility in its own country  and wishes
to test  there,  EPA  will  conduct any HA SEAs at  that  facility to
minimize  shipping  costs and  to help  provide  for  more expeditious
auditing.   However,  if  a  foreign  manufacturer elects  to use a HA
test facility in the U.S.,  then EPA will require that manufacturer

to  ship  the HA SEA  test  vehicles  from its assembly plant  (or,  if
feasible, from storage at a U.S. port  of entry) to  the test facil-
ity  in U.S.   Any  increases  in shipping  costs should  be  nominal
since  the vehicles were presumably  destined for sale in the general
area of the test facility.  The Agency's  possible use of its mobile
emission  testing  facility (discussed  earlier)  for  SEA testing may
also  lessen the  impact  of HA SEAs upon  foreign  (and domestic)
manufacturers.  When a manufacturer believes it needs more  than 24
hours  for shipping test vehicles to the appropriate HA facility,  it
can  request additional time under  §86.608(e)  of  the regulations.

     4.   Available Vehicles.   None of the manufacturers'  comments
were  specific  enough  to  demonstrate   to EPA  why  it would  not  be
possible  to complete an  audit.  The  SEA regulations  require  that
the sampling plans in Appendix VIII of 40 CFR 86 be used in select-
ing test vehicles  (§86 .607(c) ) .   These  SEA  sampling plans are
structured  to  accommodate low-volume  configurations, e.g.,  only 21
vehicles need be selected under sampling  plan "A" and the audit can
be  passed  after testing  as few as  4  vehicles.   In certain situa-
tions, not  all of the vehicles need to be shipped to the test site,
e.g.,  if  the audit was passed  before selection was completed.   A
manufacturer may  request  an alternative  random sampling plan under
§86.607(a), provided that the  request  is  made in advance of receipt
of  a test order and that  the Administrator  approves the alternative
plan.   EPA usually does  not  elect  to audit configurations  with a
production volume  so low as  to  cause unexpeditious selection.
However,  if a  HA configuration were chosen for auditing and there
were  problems  in finding  enough HA-equipped  vehicles  to  complete
the  audit,  the  manufacturer could  select low-altitude vehicles and
have them modified for HA use  as a  dealership would, under author-
ity of §86.603(c) and  §86.607(a), since  the HA regulations  require
that any vehicle (including low-altitude  vehicles) manufactured for
sale in the U.S.  shall comply  with  the HA  standards, or be capable
of  being  modified  to  do  so.   EPA is  considering the proposal  of a
sequential  sampling  plan  for LDV  SEA testing  which would  further
ameliorate  problems associated with the  lack of SEA test vehicles.
Using  sequential  sampling plans,  only a small  number  of  vehicles
(as  few as  4)  would have to be selected and tested to complete an
SEA,  and  the selection  of large  numbers  of  vehicles under the
current batch sampling plans would  be  eliminated.

     5.     Sanctions.   Paragraphs (h)  of §86.082-8 and  (h)  of
§86.082-9  require  that  all  light-duty vehicle  (LDVs) and  most
light-duty  trucks (LDTs)  must  be capable  of complying with both the
low and high-altitude emission  standards, "by  initial design,
adjustment,  or  modification," with a possible waiver of  the re-
quirement  for certain low power,  high fuel  economy LDVs.   Ac-
cordingly,  certificates of conformity  certify compliance with both
low  and high  altitude  emission  standards  ( §86.082-30(a)(3)) .
Vehicles  sold  for principal  use  at  high-altitude  locations  must
have undergone  the  required  adjustments  or modifications,  if any,
necessary to be covered by the certificate.

     EPA may issue  a test  order requiring the testing of new
high-altitude vehicles  under high-altitude conditions.  Under
Section 206(b)  of the Clean Air Act  (Act),  the purpose of  this
testing is  to determine  whether  the production vehicles  conform
with  the  regulations with respect  to  which the certificate  of
conformity was issued.   According to Section 206(a),  certificates
are  issued  when  a manufacturer  has  demonstrated conformity  with
regulations prescribed under Section  202.   Since the high-altitude
regulations are  being promulgated under the authority  of  Section
202, a manufacturer that  does  not  comply with these regulations can
not be granted or  retain  a  certificate  of  conformity.   One  of the
regulatory requirements,  as  stated previously, is that all LDVs and
most  LDTs must  be capable of meeting the applicable emission
standards  for any altitude operation.

     If the  results  of SEA  testing indicate that vehicles  do not
comply with the high-altitude standards, then the EPA Administrator
can, under the authority  of Section  206(b)(2) of  the  Act,  suspend
or  revoke the certificate covering those vehicles.   Since any
configuration is originally  issued its  certificate on  the basis  of
compliance with both  low-altitude  and high-altitude standards,  even
if  a modification or  adjustment  to  the low-altitude vehicle was
necessary in  order for it to become a  high-altitude vehicle, the
low-altitude  vehicles  will   also  be  affected by the  suspension/
revocation order.  Due to the audit  failure, the latter vehicles
will  have  not satisfied  the regulatory requirement that they  be
capable,  by  initial  design, adjustment, or  modification, of  com-
plying with the high-altitude  emission standards.

     To suspend  or  revoke  only  the certificates  for  the high-
altitude vehicles may  result  in  certain vehicle models  only being
available  in the  low-altitude  configuration.  This is the situation
that  developed during the  1977 model  year, when  high-altitude
vehicles  needed to demonstrate compliance  only  with high-altitude
standards  in  order  to be  granted  a certificate  of  conformity
applicable only  to those standards.   (Note  that  the language  of
§86.077-30(a)(3) ,  "One such  certificate. . .will  certify  compliance
with no more than one set  of applicable  standards," was amended,  in
§86.082-30(a)(3),   to  add "...except  for  low-altitude  and high-
altitude  standards.")  The  resulting limitations on model  avail-
ability in  high-altitude  areas generated adverse public  reaction
and  caused Congress, in 1977,  to  revoke EPA's separate high-
altitude  certification program.   For the  Agency  to begin  in the
1982 model  year  to selectively suspend  or revoke certificates  of
conformity,  based on altitude of operation,  could  produce the
situation  that Congress  was attempting  to rectify  in the  1977
amendments  to the Clean Air  Act.   EPA will therefore use its
statuatory authority   to  apply a  particular  sanction (e.g.,  sus-
pension of  a certificate)  to  the entire   configuration, i.e.,  at
all  altitudes, when  vehicles  fail a Selective  Enforcement Audit
based on  testing  under either low-altitude  or  high-altitude  con-
ditions, unless the manufacturer can demonstrate, under §86.612(j),
that the  decision to  suspend or revoke  a certificate of  conformity
for a configuration is not  appropriate  for the  configuration  as a

     6.    Alternative Test Procedures.   The SEA  regulations,  at
§86.608(a), require  that  SEA vehicles be  tested  according  to  the
FTP.   This was  done to ensure that the results of SEA tests could
be compared with the applicable emission  standards.  These alterna-
tive  test procedures were also suggested  for HA certification
testing,  but have been rejected by the  Agency-  The GARB  test
procedure  and  the  altitude  compensator  functional test  were  re-
jected for certification purposes because they do  not give a result
that  can  be  compared with  the  standard.   EPA rejected the mathe-
matical  correction  that  Chrysler  suggested  because  it  does  not
yield  accurate  results.  These  alternative test procedures and the
specific  reasons  they were rejected are discussed in the certifi-
cation portion of  this Summary and Analysis of  Comments.

      7.    Test Order Criteria.   In  the  determination  of which
vehicle class  should be  subject  to  a  SEA  test order,  EPA uses
several  criteria  which  provide  information  regarding   potential
nonconformance of vehicles  with  the standards.  These include
certification  emission testing  results,  manufacturers'   assembly-
line  emission  data  from  new vehicles,  and  other indications  of
noncompliance.  In this manner, EPA focuses its  audits  on  those new
vehicle  classes most likely to be  in  noncompliance with  the emis-
sion  requirements.   Therefore,  the  suggestion of  IH is  already
substantially  incorporated  into  the SEA Program.


      Based on  the above analysis it is recommended that no  changes
be made to  the high-altitude Selective  Enforcement Audit program.


!_/   Letters  from GM and  Ford  to T.D. Mott,  U.S. EPA, Ann  Arbor,
     Michigan, both dated May 28, 1980.

2/   Letters  from Japanese manufacturers  to T.D.  Mott, dated  May
~    28, 29 and 30, 1980.

3/   Letters  from Mercedes-Benz and Fiat to T.D. Mott,  dated  May 28
     and 29,  1980, respectively.

4/   Letters  from ATL and  ETC  to  T.D. Mott,  U.S. EPA,  dated  May 15
     and 16,  1980, respectively.


E-   Issue;  High-Altitude Certification

Summary of Issue

     EPA proposed  that  compliance with  the  proposed  high-altitude
(HA) standards be  shown  in  the  same  basic  manner  that low-altitude
compliance  is  shown.    That  is,  emission-data  vehicles  would be
required to be tested according to the light-duty vehicle  (LDV)  and
light-duty truck  (LOT) Federal  Test  Procedure  (FTP).   However,  the
testing would be done at HA instead of low altitude.

Summary of the Comments

     Major Subissues

     1 •     Alternative Certification Test Procedures.   The manu-
facturers  who  commented  on this  issue  mainly requested  that  EPA
drop  the  proposed  certification  program  and  adopt  some form of
alternative  certification program.   Most  commenters   claimed  that
the HA  certification program used in California  (see  the Appendix
to  this  issue)  would be acceptable  to the manufacturers  and would
reduce  their  costs  and  leadtime  requirements.    In addition, MVMA
claimed  the California procedures  have "already been  found  to meet
the needs of high-altitude population centers"  and AMC claimed  that
the California  procedures are "an  effective means of  reducing
high-altitude emissions."   However,  neither  commenter included  any
analysis or supportive data to substantiate the claim.
     2.    Testing in Foreign Countries.   Peugeot  and  Renault both
asked  EPA  to  address  the question of where can certification
testing  be done by  foreign manufacturers.  Could the testing be
done in  their  countries  and the results sent  to  EPA,  or  would  the
testing have to be done in  the U.S.?

     3.    FTP Driving Cycle Change.   Ford and Chrysler  commented
that the driving  cycle used in  the FTP  is  inappropriate for use at
HA.  They  claimed that since performance  is adversely affected at
HA, the  emission-data vehicle will  experience  decreased  accelera-
tion rates and  increased  time  at wide open  throttle (WOT)  when
being operated over  the  driving cycle at HA.   They claimed  that  a
new driving cycle should  be  developed to  represent HA driving
patterns since  the  current  driving cycle  is unrepresentative.

     4.    HA Coastdown.   Honda expressed concern  that the  dynamo-
meter power determination as described in EPA Advisory Circular  No.
55B (coastdown) should not  be used at HA.  The coastdown  procedure
is performed at  low  altitude where the air density is greater  than
at HA.   Therefore,  coastdown power  settings  obtained  at  low alti-
tude would be too high to represent HA coastdown.

Analysis of comments

     1     Alternative Certification Procedures.  Since most  commen-

ters requested that EPA adopt the State of California Air Resources
Board's (GARB) HA  certification  scheme,  a  brief  discussion  of that
program  follows.     CARB's  Manufacturers  Advisory  Correspondence
#78-2  which  explains  the  program  in  more detail  is attached  as
Appendix 1.

     CARB's  basic  requirement  is  that  the tailpipe  air  to  fuel
ratio  (TAFR) during  selected driving  modes   (e.g.,  idle,  30  mph
cruise, 50 mph  cruise, and WOT)  be shown to  be  stoichiometric  or
leaner at  elevations  up  to  6,000 feet except  in  those modes  where
the  sea level  TAFR is  richer  than  stoichiometric.   In  those
instances,  the TAFR up to 6,000 feet must not  be  richer than at sea

     GARB gives three  acceptable  methods to demonstrate  compliance
with  their HA test  requirement.  For  the "Flow  Bench Testing"
method the  fuel  and air mass  flow rates, including  secondary air
injection  if applicable,  are  measured  under   sea  level  conditions
and  under  simulated  conditions  of 6,000  feet of  altitude.    The
results are  compared and if  the  above TAFR criteria are met then
that  vehicle  is  deemed to be  in compliance.   Another method sug-
gested by  CARB is called the "Analytical Method."   This  method
first  measures  the  fuel and  air mass flow rates  at sea level  by
using  the  "Flow  Bench Testing" method.   However,   instead  of mea-
suring  the mass  flow rates  under altitude  conditions, they  are
calculated  from  the  sea level  mass   flow rates using  correction
factors which  were  derived  by  comparing  the  air  density  at  sea
level  to  that  at   6,000  feet  of  altitude.   The mass  flow rates  at
sea  level  and 6,000 feet are compared and  compliance  is  deter-
mined.   The third method  suggested by  CARB  is  called  the "Dyna-
mometer Testing"  method.   The concentrations of  oxygen (02)  and
carbon monoxide  (CO) are measured for each driving  mode  while
operating  the  vehicle or engine  on a  dynamometer.   This  is done
both  under  sea  level conditions  and  altitude  conditions.   If the
concentration of  0^  is  greater  than or equal to  one half  the
concentration of CO, then the TAFR is  considered  to be stoichio-
metric or leaner.   For the sea level driving modes  that have a rich
TAFR,  the  ratio  of  02 to  CO  at  altitude  must be greater  than  or
equal to the same ratio at sea level.

     EPA acknowledges  that  there  is  probably a  reduction  in  HA
hydrocarbon (HC)  and CO emissions which results from CARB's  compli-
ance program.  Certainly the  primary reason for increased HC and CO
emissions at HA as  compared to low altitude is  that the air-to-fuel
ratio becomes richer with increasing altitude.   This  is  due to the
fact  that  the  density of air  decreases  with   altitude.   Thus, the
mass of oxygen necessary for the combustion of  the fuel decreases
with  increasing  altitude  while  the  amount of  fuel entering  the
combustion chamber remains  about  the same.   This  results  in  an
overly rich mixture,  incomplete  combustion and increased HC and CO
emissions.    Furthermore,  fuel  economy  and  driveability   are  ad-
versely affected.    Since  CARB's  HA compliance  program seeks  to
ensure that  enough  0  is  present  to  fully  combust  the  fuel,  the


potential exists  to  improve  HA emissions.   The problem is that the
GARB certification  procedures do not  require  that the 02  be  used
efficiently to reduce  emissions.   For  example, if secondary air is
injected  into the exhaust  manifold or  somewhere else downstream of
the combustion chamber,  the TAFR at HA  can be made stoichiometric
6r  leaner very  easily by  merely being  sure  to  inject  plenty of
ai5' This would   satisfy  CARB's certification  criteria.   However,
this in  no way  guarantees  that  the tailpipe  emissions  have  been
significantly reduced.   Sufficient  oxygen is not  the  only factor
needed to assure further  combustion of the  emissions from the

     For  example, if the  temperature is  too low then there  may not
be much  oxidation of the  unburned emissions.   Proper mixing of the
injected  air  with the exhaust  stream  is necessary because  the 02
and the  unburned  emissions  must come in  contact in order to react.
Residence time is also important  since the more time the molecules
have to  get together,  the  more complete  the reaction will be.   The
GARB procedure does  not account for  any of  these factors.

     The  most  that   the GARB procedure can claim  is  that there is
sufficient  02 available  for potential  oxidation  of  the unburned
emissions during  selected driving modes.  As discussed above, there
are a  number  of  other factors which must be considered to actually
achieve  oxidation of  those unburned  emissins.    Furthermore,  the
GARB procedure does  not even require proof of sufficient oxygen for
the most complex of  driving modes -  transient  operation.   A  car-
buretion  system   designed and  calibrated to deliver enough  air to
ensure a stoichiometric or  leaner  TAFR  at idle  or cruise  or WOT
will not necessarily  give  a stoichiometric or  leaner  TAFR during
transient operation.   Since much of the  operation of  a vehicle is
transient,  especially in  urban areas where  air  pollution  is the
worst,  this  mode is very important.   The Federal  Test  Procedure
(FTP) has transient  operation as a major part of it and, therefore,
EPA's  proposed  HA  certification  program will  account for  this
important driving mode.

     For  the  above   reasons, EPA  is convinced that if  the  GARB HA
certification program were  implemented,  the reductions in emission
levels of HA  vehicles  would  be substantially less than under EPA's
proposal  is needed  to meet  the National  Ambient  Air  Quality Stan-
dards  (NAAQS) in HA areas  (see  the  issue "Air  Quality"  in  this
document),  and  EPA's  proposal  is cost effective  (see  the  chapter
"Economic Impact" in the "Regulatory Analysis" of  this rulemaking),
the Agency  finds it unacceptable  to  use  CARB's  HA certification
program  in  which HC  and  CO emissions  would be  substantially  more
than under EPA's  proposal.

     In  summary,  EPA  believes  that the  proposed  HA certification
program  will  reduce HA emissions  substantially  more  than the  GARB
program  because it  will require closer scrutiny of all the  factors
which  affect  emissions  generation  and  control.  For example, EPA's
proposal  will assure that proper attention  is given to adequate 02,


reaction temperature,  residence  time and reactant mixing instead of
just D£  concentration.   Additionally,  all  driving  modes will have
to be considered,  including  complex  transient operation, instead of
just the four modes required by  GARB.

     Another problem with the GARB HA certification program is that
the emission reductions are not  known.   Although there may well be
some reduction in  emissions  for  California-certified HA vehicles as
compared to  pre-certification HA  vehicles,  the reduction  will not
be  quantified.   If EPA  were to adopt a  HA certification program
similar to California's  (the  significantly  less reduction notwith-
standing),  the  Agency would have to increase  its  in-use  surveil-
lance  to  determine  the emission  levels  of the  HA vehicles.
Because of the large variation in  emission  levels that would likely
occur  among  different  models  under  alternative certification
schemes, it  would  take  a  larger  in-use  surveillance  program to
characterize emissions  since  the  more variation there  is  in a
population,  the  more samples  it takes  to define  the mean and
variation of  that population.  Such an in-use  surveillance program
could be quite costly.

     The reason actual  emission  levels  must be  determined  is
because of their  crucial  role in  projections  of air  quality.   The
national programs   for  reducing air pollution and  attaining the
National Ambient  Air Quality  Standards   (NAAQS)  depend on the
projection of  air  quality  in  different  regions  to some  future
date. If such projections indicate that a region will not meet the
NAAQS,  then  planning  can begin now for additional  air pollution
control programs to bring the region into compliance.  On the other
hand, if the air quality  projections indicate that a region will be
in  compliance,  then additional air pollution programs probably are
not needed.   Thus,  air quality projections are  critical  tools to
help  in  the  decisions of when  more control is needed  as  well as
when enough control has been achieved.  These projections would not
be  possible  if the emission levels of  different  sources of air
pollution  (e.g., automobiles, trucks,  power plants, etc.)  were not

     Emission levels of vehicles also need  to be known in order to
analyze  the   effects  of  proposed urban  projects such  as  parking
structures  and  traffic  corridors.   Such   projects  must  consider
whether or not  the local environment  (in  this case  the local air
quality), can withstand the  additional  stress of the proposed planl
The GARB certification procedure for HA vehicles gives little or no
information as  to  what the  emission levels of the vehicles  might
actually be.

     Another reason GARB's compliance program should be rejected in
favor of EPA's  proposed  program involves what  is  known as 207(b)
warranty protection.  In  1977, Congress authorized EPA to develop a
warranty program  to  protect consumers from  defective  emission
control systems or components.  In Section  207(b) of the Clean Air
Act, 42  U.S.C.  7541(b),   Congress stated  that  if  an  in-use   short


test could  be  developed which had reasonable  correlation with  the
FTP, then that short test could be used to determine whether  or  not
to invoke warranty regulations.

     EPA has spent a number  of years  developing  a short  test which
correlates  with  the FTP.   If a  vehicle  fails the short test,  it
is assumed  that it would fail  the FTP.  Since vehicles are  supposed
to  pass  the FTP  for  the first 50,000 miles of  their  useful life,
something  must  be  wrong  with  the  vehicle's  emission  control
system if it fails before 50,000 miles.  The vehicle owner may have
maladjusted, tampered  with,  or abused the emission control  system.
On  the  other  hand,  the  emission control  system  could  have been
improperly  assembled  and/or installed at  the  factory  or defective
emission control  components  might have been used.  If the  failure
to pass the short test and, by implication the FTP, is the manufac-
turer's  fault,  then  the manufacturer  will have  to pay for  neces-
sary replacement or repairs.

     The 207(b) warranty program will become increasingly important
as  Inspection  and Maintenance (I/M)  programs become  implemented,
and  more  and  more  vehicles  are subjected  to the  short  test.
Congress obviously intended that the  manufacturer pay  to  fix  faulty
emission control systems.    EPA has no  reason  to  believe that
Congress intended that only low-altitude consumers be  afforded this
important warranty protection.  Certainly HA consumers have  just  as
much right  to emission control system warranties  as do low-altitude

     However,  in  order to give HA consumers  this  warranty protec-
tion, a HA  standard  is needed.  Since the short  test  is  correlated
with the FTP,  only  the FTP can be used for HA certification  if  the
short test  is  to  be used  for  HA  warranty protection.  In  fact,  HA
consumers will not have any warranty protection unless the HA, full
FTP,  certification program is implemented.  Theoretically,  if
another  certification  program  (such  as  California's)  for  HA  was
promulgated, then another short test  might be developed which would
correlate with  that  certification test and  HA warranty  protection
could be  provided.   Not  only would  such a  certification  scheme
present  the problems  of  inadequate  emissions control and unknown
emission  levels   as  discussed earlier,  but  the  effort  needed  to
develop a new short test could be huge.  It could take a  tremendous
amount of time and money to develop a reliable new short  test which
could accurately  identify  vehicles   with  faulty  emission control
systems especially  when the  emission levels  at  certification  are
not even known.   It could be  many years  before  HA consumers would
have  warranty  protection.   It may  well  not  even be possible  to
develop such a short  test  and, in that case, the HA consumer might
never receive  HA  warranty protection.  EPA  does  not  believe there
is sufficient reason to  undertake  for the second  time such  a large
effort when the  Agency  already  has   a  short  test and the cost  of
EPA's proposed HA  certification program is minimal as  will  be
discussed below.


     EPA has  determined that  HA areas  need  further HC  and CO
reductions  and  that  reducing LDV and LDT  emissions  to the  levels
proposed is both  feasible and  cost  effective.    EPA is  convinced
that CARB's HA certification  program  will not  provide the  reduction
required to meet the proposed standards.  Therefore,  EPA intends to
retain its HA  certification  program  in  a  modified form to make it
even less  burdensome  than originally proposed.   As  discussed more
fully in the  issue  entitled  "Number  of Certification Vehicles" in
this document, EPA has  reduced  the  cost of certification by about
67 percent.   The  Agency  estimates that the cost of  certification
will increase  the  retail price  of  a new'HA  vehicle by  only 0.01
percent (about $.76).   It will  be even less  if  the  cost  is  spread
over all of the sales of  a manufacturer rather  than  just  HA  sales.
EPA  is  convinced  that the benefit gained  from  retaining the pro-
posed  certification program far outweighs this minimal  cost.

 /   In summary, EPA's HA certification  program  as  modified in this
document is  the most cost effective method  of assuring  that the
required  emission  reductions  are  achieved  in HA  areas.  CARB's
certification program for HA  vehicles not only wouldn't  provide the
required emission reductions  but the amount  of  emissions actually
being produced would be unknown.  This would  lead  to  a  substantial
increase in expenditures by the  Agency to determine actual emission
levels  so  that necessary air  quality projections  can  be  made.
EPA's proposed  HA  certification  program is also necessary to give
HA  consumers  the  same timely  emission control system  warranty
protection as  low-altitude consumers will  have.  EPA's program is
very  inexpensive  and  the burden on the  manufacturers  is  minor.

     2.   Testing in Foreign  Countries.

     Certification protocol  will be  the  same  for both high- and
low-altitude standards.   Currently,  manufacturers  perform emission
certification tests at the facility of their choice and  submit data
to  EPA demonstrating  their  vehicles  comply  with  the applicable
standards.   After reviewing  this data, EPA  may  select a particular
vehicle  for  conformity  testing  at  a facility  designated  by the
Administrator.  This facility may or  may not be  the manufacturer's.
These procedures are  the  same  for both domestic and  foreign manu-
facturers,  and  will  not  be  changed  by the promulgation  of high-
altitude standards.

     3.   FTP Driving Cycle Change.

     EPA received no data demonstrating that  the driving  habits of
low-altitude and high-altitude  residents  differ from one another.
Furthermore,   it  is  not  intuitively  obvious  that just because  a
vehicle performs poorer at altitude, a driver will not  demand  just
as much acceleration at altitude as  would  be  demanded at  low-alti-
tude, i.e., the high-altitude driver may simply  push harder  on the
accelerator peddle.   In this  case, where a  vehicle  operator demands
similar acceleration  the  existing driving   cycle  is  representative
of high-altitude driving  patterns.   Therefore,  there appears to be


no reason to change the existing FTP driving cycle.

     4.   High Altitude Coastdown.

     The  comments  on  this subissue are based on  the  fact  that  the
air  density under high-altitude  test  conditions  (5282 +_  328  feet
or 83.3 +_ 1.0 kilopascal) is less than that under low-altitude test
conditions.  EPA agrees that the lower air density at  high-altitude
results  in  less  aerodynamic drag  on  a  vehicle.   However,  these
high-altitude standards have already accounted for this air density

     Both the  LDV and LOT high-altitude  standards were derived  by
adding an "altitude  increment"  to  a low-altitude  baseline  to  get a
high-altitude  baseline.   Then, the  standard was determined  by
taking  a  percentage  of  the high-altitude baseline (see the  issue
entitled  "Standards"  in  this  document).   The part  of the  above
standards determination  relevant to this  discussion  is the "alti-
tude increment."

     This "altitude  increment" was obtained from MVMA data.  MVMA
tested 25 vehicles at low altitude  (St. Louis) and then tested them
at high altitude (Denver).  The sales-weighted average emissions  at
low  altitude  were  subtracted  from  the sales-weighted   average
emissions at  high altitude  to  give the "altitude increment."   In
the  MVMA  tests  at high  altitude no compensation was made  for  the
decreased  air density  when the dynamometer  load factor  was  set.
Therefore  the  dynamometer load   factors for the high-altitude
emissions tests were  somewhat greater than they would  have  been had
the  vehicles  been  subjected  to the  coastdown  procedure   at high

     It  is  logical to  assume  that since  the  dynamometer  settings
were higher than they would have been  if high-altitude coastdowns
had  been  used,  HC and  CO emissions were  somewhat more too.  This
increase  in HC  and  CO emissions  is  presumably why  the  commenter
requested  that  EPA  consider a high-altitude coastdown procedure.
Since the MVMA  tests  at  high altitude  produced  levels of HC and  CO
greater than  if high-altitude coastdown had been  used, the sales-
weighted average for high altitude  was greater.   Thus  the  "altitude
increment"  was  also  greater  as  was  the high-altitude  baselines  and
finally the high-altitude standards.  In other words,  the  fact that
MVMA did  not account  for decreased air  density  at  high  altitude
when setting the dynamometer load factor carried through the entire
high-altitude standard  setting  technique  and  produce  high-altitude
standards which are  higher  than  they would  have  been had  high-
altitude coastdowns been used by MVMA.

     If EPA had  unlimited  time  and  resources,  the  Agency  could
reestablish the standards (at a lower level) using new test program
data which  had  utilized  high-altitude coastdowns  in setting  the
high-altitude  dynamometer  load factors.  Then  a high-altitude
coastdown procedure  would be  appropriate as  a part  of the  high-


altitude  certification  testing procedure.   However, since  the
Agency does not have unlimited  time  or  resources  and  these  high-
altitude standards already account for the  decreased air density of
high-altitude conditions,  EPA  concludes that  a high-altitude
coastdown procedure is not required or correct  for this rulemaking.

Recommendat ion

     It is recommended that EPA retain the  HA certification program
as proposed except  for  the modifications  discussed in the  issue
"Number  of Certification  Vehicles" which can  be found in this

                 Appendix 1
 State of California Air Resources Board's
Manufacturers Advisory Correspondence # 78-2


                                Attachment to Manufacturers  Advisory
                                Correspondence ^73-2
                                            CA7.3 Policy Kimia
                                            Date Issued:
Subject t   Ccr-pliance with California High-Altitude Test Rcquinsn
Applicability:  1G2Q ar.d s-jbsc-t-j^r.t rr.odel year -passenger  cars,  and
     1S31 and subsequent irodal  year light-duty trucks  and medium-
     duty vehicles.
Raferanca:  Subsection S.d. of the "California Exhaust Emission
     Standards and Test Procedures for 1980 and  Subsequent  Model
     'Passenger Cars, Light-Duty Trucks, and Medium-Duty Vehicles,"
     as amended Septejnber 30, 1977.
Background:  Kany vehicle fuel altering systems  have an Inherent
     enrichment charactsHstlc with increasing altitude.  This
     characteristic can affect sessions of carbon conoxlc'e (CO),
    . which cay be significantly increased by an  excess of fuel or,
     car.versaly, by a lack of oxygen.  California's high-altitude
     test requirement was promulgated  in an effort to stabilize CO
     emissions up to 6000 feet by  requiring sufficient oxygen  in
     the exhaust to  theoretically  maintain sea level CO  emission
 Policy:    A vehicle will  be  deemed  in ccanpliance with Subsection  S.d.
      1f  the manufacturer  dssx>nstratES that the tailpipe air/fual
      ratio (TAR)  1s,  at  elevations up  to 6000 feet, stoichicsetric
      or  leaner In  each of several driving trades.   However 1f a
      Vfihlcle operates  in  a given  driving mode at  sea level with a
      TArR richer than  stoichicssetric, then for that particular driving
      Kxie the manufacturer 1s only  required  to show -that  the TAFR is,

                                  Attachment to Manufacturers Advisory
                                  Correspondence £73-Z
                                       CAR3 Policy Manual
at elevations up to 5CCO  feat,  no  richer than  the  TAR at
sea level.  The driving rodes selectsd  for  tasting shall  be
rcprosar.tatlYS of the full  ranga of normal  driving conditions,
and shall include the following stsady-stata nadss:  idle,
30 tsph road load cruise,  50 tnph read load cruise,  W.O.T.  in
the 20-30 c?h ranga.  Assuming  tha use  of dry  air and indclane
fusl  (hydrogen  to carbon  atom ratio of  1.85),  a TAR of 14.5
shall be considered a^staichiosetric ratio. The vehicle            ,
jgar.ufactur*r ray correct this value for different fuels and/or    "  .
huoidity, subject to approvaj by  the Executive Officer.
    , •                                                            t
Tbrea acceptable nethcds of detannining the TAHl are attached.
Tha first,  "Hew Bench Testing,"  is an  example of a cathod
using flow  bench measurements of the fuel ar.d air inass flow-
ratas ta datarains the TAFR's at ssa level  and altitude.  The
 second, "Analytical  Method," illustrates a theoretical c?i- \
                                                -•  -v.     .  -
 culation of the TAR. at  altitude frcm raaasunsnents of the       \
                                                                  '  w -
 TAR at sea level.  (To  usa tha "Analytical Method" to deter-   /   -V
 crin« ccmplianca of vehicles using  car-burster  fee
                                       Attachment to .M.5nui
                               -70- Attachment '„   ••
                                    Correspondence  #73-2
                                            CARS Policy Manual
                 Methods of Determining the TAFR
I.   Flcvf Bench Testing
     A.   Measure the  fuel and air rass flcwrates, Including secondary
          air Injected 1f applicable, for each selected driving code
          under saa level conditions.
     B.   ffeasure the  fu«l and air mass flowratss, Including secondary
          air injected 1f applicable, for each selected driving rode
          under simulated 6000 feet altitude conditions.
     C.   The TAFR shall be determined frcra the above data using  the
          following equations:
                                  TAFRo "  alo * mso
          Khere n  » mass flcvrrats of intake  air
                a. * mass flowrate of secondary  air injected
                Bf • mass flowrate of fuel
           CFTowrates and densities used here and on the following
           page ara at an altituds of 6000 feet, except that an "o"
           subscript indicates values under standard conditions
           at ssa level.)

                                     Attachment to Manufacturers Advisory
                              -71-    Correspondence #78-2
                                            CARB Policy Kinuil
II.  Analytical  Method (for  ncn-altitude compensated
    • systems, with or without fczdbick control)
     A.   Using the "Flc* Bench  Testing" method, treasure  the  fuel  and
          &1r rass flowratss, Including secondary air  injoctad if
          applicable, for each selected driving rode undar  sea level
          conditions, and calculate the TAFR's fron this  data.  For
          systems with feedback controls, eaJce these itsasurerants
          with the control unit first connected, and then disconnected.
     B.   Tha TAFR at an altitude of 6000 feet may  be  dstarrdned using
          tha above data (for systars with  feedback controls, using
          the Esasursnants made with tha  control ur.1t  disconnected)
          and the fallowing assumptions  and equations:
          Khare p « density of air
          T.   For Idle and cruise driving inodes:
                       »    •      *         *
                TAFR «  n, •»• m,  «  ra4^ * .S4 mfn
                         •f          K09 "fo
           2.   For W.Q.T.  driving rodes
                TAFR  -     + m   -
                           mf        .84  (1.09) nfo      1,09

                               ~72~ Attachment  to Manufacturers Advisory
                                    Correspondence  #78-2
                                            CAR3 Policy Kar.ual
III.  Dynirrseter Testing
     A.    fcisurs  the concentrations of 0^ and CO in the tail pi pa
          *hile operating  the vehicle or engine in each selected
          driving  coda,  both at ssa level and at an altituds (or
          siirulated altitude) cf 6GOQ feet.
     B.   For a given driving mode. If the concentration of 0^ is
          greater than  or  equal to one half the concentration  of CO,
          tha TAFR 1n that driving nade shall be considered to be
          stoichicnetrfc or leaner.
     C.   For a given driving mode, 1f the .concentrate on of Og is
          Isss than one half the- .concentration of CO, the  TAFR 1n
       '   that driving  tncda shall be  considered to be richer than  -
     0.   The relative uagnitudes of  the TAFR's at sea  level  and at
          an altitude of 6000 feet  shall be determined  by  the relative
          sagnitudes of the ratios  of the  0^ to CO concentrations.
          For example, 1f a vehicle operates  in a given driving mode
          at sea level  with an 0-:CO concentration  ratio of 0.3, then
          for  the  sama driving rcode at an  elevation of 6GOO feet, the
          vehicle  must operate with an 02:CO concentration ratio
          greater  than or equal to 0.3.


F.   Issue;  Number of Certification  Vehicles

Summary of Issue

     EPA  proposed  that  any certification vehicle selected  for
testing  at  low altitude could be  selected  for  testing  under
high-altitude conditions.   Additionally,  one  other certification
vehicle for each engine/system combination within an engine family
could be  selected  for high-altitude testing if  such  a vehicle is
expected  to have  high exhaust  emissions when operated  at  high

Summary of Comments

     Most  commenters  stated that  the certification costs  of  the
proposed regulation were  overly  burdensome.   (Certification costs
are  further  discussed in  the  chapter entitled Economic Impact in
the  "Regulatory Analysis"  for   this  rulemaking.)   The  number of
vehicles  selected  to  undergo certification testing (emission-data
vehicles) is,  understandably,  a major  factor in certification
costs.   Under  the proposal,  EPA  could  select as  many  (and even
more) vehicles  for testing under high-altitude conditions as were
tested at  low  altitude.   The commenters  observed that if the same
number  of emission-data vehicles  were  tested  under high-altitude
conditions  as  were tested  at  low altitude,  the  cost  of certifi-
cation testing  for high altitude could  be more than  the cost for
low-altitude certification testing.  This is true because the cost
of  shipping vehicles  to  Denver  for  high-altitude  testing  may be
substantial and, in addition,  testing at  commercial  facilities will
be more expensive  than testing at the manufacturers' facilities due
to the extra link  in the profit chain.

     The  commenters continued that  although  EPA's  proposed high-
altitude  certification program  would be  certifying   less  than  4
percent of LDV  and LDT annual sales,  the  cost of that certification
program could be substantially more than  the  cost  of certifying the
other 96 percent of LDV and LDT annual sales.

     Chrysler  claimed the  proposed  regulations were  inconsistent
concerning  the number of  emission-data vehicles  which  might be
selected  for  testing  under high-altitude conditions.   They  stated
that  §86.082-24(b)(l)(v)  allowed the Administrator  to select only
one  vehicle for  each engine/system  combination  within  an engine
family  while  §86.082-26(a)(3)(i)(D)  allowed  the Administrator to
select for high-altitude testing, any vehicle  that was  selected for
testing at low altitude under §86.082-24(b)(1)(ii) through  (vii).
The apparent contradiction occurs if the  Administrator  selects  (for
low  altitude  testing)  more than one  emission-data vehicle to
represent  a  particular engine/system combination within  an  engine
family.   In practice,  the  usual  case is  that more than one  vehicle
per  engine/system combination  is  selected  for  testing  at low

Analysis of Comments

     The proposed regulation was not as  clear  as  it  could have been
concerning the maximum number of certification vehicles which
EPA  could select  for  testing  under high-altitude  conditions.
However, the  proposed  regulation was not inconsistent as  Chrysler
claimed.   Section  86.082-26  (a)(3)(i)(D) was  correctly interpreted
by Chrysler.   It would have allowed the  Administrator  to select  any
vehicle  that  was  tested at  low altitude  to  be tested under high-
altitude conditions.

     Chrysler's confusion arises from their interpretation of
§86.082-24(b)(l)(V).   Their  interpretation  that this  subparagraph
allowed  the Administrator to select a maximum  of  only  one emission-
data vehicle  per engine/system  combination is  not  correct.  This
subparagraph was intended  to allow the Administrator  to select  one
emission-data  vehicle   per  engine/system  combination  for   testing
under  high-altitude  conditions  that had  not  been previously
selected  for  testing  at  low altitude.   It  would  have  given  the
Administrator  the  option  of  picking a high-altitude,  worst case
calibration if  that calibration had not been selected for  testing
at low altitude.

     EPA agrees that, as proposed,  the possibility exists  that  the
cost of certifying the high-altitude fleet could  be  greater than
the cost of certifying the  low-altitude  fleet.  As discussed  above,
the  maximum  number of  certification vehicles which  could be  se-
lected  is  actually greater for high-altitude certification.  This
fact together with the increased cost of conducting  a  high-altitude
certification test  due  to  vehicle  shipping expenses and commercial
facility  usage  certainly  allows  the possibility of  an expensive
certification program for the high-altitude fleet.

     However, it was never EPA's intent to test the maximum  allow-
able number  of  emission-data  vehicles.   That maximum would have
been about  six emission-data vehicles  per  engine family  assuming
there  is  only  one engine/system  combination per  engine   family.
(This is presently true for the large majority  of engine families.)
In the draft "Regulatory Analysis"  for this rulemaking, EPA assumed
that only three emission-data vehicles per engine  familyl/  would be
tested.   This assumption was intended as a  maximum and a maximum
certification testing cost was  developed from it.  This certifica-
tion testing cost was  (215 engine  families)  x  (3 tests per  family)
x $1,800 per test) x (2 model years) = $2.3M.  Spreading this
maximum  certification  testing cost  over the 1.1 million high-alti-
tude vehicles expected  to  be sold  during  the 1982 and 1983  model
years,   gives  certification testing costs  of  about $2.00 per high-
altitude vehicle.   This represents  a  0.029 percent  increase  in  the
new car retail price if the average retail price  is  assumed to have
been $7,000 2f in 1979.

     In  the Preamble  to the  NPRM,  EPA again  stated that the $2.3M
for  certification  testing  was  a maximum.   Also,  EPA stated that


while  the  proposed  rules  provide broad  selection criteria,  the
number of vehicles actually chosen  for  testing will be  small  and
limited  to vehicles which,  in the Agency's  engineering  judgment,
are  likely to  have poor  emission  performance  at high  altitude.

     Although EPA made  it  clear   in  the  proposal that the  actual
number of certification vehicles  selected  for  testing  under high-
altitude  conditions would  be  small, the  Agency appreciates  the
concern  of the  industry that  high altitude  certification  testing
could possibly be  very expensive.   In order to assure  the industry
that  the  cost  of high-altitude certification  testing is kept
minimal,  we have  changed the  selection  criteria  for  certification

     The new selection  criteria require  the manufacturer  to choose
the  one  emission-data  vehicle  per engine  family  expected  to have
the  worst  emissions  when  tested  under high-altitude  conditions.
The emission-data  vehicle  selected for testing under  high-altitude
conditions  will  be  one of  the emission-data vehicles  previously
selected  for  testing  at low altitude.  Thus,  this regulation will
not cause  the manufacturers  to incur  the  additional cost  of build-
ing  a  new  emission-data vehicle  and of accumulating 4,000  miles.

     The  total cost of  certification has been modified  also.  In  the
draft "Regulatory  Analysis"  EPA estimated  that 215 engine families
would  be affected by  the  proposed  regulation.   The  Agency  had
counted  all LDV and LOT engine families  in that  estimate.   It is
now  recognized   that  vehicles  certified  for  California  sale only
will be exempt from this regulation.  Thus, the estimated  number of
LDV and  LDT engine families  to be certified per model  year is  156.
A  retest  rate of  50  percent is used  in  calculating  certification
costs.   Retests are  often  required  because of  equipment malfunc-
tion, operator  error,  manufacturer and administrative  errors,  lack
of correlation with previous test, etc.   The  cost of  certification
now becomes (156 engine families  per model year)  x  (1.5  tests  per
family) x  ($1,800  per  test)  x  (2  model years)  = $842,400.  If this
maximum  certification  testing  cost is spread  over the  1.1  million
high-altitude vehicles  expected to be sold during  the 1982 and 1983
model  years,  then the  retail price  increase  of  a  high-altitude
vehicle due to certification testing  is about $0.76 or 0.01 percent
of a  $7,000 vehicle.    The impact  on  sales  of  a $0.76  retail price
increase would be  insignificant.

     The  new emission-data  vehicle  selection criteria,  while  not
providing  the  extent  of assurance for high-altitude  certification
that  the  proposed selection  criteria would  have,  will  give  EPA
adequate  assurance  that high-altitude  vehicles  are  meeting  the
high-altitude standards.  Since  the  Administrator can select  any
of the low-altitude emission-data  vehicles  in an engine family,  the
manufacturers  assume   substantial  risk if  they  do not  adequately
design all  of their calibrations  to  meet  high-altitude standards.
Also,  Selective  Enforcement Audits   (SEAs) at  high altitude   lend

incentive to  the manufacturers to adequately  design  all  of their
high-altitude calibrations.

     In summary, although EPA emphasized that the number of certi-
fication vehicles  selected  for  testing under high-altitude condi-
tions would be  kept to a minimum,  the Agency recognizes  that the
manufacturers would  prefer more  definitive  language.   EPA has
concluded that  the new selection criteria (i.e. one emission-data
vehicle per  engine family)  does not  jeopardize the high-altitude
certification  program  and  allows  the  Agency  more  accurately to
estimate the certification costs  of  this regulation.

Rec ommend at ion

     It  is  recommended that  the certification  vehicle selection
criteria  be  changed to  allow the Administrator  to select  one
emission-data vehicle  per  engine  family for exhaust and evaporative
emission testing  under high-altitude   conditions.   This emission-
data  vehicle  can  be  any engine -calibration and  any  evaporative
emission control system offered by the  manufacturer.


I/   "Draft  Regulatory  Analysis;  Environmental and Economic Impact
~~    Statement  for  the Proposed  1982  and  1983 Model  Year High-
     Altitude  Motor  Vehicle  Emission  Standards,"   ECTD,  OMSAPC,
     OANR, EPA.,  pg. 43.

2/   Automotive  News,  1980 Market Data Book Issue,  April 30, 1980.

G.   Issue;  Economic Impact

Summary of Issue

     In the NPRM, EPA assessed  the  economic  impact  of the proposed
regulations.   Among other things,  the Agency  projected  that  vehi-
cles  using  electronic  feedback  emission control  hardware  would
automatically meet  the  standards, or would only require  an adjust-
ment to better  control  open-loop emissions at no cost.   EPA  esti-
mated that  feedback  systems would be utilized  on 90 percent of the
LDVs  in  1982  and  1983.   Non-feedback  vehicles  which required
additional  hardware were  estimated to include  10  percent of  the
LDVs and  all  of the LDTs  sold  at high altitude.   For these  vehi-
cles, EPA estimated an average  of  two aneroids would be required
per vehicle to meet the high-altitude standards, at  an average cost
of $10  per aneroid  (1979  dollars).   The  total  cost of  the package
was estimated  to be $2.32 million  for certification,  $1.4 million
for LDV hardware, and $6.6 million  for LDT hardware.   No change in
fuel consumption was  assumed  in the NPRM.   The  cost  effectiveness
of  the  proposed high-altitude  standards  was  $170  per  ton of  HC
reduced and  $5  per ton of  CO reduced.   The average  cost increase
for a high-altitude vehicle which required additional hardware  was

     In this  section,  the  comments concerning  hardware cost  and
complexity, economic  impact  on  individual manufacturers,  certifi-
cation costs, SEA costs,  and  cost effectiveness  are analyzed.   The
economic  issues relating  to  the $40  vehicle  modification  limit,
fuel economy, exemptions,  and available facilities are discussed in
their respective sections  of this report.

Summary of Comments

     Manufacturers  were unanimous  in attacking  the proposed  stan-
dards because of their  economic  impact.   Generally, their comments
stated  that  EPA had  significantly  underestimated  the cost of  the

     A few private individuals and one  from a high-altitude dealer-
ship commented,  in  a  general way,  that  the  proposed regulations
would unnecessarily increase consumer costs in  high-altitude areas.

Major Subissues

     1.      Requisite Hardware And  Its Cost.     Only comments  con-
taining  specific  information  on   high-altitude  emission  control
hardware are summarized below.  Since EPA has previously  decided to
delete the proposed $40 limit for modifying a vehicle to  conform to
the  emission  standards,  only  those  comments  concerning  vehicle
modification costs that are relevant to the  remaining issue of  the
increment  in new vehicle prices are  summarized  below.

     Ford   -  EPA was given two  different  estimates  from  Ford  con-

earning an  increase  in  the retail  price  equivalent  (RPE)  for
newly-manufactured  high-altitude vehicles.   In  comments  at  the
public  hearing,  a  price  for a  non-feedback  system (aneroid)  was
estimated to range between $35 and $50.   Generally,  this  is a small
increase over  what Ford is currently charging  for an  aneroid
carburetor,  i.e.,  $36  to  $37.50.   The  added cost  was  attributed
to  the  need  for  additional  carburetor  work.   In  Ford's written
comments, a RPE of  $200 to  $225  for LDVs  and  $150 to $180' for LDTs
was  presented.   No elaboration  was  provided to  justify  these
costs.   If  a crash  program .were required to comply with  the
standards,  the  shortened  development  cycle  woul-d  increase these
costs to $800 to $900 for LDVs and $450  to $500 for  LDTs.

     Ford  presented cost  information for  "minimum" and "maximum"
vehicle modifications in their written comments.

     LDV Maximum Modification - $600  (1980 dollars)

               Axle Ratio Change
               Replace Carburetor
               Re-Indexed Distributor Stator
               Transmission Aneroid
               Revised Air Pump Pulley
               Change Speedometer Gear

     LDV Minimum Modification - $280  (1980 dollars)

               Axle Ratio Change
               High Flow PCV
               Revised Choke Pulldown
               Re-Indexed Distributor Stator
               Change Speedometer Gear

     LPT Maximum Modification - $1,100  (1980  dollars)

               Change Front and Rear Axle Ratio
               Carburetor Change with Aneroid
               High Flow PCV
               Revised Choke Pulldown
               Re-Indexed Distributor Stator
               Transmission Aneroid
               Change Speedometer Gear
               Change Driveshaft Assembly

     LPT Minimum Modification - $50 (1980 dollars)

               High Flow PCV Valve
               Revised Choke Pulldown
               Re-Indexed Distributor Stator
               Transmission Aneroid

The  above costs  include labor based  on rates  typical  of Ford
dealers in Denver.


     Ford  also provided  cost  information  at  the  public  hearing.

          Modification             Cost per Vehicle

          Adjust Choke               $ 40 - $ 50
          CAN Change *               $ 30 - $ 50
          Axle Change                $220 - $230
          Carburetor Change          $140 - $330

     Chrysler - This manufacturer presented various comments on the
RPE  for  newly-manufactured vehicles  and  on the cost  of modifying
vehicles.   For feedback  vehicles  (LDVs),  Chrysler  indicated that
two  types  of emission control changes might be  required:  replace-
ment of the electronic spark advance (ESA) module for high-altitude
vehicles  and the  addition of a manifold absolute  pressure  (MAP)
sensor.  Chrysler stated at the public hearing  and in their written
comments that the high-altitude RPE of these changes would be about
$100 and the modification would be  about $200.   They indicated that
the MAP  sensor  accounted  for the greatest  portion  of  these costs.
The new vehicle RPE was broken down as follows:

                   New Car Factory  Installation

Average per Vehicle Variable Design Piece Cost,
Plus, Average Proration of Program  Costs               $55

Fixed and Off Standard Allowance,
Margin and Contingency                                 $20

Dealer Mark-up (includes profit,  overhead, etc.)     $15 to $ 25

Suggested Retail                                    $90 to $100

Chrysler stated that non-feedback  systems  would  have costs similar
to  those for  their feedback  systems.   Subsequent to  Chrysler's
final  written  comments  on the proposed  rules, EPA received  a
request  to  provide a decision in  advance of the  final  rulemaking
pertaining to the  proposed $40 limit  for modifying  a vehicle.  EPA
requested a clarification and elaboration of Chrysler's request and
received additional  information  on costs.  At that  time,  Chrysler
had  decided  that  a  MAP sensor would  not be required but that  a
change in the  ESA  module  would still be needed  to  recalibrate the
opeiy-loop portion  of the  system  for high  altitude.   This  would be
accomplished at  the factory on  newly-manufactured vehicles  at  no
increase  in  price  because there is  essentially no difference  in
cost  for  a high-altitude  unit  versus a  low-altitude  unit.   They
also stated  that  the cost of  replacing  the ESA unit  as  a modifi-
cation would be  about  $270 and  not  the $200 previously reported.
For modifying non-feedback systems  they suggested that the RPE of a
new carburetor was  about $75 to $100 and that the RPE of an aneroid
was about $25.   Labor  for changing carburetors  was  not  estimated.
Chrysler also commented that it was likely that  they may institute
a program for exchanging  the replaced  parts  for  the "modification"

parts which will  reduce  the overall cost of new  vehicle  modifica-
tions.   Replacement  of  the ESA was  cited as  an example where  a
small handling  charge and the  labor  to install  the part  would  be
the only costs of the modification.

     GM - Some LDVs might require wiring harness changes to accomo-
date  additional  control  features.   Since  this  would not  be  prac-
tical on high-altitude LDVs  only,  a cost penalty would result  for
every such  car nationwide.   GM also commented  that  high-altitude
LDVs  would  probably need a  barometric  pressure  sensor and a  pro-
grammable read  only memory  (PROM)  change  at  an  estimated cost  of
$60.  For  LDTs,  GM stated that  air pumps would be  needed  on  their
4.1 liter,  5.0  liter  4-bbl  and  5.0 liter 2-bbl  engines.   These air
pumps were  estimated  to cost about  $50 per unit.  GM  pointed  out
that, if strictly interpreted, the proposed regulations would  force
the addition of air pumps on both high- and low-altitude production
at  an estimated cost  of $25 million.   They  requested that GM  be
allowed to  place  air  pumps only on the  22,000  high-altitude  vehi-
cles  involved.  For diesel  engines, GM  provided  no  cost  estimates,
but  stated  they were optimistic that the  proposed  standards  could
be met with a reasonable recalibration effort.

     AM  -  The  only  significant comment 'concerning  hardware  and
its cost  was  that AM agreed with  EPA that aneroids could be  pur-
chased  for  under $10, but  added  that  design  and  retooling  would
more  than double  the cost  due to limited application.   AM  also
commented in  general  that the  adjustment of parameters covered  by
the parameter  adjustment regulations  (PAR)  would  increase  the  cost
of modifications.

     Volkswagen - Commented  that in the past they  have offered  an
optional high-altitude package  which  included an  aneroid  at a  cost
of between $60 to $80 to the consumer.  Volkswagen claimed the full
cost  of  the option was  $165 and that PAR may make it more expen-
sive.   They claimed they  did  not have enough  time  to supply a
breakdown of the  component  costs for  their  1977 high-altitude  kits
but that  they would provide  the information when  it was available.
(EPA has received no additional  information from Volkswagen to this

     IH - Commented that it  was possible that carburetors  could  be
replaced  as  part  of  a vehicle  modification and  that  the  old  car-
buretor could  be sold as  a  reconditioned  part.  IH  indicated  the
modification cost in  such  instances could be about  $100.   Also,  IH
commented that  fixed fuel  metering systems  would  require  idle
mixture recalibration at altitude  and  that timing and  idle  speed
may also  need  to be  reset.   Thus, three of the  sealed  parameters
may need  to be defeated  in  order  to allow for  adjustment.   Since
PAR requires  that sealed parameters  can not  be  defeated  for  less
than $20, a minimum of $60 may be involved.

     Toyota - The cost to meet the proposed standards was estimated
to vary from $30  to $50.  Toyota commented that  they were planning

to use  an automatic  altitude  compensation  system on  all high-
altitude models  (except  feedback systems) even  in the absence  of
high-altitude standards.   It was not  clear  whether the  estimated
$30 to  $50  was  the full  cost  of their altitude system or  whether
the  altitude standards  would add  this amount to the  existing
price.  Toyota stated  that an axle change was  needed  as  part of  a
vehicle  modification.    They also  commented   that  their  feedback
systems  would  require  an altitude  compensating device  and that
their  evaporative  controls would also  require  additional  compen-
sation  because  some data  indicated  an  evaporative emission  ratio
for low-to-high altitudes  to be 1.7  instead  of  the 1.3 calculated
by EPA.   No further explanation was  given.   Their estimate  of  $30
to  $50  also included  whatever  changes  would  be  needed  to  bring
feedback systems and evaporative control  into compliance.

     Honda  - An automatic  compensation device  (Air Jet Controller)
will be  used  instead  of a  fixed  fuel  metering  calibration  which,
according to Honda, tends to have  some  deficiencies  when  tempor-
arily operated at different  altitudes.   The  price for modifying  a
vehicle is itemized below:

               Item                       Cost

               Air Jet Controller          $ 90
               Replacement Carburetor     $300
               Labor Cost                 $ 30
                 Total                    $420

     The Honda  comments  did not  specifically  address new vehicle
prices for  factory  installed  original equipment orders.  However,
the Air  Jet Controller  described  above is  presumably  the same
altitude compensating system that Honda has provided since 1977 on
most of their models.  Honda describes this  system as being offered
"economically" to high-altitude  customers.

     Nissan  -  The following table  lists  the  components and costs
that Nissan  believed would be  necessary  to modify  a  low-altitude
vehicle into a high-altitude configuration.

Vehicle Type             Component             Modification Cost

Garb Vehicle     Altitude Compensator  Unit
                 Check Valve
                 Vacuum Tank
                 Solenoid Valve
                 Vacuum Switch
                 Timer Unit
                 Vacuum Hose & Harness           $130 -  $170

EFI Vehicle      Altitude Compensator  Unit
                 Harness                          $ 45 -  $ 70

Diesel Vehicle   Aneroid  Compensator
                 Bracket                          $165 -  $185

No estimate of the  price increase  for  factory installed  high-
altitude components was  given.

     2.    Certification.   Several  manufacturers and  the  Motor
Vehicle  Manufacturers  Association (MVMA)  commented  on  the  cost
burden that the proposed standard  would inflict on the  indus-
try.  MVMA stated that certification  testing  is very expensive and
indicated that  special  4,000 mile emission data vehicles  and
50,000 mile durability vehicles would have to be built.   Further-
more they  estimated  that  the  high-altitude certification require-
ment  would involve  25 percent  of the  low-altitude fleet.   GM
stated  that  most of  their  cars  will meet  the  standards anyway;
therefore, certification is the  real cost burden of high-altitude
emission standards.   Based upon this fact they said standards are

     All commenters were unanimous in their advocacy of an alterna-
tive certification program that would allegedly lessen the certifi-
cation burden.   Commenters  urged  EPA to  adopt a program tailored
after  the State of  California's high-altitude  requirement.  This
program allows  manufacturers  to  use  engineering evaluations
in  lieu of full FTP certification  testing.  Ford was  the  only
commenter to try and  quantify  the alleged saving.  They estimated
the alternative  certification  scheme would save $750,000 per year
for their LDVs  or about  $20 to  $25 per high-altitude  vehicle.

     Peugeot asked who  pays  for  shipping  vehicles  to  the United
States for high-altitude certification testing?

     3.    Selective Enforcement Audits.   All  of the  comments
concerning high-altitude SEA stated  that  it would be too  expensive
and burdensome.  Manufacturers  pointed to  logistical  problems
such  as  the  probable  lack of  an  adequate number of  vehicles
already at high-altitude dealerships  from which to select SEA test
vehicles.   They  concluded that vehicles may  have to be shipped in
from  low  altitude  at a prohibitive  cost.   Chrysler  was the only
manufacturer that presented  cost  data for high-altitude SEA.  This
data is summarized below:

Rental of high altitude test  facility          $450 per  test,
                                          plus additional costs

Drop shipment per vehicle                       $ 30 - $120

Shipping costs per vehicle  (up  to 70            $500 - $600
  vehicles involved)

One fulltime engineer to coordinate SEA
  (surveillance) program                       $50,000  per  year


     Chrysler also noted that if  it must  lease  high-altitude  test
facilities the cost could  be  $1.5 million dollars for two  years.
In  a  related comment,  Chrysler also implied  that their  own  sur-
veillance program would be more costly because  it  is difficult  to
conduct such a  program  at  a rented facility, and  that repair and
diagnosis are virtually  impossible.   No  additional explantion  of
these  alleged problems  was given.  It  was indicated  that,  a  full
time  engineer would be required  to select vehicles,  test, and
coordinate this  program.                                .     '

     4.   Economic  Effects  on Manufacturers.  Several manufacturers
commented that  the standards  should  not  be promulgated because
they were so costly at  a time when the U.S. automotive  industry was
experiencing record losses.  Ford  also  commented that  their  finan-
cial and technical  resources are already being strained excessively
by  the  requirements to  achieve  fuel economy  improvements and  meet
the cumulative effects  of other governmental regulations.

     Jaguar, IH, AM, and Chrysler  commented  that the burden  of the
regulation would be disproportiately greater for the smaller  volume
manufacturers.   This  would raise vehicle costs  more  for small
manufacturers than  for  larger ones.

     5.    Cost Effectiveness.   Manufacturers generally  commented
that the standards  would be less cost effective than EPA calculated
in  the Draft Regulatory Analysis when all of the costs  of the
standards are accounted  for.

Analysis of  Comments

     1.   Requisite Hardware  and Its  Cost.   EPA is  frequently
confronted  with  the   issue of what  the consumer cost will  be
for systems  installed  on motor vehicles  for  the  purpose of  con-
trolling  emissions.   Ideally,  it  would be desirable to  determine
the economic impact on the consumer  for any  emission  standard
proposed  and  on any vehicle  for  which such  a  .standard  would  be
applicable.    Such  a task  as  this requires  a  very high  level  of
effort,  whether it is  performed by EPA  or by the manufacturer
when  commenting  on a  rulemaking.   Therefore,  it  is usually  more
realistic to use  generic  descriptions  of  the  requisite control
hardware to represent  the  costs of all  components  or systems  of a
similar nature.  This is the approach that  EPA used to  estimate the
costs of  emission  control  in the  Draft  Regulatory  Analysis  and  is
the approach that manufacturers used in responding to the  Notice  of
Proposed Rulemaking.

     Using generic descriptions of the  requisite  control hardware
can be  very useful if proper attention  is given to  detail and
supporting   evidence.    In almost  every case, the comments  on
hardware costs  were  general  and provided  no breakdown  of the
associated cost  elements or other  supporting  detail.  This lack  of
substance and, hence,  justification,  prevents EPA from effectively
analyzing the manufacturers'  technology cost comments.   As  an

example,  Ford and  Volkswagen stated  that  in  1977,  they offered
vehicles  for  sale with an optional aneroid system.  Ford  said they
charged up to $37.50 for this option  and Volkswagen  said the actual
retail cost  of their system  was  $165.   Ford  provided EPA with no
further description or cost breakdown  for  their system,  while
Volkswagen  provided  a description but  no cost  breakdown  of their
system.  Without further information,  it is  impossible to determine
not  only  why the costs  of  these  two  systems  are so different but
what  the  charge  should be  for  these  types  of systems in 1982 and

      The  Agency  attempted  to ensure  that  comments  would contain
useful information by  requesting  at the public hearings  that
manufacturers  provide  greater detail  in  their  final  written sub-
mittals on  this  rulemaking.   Despite  this request and a reopening
of the comment  period  to allow for further comments,  few manufac-
turers significantly expanded on  their  cost comments.   In fairness
to the manufacturers, it must be  pointed  out  that many of them may
have  been unable to provide  substantive comments because  of their
relative  unfamiliarity with the high-altitude  requirements of their
new  1981  emission systems which will  generally also be used in 1982
and  1983.

      In  addition to  the general and  unsupported nature  of the
manufacturers' comments, EPA's technology analysis found that some
estimates appeared to be very pessimistic and could not be used as
generic  descriptors  of  a  particular  manufacturer's high-altitude
requirements.  As an  example, Volkswagen  and  Nissan estimated that
they  would have to modify their electronic fuel  injection system by
adding an altitude sensor  and  that this modification  would be
expensive.   The  technology assessment  (Issue B) presents evidence
that  these  systems  should have the  inherent  capability of meetng
the  standards without any  change.   Also, Chrysler continually
stated that a manifold absolute pressure (MAP) sensor was needed on
their  high-altitude feedback systems,  but then in response to EPA's
specific  request  for additional  information, stated  that the MAP
sensor would not be needed.   EPA believes  that these  examples
illustrate the  generally conservative trend in  the cost comments.

      Some  of the comments   from  the  same  source  were internally
inconsistent.    In  their  final  written  comments,  Ford  estimated
the  retail  price equivalent (RPE) increase  for  a  factory produced
high-altitude vehicle to be $200  to $225.  At the  public hearings,
a  Ford representative estimated  the  new car RPE  for  an aneroid
system at up to  $50.   In  addition,  although  Ford presented no
justification for their  $200  to  $225  estimate,  they did present a
list  of items  which  were part of a "modification kit."  This list
should  also  represent the  items  that  Ford  would have to  use in
producing a  new  car at  the  factory.   Producing the high-altitude
vehicle is obviously cheaper  than modifying  a vehicle after it is
built:   there are no existing parts  to replace  or modify.   If we
assume that Ford's upper  limit  of $225 is representative of their
"maximum" modification,  the  cost  for  some items can be segregated

and their retail price discussed.   In  this brief analysis assume an
optional axle ratio is  $30  and  the carburetor is $50 as stated at
the hearing:  a total of $80.  If  this cost is subtracted from the
$225  estimate, then  $145 is left to account  for the different
distributor  stator,  transmission  aneroid,  air  pump  pulley,  and
speedometer gear.  These  parts  and their installation as original
equipment should be nowhere  near that  cost.   An examination of the
lower cost  estimate  of $200  for  a new  car  and  Ford's "minimum"
modification is even more  inconsistent.   Ford  lists an axle change
as part of this modification.   However,  the axle they are changing
to must already be used  on a vehicle that also must have some other
modification to meet the standards, so a true minimum modification
can only include  the  changes that must be made to the vehicle
already possessing the axle  that any other  vehicle must change to.
Therefore,  an  optional  axle  should not  be  part  of  the "minimum"
high-altitude package.   Nevertheless, we will  assume $30  for  an
optional axle.   This  leaves  $170 ($200-$30) to  account  for  a
different  PCV  valve,  distributor  stator,   speedometer gear,  and
choke adjustment.   Again this  seems  very unreasonable  for  these
items as original  equipment.

     The above serves only to indicate that if  EPA were to accept
industry cost estimates on face value, a representative indication
of the economic impact  of  these proposed regulations would probably
not result.  Therefore, EPA must develop  its own cost estimates of
the requisite control hardware based  on  the comments  and  the best
judgment of its technical  staff.

     Some  conclusions  regarding  the cost  estimates contained
in EPA's Draft  Regulatory Analysis can  be  made based  on  the com-
ments, however.  The Agency's estimate of the most likely control
hardware, which was based on discussions  with  industry representa-
tives, was  essentially  correct, but the  complexity  of the changes
which may  be required  for  some feedback systems was in error.
The development  effort  was also  underestimated.    Therefore,  the
revised analysis should  pay careful attention to these two areas in

     As  previously stated,  EPA's  costing  methodology should  be
based on generic descriptions  of the systems  that the comments and
the Agency's technical  experience  indicate most  likely to  be used
by manufacturers to meet the proposed  standards.   Implicit in this
approach is the fact  that  some individual systems will cost more or
less than  the  generic  system used  in the analysis.   However,  in
order to ensure that the  analysis  does not  underestimate  the cost
of this  regulation,  the generic systems should  be conservatively
chosen.   This  requirement is  met by using  the following  five
generic systems in the  analysis:

     Unmodified feedback system  - These  systems have  the  inherent
     capability to meet  both the  low-  and  high-altitude  stan-
     dards  as  they are currently designed.   These systems  are
     characterized by  the  GM C-4  system and the Bosch Jetronic fuel

     injection   systems  used  by  Volkswagen,  Nissan,  and  others.

     Recalibrated  feedback  system  - These systems cannot meet the
     proposed  standards  as  currently designed.  A special  calibra-
     tion to reduce open-loop emissions will be necessary.   There-
     fore,  a different electronic  unit  will be used for high and
     low altitudes.   These  systems  are characterized  by  the two
     electronic  spark advance modules that Chrysler  estimates  they
     will need.

     Aneroid non-feedback system  - These  sytems  will  use  a  pres-
     sure-sensing  device on the carburetor  to lean the  fuel-air
     mixture at high altitude.  These systems are characterized by
     the aneroid  carburetors described by  Ford  and Chrysler for
     which EPA has the best information.

     Air injection non-feedback  system  -  Although  EPA cannot
     confirm that  air pumps will be necessary on GM  2.2 liter, 5.0
     liter  2-bbl,  and 5.0  liter  4-bbl LDT  engines, the  analysis
     should account for  this possibility.

     Diesel engine system  - As discussed in the technology assess-
     ment(IssueB),the  analysis -should assume  that  diesel-
     engined vehicles can  comply  with  the  proposed standards by
     simple recalibration.   No additional hardware such as aneroids
     appears to be necessary.

     By  using  these  generic  systems to characterize the high-
altitude motor vehicle fleet,  a  conservative  estimate  will be
ensured  because (1)  there  are likely to  be more feedback systems
that will  automatically meet the  standards  than  are identified  in
the  Agency's technical assessment, (2) there  are likely to be
non-feedback systems, such  as those used by  IH,  that  will employ
different  fixed-calibrations  at high  altitude instead  of  the  more
expensive and  complex aneroid carburetors, and  (3) there are likely
to be  non-feedback systems, as suggested in  the  Ford,  IH, and  AM
comments,  that  will  require changes  as simple as readjusting  idle
mixture  and choke.

     The economic  analysis should  retain  the  assumption  that
current  evaporative  emission control systems  can comply  with the
proposed high-altitude  standard.   Only one  commenter specifically
commented that EPA's calculated ratio of 1.3 was  incorrect.  Toyota
alluded  to "some" data that indicated  for  some  of  their systems
the  correct ratio was  1.7.   No  data or  further explanation  of
Toyota's contention were  supplied  to EPA for  analysis.   Ford had
included the  cost of an  evaporative cannister change  as  part  of
a high-altitude  modification in their comments  at  the public
hearings.   However,  this  was  excluded  in  the subsequent  and  more
detailed final  written  comments.   EPA assumes that  Ford had found
such a change unnecessary.

     2".    Certification.   The  commenters raised three basic issues

regarding certification  costs:  (1) full  certification  testing  as
proposed is expensive and burdensome,  (2) significant cost savings
can be  achieved by  using  an  alternative  certification technique
patterned after  California's high-altitude  program,  and  (3)  who
pays the cost of shipping certification vehicles to a high-altitude
test location?

     MVMA indicated  in their comments at  the public hearings that
the proposed  high-altitude regulations would require the building
of special 50,000-mile durability vehicles and 4,000 emission data
vehicles.  EPA  agrees  that  this would be  very  costly and burden-
some,  but the high-altitude standards  as proposed would avoid this
added expense by allowing  the use of  low-altitude  durability  and
emission data vehicles  for  high-altitude certification.   Also  as
discussed in Issue F, EPA expects to reduce the number of high-al-
titude certification  vehicles and, hence, the cost of certification
from  that  which was possible in  the  proposal.   Instead of  the
possibility that three vehicles per engine family could be tested,
EPA will  reduce this number  to  one vehicle  per  family.  If  156
engine families  are certified at  $1,800 per high-altitude test,  the
cost  is reduced from $2.3  million, as  estimated  in the  Draft
Regulatory Analysis,  to  about  $842,400.   This is about  $0.76  per
high-altitude vehicle.   EPA  dcres not consider  this to be a cost
burden on the manufacturers.

     EPA accepts the manufacturers'  assertions  that  alternative
certification could significantly reduce the  costs of high-altitude
regulations.   However, EPA rejects  the  assertion that alternative
certification is appropriate  for  a  Federal high-altitude  motor
vehicle emissions program.   Alternative  certification is discussed
in detail  in Issue  E,   but  because of  its significance to  the
cost  of regulation,  it  will be briefly discussed here.   It  is
important to  realize that the  savings attributable  to an alterna-
tive  certification  technique  are mainly due  to  the potential
savings in development efforts.  Also,  the savings  in development
are dependent on the fact  that  the alternative  technique  used  in
certification must also be the  technique used in Selective Enforce-
ment Audits  (SEA) of  production vehicles.  If full FTP testing were
used  in  SEA,  EPA believes  that manufacturers would  also  do  their
development  work  using full  FTP testing to provide them with
confidence that   they can pass  an FTP SEA  and, hence,  will not  be
subject  to very expensive  production  line changes and later,
recalls.  EPA feels  that FTP  SEA is  needed to assure that produc-
tion  vehicles do indeed  meet  the  high-altitude  standards;  there-
fore,  development  will not  be significantly  different  whether  or
not EPA allowed  alternative  certification  or  retained  full  FTP
certification.   As  calculated  above,  the  difference cannot  be
greater than  about $0.76 per high-altitude  vehicle.   EPA believes
the benefits  of   full  certification  outweigh this  small cost.   With
regard  to  Peugeot's  comment concerning  shipping  costs,  current
Federal emission certification  procedures call  for  the vehicle's
manufacturer to  assume  the cost  of  transportation.  This will
remain unchanged for  the  high-altitude standards.


     3.    Selective Enforcement Audits.   EPA  is aware  of the
manufacturer^1concerns  about  the cost  of a high-altitude SEA and
will attempt to administer the HA SEA  program  so as  to minimize the
financial burden  on the  industry.   However,  EPA  believes  that  a
high altitude SEA program is necessary for EPA to  fulfill the tasks
mandated by  Congress in the Clean  Air  Act (Act).  Section 206(b)
(10) of  the Act authorizes testing af  vehicles  from the assembly
line.    The  enforcement mechanism  EPA  presently  uses  to perform
these assembly line  tests is the  SEA  program, the major purpose of
which is to  provide a deterrent to the production of noncomplying
vehicles.  Accomplishing this purpose will help to ensure that the
air  quality  benefits  anticipated  from  adopting  the high-altitude
emission standards will be achieved.

     Any increased  cost due  to high-altitude  SEA testing  will
depend on many  factors,  the most significant  of  which are whether
the  manufacturer  has  its own  high-altitude test  facility and the
location of whatever facilities it employs to  conduct high-altitude
testing.  With regard to  facility location,  any manufacturer,
either  foreign  or  domestic,  which tests  in  the  U.S.  should not
experience  any  substantial  increases  in  shipping  costs.   This is
because  during  audits  of low-altitude vehicles, manufacturers ship
vehicles to  test  facilities which  are often hundreds of miles away
from the assembly  plant and then must re-ship them to the correct
(dealer) destination.   When  auditing high-altitude  vehicles  at  a
location such as  Denver,  Colorado,  the  cost of  shipment to Denver
represents part of  the shipping  costs the manufacturer would incur
in  delivering  the vehicle to  its  correct destination,  i.e.,  at  a
high-altitude  dealer in the  Western U.S.   In  the latter  case,
therefore,   little  or  no  shipping  cost  increase  will be incurred.

     Foreign manufacturers which elect to  test  in their  home
countries can be  accommodated under the  existing  SEA regulations.
These manufacturers may incur some extra costs in  shipping to their
local high-altitude facility,  but, as  discussed  in Subissue  4 on
SEA test vehicles, not all vehicles selected may have to be shipped
to the test  site.  With regard to the  cost of  performing high-alti-
tude  testing,  manufacturers  having their  own  high-altitude test
facilities  should  experience  costs similar to those for  low-alti-
tude testing.   If  the  manufacturer  must use a contractor  facility,
however, some additional costs will be incurred.

     EPA has  received  manufacturer estimates  of  the cost of
performing high-altitude  SEA testing at  a  contractor  facility
ranging  from approximately  $800  to  $1050 per test.   Automotive
Testing  laboratory  (ATL)  and   Environmental  Testing  Corporation
(ETC) have submitted information to EPA  indicating that their costs
of  performing  all  of  the procedures  involved in  the  SEA testing
requirements  (drain/refuel, preconditioning,  soak, heat-build, and
emission tests)  average  out  to  about  $875,  which  is  in general
agreement with the manufacturer estimates.

     Manufacturers that must use contractor facilities are general-

ly  small  volume manufacturers whose  low testing volume  does  not
warrant establishing  their  own high-altitude test  facility.   The
EPA emission  testing  laboratory  in Ann  Arbor,  Michigan,  which is
representative  of  a manufacturer  that  only tests vehicles  on an
infrequent basis,  estimates  its  own costs  at  about  $750-1000  per
test.   This cost  is  comparable  to the cost  at  a high-altitude
contractor facility.  Therefore,  a  small manufacturer should incur
no  substantial  cost increases when  contracting  for high-altitude
SEA testing.

     It  should  be  emphasized, when  considering   the  incremental
costs of  a  high-altitude  SEA program,  that  high-altitude  SEA test
orders, if passed,  will  count towards a manufacturer's annual quota
of  audits.   High-altitude audits  are merely being substituted  for
low-altitude  audits  and do  not   increase  the quota.   Therefore,
manufacturers whose audited  vehicles comply with the standard will
experience no increase  in the number of audits they must perform
due to  the  implementation  of high-altitude regulations  in  1982.

     4.   Economic Effects on Manufacturers.   EPA will  make every
attempt to  prescribe  standards that are  the least  costly  to  in-
dustry but that also  adequately protect  the health  and  welfare of
higti7altitude  residents.   In addition, EPA will  implement  and
enforce these  standards  so  as  to minimize compliance costs.

     EPA  agrees  with  the commenters that  the standards  have  the
potential of impacting  smaller  manufacturers  more  heavily  than
larger manufacturers,  simply  because of the  lower production volume
over which fixed costs  can be amortized.   The Regulatory  Analysis
should  identify the  cost of  compliance for each  manufacturer.

     5.   Cost Effectiveness.   The  Regulatory Analysis will include
a calculation of the  cost effectiveness  of  the proposed standards
using  EPA's  revised  cost methodology  and updated air quality


     EPA's Regulatory Analysis should  include a  determination of
the proposed  standard's economic  impact  by  using  generic  descrip-
tions of  the  emission control  systems  that  will be  used to comply
with the regulations.  The analysis  should also reflect the reduced
certification requirement  as  recommended  in  Issue  F.   The  economic
impact  on individual manufacturers  should be  discussed  and  a
new cost-effectiveness  figure  should be calculated.  The Regula-
tory Analysis should not include additional  costs for high-altitude


ll.   Issue;  Environmental Impact

Summary of Issue

     The Environmental Protection  Agency  (EPA)  estimated  that the
interim high-altitude  standards  would  significantly reduce hydro-
carbon  (HC)  and carbon monoxide (CO) emissions from high-altitude
vehicles.   For  Denver, Colorado  the reduction in 1987 would be 0.8
tons/day  for HC and  19.8 tons/day for CO  or a reduction  of 0.6
percent and 2.0 percent for the pollutants,  respectively.

Summary of Comments

     All  automobile  manufacturers commented  that the  interim
standards  are  unjustified and will not result  in  any significant
improvement  in  air quality.  Opposing this view were comments from
political  representatives  and  the  general public which stated that
the standards were necessary to improve  air  quality  and protect the
public health.

Major Subissues

     1.     Justification  for the Standards.   Industry representa-
tives basically stated that Denver's air pollution  problem was not
unique and  was not  serious  enough  to warrant  special  action.

     The  Motor  Vehicle Manufacturers Association (MVMA) submitted
data from  low and  high altitudes of CO  and  ozone levels and of the
number  of  exceedances of  the CO  standards.  MVMA concluded that no
general  trend  relating higher air quality  levels  or exceedances
with increasing altitude can be established.   MVMA also stated that
the National Jewish Hospital monitoring  site in Denver was an
apparent  anomaly because  it  had  a  greater  number  of exceedances
than  the  other  Denver sites.   The MVMA also submitted trend data
showing an improvement  in Denver area  CO  and ozone  levels between
1973 and 1977.

     Chrysler stated  that  eight  of the  twenty cities listed in the
Draft Regulatory Analysis  (RA) as high  altitude  do not meet the EPA
definition  of  high  altitude.  Chrysler  further  commented that
Denver  has now  dropped to fifth place in number of days in viola-
tion of the  air quality  standards  according  to  the  1979 Council on
Environmental Quality (CEQ) Report, instead of being second only to
Los Angeles  as  stated in the RA.

     Many  industry  representatives  pointed  out  that  recent air
quality trends  up  to  1977 have  shown  an  improvement in pollution
levels, and  that  because many new cars  have the  capability to
compensate somewhat for altitude changes,  this air  quality  improve-
ment  will continue  without  the  standards.   Chrysler  went even
further and  stated that  the  ambient air  quality  standard for CO
in Denver would  be  met  within the next  few years even  without


     2.   Effects of CO on Health.   Chrysler  stated  that  no  medical
evidence exists which demonstrates  the  relationship  between  ambient
CO  levels  and  health problems in  the  general public.   Commenters
from the  general  public stated that the  effects of CO  on  indivi-
duals at high altitude were-more  pronounced  than  the effects of  the
same level  of  CO  on  individuals  at  low altitude  because  of  the
thinner air at higher elevations.

     3.    Effectiveness of Interim Standards.   Commenters  pointed
to  EPA's  own analysis of the interim standards'   effect  'on  air
pollution as  evidence of  the  ineffectiveness of these  standards.

     The Colorado  Department  of  Highways  stated  that EPA's  Mobile
Source Emission Factors document  (March 1978) shows low- to high-
altitude ratios  for  recent model year vehicles  to  be 2.06  for  CO
and 1.62 for HC's.   They pointed out that applying  these ratios to
the  1981  low-altitude standards  would result  in  high-altitude
emissions levels  below the interim standards,  and   concluded that
high-altitude  certification  would be  an  unnecessary expense.

     Ford  stated  that a  proportional  relationship   exists  between
low- and  high-altitude  emission levels,   and that  without stan-
dards  high-altitude  emissions will  continue  to decrease  propor-
tionally,  particularly  with  voluntary offerings of high-altitude

     Chrysler referred  to  an EPA  Issue Paper,  February  12, 1978,
"High  Altitude  Emissions  Standards for 1981-83  Model Year  Cars,"
which  concluded  that there would  be  no  air  quality benefit from
1981-83 standards.

     The MVMA  also submitted emission trend  data  for  CO and   HC,
and concluded that high-altitude emission levels have continued  to
decline even though high-altitude standards were  in  effect for only
one model year—1977.   MVMA  stated  that  the reductions  due  to  the
high-altitude standards, shown in  the  regulatory analysis  between
1980 and  1987  in  Denver, are so  small over what   they would  be
without standards  as  to be within the expected  error of emission
inventory analysis.

     The Utah Division  of Environmental  Health commented that  the
ratio of high-  to  low-altitude emissions  has  increased as a  result
of  the Federal Motor  Vehicle  Emission Control  Program  (FMVECP).
They stated  that  the  pre-controlled CO  ratio was  1.61  while   for
1968-74 model years it was  2.46.  For 1975-1983,  with the exception
of  1977,  the ratio  was  2.06.   Utah goes  on  to state  that high-
altitude CO emissions in 1975 were 20 percent greater than  if they
had been  maintained  at pre-controlled levels.   This statement  is
obviously in error.   Examination of that  attached  tables indicate
that they meant emissions were 20 percent  greater than if the high
to  low altitude ratio were maintained  at  the precontrolled  level.


     4.   The Effect  of the  Standards on Ambient Nitrogen Dioxide
and Ozone.    Chrysler  stated that  some high-altitude nitrogen
dioxide (NO2) levels are currently just below the National Ambient
Air Quality Standards  (NAAQS) and  that  if  the  standards  result  in
leaning the  engines fuel-air mixture,  the standards  may be  vio-
lated.  They also  pointed  out  that  NO2 is a  catalyst  for  photo-
chemical  smog  and  that any  increase  in oxides of  nitrogen  (NOx)
from  motor  vehicles could  lead  to a  more severe  ozone  problem.

     5.   The  Effect  of  the Standards  on  the  "Brown Cloud".
Industry  representativesnotedthatthestandardswillhaveno
beneficial effect on the brown cloud.

     6.    Non-Resident Vehicles.   Commenterspointed  out  that
out-of-state cars  are a significant  portion  of  Denver's total
vehicle population  and  so  all cars must  be able to meet  the  stan-
dards when sold, instead of merely being capable of modification  to
meet the standards.

     7.    In-Use Modifications.  Very  few  in-use vehicles will  be
modified and so there  is no air quality justification for requiring
high-altitude certification.

Analysis of Comments

     1.    Justification for the  Standards.   The Clean Air Act
requires  attainment of the CO and oxidant standards by  1982.   An
extension up to  1987  can be allowed  if all  reasonable control
measures  will  not attain the  standards by  1982.   Denver and
Boulder,  Colorado,  and  Salt Lake City,  Utah,  require extensions  to
meet both  the ozone and the CO standards.  Albuquerque,  New Mexico,
has both  an  ozone and  CO  problem, but  is  expected  to  achieve the
ozone standard by 1982.  Albuquerque, New Mexico, Colorado Springs,
Greeley,  and Fort Collins, Colorado require extensions  to meet the
CO standard.   These areas also are required to implement an inspec-
tion and  maintenance (I/M)  program to  reduce HC and CO emissions.
Even with  I/M and other transportation control measures, attainment
of  the standards  in  the Denver  area by  1987 is not assured.

     Chrysler is  correct  in that Denver  is  listed  in  the 1979 CEQ
Report  as  being the fifth  worst  city  in the nation in  number  of
days in 1977 in  violation of  the NAAQS.  Denver was second only to
New York City in violations of the CO standard; however, Denver had
127 days  in 1977 over the CO standard while  New York had  247.
No other  cities  had more than  100  days of violation of the  CO
standard in 1977.  Chrysler's  comment concerning eight  of the areas
listed  as high  altitude not  meeting  EPA's  definition  is  relevant.
The RA has been revised to remove seven of  the cities from the list
of high-altitude areas.   Reno,  Nevada  (Washoe County), was  not
included  in  the original proposal of high-altitude areas but has
since been included.

     The  MVMA  statement that  there  is  no general  trend relating

higher  CO  and  ozone  air quality  levels or  exceedances  with  in-
creasing altitude is  not  surprising.   Ozone is a very  complicated
pollutant which  is  not directly emitted  but  formed in the  atmos-
phere  from  the  photochemical  reaction of  NO and  HC.   There  are
both mobile  and stationary  sources of  these  two  pollutants.   The
high-altitude  areas  with ozone problems  are  isolated  and are  not
affected by  long range transport of ozone  precursors  as are many
sea level cities.

     CO is directly emitted,  almost  entirely,  from mobile  sources—•
motor vehicles.   However, CO  is generally  a  localized problem in
areas with high  traffic  density.   Ambient CO levels are  dependent
on  the  density of  CO emissions  and atmospheric dispersion  condi-
tions such as  mixing  depth  and wind speed.    CO emission  densities
are  in  turn dependent on traffic  volume, vehicle mix, vehicle
speed, ambient temperature,  percentage  of vehicles operating  from  a
cold or hot  start-up,  and altitude.  Finally, the  geometry  of  the
traffic pattern and distance of the  receptor or monitoring location
is critical to the CO level  measured.

     Given all  of  these  factors,  it is far from  surprising  that  a
plot of air quality levels or exceedances against  altitude does  not
produce a one to one relationship.   The fact remains that  emissions
of  CO  and HC  from  mobile sources  are higher  at high  altitude,
exacerbating existing air quality problems.

     The MVMA  assertion  that  the National  Jewish Hosital site in
Denver may be providing anomalous CO data is related to  the  factors
mentioned  above, concerning  the  localized nature  of  ambient  CO
levels.  The fact that all but one  of the sites measuring  CO  in  the
Denver  area  experience violations   of  the standard  indicates that
the  CO problem in the  Denver area  is pervasive  and more of  a
regional nature than is usually the  case.  However,  there  is  a wide
variation in CO  levels due to  variations  in traffic density  within
the Denver area.

     The one site which did not measure  CO  violations in  1978 is  a
new site located on the extreme southern fringe of the metropolitan
area.  This  site is normally  outside of  the "urban  plume" and only
is  affected by  traffic on  a single arterial.   The other sites
ranged  from  four exceedances  above  the  standards at the  Overland
site to  125  exceedances  at  the National Jewish site in 1978.   The
CAMP station experienced  50  exceedances;  CARIH,  25:  Arvada,  15;  and
Welby, 10.  Welby is  located  on the extreme northeastern  fringe of
the  metropolitan area, but  is often  within  the urban  plume  and
indicative of  the  urban  background  CO concentration.  Neither  the
CARIS or  Arvada sites are located  in  high  traffic  density  areas.
The  National  Jewish  site is  at  the intersection of  Colfax  and
Colorado Boulevard,  two  fairly high density arterials.    The  total
average daily  traffic  on  these two  streets  was about 69,000  vehi-
cles in 1978.   The  CAMP  station is  at  the intersection  of 21st  and
Broadway and  Champa Streets.   The  total  average  daily traffic on
these streets was 20,000 in  1978.


     The high  CO levels and  exceedances  recorded  at the National
Jewish  site is  due to the higher traffic  density at  this site
compared to the  other  sites.   The traffic density at this site is
not the highest  in  the Denver area,  however.  For example,  Inter-
state 25 and U.S. 6, which intersect, had  a combined  volume of over
215,000 vehicles  per  day in  1978.   Many  other intersections have
densities similar to that at the National  Jewish site.  Denver does
not have a  center city  "street  canyon" monitoring  site  which may
produce even  higher  CO  levels  due  to the  combination  of poor
dispersion and high density.

     The MVMA  statements about  decreasing trends  in CO  and ozone
must be  qualified.   Ozone  is  a regional  scale pollutant,  but the
area  of highest  concentration  varies  as  the urban plume  drifts
across the city  and reacts  photochemically.   It is unlikely  that a
particular monitor will coincide with  the highest actual  concentra-
tion.   The  station measuring  the highest  concentration  will also
change  from day to day.   Due to this  variation,  ozone  trends are
difficult to establish.  Based on a photochemical dispersion model
calibrated for  the Denver area,  the State of  Colorado was not able
to project attainment  of the  ozone standard by 1987  using Mobile I
emission factors and I/M.

     The MVMA  trend chart for  CO stops at  1977-  CO  levels in 1978
were higher than 1977 and not significantly different than those in
1975 and 1976.  In 1977 the National  Jewish site had  94 exceedances
of the CO standard versus 125 in 1978,  the  CAMP site  had  31 in 1977
versus 50 in 1978.  Colorado  was able  to  predict attainment  of the
CO  standard by 1987  using Mobile  I  and I/M,  but the Mobile I
emission factors are lower than those used  in  the RA.  Mobile I was
based on  the   assumption  that  1980 and later model  year vehicles
would exhibit  the same  ratio  of  high-  to  low-altitude emissions as
1975 and  1976  model year vehicles.   Data from prototype 1980 and
1981 control system vehicles were used  in  the  RA to update emission
factors for 1980-83  model  year vehicles without high-altitude
standards.    This analysis  has since  been revised  to  include new
information.   The new  vehicle CO emission rates  for  1980  light-
duty vehicles  at high altitude  has been  increased  in the revised
analysis from  6.18  to  9.44  grams per mile (gpm) and for 1981-1983
from  2.88 to  6.24 gpm.   Light-duty  truck  emission rates were
increased from  29.90 to  38.31  gpm for  1979 through 1982  model year
vehicles, and  from  8.00 to  27.68 gpm for 1983.  The deterioration
rates  were assumed to  be  the  same  at high altitude  as  at low
altitude.  This assumption may not turn out to be valid,  especially
for  light-duty vehicles.   In  the absence  of standards, vehicles
will be designed  for  low altitude.  This will cause  emissions from
vehicles with  disabled control  systems  to be higher  than  at sea
level due to  richer  mixtures.   There may also be higher tampering
rates at high  altitude due  to poorer  fuel economy  or performance
from  failure  to  design for high-altitude use.   Furthermore, the
Colorado I/M  program  has been revised by the Colorado Legislature
and may not provide  as much  emission reduction by  1987  as was
assumed when  attainment  of  the CO standard  was  demonstrated.

     The estimates in  the  RA for the  air  quality benefits of the
standards may be substantially higher  if  there  is  a higher reliance
on control  technologies  which are  not inherently altitude compen-
sating.  Ford Motor Company stated at  the public  hearing that most
of their vehicles  would  utilize non-feedback carburetors in model
years  1982  and  1983.   The  RA has been revised to account for this
change in technology  by Ford.  Other manufacturers may rely more on
technology which is not altitude compensating over at least part of
the  vehicle operation cycle.    These  standards  are  necessary to
ensure  that  excessive  emissions  from  such  systems will not result
in high-altitude areas.   The RA has  also  been revised to account
for the higher usage of  light-duty trucks in the  Denver area.  The
reduction  in  total Denver area  1987  emissions  has  increased from
0.6  percent to 1.0  pecent  for  HC's  and  from 2.0 percent  to 3.4
percent for CO.

     Without the high-altitude standards, the State of Colorado and
other  high-altitude  states  would be  required  to  adopt additional
control measures to make up for the loss in motor vehicle emission
reductions.   In order  to be  granted  an extension beyond 1982, the
Clean  Air  Act  requires that all reasonably  available  control
measures be adopted as  expeditiously as practicable.  Attainment of
the  standards is required by  1987.   It would not be reasonable to
expect high-altitude  nonattainment states to provide any additional
measures beyond those that  are already required  in order to make up
for the lack of the interim standards.

     2.    Effects  of CO  on Health.   Justification of the NAAQS for
CO is  not   necessary in  an  automotive emission regulation action.
Ambient  standards  are  promulgated  in  separate  rulemaking actions
which  provide  an opportunity  for  public  review  and  comment.
However, a  brief summary of  the NAAQS for  CO will be presented in
response to Chrysler's  comment.   The justification for  the CO
standard is  contained  in the air quality criteria document.   Air
quality  criteria documents  are  required by Section  108(a)  of the
Clean  Air  Act  to  identify effects on public health  and  welfare
caused by varying amounts of  pollutants in the air.  These criteria
must be supported by  the latest  available  accurate scientific
information.   The  purpose of these  criteria  is  to  identify air
pollution  effects  and  serve as  the basis  for  NAAQS.   The original
criteria document for  CO,  the National  Air  Pollution  Control
Administration publication  AP-62, was  issued in  1970.

     Section 108(c) of the Clean Air  Act requires that the Admin-
istrator of  the EPA  from time to time review and, as appropriate,
modify  and  reissue criteria  published pursuant to Section 108(a).
Section  109(d)(l)  requires both  that  the Administrator complete a
thorough review and,  as  may  be  appropriate,  make  revisions in the
criteria by December  31, 1980,  and at five-year  intervals there-
after.  EPA pubished  a preprint of a revised criteria document for
CO in  October  1979, (EPA-600/8-79-022).  This document states that
fetuses,  persons   with  cardiovascular or  central nervous  system
defects,  sickle  cell anemics, young children, older  persons,


persons living at high altitudes,  and those taking drugs, comprise
groups at special risk to CO exposure.   There  is  little information
regarding the  high  risk groups;  however,  it  is apparent  that
exposure for eight hours to CO concentrations  as  low as 15-18 parts
per million (ppm)  may be detrimental to  the  health of persons
suffering  cardiac  impairment.  Such  concentrations  are  routinely
exceeded in high-altitude areas.  In 1977,  there were 18 days with
CO levels above 15 ppm in the Denver area.

     CO  affects  health  because  it  decreases the  oxygen carrying
capacity of  blood.   At  high  altitude  there is  less oxygen avail-
able anyway, and  so the effects are additive.  While residents of
high-altitude  areas may somewhat  adapt  to the  lack  of  oxygen
(18  percent  less  available  oxygen  in  Denver  than at  sea  level)
overlong periods of  time, visitors and  tourists  are not able to do

     3.   Effectiveness of Interim Standards.  The  Colorado Depart-
ment of Highways comment that the  interim  standards are higher than
the  high-  to  low-altitude ratio  for 1978  model year vehicles
applied  to  the  low-altitude  standards disregards the effect of the
control  technology  which  will be  used to meet  the low-altitude
standard.   Data from  prototype vehicles  (tested at  low and  high
altitudes and representative  of the types of  control technology to
be used  in 1982 and  1983)  was used in the regulatory analysis to
determine  the  expected  high-altitude  emission rates without stan-
dards,  as  explained in  the  Justification of  Standards Section.

     The  EPA  Issue  Paper  referenced by Chrysler  was also written
without  consideration  of the effect of control  technology differ-
ences  on the high-to low-altitude ratio.   The issue  paper  and
Mobile I emission  factors  were  developed prior to  the availability
of emission data on  prototype 1981 control  systems.   In the absence
of such data, the assumption that  1981-1983  vehicles would have the
same high-  to  low-altitude ratio  as 1975  and 1976 vehicles is the
best that  could be  made.   However,  the  high-  to  low-altitude ratio
has  changed  as  the control technology  has changed.  The following
table  gives the high-  to low-altitude ratio  for various  technology
classes  as calculated  from  Mobile I  emission factors based on
actual test data.

          Model Year        High-  to Low-Altitude Ratio
                                 CO            HC

          Pre-1968              1.61          1.36

          1968-1974             2.46          1.67

          1975-1976             2.06          1.62

     As  can be  seen, the ratio does vary with control technology.
1981 model year emission  standards  for  low  altitude are  0.41,  3.4,
and 1.0  grams per  mile  for  HC,  CO,  and  NOx  respectively  (excluding


waivers).    In  1975 and  1976,  the  standards were  1.5,  15,  and 2.
Considerable changes in  control  technology  will  occur between the
1976 and 1981 model years, and the high- to low-altitude ratio can
also be expected to change.   The use of prototype data provides a
better  estimate of how emissions  will vary with altitude  than
assuming  that the ratio will remain constant  when the control
technology changes.

     This   same  discussion  applies  to  Ford's  comment  that  high-
altitude emissions  will continue to  decrease  proportionally  with
low-altitude emissions.   Ford  also  stated  that  some high-altitude
calibrations will be made available  voluntarily,  but the impact of
such a  voluntary program would be impossible  to estimate.   In
fact, Ford was unable  to determine the number of vehicles sold with
optional high-altitude  calibrations  in  past voluntary programs.

     The MVMA  similarly relied  on  past trends  in low-  to  high-
altitude emissions and  did  not  consider the  impact of  the  newer
technology's response to  altitude changes.  MVMA also referred to
the  continued decline  in high-altitude emission  rates  after  1977
when no high-altitude  standards were  in effect.  This decline is in
part due to  the  turnover of vehicles,  i.e.,  older high polluting
vehicles being replaced  by  new  lower polluting vehicles.   Another
factor in this decline was the carryover of 1977  certifications of
high-altitude vehicles  into 1978 and  1979.   With the  change  in
emission standards in  1980  this  carryover  stopped; therefore,  the
rate of decline  will  not continue  to be enhanced  by this effect.

     The MVMA  statement that the emission  reductions due  to  the
interim standards in the Denver  area  are so  small as to be  within
the  errors  of emission  inventory  analysis  is misleading.   An
emission  inventory,  particularly  for motor vehicles, has many
sources of error.   The  reductions due  to the interim standards  were
calculated by holding those other sources of  errors constant.
Thus, these  sources of error were moderated in  the  analysis,  and
the reductions indicated are as  good  an estimate  of the impact of
the  standards as  can  be made.   As  stated  in  the Justification of
Standards  Section,  the  RA has been revised and the estimated  impact
of  the  interim  standards increased.  The reductions  presented  in
the  draft  analysis  were  significant  and  favorably  comparable  to
other emission control  strategies of  similar  cost  as presented in
the RA.   The revised  estimates are even more favorable.

     Another benefit  of the standards will be  to provide  the
protection of the warranty provided  by Section 207(b) of the Clean
Air Act.  This warranty provides that properly maintained vehicles
failing an I/M test must be  corrected  at the vehicle manufacturers'
expense for the vehicle's useful  life, although after the first two
years or  24,000  miles the manufacturer's  liability  is  limited  to
devices which are  solely or primarily used  for  emission control.
EPA regulations will make  this  warranty available in low-altitude
areas beginning  with the 1981 model  year.   Since  1981 vehicles are
not  required to meet  standards at high  altitude, the warranty


cannot apply  at  high  altitude.   Promulgation  of the  1982  and  1983
interim  high-altitude  standards will  end  this  inequity  for  con-
sumers in  the high-altitude areas with  I/M  programs.   Additional
air  quality benefits may  also  result,  since  any cost limits  on
maintenance  required to pass  an I/M program  will  not apply  to
vehicles covered by the warranty.

     The Utah Division  of Environmental  Health  commented  that  the
high-  to low-altitude  ratio  for pre-controlled vehicles (pre-1968)
was  lower than  for controlled vehicles (post-1968).   The Clean  Air
Act, however,  requires  EPA  to  base the high-altitude standards  on
1970 model  year  emission  rates.   It  is unfortunate  that the high-
to  low-altitude  ratio for the  1970  control  technology  was higher
than either  pre-controlled or  catalytic converter controlled
vehicles because  this  relationship  results  in a  more  lenient
standard than if any  other  model year was used  as  the baseline.
This  fact,  however,  should  be  considered  upon  setting the interim
standards.   The most stringent standard that  can be  justified  from
the  available data  on 1970 model year high-altitude emissions
should be used.

     4.   The Effect of the Standards on Ambient Nitrogen Dioxide
and Ozone.    While controlling  HC and CO  emissions  may cause  an
increase in  NOx emissions over  what they would be without  the
standards,  the  high-altitude  NOx  standard must still  be met.
The  high-altitude NOx standard is  lower than  present  fleet average
high-altitude NOx  emission levels.  Even though high-altitude
emissions of  NOx of 1982 and 1983 vehicles may increase  slightly
over  what  they would be  without  standards,  the high-altitude  NOx
standard (1.0  gram per mile for light-duty vehicles)  is  much lower
than high-altitude NOx levels for  any model year prior to 1981  (the
lowest new vehicle  NOx rate prior  to 1981  was  1.5 gpm  and  the
average  fleet  NOx  rate  for  1982 is  1.77 gpm).  Thus,  overall
ambient  N02  levels will  continue  to  decline with the  interim
high-altitude standards.

     Denver  is the  only high-altitude area  with high levels  of
N02-   Denver   only marginally exceeded  the standard   from  1975  to
1977,  and  in  1978 N02 levels were  below the  standard.   Denver
also has levels of  ozone which  exceed the national standards.
Analyses  of attaining  the ozone standard by  the State of  Colorado
and EPA indicate that reductions in HC emissions are  more  critical
than reductions  in N02»   Furthermore,  reductions  in  vehicle miles
traveled (VMT)  in  the Denver  area  are  needed, in addition  to
reductions   in per-vehicle  emissions,  in  order  to provide enough
reduction in HC's to  attain  the  ozone  standard.  These required  VMT
reductions  will also  reduce ambient N02 levels.

     5.     The Effect  of  the Standards on the "Brown  Cloud".    The
assertion that the   standards  will  have  no  beneficial eTfect  on
Denver's  "brown  cloud"  is  based  on the MVMA's  "1978  Denver Winter
Haze Study."   The MVMA study concluded that automobiles contribute


about 14  percent  of the  "brown  cloud."   About  36  percent  of the
cloud was  unidentified,  14 percent  was  from  diesel vehicles, and
about 27  percent  was from  fuel  combustion  in stationary sources.
The remaining 9 percent was water and crustal material.  The  study
relied highly on emission factors for these allocations.  The only
emission data  for  particulates from motor vehicles  at high  alti-
tude, used  in  the study,  were from ten  1970  model year vehicles
which were  restored  as  completely  as possible  to   a  new vehicle
condition.  Data presented  by  the  MVMA  does  show that particulate
emissions from automobiles are  increased by rich air-fuel mixtures.
However, the ten  1970  model year vehicles were  tuned  to manufac-
turers'   specifications  and may  not  have been  as rich  as  in-use
vehicles.  Furthermore,  no catalytic  converter vehicles were tested
to establish high-altitude particulate emission rates.

     The lack of particulate emission data from in-use vehicles at
high  altitude  leaves  the contribution  of  motor vehicles  to the
brown cloud still  very  much in  question.

     The primary effect  of the  proposed standards will be to reduce
HC  and  CO  emissions,  by obtaining  altitude  compensation  of  non-
feedback vehicles  and  phases  of feedback  vehicle operation  which
are  "open  loop."   This  compensation will  provide leaner air-fuel
mixtures which will  also  lower particulate  emissions.   The effect
of  these  lower particulate  emissions on  the brown cloud cannot be
determined at this time,  but the  effect will tend to be beneficial.

     6.    Non-Resident Vehicles.   Although there may be a signifi-
cant  number of non-resident  vehicles  in the  Denver area,  high
levels  of CO and  ozone   are primarily  due to  rush  hour traffic.
Non-resident vehicles  are not  a  significant  part of rush  hour

     7.    In-Use Modifications.   The  State of Colorado is requiring
the  use of high-altitude  performance adjustments  developed  under
Section 215 of  the  Clean  Air Act  on  vehicles  failing  the I/M
program.   Such  a  requirement  could  also be  used  for  the interim
high-altitude standards.  Of course,  the proposed regulations
require all new vehicles  sold for principal use at high altitude to
be modified prior  to  delivery.


     The finding required by Section 202(f)(3)(c) of the Clean Air
Act,  that   the  interim  high-altitude standards  will result  in  a
significant improvement in air quality, should be made  in the


I.   Issue - Leadtime

Summary of Issue

     EPA  proposed  that  the  interim  high-altitude  standards take
effect  in  the  1982 model  year  for light-duty vehicles and  light-
duty trucks.

Summary of Comments

     Comments on the  leadtime which is available before the stan-
dards  become  effective  were directed at  the  time  required  to
develop the  necessary hardware  and the exaggeration of the  normal
development  time  because  of  inadequate high-altitude  test  facil-

Major Subissues

     Development Leadtime - Cars:    Many  manufacturers  commented
that time was not  available to develop  hardware  for the 1982 model
year. GM commented that  their C-4 system could meet the 1982 date
only  if any necessary modifications  were  extremely minor.   In
another comment, GM stated that leadtime was nonexistent  for 1982
because they have  already begun certifying  some subcompact models
for  that  year.   Chrysler commented that  they had  enough  time  if
all  that  would be needed were  modifications to the electronic
components of the control system.  But  if more significant hardware
changes needed  to  be made  (i.e.,  MAP  sensor),  the  decision would
have to have been  made in the spring of 1980.  However, in a later
communication with EPA (see the docket) Chrysler stated that they
would not need a MAP  sensor.  Nissan stated  that  for 1982, a final
decision on the system must be made in  the summer of 1980, and also
that development would take one  year.   Ford  commented  that for the
1982  model year,  development  should  begin in  July  1980.   Ford
also  stated  they  didn't  have enough leadtime  for  aneroids  on all
vehicles but were  planning to meet standards with unique calibra-
tion.  AMC  stated  that they could  not  adapt  GM's  control system to
their vehicles by  1982 and possibly not by  1983 because of  a lack
of experience with the system and  conflicting  resource commitments
with  other  programs.    NADA  commented  that  the  interim standards
should  not  be  finalized  because manufacturers need  until  1984  to
design  high-altitude   vehicles.    Jaguar  submitted  two  divergent
comments.    First,   they  said  there was insufficient   leadtime for
testing to  determine  changes.   Second, they  said  they  were con-
fident  they could meet  the  standards  except for those  engines
which were granted a CO  waiver-   Finally, Jaguar stated  their
suppliers  need 6-10 months notice  before  production starts to make
hardware change.   Toyota  and  Puegeot generally commented there was
insufficient time to comply.

     Development Leadtime - Trucks:  Chrysler stated that there is
no time left  to make  the necessary carburetor tooling changes  on
their 318-2 trucks.   AMC  maintained there  was  inadequate resources


and  time  to  modify their trucks  for  1982  or even by  1983.   They
claimed that extensive  retooling  and  design would be  needed.   GM
stated that air pump capacity for 1982 would not be sufficient for
national  production,  but if  allowed  to put  them on  at altitude
only,  they  would  have  enough.   GM also commented  that  the truck
standard should be delayed until  1983.   Ford commented  in a general
statement that there  was inadequate leadtime for all of  their
vehicles  to meet the  1982  standards.   IH commented  there  was
inadequate leadtime to  incorporate aneroids on their trucks by the
1982 model  year and indicated  they  would  be forced  to  use fixed
calibrated carburetors.

     Leadtime - Facilities;    Several  manufacturers  commented that
there  were  inadequate  facilities   for  high-altitude testing.
Ford stated that their  facilities  were limited.  More specifically,
Fuji made  two  comments  concerning their need to  construct  a high
altitude  test  SHED because  of  the likely  unavailability  of com-
mercial facilities  at  Denver,  Colorado.   In their  comment  at  the
public hearings,  they  said   it  would  take  22 months  to  build  and
operate  their  SHED.   However,  in  their written comments,  they
indicated that 12  months would be  needed.  Nissan commented that if
demonstration  tests are required, more facilities  will  be needed
and  that  even  meeting  the  standards  in 1983 would  be difficult.

Analysis of Comments

     Development Leadtime -  General;   The determination of adequate
leadtime  involves  two   central  issues:   technical  complexity  and
availability of testing facilities.   In  this analysis the issue of
technical  complexity  is  examined  to  find  if  enough  leadtime  is
available to adequately develop and certify high-altitude emission
control  hardware for  1982  model year vehicles.   The issue  of
available facilities is  examined  in the  section entitled, "Adequacy
of Existing High-Altitude Test Facilities."

     Leadtime  is  dependent  upon  the  complexity of  the  requisite
control technology  and  the  effort required  to  translate  the tech-
nology  into  production  hardware.   Manufacturers'  comments  lacked
adequate detail with which a  specific analysis could be conducted.
Alternatively,   this analysis  of leadtime is  based  on "worst case"
examples which  will require  the  longest  time.    If  adequate time
exists in which to  develop,  certify,  and produce  the "worst case"
examples, than  it  is reasonable  to expect  that  other less complex
and, hence,  less  time  consuming changes can be made.   Therefore,
this analysis begins with a  delineation of "worst case" development
requirements to characterize the  level of  effort  which  will  be
required to meet  the 1982-1983  standards.   After  the hardware  has
been described, it  will be  related  to the  historical development-
certification schedule  of the automotive industry.  Conclusions can
then be  drawn  regarding the adequacy of  leadtime based  on  the
complexity of  the required hardware  and the way in  which  the
industry has historically dealt  with  similar problems in the past.

Finally, this analysis will briefly review some of the comments for
support of the conclusion.

     The  principle  control strategy for vehicles  that  do not have
the  inherent capability  to  meet  the  standards  is  to  enlean  the
.fuel-air mixture  to  promote more complete combustion.   After
carefully reviewing  all of the  comments and  after conducting
an  independent  investigation, EPA Relieves that  this will  be
achieved  with  recalibrations  of  engine  and emission control param-
eters.   The  required  recalibrations will probably  include  short
leadtime  tooling  on  both  feedback  and nonfeedback  systems.
The  most  critical,  or  "worst  case," hardware modifications include
calibration  changes to carburetors  for  non-feedback systems and the
addition  of  electronic  components  for  feedback  systems.   Other
techniques include  changes to timing, air pump, and EGR.

     Several  commenters pointed out  that not enough time is avail-
able  for developing and  tooling  long-leadtime  items.   EPA  is  in
basic  agreement  with  these comments.  However,  the Agency rejects
the  position that major hardware and tooling changes are necessary
to  accomplish  the  types  of  control  strategies  mentioned  above.

     For  non-feedback  systems, modifying  carburetors to accomplish
enleanment  can  be  accomplished by using either fixed  calibra-
tions  or automatically  compensating aneroids.    Aneroid  controls
are  preferred because they can   provide near  optimal control
at various altitudes and,  because,  if  properly designed, they have
the  potential of  providing less complex and  lower cost  high-
altitude  modifications.   Aneroids  are currently  available on some
car/truck  models;  other  models could  easily  change  to  existing
aneroid controlled  carburetors;  while still other carburetors could
be modified  by  machining air  bleed passages or through  simple
modifications to castings.

     The remaining  non-feedback carburetors, could be redesigned to
accept  an aneroid  only by more complex  changes  to  die patterns.
This type of change is a long leadtime  modification.  In developing
the  parameter  adjustment  regulations,  manufacturers commented that
these more complex  changes can take  1.5  or more years to complete.
Therefore, aneroids can not  be  used to  comply with  the proposed
high-altitude standards in all cases.  In these instances, however,
manufacturers  can obtain  the  same  emission control  results  at the
design  altitude  by using  carburetors  specifically  calibrated for
use  at  high  altitudes  (fixed calibration).  This  type  of control
hardware  has been  certified  for high  altitude  sales  in  the past
by GM.   Fixed  calibration carburetors  cannot  be optimized for
different altitudes and can be  somewhat  more expensive if vehicles
are  modified from  a low-altitude  configuration  to a high-altitude
configuration.   But  they do offer substantial  control  at high

     Optimal high-altitude  fixed  calibrations  can usually be
achieved by  simple  machining  or  readjustment of certain carburetor


parameters.    Fixed  calibrations  will not  require  long  leadtime
retooling efforts  as might  be  necessary if the  whole  carburetor
casting pattern had  to be modified  in order  to accept an aneroid.
Recalibration of  low-altitude engine/emission  control  systems for
high-altitude use  can be  accomplished  by  changing such items as the
fuel  jet(s),  the   choke,  the power  enrichment circuit,  the  idle
fuel-air  mixture,  the idle  speed,  etc.   The time to make the
tooling  changes required to produce the above  described  fixed
calibrations is  basically  a  function of  the number of  tests
that are needed.   In the  Regulatory Analysis  for  this rulemaking,
EPA has estimated  that not more  than about 150 tests on the average
(i.e., Federal Test  Procedure not  including  evaporative emissions
determination) will be required  for  each  IDV  and LOT engine family
to  determine  high-altitude  fixed  calibrations.   At  the  very slow
testing rate of only one  test  per day,  the 150 tests can be finish-
ed  in  less  than six months, thereby leaving  plenty of  time  to
implement  any  minor  tooling  changes  before  August  1,  1981.

     EPA  currently  estimates  that 70  percent of  the vehicles
manufactured  in  1982 and  1983  will  use  feedback (electronically
controlled)  fuel systems.   All  of these systems have  an inherent
capability to compensate  for changes in altitude.   In this regard,
some  systems  have  a greater range  of compensating  authority than
others.  Although many systems  appear  to be  able  to automatically
meet  the  high-altitude  standards,  others will need  to  be recali-
brated.   As  delineated  in  the  comments at  the  public  hearings,
leadtime  is  most  critical  if a manifold absolute  pressure  (MAP)
sensor must  be added to the feedback system.   However, MAP sensors
are no longer expected to be  necessary as  indicated  by Chrysler's
statement.    Reprogramming  the electronic  cont.rol unit may  be
required  for  some vehicles, but,  as  stated  by GM  and  Chrysler,
it  is  not as difficult  as  adding  a MAP sensor.   Chrysler speci-
fically commented  that adequate  leadtime  existed to recalibrate the

     At  this  point,  the  worst  case  items  for feedback  and  non-
feedback  systems  have been  delineated.   It  has  been  shown  that
the requisite hardware  changes do not  involve  long tooling  or
development, leadtimes.  What will  be required are modifications  to
existing hardware  which  include the  two "worst case"  examples  of
recalibrating fuel  systems:   fixed  calibrations, for non-feedback
fuel  systems  and  reprogramming  the  electronics control  unit for
feedback fuel systems.  Now that the scope of the required changes
has been  described,   the  worst  case recalibration efforts  can  be
related to  the  historical  development,  certification,  and produc-
tion cycle of the  industry.

     Current  development, certification,  and  production schedules
vary  with each  manufacturer.    Table  1  shows  Chrysler's projected
schedule  for  certifying  1982 low-altitude LDVs  and LDTs.   EPA's
past  experience with industry schedules shows  that Chrysler's
schedule is somewhat optimistic.  As an  example, Chrysler projects
the submission of  final  certification  documents to EPA  is May 26,


while  the Agency .typically receives  these submissions as late
as June or July.  However, Chrysler's"scheme is useful as a  repre-
sentative schedule of events.

     Historically,  manufacturers' production hardware calibrations
are determined  through a  series of iterations which occur through-
out the development and certification process.  Calibration changes
can occur even after a certificate of conformity has been issued  by
applying for  "running  changes."  Therefore, depending on the
complexity,  production calibrations can be finalized as late  as the
beginning of  production which  usually occurs  near  August  1.

     It  may  be argued  that  calibrations must be  developed to  a
great  degree  in time  for the building  of  50,000-mile  durability
vehicles or,  alternatively,  at  least  in time  for 4,000-mile
emission data  vehicles.  This  is  true for vehicles which must
currently be certified  for compliance with  low-altitude  standards.
It  is  not true  for  compliance  with  high-altitude  standards.   As
discussed in  the  section entitled,  "Number of  Certification
Vehicles," manufacturers  will  not  be  required to  build and ac-
cumulate  mileage  on high-altitude hardware  for 50,000-mile  dura-
bility or 4,000-mile emission data tests.  Even though preliminary
calibrations would  be  specified  to  EPA earlier,  specific calibra-
tions would not absolutely need  to be developed and  built until the
high-altitude  emission  tests  were ready to be conducted.   These
tests  would  not  be performed  until  the 4,000-mile  low-altitude
tests had been completed and  the  vehicles were ready to be modified
into high-altitude test configurations.  Therefore,  in "worst
case"  situations  the  first high-altitude  test  hardware  could  be
delayed  until  a March-June  time  frame.   Final  production calibra-
tions might be completed as  late  as August.

     From the  time  the  final high-altitude  standards are scheduled
to be published in November 1980, until the start  of production  in
August  1981  is about  9  months.   EPA believes that  this provides
the  industry  with  adequate  leadtime  to  meet  the   1982  standards
for  the  worst  case  recalibrations.   As  discussed  above, EPA  is
convinced that  the  150  tests which may  be needed  to recalibrate a
low-altitude engine family (reprogramming of the electronic control
unit requires  even less testing)  can be  done in six months  at
most. This conclusion  is further supported  by the  fact  that many
manufacturers  appear  to  have  already  had  significant  experience
with the  affects of altitude on  fuel  systems.   This experience  is
based  on several  things.  Many manufacturers  either have  high-
altitude test  facilities, as described in the issue entitled,
"Adequacy of Existing High-Altitude  Test  Facilities," or have
experience with non-facility high-altitude  tests such as con-
ducted by AMC  and  others  for  driveability  and  performance  demon-
strations.  In  1977, manufacturers produced vehicles in compliance
with mandatory high-altitude  standards.   Several manufacturers have
participated  in the voluntary high-altitude certification programs
subsequent  to  1977.   Among them  are  Volkswagen,  GM,  Ford, and
Chrysler.  Finally, vehicles certified  to the California standards

must demonstrate  control  of emissions  at  high altitude,  although
the requirement is' admittedly less  rigorous  than  that necessary for
1982 and  1983  standards.   All  of the above examples indicate  that
manufacturers  have  amassed a  significant  body  of  knowledge  from
which  they  can draw  upon when  developing  high-altitude  calibra-
tions.    This  experience  should  enhance  the  rate  at  which high-
altitude hardware can be developed.

     Although many of  the  general comments  indicated that  leadtime
was not adequate  for the  1982 model year, there  is  support for the
conclusion that  recalibrations  can be  produced  in  time for 1982.
Ford said that the time required to build,  develop, and  certify an
emission-data vehicle  calibration  is  one  year.   Previously it  was
pointed out  that final  calibrations  could be  delayed until  very
near the  start of production  which  is August.   Assuming a worst
case situation in which  Ford  does  not begin development until  the
final  rule  is published  (November  1980),  and  that they  need  to
delay  the  finalization of production hardware  until  August 1981,
they would still  have approximately 9  of the 12 months  they suggest
is necessary.  When  it is remembered  that neither  the 50,000-mile
durability vehicle  nor the 4,000-mile  emission-data  vehicle  will
need to be run for high-altitude  certification, it is apparent  that
adequate  leadtime exists  for Ford.   The overall  burden of meeting
the  high-altitude  standard  is  further moderated  for  Ford  in
light  of  the  fact that  about  50 percent of  their  models  in  past
years have been available with  a  high-altitude option.  This option
apparently consisted of  an aneroid carburetor.   Since Ford stated
that their aneroid carburetors  could meet  the  standards, presumably
little or no  effort  need  be  directed  at aneroid equipped  vehicles
so  their  resources  can  be used to  develop  calibrations  for   the
remaining non-aneroid  models.   Ford   also indicated at the public
hearings  that  they  had been  planning to  meet  the  standards  with
fixed calibrations rather than  designing every car to meet  both  the
high-  and low-altitude  standards.    Because  EPA has  deleted   the
$40  modification  limit,  Ford can now proceed  with  their  previous

     Chrysler  stated  that they required  three  changes to recali-
brate vehicles to meet the high-altitude standards:   reprogram the
electronic control  unit,   add  a  MAP  sensor,  and the  addition  of
aneroids to some truck families.   At  the public hearings,  Chrysler
said  that recalibrating  the electronic  unit  could be  delayed
until  about  October  or  September.    They  commented that  the   MAP
sensor  was  a more critical problem.  However, since  then  they
have stated  a MAP sensor  is  no longer necessary.   Chrysler  com-
mented on the  aneroid  carburetor leadtime  issue  subsequent to  the
hearing.^/   They indicated that  if they  were  allowed  to place
aneroid carburetors  on only  the vehicles  sold  at  high altitude,
they could avoid problems  that might  "make  it impossible to design
and  tool  the necessary hardware in  time  for  the 1982  year."    By
deleting  the  $40 limit  on  the cost  of modifications,  EPA  has
removed the obstacle which Chrysler alluded  to.  With  the  deletion
of mileage  accumulation,   Chrysler  should have  adequate leadtime.

     IH said they  would not  have  enough time  to add aneroids
and that their only approach would  be to  develop fixed calibrations
for high-altitude vehicles.   Again, this will be possible now that
the $40 modification  limit  has been  deleted.   In comments  on the
proposal,  Jaguar  stated  they needed  6-10  months  notice  for their
suppliers  to produce the necessary high-altitude hardware.   If the
regulation is promulgated in November 1980 and production begin in
August 1981.  Jaguar would have up to 3  months in which to develop
high-altitude calibrations.   Further, in  a  letter  dated April 2,
1980,  Jaguar stated they  are confident  they  can  meet  the standard
on all  engine families  except  the  215 CID  V-8  and the 326 CID
V-12._3/  Those engines have  been  granted  waivers from the statutory
CO standard.4/  For waivered engines, EPA has provided an alterna-
tive high-altitude  standard  which  is more lenient.   The Agency's
technology review shows Jaguar should be able to  meet  that  alter-
native standard.   Furthermore, Jaguar has stated that  they  will be
conducting  high-altitude  testing  for six weeks  during July  and
August  1980._3_/    GM, like Ford, will  not  require  development
testing  for many  of  the vehicles in their  product  line.   Data
presented by GM  shows  that  their  C4  systems  has the capability to
meet the  standards  for the  majority  of  their LDVs.   The potential
development burden is,  therefore,  greatly  reduced  and,  hence,
leadtime required to recalibrate non-complying vehicles should also
be reduced.   Based on the  above,  Ford,  Chrysler,  Jaguar,  IH, and
GM, in particular,  appear to already be  well on the way to comply
with the 1982 and 1983 standards.

     Development  Leadtime -  Specific:   GM  commented  that  leadtime
was  inadequate  for  their  subcompact  cars which  have already
begun 1982  certification  testing.   EPA  has  confirmed  that  GM has
begun durability  testing for  one  model  line  of  subcompact cars.
Apparently  GM  plans  to  introduce  this model  early  in  1981.
These subcompacts  utilize  a  new  front wheel  drive, transverse
mounted engine.  There is no preexisting data to indicate  whether
this  engine would require additional  development  to meet the
high-altitude standards.   However,  the  subcompacts will use the
same C-4  emission  control system as  other  GM cars.   For the other
cars this  system  apparently  either has  the inherent capability to
meet the  standards  or  can  do so  with a  relatively minor modifica-
tion.    EPA believes  that  the  use of  the  C-4 system  in  GM's new
subcompact model  will allow the vehicles   to be  certified and
produced without  significantly compromising GM's current production

     AMC commented that they will use GM's  C-4 system on their  1982
LDVs.   They  claimed that this system had  the ability  to meet the
standards  but  they would be  unable  to  recalibrate the  system in
time to comply.   AMC presented no  data to  substantiate this claim.
This same  argument, however,  was  used in  their  application for a
waiver from the  statutory CO standards which  are applicable  to  1981
and 1982  model  year  vehicles.   In  response to  that  waiver, EPA
carefully considered AMC's  alleged  leadtime problems.2/  The Agency
concluded  that AMC could  not complete development of the C-4 system

for the 1981 model year but  that  they  should be able to certify the
system by  the  1982 model year.   AMC  was granted a CO  waiver for
1981.  By approving the waiver, EPA noted that the effort saved in
developing a  system  for  1981 should  enhance  AMC's ability to
calibrate  and certify the C-4  system for 1982.   Regarding the
high-altitude standards,  AMC and GM  have  similar  situations.
It  appears  that   once  the C-4 system has  been  calibrated  at low
altitude, any  recalibration,  if  required at all, will  be  a rela-
tively simple task.  Therefore, there  is no reason to believe that
AMC  cannot  comply with  the high-altitude  standards  beginning in

     EPA concludes,  therefore,  that  adequate  leadtime  exists for
specific vehicles to  comply with the high-altitude standards
beginning in the  1982 model year.  This conclusion  is  based pri-
marily on the  fact that  time  is  available  in  which  to develop and
certifiy the required  "worst  case"  hardware,  i.e.,  recalibrations
of  low-altitude  engine  and  emission  control  parameters.   The
conclusion  is further supported by the fact that most manufacturers
already have significant experience with  the effects of altitude on
vehicle emissions and  that many vehicles have already demonstrated
the ability to  meet the standards.

     However, EPA recognizes that  in light of the late promulgation
date of  this rule, that  the  resources,  personnel  and facilities,
may occasionally be strained  to  do  all  the  work necessary  for all
engine  families.   This  problem  is perceived to be  particularly
acute  in the  truck field where the  technical  difficulties  associ-
ated with compliance are  greater, in  part,  because of the  absence
of feedback control systems  and the wide variety of configurations,
all requiring  unique  calibrations.    Relief from some of  the de-
velopment  and  certification  burden will assure  success   for  the
remainder.   Thus,  on  exemption in  1982 for some fraction of  the LDT
fleet based upon  sales  or number  of models  is very utilitarian at
this point.

Recommendat ion

     Adequate leadtime exists  for LDVs in which to develop, certi-
fy, and  produce  vehicles  in  compliance with  the  1982 and  1983
high-altitude  standards.    LDVs  manufactured   for  the  1982  model
years  should  be  included  in the high-altitude standards.   It
appears that the manufacturers of LDTs may be excessively strained
to  obtain  the  necessary certification for their entire  fleets in
time for  the  start  of 1982 production.  On  the other hand,  the
problem  seems not so severe  as  to abandon  1982  altogether.  A
rational compromise is to provide a sales-based exemption for some
fraction of  the LDT  fleet,  perhaps, 30  percent,  as  recommended by
Ford.  This would alleviate  the time constraints.

                Table 1

Chrysler 1982 MY Certification Program
4k Data
(1/28) (3/24) (5/27) (7/1)
Hardware Emission Hardware Dur.
Chart Hardware Delivery Test
Published Calibrated Start
(9/25) (11/13) (12/15) (5/4) (6/30) (7/28)
4k 4k 4k 4k EPA Job fl
Final Hardware Start Stop Cert.
Calib. Delivery
Cert .
to EPA
Stop '

J.   Issue;  Exemptions

Summary of Issue

     The high  altitude  NPRM proposed  to  require all  vehicles  to
meet  or  be  modifiable to  meet  the high-altitude  as well  as  the
low-altitude standards.   This would  ensure the  same selection  of
vehicles at  high altitude  as  at  low  altitude.   However,  EPA in-
tended to  offer exemptions  from the  high-altitude rules  to those
fuel  efficient  vehicles whose  low power-to-weight ratios  lead  to
technical  difficulty  in  achieving compliance  and  which  tend  to
make  them  unsuitable  for high  altitude use anyway because  of poor

Summary of Comments

     The variety of  possible criteria  that were  suggested included
(1)  exemption  for vehicles  having automatic compensating  devices
(Honda), (2)  exemption for  all  vehicles  having  fixed calibration
(GM), (3)  exemption  for  all  high fuel  economy vehicles,  based upon
power-to-weight  ratio or  percentage  of  sales  (GM, AMC,  Honda,
Chrysler, Ford).

     In  addition,  most  manufacturers   objected  to EPA's  labeling
idea  that  exempted vehicles  be  labeled  "unsafe at altitude" (Ford,
AMC,  GM, Chrysler).   A more accurate label would be  "unsuitable."

Major Subissues

      1.    Need  for Exemptions.   This  addresses the basic  issue  of
whether  exemptions  are necessary  and  desirable  at all,  and their

     2.    Circumscription of Exemptions.   This  section delineates
the various criteria which have been suggested by manufacturers and
EPA  to  be  used  to  determine exemptions and  responds  to  comments
about the proper labeling for exempted vehicles.

Analysis of Comments

      1.    Need for Exemptions.   There  are three  possible  reasons
for  providing  for exemptions:   (1) to  save the  manufacturers  the
needless expense of  certifying  for high altitude, certain vehicles
that  are sold  there  in very small  quantity,  (2) to avoid having
the most fuel economic  vehicles  eliminated from  the  general market
because they could not comply with the high-altitude  standards,  and
(3) to offer relief  to the manufacturers  if  there  is insufficient
leadtime to  complete  the  development   and  certification  processes
before  production.    [The  rule  requires compliance  with both  the
high- and  low-altitude  standards (with  modification,  if necessary)
for certification;  hence,  failure  to  comply with either  standard
precludes  certification  and, therefore, marketing at  any location,
regardless  of altitude.]   The  first argument  is  strictly economic,


the  second,  technical  and societal  (need  to conserve  fuel),  the
third, temporal.

     EPA  does not  consider  it  particularly valid  to  exempt  low
sales volume  vehicles  per  se,  if  in  fact  their low sales do  not
reflect a  high-altitude performance problem,  but only the special-
ized nature of the vehicle (e.g., trailer tow packages).

     The  issue  of fuel  economy  is  not  restricted  to vehicles  of
maximum  fuel  economy  in  the absolute sense, but rather to  those
vehicles within a utilitarian classification.  Thus  a half  ton  LOT
could be "fuel economic" in the relative sense of being superior to
other half ton trucks  and yet  certainly  be  inferior to the best
subcompact auto.   The claim  of technical difficulty  is  based upon
the  fact that high fuel economy  vehicles  typically have  low power-
to-weight  and low drive train ratios (the  latter obtained by  a  low
rear  axle  ratio).   The  problem such vehicles  have with  a  high-
altitude  standard is   that  the  combination  of   reduced  available
power  (due to  less  dense  air),  the  already low power, and high
gearing (low axle ratio) force the vehicles to spend  excessive time
in  the  "power enrichment" mode  during the FTP.   This may  produce
too much HC and CO,  despite  the  usual calibration changes that  are
effective at  higher   elevations:  timing and  carburetor  flow.
Technical  solutions  appear  to  exist  for  the few possible  "worst
case" situations.   The most direct would be to disconnect the  power
enrichment mechanism.   While this  sacrifices perhaps  five  or more
percent of the available  power,  it  eliminates  the  source of  the
ultra-rich operation.  This may,  however,  lead to complications  not
only in driveability, but more significantly,  in  durability  because
of too-lean operation at maximum load.  An alternative solution, if
permitted, is to change the  rear  axle ratio.  This  approach "gears
down" the  entire vehicle and  thus avoids some portion of  the use of
the  power enrichment.  All  in  all,  it  is possible in isolated
cases -that either  compliance is  impossible or,  if possible,   it
results  in a vehicle  of  unacceptable driveability   or  durability
unless  axle  ratio changes  are  permitted.   Such vehicles  are  ex-
pected to  be relatively fuel  economic ones.   On  the  other hand, no
such vehicles have yet been identified (see Technology issue).   The
new vehicles, such as  the  Chrysler  K and  GM J cars,  have emissions
performance unknown to EPA as yet.

     The  leadtime  analysis suggests  that  there  may  be  some  manu-
facturers  whose personnel  resources would be strained to complete
all the requisite tasks leading  up  to and including  certification.
The argument would be  credible  of  course, only  for  the  1982  stan-
dards.   If a  portion of the  fleet  were  granted  an  exemption,  then
the  work  burden on  the manufacturers is  lightened  and  presumably
they could get the remaining  portion properly certified in a timely
manner.  As the issue is basically that of leadtime,  therefore,  the
analysis is not repeated here.

     What, then,  are  the  ramifications of  providing or not  pro-
viding exemptions?  First,  if exemptions  are  not offered, then  all

vehicles,  including those with  small  or zero high-altitude sales,
must comply.   There is  a  possibility,  perhaps remote,  that  some
fuel economic ones will not  be able  to comply  with the high-
altitude  rules  by the  usual recalibration methods, including
automatic  schemes.  Those  which cannot comply  are faced  with
certain options.

     First,  probably all of  these vehicles  can achieve compliance
by having the power enrichment disconnected.  Being thus certified,
the vehicle will be offered for sale at low altitude, but probably
not sold at  high altitude because  of the anticipated durability and
driveability problems  of  such  a high-altitude configuration.  It is
possible  that this extreme  fix may not even suffice on a  few
vehicle configurations, thus  forcing the second option.

     Second, they may retire from the  general market  (low,  as  well
as high altitude),  thus costing the nation one fuel economic option
to the consumer-  This  concern  is  also addressed in the issue, Model

     The third possible option  for  non-complying  vehicles,  if
permitted,  would  be  a  change  in the  rear axle  ratio.   Such a
change was not a viable  option  in the  proposal  because of  the $40
limit on modifications but  is now possible because  EPA is deleting
this requirement.  Therefore,  if now permitted,  it  could be expec-
ted that a number of less fuel economic vehicles might also  incorp-
orate this  fix instead  of extensive recalibration of the carburetor
and timing,  or the  introduction  of automatic compensating  devices
(i.e.,  rather ordinary fixes). These vehicles would not suffer the
durability and driveability problems which  might plague  those few
whose power  enrichment was  cut off.   With  this situation,  there
should be no vehicle-engine-transmission combination that could not
meet the standard  and, hence, in  a  general  sense  to  the consumer,
model  availability is maximized.   Manufacturers  should be  more
willing to  sell  these  vehicles  at high altitude because with  the
power enrichment  mode  still  available, the potential durability and
driveability problems  will not occur.  Also, these vehicles, unlike
other  fuel  economic,  low power-to-weight  vehicles,  will  tend  to
have better  performance  (acceleration) because of the higher
gearing and, hence, are  likely to be  better received by the high-
altitude  consumer.  These  vehicles,  however, would likely  be
somewhat less fuel  economic.

     However, it must be  recognized that by allowing  axle changes,
the overall  drivetrain gearing  ratio  becomes a limited  option  to
the consumer.   Thus,  while  he  will be  able to  get any model,
engine,  and  transmission,  he  may not be  able  to  get at  high
altitude,  all  of the rear  axle  ratios  that are available  at  low
altitude.    While  this may  not  seem  a  significant  loss,  as  most
consumers are  not  particularly  sensitive  to the axle  choices,  it
should  be  remembered  that  those  vehicle-axle  combinations  that
would not be available  at altitude are most  likely those of  maximum
fuel economy (at  least  relatively) and may,  therefore, have  a large

degree of  public  notoriety.  Their failure to be  sold  at altitude
may have  a significant  impact  on the public perception  of  model
availability,  despite  their  lack of suitability for high-altitude
     In summary, then, if exemptions  are not permitted, all engine-
vehicle combinations will have to be  certified at both high and low
altitudes or will not be  allowed  to  be sold at all.  If axle ratio
changes  are  not permitted as  a high-altitude  control technology,
then  some  fuel  economic  vehicles may have  to  resort  to  discon-
nection  of  the  power  enrichment.   With  this  fix,  probably  most
engine-vehicle-transmission combinations can comply, although a few
may not.   Potential  driveability  and  durability  problems  arising
from  a  lack  of power  enrichment may force some manufacturers
from offering  those few vehicles at  high  altitude, despite certi-
fication.   Of  those  offered  though,  all  drivetrain options (axle
ratios)  will be  available.   If, on the other hand, axle ratio
changes  are  permitted,  then  probably  disconnection  of power
enrichment  will not  likely be  used.    All  engine-vehicle-trans-
mission  combinations  will be certified at high  altitude  although
many  axles  may not be.  Those  will tend to be  the higher  fuel
economy  vehicles  which may be  especially sought by the  public
despite  poor  performance  at altitude.   In any  event,  without
exemptions  the  manufacturers  will have to finance  development and
certification  of high  altitude  configurations,  despite  the  pur-
ported limited  sales of very high fuel  economy vehicles.

     On  the  other hand,  if  exemptions are permitted  and  properly
circumscribed,  then  fuel  economic vehicles (i.e.,   those  with low
power-to-weight ratio which are  underpowered at high altitude)  will
be offered  exemptions.   This  means,  of course,  that such  vehicles
will  not be sold  at all at high altitude because they are not
certificated.   It  may be that  these vehicles would have  been low
sales  volume vehicles anyway  at high altitude,  owing to their
relatively  poor performance,  and that little  in  the way  of  pur-
chasing  options has  been  lost   to the  consumer.    However,  these
exempted vehicles,  though  few in number,  are among  the most  fuel
economic  and  probably  of considerable consumer  interest  despite
their poor performance at altitude.  Their absence  from the market
may  impact the perceived model  availability more than  actual

     For  exempted  vehicles, some  savings lie  in the avoidance
of the cost of  development and certification of vehicles that  have
little utility at high altitude.   If  technically feasible,  however,
the manufacturer may elect to obtain high- as well as low-altitude
certification if he feels that  the sales potential  at high altitude
warrants the  effort.   Therefore, the availability  of an exemption
will not  automatically preclude  all  eligible  vehicles  from being
offered for sale at high altitude.

     2.    Circumscription of Exemptions.   The  scope of the exemp-
tion  impacts  heavily  on  industry's  reliance on  disconnection of

power enrichment,  use  of axle  ratio  changes  (if permitted),  and
industry's overall cost of development and certification.   A very
limited exemption, that which  exempts  only  the worst performers at
high altitude, may still dictate in some instances disablement of
the power enrichment.   Although certified,  these  vehicles probably
would not be offered at  altitude.  This may  have a practical effect
of removing  from  sale  at  altitude  entire  carline/engine/transmis-
sion combinations.  However, permitting  changes of axle  ratio
may lead to a greater  offering at high altitude of vehicle-engine-
transmission combinations.

     The principal negative considerations of  allowing axle changes
are  that (1)  it would  make   in-use  retrofit and  dealer  trade
modification  exceedingly  expensive,  thus  discouraging  those
activities   (Dealer  trades could  be  preserved  if  trade-in of
the essentially new replaced axle were permitted by  the  manu-
facturer); and (2), it  would  remove  the most  fuel economic  vehi-
cles  from the market  at high altitude.   However,  because  any
exemptions  do the latter  to some  degree,  only  an  absence of
exemptions  offers any hope  of  getting the most economic  cars
to market at  high altitude.   Clearly, however,  allowing  axle
changes  would limit   to  a  larger  degree the models  available
at high altitude   (both the more fuel efficient  models  and limited
sales  models) than  a performance or technological  exemption.

     The basic purpose for the  exemption rule is, once  again,  to
avoid  the  loss  of  fuel economic vehicles from  the  low-altitude
market because those  vehicles  could  not, without great  difficulty,
comply with  the  high-altitude rule.   This is  less of  a  concern
if axle  ratio changes  are  permitted.  But  allowing axle  ratio
changes would likely significantly limit model availability at high

     With this purpose  in mind, reasonable  criteria for exemptions
can be evaluated.   These are:

     (1)  Percent  of sales volume.

     (2)  Fuel economy number.

     (3)  Unacceptable performance,  as determined by  design  para-

     (4)  Unacceptable  performance,   as  determined by  acceleration

     (5)  All automatic altitude compensating vehicles.

     (6)  All fixed calibration vehicles.

     (7)  Any vehicle  configuration for which a  demonstration of
inability to comply is provided.

     The basic advantages and disadvantages  of  these are summarized

(1)  Percent of sales volume (10-30 percent)

     (a)  It  provides  the most economic  exemption  from the manu-
facturers' viewpoint.

     (b)  It does not consider technological  feasibility.

     (c)  It  is  imprecise  and  may  offer  exclusion needlessly
or refuse it improperly.

     (d)  It,  or  a  modification  such as percent of  models,  cor-
rectly  addresses  the  issue  of  inadequate  leadtime for  1982.

     (e)  It  fails  to  address the issue of technical difficulty,
poor performance, and fuel economy.

     (f)  Because  it is  likely  to  be  defined  favorably  for  the
manufacturers, there is  likely  to be maximum  reduction  in model
availability through excessive exclusion.

(2)  Fuel economy number

     (a)  It  is  an  absolute,  unambiguous criterion that  does  not
require additional  testing by the  manufacturer.

     (b)  Fuel economy  data is obtained during the certification
testing;  hence,  the  information becomes  available very  late.
Earlier testing is  invalid as the  prototype  would likely not comply
with even the low-altitude standards.

     (c)  This would exclude many vehicles  in need of exemption,
namely  those  of  lower  absolute  fuel  economy,  but  relatively high
fuel economy for  their size.  Hence,  it misses  the point.

     (d)  Being an  absolute criterion,   as both  the car and truck
fleets  are  scaled  down,  a  continually  larger  fraction  would  be
exempted  in succeeding  years.   Therefore,  the  value would have to
be revised annually.

     (e)  EPA  will  have  to  determine  the appropriate  cut-off

(3)    Unacceptable performance,  as determined  by design parameters

     (a)  It  is  an  absolute,  unambiguous  criterion that  does not
require any testing; hence,  there  would  be no  unexpected  failures.


     (b)  The necessary data would be available very early  to  the

     (c)  It is possible for a manufacturer to adjust his offering
to maximize exemptions.

     (d)  Being an  absolute  criterion,  as  both the car  and  truck
fleets  are  scaled  down,  a  continually  larger fraction would  be
exempted in succeeding years.  Therefore,  the  value would have  to
be revised annually.

     (e)  The  values of  the parameters  could be set annually
by each manufacturer's marketing  strategy,  thus solving  (d)  above.

(4)  Unacceptable  performance, as  determined by  acceleration

     (a)  Acceleration requires testing  to establish  the minumum
acceptable  level  and to qualify  certain vehicles  for  exemption.
Thus, it is time-consuming.

     (b)  Testing  could not occur before the certification testing
because earlier  prototype  versions that do not meet the low-
altitude standards  could not  be  trusted to have the same perfor-
mance as the certification  version.

     (c)  The acceleration  limit  can  be  set annually by  each  manu-
facturer's marketing strategy.

     (d)  A simple  maximum  acceleration  test may not properly
reflect adequate overall performance or the increase  in the time  in
power enrichment due to  increased altitude.

(5)     All automatic  altitude compensating vehicles (but permit

     (a)  Exempts  all those that most easily comply.

     (b)  Saves considerable  certification expense  with potentially
little  air  quality  loss as  all  such  vehicles are likely to come
close to compliance,  if not in fact  comply.   However,  the  reduc-
tions would not be assured.

     (c)  Would exempt such a large  portion of the  fleet that
discrimination  could be  augued by those forced to comply.

     (d)  Would leave  some fuel efficient,  low-altitude vehi-
cles  still  forced  with  compliance  with  the high-altitude  stan-
dards.   The failure of  these to comply would  have  a serious
deleterious effect on model availability of fuel  economic vehicles
at low altitude.


(6)  All fixed calibration vehicles  (but permit sales)

     (a)  Exempts all  those  whose non-certification  most signifi-
cantly impacts air quality.

     (b)  Would  exempt  such a large  portion of  the fleet  that
discrimination could be argued by  those forced to comply.

     (c)  Would  leave  some  fuel  efficient,  low-altitude vehicles
still  forced  to comply.   Any failure  to comply  would  impair
the availability of fuel economic  cars  at  low altitude.

(7)   Any vehicle  configuration for which a  demonstration of
inability to comply is provided

     (a)  This criterion meets the purpose of the exemption exactly
(technical ability).

     (b)  Like waivers, it requires  continuing judgmental effort by

     (c)  EPA  could easily  be  inundated  by industry applications
for exemptions.

     (d)  The  subjective  nature  of the  exemption could  lead  to
inequities  and, therefore,  claims of  abuse of power by  EPA.

     (e)  Every  manufacturer could,  and  likely  would,  request
waivers regardless of his true capability  to comply.

     It  is  clear  that some  of  the above  schemes  can  readily be
rejected.   Options  (5)  and  (6)  simply seek to  serve special in-
terests.   In  fact,  adoption of both  together would  result in no
regulation  at  all.   Option  (1) addresses exemptions  for leadtime
considerations,  but is  irrelevant  to  the  issues  of  fuel  economy
and performance.  Option  (2) would miss all the relatively,  but not
absolutely,  fuel economic vehicles.   Also, knowledge of exempted
vehicles  would be available too  late  to  be useful,  and the manu-
facturers  would  be  forced to  invest  in   compliance  efforts  as  a
hedge.   Options  (3)  and  (4)  address  the  proper  goal;  that many
fuel  economic vehicles  of  all sizes have technical  difficulty
because  of  poor  performance  associated with  its  economy.  Option
(4), however,  like  Option (2),  keeps the  manufacturers in the  dark
until the  last minute about the eligibility of their vehicles for
exemption.   Option  (7) directly addresses the  reason  for exemp-
tions, the technical inability of certain  vehicle configurations  to
comply  using  any  means.   However,  its   implementation  is  fraught
with difficulties as listed.

     Some  of  the objections  of the manufacturers  to the  proposed
labeling  requirement are reasonable.  The  intended vehicles  to  be
exempted are not necessarily unsafe and labeling  them as  such  would

cause  problems  in future  years  when these  vehicles  may well  be
offered at high  altitude  in response to market  demands.   Rather,
the label should reflect the true exemption criterion, namely that
the vehicle  is  presently considered  by the manufacturers  and
verified by  test to have  unsuitable  performance  for  general  high
altitude use and that the vehicle does not meet the requisite high
altitude  standard.   It is necessary to have exempted vehicles
labeled so that a dealer will  know that  the sale of that vehicle to
a high-altitude  customer is forbidden; it is furthermore necessary
to  explain  the  rationale  of  the exemption  for  the benefit of  a
potential  high-altitude consumer shopping an adjacent low-altitude


     The basic  criterion   for  exemption  should  be based  upon  un-
acceptable performance at  high altitude.  This should offer  relief
to those vehicles which might  have  technical  problems.  Of the  two
schemes which are directed at unacceptable performance,  Option  (3)
is  the simplest  and  most  beneficial  to the manufacturers  while
compromising nothing  to  EPA over Option  (4).   Option  (3),  which
utilizes  design  parameters to measure performance capability,
should provide  the manufacturers with  the same  exemptions  as
Option (4), which utilizes acceleration  testing.   Yet,  because  the
exemption information  is available early on, the manufacturers  need
not expend  effort  attempting  to comply  as  a hedge  against  unex-
pected failure to quality  for  exemption  later on.   Also,  there  is
no testing cost, nor concern with high-altitude testing facilities
for acceleration tests.

     From  the  perspective of  maximizing  model  availability,  the
acceptance of axle ratio changes as  a control technique  would  seem
reasonable.  However,  model configurations would likely be limited,
and the  lost configurations would  likely be  those with low  axle
ratios and high,  advertised fuel  economy.   Otherwise  though,  some
relatively low  power-to-weight  vehicles  may be  forced  to disable
their  power  enrichment mechanisms,  leading in  turn to  possible
durability  and  driveability  problems.   This  may discourage  the
manufacturers from  offering these  vehicles  at high altitude.   On
balance, however, the  potential cost problems with regard to  in-use
and dealer-trade modifications if axle ratio changes  were allowed,
may  lead  to  an unacceptable restriction  of those  activities.
Therefore,  axle changes  should not  be included  in any vehicle
exemption criteria.

     Finally, the labeling  requirement should simply state that  the
performance  of   the vehicle  is  unsuitable  for high-altitude  use
because of its  poor  performance  and that it does  not  comply with
the required  standard.

     A second  exemption  provision,  based  upon  a percentage  of
sales, should be  provided  for 1982  because of the  apparent  exis-
tence of leadtime problems among a few manufacturers  (See Leadtime
Issue,  I).   Several  options  are  available.   The  sales-based

exemptions may be  given  to  LDVs,  LDTs, or both.  The  actual  per-
centage is arbitrary.   To minimize the breadth of the exemption and
to ease  the administrative burden,  only one class  of vehicles
should  be considered.  LDTs  ought  to be selected  because the
leadtime analysis suggests that greater technical  difficulties are
present among that  group.  Also, LDTs, are the fewer  in number  and,
thus, further enhance the restriction and  ease the administration.
One manufacturer asked  for  a  30  percent  and lacking  any  further
input, that is recommended.

     Vehicles exempted under  this  provision  should  still be  eli-
gible  for sale  at high  altitude;  to be  otherwise,  would be to
penalize the manufacturers for circumstances  beyond  their control,
namely the late promulgation of the  1982 rule.

K.   Issue;  Model Availability

Summary of Issue

     The 1977 high-altitude rule  required  simply that vehicles sold
at  high  altitude  comply  with the  standard.    Consequently,  many
manufacturers  found  it  more economical  to eliminate  certain
vehicle/engine/transmission  combinations   from  the  high-altitude
market than  to  undergo the development and certification expense.
This occurred with sufficient frequency to become a major annoyance
to  the  consumer and a potential economic  handicap  to  the dealer.
The  proposed  rule  sought  to remove this  deficiency  by requiring
that all vehicles  comply  or be modifiable to  comply at reasonable
cost  ($40).   This would  have maximized model  availability because
all  vehicles would have had  a  high-altitude  counterpart.   The
dollar  limit  is being removed in  this final rulemaking,  but the
modifiable requirement  remains.   In addition,  some room  for a
limited  number  of exemptions to  the rule is  being considered.
These exemptions  primarily  would apply to high  fuel economy vehi-
cles which might, have  technical difficulty complying.   Such exemp-
tions would  preclude  high-altitude  sales,  but  would  permit  low-
altitude sales.

     There are  other  potential restrictions  to  model availability
that have  been  raised as a  consequence of the  modification  rule.
First, if a vehicle configuration cannot be made to comply with the
high-altitude  standard,  then it  cannot be certified even for
low-altitude sale, except  by exemption.  If  not exempted, the
configuration cannot  be  sold anywhere.   Second,  if exempted, the
vehicle  still  cannot be  sold at  high altitude.   Thus, avail-
ability is affected.

     For 1982, a special,  sales-based exemption is being considered
in  order to avoid  possible  failures  to certify due to insufficient
time to get all  the development and  certification work done.   Such
exempted vehicles would still be  sold at high altitude.  Failure to
have  this  exemption may seriously impact model availability at all

Summary of Comments

     A number of commenters claimed that  the $40  limit  to modify
any  vehicle  configuration  to  its  high-altitude  equivalent  would
reduce  model  availability  rather  than maximize  it.    This  would
occur because  the  infeasibility  of holding to  $40  would prevent
certification  altogether  of  some   configurations  (Honda,  Toyota,
Ford, GM).   Two manufacturers  felt  that the mere presence of this
rule  on  top of  the other  emissions and  fuel  economy  rules  would
reduce their sales  offerings simply because of a lack of resources
(AMC, Chrysler).   Some commenters pointed out  a failure to certify
at  all on  either technical  or  business grounds would reduce avail-
ability at high  and low altitude;  the vehicles lost would likely be
the  most fuel economical  (Ford, NADA,  Chrysler).  Renault asserted

the obvious  fact  that no manufacturer should be  required  to  sell
anything at high altitude.

Analysis of Comments

     EPA recognizes, on the basis of the 1977 experience,  that  the
regulation must  be  carefully  structured  in  order  to prevent
undue hardship either to the consuming public or to the dealers  (at
high  and  low  altitudes).   The  public  seeks  and, indeed, a  free
competitive market demands,  a variety of vehicles  from which
to choose.   The market  is  sensitive to  selection  among car lines,
engine  size,  and  transmission  options.    It  is  usually  insensi-
tive to axle ratio offerings except  in a  few specialized instances,
usually in  the  truck  line,  or trailer tow packages for cars.
On  the  other  hand,  it  is  sensitive  to fuel economy,  especially
to  widely-advertised claims of  exceptional  performance.    Impli-
cit in  any claim of extreme economy is the presence of a very
high  geared drive  train,   including a  low numerical  axle  ratio.
Thus,  any effort to maximize model  availability should empha-
size  those  vehicle descriptors  to which the market  is sensitive.

     In brief,  EPA  sees  four  situations  which  may reduce model

     1)   Technical failure  to meet  the high-altitude standard,  but
configuration  is  exempted — results in  configuration loss  only  at
high altitude.

     2)   Technical  failure  to  meet the high-altitude  standard  -
results in nationwide loss  of vehicle configuration.

     3)   Business decision to restrict  sales  despite compliance  -
results in  loss of certain  configurations  presumably only  at high

     4)   For  1982 only,  inadequate leadtime may  preclude  the
timely  certification of vehicles  that   are  otherwise   capable  of
of certification.

     The  first situation  is likely  to occur if exemptions  are
offered and result  in  a loss  of  availability  at high  altitude.
However,  this  loss is minimized by limiting the  scope of  the
exemption only  to those vehicles which  require  it:    certain  low
power-to^weight vehicles whose  weak  performance  would make  com-
pliance difficult  or impossible.  These lowest performance vehicles
(low power-to-weight) are also those least suited  for  use  at  high
altitude  because  their  low  performance  at low altitude  degrades
into  unacceptable  performance  at  high altitude.  Hence, these
exemptions will have minimal impact on  the consumer  at high  alti-
tude,  and  of course, none at low  altitude.  However, those exempted
will also be  the  most  fuel  economic,  and  although unsuitable  for
high  altitude by the traditional  criterion (performance),  the
current interest in fuel economy, coupled with the  intense national


advertising of these vehicles,  is  likely  to  lead to some customer
interest in  these  exempted  vehicles  at  high  altitude wherein they
would not be available.

     Of  course,  it  should also  be realized that  a given  car
line/engine/transmission  combination or  even  car line/engine
combination can be  eliminated  from high altitude sales  by  the
exemption and not only certain  axle ratio  offerings.  This is
especially true if the manufacturer offers only a single axle ratio
(e.g., Chevette).

     The  second  situation  should  be avoided,  especially  if  the
vehicle  in  question  is  particularly  fuel  economic  as would  likely
be the  case.  However; as technical difficulty has never been
demonstrated in any particular case and with the exemption criter-
ion properly circumscribed,  any  vehicle having technical difficulty
would  be eligible for  exemption.   Thus, this  adverse  situation
(affecting the CAFE averages)  is not  expected at all.

     The third situation may well occur and EPA has no control over
it.   However,  present  experience  shows  that  there  is  very  little
actual  restriction of, models  available  at high  altitude.   There-
fore, so  long  as  the manufacturers  are required  to certify vehi-
cles,  EPA expects that  they will  sell  them at  high altitude.

     The fourth situation may occur  in  1982 because of  the short
time  between  promulgation  and production.   If it were  likely to
occur extensively across the  board,  then  it  would  be necessary to
conclude that  promulgation  for  1982  is  unrealistic.   However,  for
the limited situations wherein leadtime may be a problem because of
insufficient personnel  resources,  abandonment of  the rule for 1982
would be  contrary  to the  needs of the  high-altitude  urban  areas.
Hence model availability would be  impacted unless an exemption were
granted for those vehicles  unable  to certify  in time.  While
exemption usually  would  imply  forbidden sales at altitude, it would
make  more sense  here  to  allow sales,  thus not  penalizing  the
manufacturer for his  leadtime  problem and  simultaneously,  retaining
model availability at high  altitude as well as at low.

     It is possible,  though  unlikely,  that some low power-to-weight
vehicle  is not eligible for exemption and simultaneously unable to
comply  with the  usual  recalibrations which  would  not  adversely
affect performance.  If  this were  to  occur, the vehicle could still
achieve compliance by the  more extreme fix of disconnection  of  the
power  enrichment   mechanism  in  the   high-altitude  configuration.
However, this  fix may render  the vehicle unsatisfactory because of
degraded performance, driveability,  or  durability, and  hence  the
manufacturer may  indeed not  actually offer  it  for sale at  high

Recommendat ion

     No  action  required;  issue is resolved by the exemption pro-
visions.  The more  extreme  scenarios  suggested above are only
speculation with  no  evidence  presently available  to  suggest  they
may actually occur.

L.   jssue - EPA's Legal Authority

Summary of Issue

     EPA  proposed  that all  light-duty  motor  vehicles shall meet,
or be  capable  of being modified  to  meet,  the high-altitude stan-
dards.  Any  such  modification shall  be capable of being performed
by commercial  repair  facilities  at  a  cost  to the  ultimate  pur-
chaser, or  any subsequent  purchaser,  of  $40  (1979  dollars).   In
addition,  the  vehicle  manufacturer would  be  liable to ensure that
all vehicles  sold for  principal  use at high  altitude  are  in the
configuration  that  provides for compliance with'the high-altitude
standards. The Agency also  stated that  the  sale  of high-altitude
vehicles  for principal use  at low altitude would not be considered
a violation of Section 203(a)(l) of the Act.

Summary of Comments

     Industry  representatives  commented  that  EPA's $40  maximum
cost  was  unauthorized and  constituted  illegal  price fixing.
Commenters  also stated  that  manufacturers could  not be  held
liable  for  dealer  actions  and  that  EPA  lacked authority  to  re-
call  vehicles  built to  conform with  the  high-altitude standards
when operated  at  low altitude.   One  company commented that  EPA no
longer had  the authority to  promulgate interim high-altitude
standards at all.

Major Subissues

     1.   Basic Authority.  Ford stated that they believed that EPA
no longer had  the authority  to  set  a standard that would require
all vehicles  to  meet proportional  or alternative standards  at
high-altitude  for 1982-1983 model  year vehicles.

     2.   $40 Maximum Fee1.  Most manufacturers  commented that EPA's
maximum allowable charge constitutes price fixing and is in viola-
tion of the antitrust laws.  Ford  stated that  forcing manufacturers
to reimburse  independent  repair  facilities for high-altitude
modifications was equivalent to  taking property without due process
of law.   GM stated  that even  if EPA  intends to  use the maximum
charge to only assure  that the  modification  could  be done for $40
or less,  and then allow the  free marketplace to  charge any price
that  competition  allows,  the maximum  charge  is  still illegal and

     3.    Liability for Sale.  Most manufacturers commented  that
EPA had  misunderstood  the dealer/manufacturer relationship.   GM
stated that  the manufacturer  does not sell or deliver vehicles to
the ultimate purchaser;  therefore,  they cannot be  held  liable for
the dealer's action.  Furthermore,  GM cited   Section 207(h)(l)  of
the Act   as  specifically  imposing  direct responsibility for  the
ultimate sale of a vehicle upon  the dealer.

     4.   Recall Authority.  Ford commented that EPA lacks author-
ity to  recall  vehicles based upon  testing at  any  altitude  other
than the altitude at which  the vehicles  in  question are principally
to be operated.

     5.   EPA Has  Not  Met Statutory Requirements for Standards.
Chrysler commented that contrary to  Section 202(f)  of the Act, EPA
has not considered and  made a finding with  respect to:

     A.   The economic  impact of  the standards;

     B.   The availability  of control technology; and

     C.   The  likelihood  of  a  significant  improvement in  air

     6.   Low Altitude Sale of  High-Altitude  Vehicles.     Ford
commented  that recall  and performance  warranty actions  against
high-altitude vehicles found to be  in noncompliance with  low-
altitude standards would be illegal because those vehicles would be
adjusted or modified  (if necessary)  for principal use at  high
altitude.   Ford's concern is  compounded by  the  fact that  EPA
explicitly intended to allow the sale Of high-altitude vehicles at
low altitudes (the reverse situation was, of course,  not allowed).
Thus,  the  number  of high-altitude  vehicles  operating at low al-
titude could have been substantially more than  if  only residence
changes  and  transient   operation  accounted for  such  low-altitude
operation of high-altitude  vehicles.

Analysis of Comments

     1.    Basic Authority.  The  Clean  Air  Act does not explicitly
forbid  EPA from  setting  alternative  standards  for  high-altitude
vehicles.  Section 206(f)(l) repealed the high-altitude regulations
applicable to 1977 model year  motor  vehicles which  did differenti-
ate between  high  and  low  altitudes.    However,  Section  206(f)(l)
continues on to state that:

     "Any  future  regulation affecting the  sale  or  distribution of
     motor vehicles or  engines manufactured before  the  model  year
     1984 in high  altitude areas of the country shall  take  effect
     no earlier than model  year  1981."

Since  the  proposed regulations  apply to  the  1982  and  1983  model
year,  the  prohibition   on  high-altitude regulations has  expired.

     Furthermore,   Section  202(f)(2)  assumes EPA will have to set
alternative standards,   as  the  subsection  forbids the  Agency  from
setting standards that  are  more  stringent at high altitude than at
non-high-altitude locations.   There would  have  been  no  reason for
Congress to  include  this  subsection if  it desired to  forbid  EPA
from setting alternative standards.   The  clear  intent  of Congress
is  to  enable  EPA to  set  standards which are  numerically  less


stringent or  as  stringent  for high altitude until the  1984 model
year.   Therefore,  Ford's  interpretation  of the Clean Air Act
appears to be incorrect.

     2.   $40 Maximum Fee.  EPA disagrees with  those  manufacturers
who  considered  the  $40  maximum  allowable  charge  to be  illegal.
However, for other reasons,  EPA has decided  to delete the proposed
$40 limit (see 45 Federal Register 49254,  July 24,  1980).  One, EPA
agrees with many"commenters  that  $40  no longer represents a reason-
able upper  limit for high-altitude modifications.   Two,  EPA agrees
that one result of maintaining the $40 limit would be to encourage
some manufacturers to  place unnecessary  emission  control  hardware
on all  vehicles, rather  than  just vehicles  sold at high altitude.
Since  high-altitude  sales represent  only  about  3  percent of
national sales,  this  could  significantly increase the  total cost of
the  standards.   Furthermore,  since the  emissions  reductions would
occur  at  high altitude only,  the  cost effectiveness  of  the stan-
dards would diminish.

     Another option would have been to raise the maximum allowable
charge.   However  this,  would have  greatly eroded  the  potential
benefits of  a maximum charge,  and  would have made the concept
practically worthless.  Thus,  EPA has decided to delete the maximum
allowable charge altogether.

     3.   Liability for Sale.   The question presented  is  whether
the  vehicle  manufacturers can  be  held  liable  for the sale of
motor  vehicles  configured  to  meet low-altitude emission standards
for  use at high-altitude  locations.   Section  203(A)(1) of the
Clean  Air Act prohibits  the vehicle  manufacturer  from  the  "...
distribution  in  commerce,  the sale,  or  the offering  for  sale, or
the introduction, or  delivery  for introduction, into commerce  .  .  .
of any new  motor vehicle or new motor vehicle engine .  . . unless
such vehicle  or  engine is  covered by a  certificate  of conformity
issued  (and  in  effect) under  regulations  prescribed  under  this
part."  Section 206(a)(l) provides that a certificate of conformity
shall  be  issued if  the  Administrator determines  that  the vehicle
conforms  to  the  emission   standards  prescribed  under  §202.    The
requirement  that  all vehicles meet  the  applicable  emission  stan-
dards  is clear.   The  only distinction drawn  by  Congress with regard
to high-altitude  use of vehicles  is  in  §202f(l);  §202f(2) merely
prohibits the establishment of high-altitude emission standards for
certification which are more  stringent than non-high-altitude

     Recognizing  the technological difficulties  of  designing
a  vehicle which could  meet  emission standards at  all altitudes,
the  proposed  regulations  do not  require that  all vehicles  be
capable of meeting  standards at high altitudes, but  that  they
be  capable  of  meeting  the  standards  by adjustment  or modifica-
tion,  §86.082-8(h)(i).    The  flexibility  in   the  regulation  does
not  relieve  the manufacturer of  his  responsibility to  see  that
the  vehicle  as sold  meets  the  standards.   Because  §203(a)(l)

prohibits  the  manufacturers  from  selling a  vehicle without a
certificate of  conformity  to  the emission  standards,  it  is the
Agency's position  that  if  the manufacturer  sells  a vehicle  which
conforms only to low-altitude standards  for principal use at a high
altitude, that vehicle would not  be  covered  by the certificate of
conformity,  so that the  manufacturer  would violate  §203(a)(l).  The
questions which arise with respect to §86.082-30  (4)(i) and (ii) of
the  proposed rules  arise  because of the nature of the  dealer/
manufacturer relationship.

     The standard  dealer/manufacturer arrangement  is  a  franchise
type agreement  under  which  the  manufacturer  sells the vehicles to
the dealer, who resells  them to  the ultimate  consumer.  The vehicle
manufacturers assert that because they do not sell vehicles to the
ultimate consumer that they should not be held responsible for the
improper sale  of  vehicles,  that  the  independent dealers  should be
responsible for their own actions. The  use of "... the offering
for  sale,  the  introduction,  or  delivery  for  introduction,  in
commerce .  .  ."in §203(a)(l) strongly indicates that Congress did
not  intend  the manufacturers  to  escape liability for  prohibited
acts through their distributor  agreements.  Given that Congress was
aware  that  automobiles  are  primarily sold  through manufacturers'
dealers, the  proscription of only the "sale" to the dealer — but
not  to  the  ultimate  consumer —  is  illogical.   Such  a  narrow and
crabbed  reading  would mean that  neither the  manufacturer  nor the
dealer  would  be  liable  for the  distribution  and sale  of  non-
certified cars.   In  addition, §203(a)(4)(A) prohibits the manufac-
turer  from  selling a vehicle  which  does not conform  to   §207(a).
Section 207(a) requires  the manufacturer  to warrant to the ultimate
purchaser that  the vehicle  will  conform to  the applicable regula-
tions  under  §202.   It  is  thus  much more  likely that Congress
intended "sale"  as used  in §203(a)   (1) to  mean  the sale  to the
ultimate consumer  since  that is  the apparent  use  of  the  term in
§207(a).  Both  §203(a)(l)  and  §203(a) (4)(A)  create a duty on the
manufacturer  running  to  the  ultimate  consumer,  not  just  to his

     Although  the  manufacturer  may  shift  the performance  of the
required acts  to  another party,  the  responsibility for  the proper
performance of  the  duty  cannot  be shifted,  because §203(a)(l) and
§203(a)(4)(A) place their prohibitions solely on the manufacturer.
The  requirement  that a vehicle  conform to  standards creates a
non-delegable  duty.   The  doctrine  of  the  non-delegable  duty  is
usually applied  only  when violation of  a duty can  result  in
harm to  an  individual or the public.   The  public health  concerns
connected with air pollution certainly qualify.

     In  U.S.  vs.  Ira  S. Bushey &  Sons, Inc.,  363  F Supp  110, the
court held  that the public interest of preserving  the environmental
integrity of  the  waters  dictated that  the parent  company  be held
liable  since  it  profited  from  the  operations  of  its subsidiary.
While  the  facts  are  somewhat  different the  case  does  show that
courts look behind the  apparent  structure of a  business  where the

public  interest  is concerned  to  determine where liability should
finally rest.   In a case  involving similar facts under the Food,
Drug  and  Cosmetic Act,  U..S.  vs.  Par fait Power  Puff  Company, Inc.
163 F2d 1008  (7th  Cir  1947) the doctrine  of  the  nondelegable duty
was used  to  hold a manufacturer  and  distributor of hair products
criminally liable for introducing an  adultered and  misbranded
product (hair  lacquer  pads)  into  interstate commerce, when another
party  the  defendant  contracted with to  manufacture and distribute
the product  changed  the contents  of  the product and shipped them
into interstate commerce.  In holding the defendant  liable, despite
their  orders  to  the  other  party  to  discontinue manufacture,  the
court stated that:

     "In other words, one who owes a certain duty to  the public and
     entrusts its performance to another, whether it be  an indepen-
     dent  contractor or agent, becomes  responsible criminally for
     the  failure  of  the person to whom  he has delegated the obli-
     gation to  comply  with the law, if  the nonperformance of such
     duty  is a  crime.   Defendant  may  not put  into operation forces
     effectuating a placement in commerce of a prohibited commodity
     in its behalf and then claim immunity because  the  instrument-
     ability it  has  voluntarily selected has  failed to live up  to
     the  standards of  the  law,"  U.S. vs.  Parfait Power Puff,  163
     F2d-1008, 1009.

     The  situations  are  analogous  because  the  liability  arises
under a  Congressional enactment intended  for the benefit  and
protection of the  public.   While Parfait  Power Puff  involved
a  criminal statute,  this  is  not  a distinguishing factor as crim-
inal  statutes  are usually read more  strictly  than  civil statutes.
Thus,  under  the  doctrine  of  a nondelegable  duty, a manufacturer
cannot  use its distribution system to escape  liability for viola-
tions of  §§203(a)  (1)  and  203(a)(4) of the Clean  Air Act.

      In  spite  of  the  direct responsibility placed upon the manu-
facturers by the Clean  Air Act  to ensure  that vehicles  sold
conform to emission  standards,  the  vehicle manufacturers have
stated  that  they feel   the  imposition of liability  for  the sale  of
low-altitude vehicles  for  primary use at a high altitude holds them
vicariously  liable for  the actions of  their  independent dealers.
The essence of vicarious liability is the imputation  of fault upon
a  person  who otherwise  is faultless.    This  imputed  negligence  is
founded  upon the  existence of some relationship between the par-
ties, such  as  the  relationship between master and  servant  or
employer and employee.

      The manufacturers  have  stated  that  no such relationship  exists
between themselves and  their dealers; that the dealers are  indepen-
dent  businessmen over  whom the manufacturers  have no  control.  The
courts have  tended to  agree that  no agency relation exists between
the  auto  manufacturers and  their dealers  for   general  purposes,
based  on  a theory of  "right  to control".   Anson v. General  Motors
Corporation,  337 F.  Supp.  209, 213  (ND Ohio 1974).    When it has

been  demonstrated  that the manufacturer has  a  right to control  a
specific  area of  performance,  such as  the making  of  repairs or
predelivery  service,  a  limited  agency  relation has  been  found.
Yale  & Tonn,  Inc. v.  Sharpe,  118  GA App 480, 104 S.E.2d 318,  323,
324  (Ga:  Ct~.  App.  1968)  Tmaking repairs); Ford Motor Company v.
Pittman,  227  So.2d  246,  250 Fla.  Dist. Ct.  App.  1969) (no  delivery
service check).

      The  manufacturers should  be able to  exert  control  over  the
sale  of vehicles configured for low altitude for  high-altitude  use,
either  through sanctions  on  the dealers  for  violations,  or  some
sort  of  indemnification  arrangement should the dealer not conform
to  the  manufacturer's procedures.  In addition,  the manufacturers
will  have to  dictate how the  modifications and adjustments  are to
be made,  which will  entail a  large  measure  of  control.  Because of
the  limited  agency  relationship,  the vehicle  manufacturers  (the
principal) will  be liable for the actions of the dealers  (the

      Even  if  the  dealers are not  the  agents of the manufacturers
for  the  sale of  low-altitude vehicles  for  high-altitude use,
holding  the vehicle  manufacturers  vicariously  liable  for  such  a
sale  is  not  necessarily  impermissible.    Although  several  recent
cases have invalidated EPA assignments  of vicarious  liability,  they
are   factually  distinguishable,   and  involve  different  statutes.
Vicarious liability was deemed unacceptable  in Amoco Oil Co.  v. EPA
(Amoco  I), 501  F2d  722  (1974)  because the  regulation  imposed
liability  by  an  irrebuttable presumption.   In  that  case,  Amoco
challenged new regulations which would hold the refiner liable for
the  sale  of gasoline contaminated with lead  from  a pump normally
used  to dispense unleaded gasoline.  The court felt the regulation
should provide an opportunity  to show that  the contamination  of the
gasoline resulted from an unforeseeable act  of vandalism by a third
party or  from an unpreventable breach of contract by a distributor
(501  F2d  at  748),  but otherwise  did  not  question the validity of
holding the refiner vicariously liable.

     EPA revised the regulation in question  to reflect the decision
in Amoco  I and the new regulation was challenged in Amoco Oil
Co. v. EPA (Amoco  II).  543 F2d 270  (1976).   In  striking  down the
regulation the court stated that:

      "In  the  absence  of any  indication  of a  specific intention
     on the part of Congress to  create a  'new tort1 the traditional
      common law rules  of  vicarious  liability must  apply"  (543 F2d
     at 275).

     The  traditional  common  law rule  is that  there  must be  a
closely integrated  relationship existing between  the person  to be
held  vicariously  liable  and  the  negligent party,  the  essence of
which is  control  of  the  acts  of  the negligent party (543  F2d at
276).  The court  then looked  at the traditional lessee-lessor

 relation and determined that Amoco could not be held liable for the
 actions of  its  tenant  under  the  Common  Law.   The  court was careful
 to  state  however  that they  were  "...  not  prepared  to  raise the
 general rule as a complete bar to refiner  liability..."  Amoco II
 at 276.

     The  proposed  high-altitude regulations  are  distinguishable
 from  the  regulations  promulgated under §211(c)(1)(B) of the Clean
 Air Act  and which  were held invalid in Amoco I  and II.   Section
 211 (c)(l)(B) provides that the administrator may  regulate the sale
 of  any fuel  additive  which  would  impair  the  performance  of any
 emission control  system or device.   The language  of the Clean Air
 Act does not  mention  or place any express obligations or restric-
 tions on the refiners.  Sections 203(a)(l)  and (a)(4) and 207(a) do
 place  express  obligations  on the manufacturers to  see  that  they
 sell only certified vehicles.  Sale of an uncertified vehicle is in
 essence a "new  tort" created  by  Congress to  place liability on the
 manufacturer.   It  is especially  important to keep in mind that EPA
 could  require   all  vehicles  to  meet standards at  high  altitudes
 without modification.

     In Amoco v.  U.S. , 450 F. Supp.  185 (W.D. Mo. 1978)  the court
 disagreed with EPA's interpretation of its  own regulation and found
 that  the  refiner was   not  a  retailer simply because it  leased the
 premises to  the actual retailer.   The court found that  because of
 EPA's  interpretation of the regulation  it  was, in effect,  holding
 Amoco  vicariously  liable  under  the same circumstances as Amoco II
 without  the further  justification   for  its  actions found  in  the
 vehicle certification requirements  as discussed above.

     The most  recent  decision  of Chrysler Corporation v.  EPA,
 600  F2d 904  (DC Cir.  1979) which  invalidated  EPA regulations
 promulgated under  the  Noise  Control  Act  is also  distinguishable.
 Unlike  the  statute  involved in  Chrysler,   Congress here  clearly
 expressed its  intent  that the vehicle manufacturer  be held  liable
 for  selling uncertified  vehicles  in  §§203(a)(l),   203(a)(4)  and
 207(a).  By contrasts  in  the  Chrysler case,  the regulations  placed
 warranty liability  on  the manufacturer  of  an unfinished  truck for
 work  performed by a  subsequent manufacturer who  completes  the
 truck.  Besides not finding any  authority in the Noise Control Act
 of  1972,  the court  noted that  the  legislative history  expressly
 stated  that the manufacturer was  to be  liable only for  changes
 in  noise emissions .which were in  fact  in  each  manufacturers'
 control.  The  proposed high-altitude regulations  require  that the
manufacturer be  liable  only for his  own vehicles and for  the
modifications  and  instructions  done to  his  specifications.

     EPA has concluded that the  requirement of  the proposal  whereby
 the manufacturer  must affix a  label to high-altitude vehicles
 stating  that  the vehicle was  sold to  the  ultimate  purchaser
 for  principal  use a  high  altitude is  legal and appropriate.
EPA recognized,  however,  that in  certain  instances,  the manufac-
turer may not know the ultimate destination of a specific  vehicle.

Due to consumer demand, some low altitude vehicles may be modified
by dealerships  to  comply  with  the certified high altitude  config-
uration  (and  thereby  retain the  certificates).   The  Agency has
therefore  revised  the  regulations  to  allow a dealer  to  perform
these modifications and then to  affix a label stating the  vehicle
has now  been  modified for principal  use  in a high altitude  loca-
tion.  However,  it  should be emphasized that in making the neces-
sary modifications and affixing the high altitude  label, the dealer
is merely acting on the manufacturer's behalf.  The manufacturer  is
still responsible for  assuring that  the vehicle  is in the  config-
uration  appropriate  for  the  destination  of  its  ultimate  use and
that  the vehicle bears a label  consistent  with that destination.

     One  other  point  raised by  the  vehicle manufacturers   is  that
§207 (h)(l) of the Clean Air Act  requires  the dealer to furnish the
purchaser with  a  certificate  that the vehicle conforms  to the
applicable regulations under §202.   While  this section does  place  a
duty onto the dealer, there is  no  reason why that should  release
the vehicle manufacturers of their  duty to  also certify the vehi-
cles as required by §203.

     4.   Recall Authority.  Paragraphs  (h) of §86.082-8 and (h)  of
§86.082-9  require  that  all light-duty  vehicles  (LDVs)  and   most
light-duty trucks (LDTs) must be  capable of  complying with both the
low  and  high-altitude emission standards,  "by initial  design,
adjustment,  or  modification,"  with a possible  waiver  of   this
requirement for certain low-power,  high fuel economy LDVs.   Accord-
ingly, certificates of  conformity certify compliance with both low
and high-altitude emission standards  (§86 .082-30(a)(3) ) .

     EPA  may  perform  surveys of  in-use high-altitude vehicles  to
determine  whether  they  conform to   regulations  prescribed under
section 202 throughout their  useful  lives.   Since  the high-altitude
regulations are being  promulgated  under the authority of sections
202(a) and 202(f), a manufacturer  whose  in-use vehicles  do not
comply with  these regulations  may  be ordered to  remedy   noncon-
forming  vehicles when  it  can be  determined, from available infor-
mation,  that  a  substantial  number  of properly maintained and  used
in-use vehicles  do not comply  with these section 202 regulations.
One of the regulatory requirements,  as stated previously,   is  that
all LDVs  and  LDTs (except that certain  low-powered vehicles may be
exempted) must  be capable of meeting the  applicable emission
standards for any altitude of operation.

     If  in-use  testing at  high altitudes  indicates  that  a   sub-
stantial  number of vehicles in use at high  altitudes do not comply
with high-altitude  standards,  a  recall  order  may be  issued for
the high-altitude  vehicles.   However,  testing conducted  at   high
altitudes  on  high-altitude vehicles  may not warrant  the recall  of
low-altitude  vehicles.    Action  to  recall  low-altitude  vehicles
would be  appropriate  only when  the  Administrator could determine
from  the  high-altitude  data that  low-altitude  vehicles  did not
comply with   section  202  requirements  for  low-altitude  vehicles.


     However,  circumstances can  be  foreseen where testing at high
altitudes  may warrant  a recall  of low-altitude vehicles.   This
action would  be  appropriate,  for example,  when a defect in design
or materials  existed  in  a component  (e.g.,  a malfunctioning three-
way  catalyst)  which  was  necessary to assure vehicle compliance at
either altitude.

     A similar analysis could  be  made of the issue of  whether
low-altitude  testing  would   predict  that  high-altitude  vehicles
operating  at  high  altitudes  were failing  to comply  with  the sec-
tion 202  requirements and,  therefore,  warrant  the recall  of high-
altitude vehicles.

     5.  EPA  Has Not Met Statutory Requirements for Standards.
Chrysler  correctly  pointed  out in their  written comments  that
section  202(f) of the Clean Air Act permits EPA to promulgate
interim high-altitude standards  only after  the Administrator  has
considered and  made a  finding with  respect  to:   (1) economic
impact, (2) availability of emission control hardware,  and  (3)  the
likelihood  that  any  significant  improvement  in air quality  will

     All  three of  these  issues  were specifically addressed  in  the
draft Regulatory Analysis which was prepared as a support  document
for the proposed  standards.   These issues were  further discussed in
the  Preamble  of  the  proposal.    For the  final  rulemaking,  these
issues  will  be  again analyzed and made available  for public
review.    Therefore,  the  Administrator has  met  the  conditions
of section 202(f) for promulgating high-altitude standards  for 1982
and 1983 model year light-duty motor vehicles.

     6.    Low Altitude Sale of High-Altitude Vehicles.   After
further consideration, EPA agrees  with  Ford that the low-altitude
sale of  vehicles  that are designed or modified for sale  at  high
altitude would be in violation of section 203(a)(l) of the  Act.   In
the NPRM EPA  stated  that the  sale of high-altitude vehicles at  low
altitude would be legal.   However, Ford's comment correctly pointed
out  that  sections  207 (b) and (c) of  the Act allow  that recall  or
performance  warranty  protection  may only  be undertaken upon
making the determination that vehicles are  in noncompliance  with
applicable  standards.   Therefore,  the  Agency could not  require
recall or  performance warranty action  if  such  vehicles  were  found
to be  in  noncompliance with the  low-altitude standards if  the
Agency were  to allow the  sale  of  high-altitude  vehicles  at  low

     The  possibility does   exist  that  high-altitude  vehicles
operating  at  low  altitude would not meet  the  low-altitude  stan-
dards,  especially the NOx standard.   Hence,  it would be  illegal  for
EPA  to  allow the  sale  of  high-altitude  vehicles at low  altitude
anyway because such  vehicles  may not meet  the statutory  require-
ments.   In the proposal, EPA  believed that a low-altitude  consumer


who lived at  an  altitude  that  approached  the  official  4,000 foot
cut-off point between high and  low  altitudes  would  be  better off
concerning fuel economy, performance, and HC  and CO emissions if he
were to operate a high-altitude  vehicle  rather than a low-altitude
vehicle.   However,  since the possibility exists that not only would
these  "fringe area"  low-altitude  consumers buy high-altitude
vehicles  but many  consumers who live  at very  low altitudes would
buy high-altitude vehicles,  the  Agency has  concluded  that the
change to the Final Rule is necessary.


     It is  recommended that low-altitude vehicles be sold  at low
altitude  only and that high-altitude  vehicles  be sold at  high
altitude  only.   In view of the  revocation  of  the $40 maximum
allowable charge, it  is recommended  that no  other changes be made
in this Final Rule.

M.   Issue;  Parameter Adjustment

Summary of Issue

     In the  proposal  EPA  anticipated  that some manufacturers might
be  concerned  about  the effect of the parameter adjustment regula-
tions  on  compliance  with  the proposed high-altitude regulations.
EPA admitted that  the parameter adjustment  requirements  might
increase the costs of high-altitude  compliance, but otherwise found
the two sets of regulations to be compatible.

Summary of Comments

     Many commenters  argued  that the parameter adjustment regula-
tions would make compliance with the proposed high-altitude regula-
tions  more  difficult  and expensive.   One commenter expressed
concern over whether  vehicles  that  were certified as high-altitude
vehicles  at  5,400 feet  and which had sealed  parameters  would
perform  satisfactorily and  meet emissions  requirements  at  lower
high-altitude elevations (e.g., 4,200 feet).

Major Subissues

     1.   Possible  Conflict  Between High-Altitude and Parameter
Adjustment Regulations.  Many  commenters argued that the parameter
adjustment regulations, which  begin to  take  effect  in  1981,  would
make it more difficult and expensive to comply  with  the  proposed
high-altitude regulations.

     2.   High-Altitude Areas  Near 4000 Feet.    One  commenter
inquired  into  the  assurances  EPA  had  that  vehicles with  sealed
parameters  that  met  high-altitude   certification requirements  at
5,400  feet   (Denver)  would also  perform  satisfactorily  and  meet
emissions requirements at  lower  elevations  which are still defined
as high altitude (e.g., 4,200 feet).

Analysis of Comments

     1.   Possible  Conflict  Between High-Altitude and Parameter
Adjustment Regulations.   Beginning  with the  1981 model  year,  LDV
and LDT manufacturers must  comply with "parameter adjustment"
regulations  (44 Federal Register 2960).   The parameter adjustment
regulations  will  permit EPA,  and require  manufacturers,   to  test
vehicles with their engines adjusted to  any combination of settings
within  the physically adjustable ranges of  their adjustable para-
meters,  as  opposed  to the  previous practice  of  setting  those
adjustable parameters  to   the  manufacturer's specifications.   For
gasoline-fueled LDV's and  LDT's with  carburetion   systems,  idle
air/fuel  mixture and choke valve  action (e.g.,  bimetal  spring
tension and  vacuum pull-off  adjustments) will be subject  to  EPA
adjustment beginning with  the  1981  model year,  and  idle speed and
initial spark  timing  will  be subject to adjustment  beginning with

the  1982  model year.   Gasoline-fueled  LDV's and  LDT's  with fuel
injection systems will  follow the same schedule, except that choke
parameters will not be  affected.   There is as yet ho schedule for
adjusting  specific  parameters  on diesel-powered LDV's  and LDT's.
These schedules do  not  exclude  the possibility of EPA determining
other engine  parameters to  be  subject to the parameter adjustment
regulations in  subsequent  model years,   though EPA is required to
give manufacturers  adequate notice  before  determining additional
parameters to be subject to  adjustment.

     There are several actions manufacturers  may  take  to facilitate
compliance with the parameter adjustment  regulations;  it is antici-
pated that many manufacturers will  simply choose to either narrow
the physically adjustable ranges of  certain parameters or else make
them entirely nonadjustable  (i.e., "fix" or  "seal" them)-  Parame-
ters which potentially  need  no  adjustment during a vehicle's life,
such as idle mixture and  choke  valve  action,  are  likely  to be
fixed or  sealed by many manufacturers,  while  parameters  which do
often require adjustment in  service,  such as  idle speed and initial
spark timing,  will  likely  have  their physically adjustable ranges

     It is likely,  however,  that  some of the parameters which are
limited or sealed  due  to  the  parameter adjustment regulations
might be  some of  the  same  parameters  that  would be adjusted or
recalibrated by some manufacturer in order  to comply with  the
1982/1983 high-altitude  standards.   This  is  really only a problem
for non-original equipment  high-altitude vehicles which might have
to be recalibrated (due to a  dealer trade for example).   Idle
mixture,  choke bimetal  spring  tension,  and ignition  timing  are
parameters which might both  be affected by the parameter adjustment
regulations and part  of the recalibration recommended by manufac-
turers  for high-altitude vehicles.  It is certainly plausible that
in  the  absence of  parameter adjustment  regulations,  these  para-
meters  could be allowed enough variance such that  recalibration to
high altitude  could  be performed  simply  and cheaply,  while  the
existence of parameter adjustment regulations would make  such
recalibrations more difficult and costly.  EPA has recognized this
situation; in the  NPRM EPA stated  that "the two sets of regulations
are  completely compatible,   although the  existence  of  parameter
adjustment regulations  may  increase  the  cost of the high-altitude
regulations in some instances."

     No commenter  disagreed with EPA's  conclusion that  the para-
meter adjustment  and high-altitude  concepts  are  compatible.    A
number  of commenters did argue,  however,  that the constraints
imposed  by the parameter adjustment regulations would prohibit the
manufacturers from providing the requisite high-altitude modifica-
tions for  less  than the $40 maximum  charge  proposed  in the NPRM.
It was  pointed out  that,   according  to  the parameter  adjustment
regulations,  parameter  adjustments  cannot be approved if  they can
be defeated in less  than 30 minutes or  for  less  than $20.   If one
adjustment must cost at  least $20, there is  little else that could

 be done and still keep the  charge under  the $40 maximum proposed in
 the NPRM.   If at least two such parameters had  to be adjusted to
 meet  the high-altitude standards,  then by definition  the $40
 maximum charge would  be  exceeded.

      EPA agrees that  the monetary restrictions imposed by both the
 parameter adjustment   and proposed  high-altitude  regulations would
 make compliance by manufacturers  with  the  latter very difficult.
 Thus,  despite the fact  that we  consider it  unlikely that manufac-
 turers will choose to comply with the high-altitude regulations by
 recalibration of parameters outside of their physically adjustable
 ranges (unlikely except  in  the case of dealer trades), this is yet
 another reason  why  EPA determined  the  $40 maximum charge  to be
 undesirable.   EPA  has  thus  decided  to  remove the $40 maximum charge
 from the regulations.

      2.     High-Altitude Areas Near 4000 Feet.   It  must  be empha-
 sized  again that EPA  expects  the great  majority  of 1982  and 1983
 LDV's  to employ three-way  catalytic  converters  with oxygen-sensor
 feedback control over  the carburetor air-fuel ratio.  Many of these
 vehicles will not require any high-altitude modifications  and
 should meet emissions  standards  (and should have  acceptable  per-
 formance and  driveability)  over  a  wide range  of  elevations.   It is
 anticipated  that some LDV's and all LDT's will not utilize three-
 way systems in  1982  and 1983.  EPA  expects  most   (if not  all)  of
 these  non-three-way  catalyst vehicles and some  three-way  catalyst
 vehicles  to  utilize   aneroid  (pressure  sensing)  devices  to  meet
 high-altitude  requirements.  Because most aneroids  act as  automatic
 altitude  compensating devices, again  the  stated concern would  not
 be  relevant.   In fact, the  commenter's concern  applies  only to the
 few (if any) vehicles which would  require either  recalibration  of
 engine  parameters outside  of  their physically adjustable  ranges,
 separate  high-altitude parts.   It  is  true that such high-altitude
 vehicles  would  have  somewhat  different  emissions   and  performance
 characteristics  at,  say, 4,200 feet  than  they  would at the  high-
 altitude  certification  elevation of 5,400 feet.    And if  certain
 parameters  were sealed,  field adjustment would be  more difficult.

     There  is  no problem in this regard with HC and CO emissions,
 of  course,  since  it  is well  known  that lower elevations  promote
 leaner  mixtures and  lower  HC  and  CO levels.   Leaner mixtures  do,
 however,  produce higher  NOx levels.   The recent MVMA high-altitude
 baseline  program found that 1970 vehicles  tested in St. Louis  (520
 feet)  emitted  approximately  87 percent  more NOx than  the same
 vehicles  tested in Denver  (5,490 feet).   Assuming a linear rela-
 tionship  between  the  percentage NOx  increase and altitude,   one
might  expect  about a  21 percent increase in  NOx   emissions going
 from 5,400  feet to 4,200 feet.   Of course,  it must be noted  that
 these  were  1970 vehicles not designed  with high-altitude emissions
performance  in mind.   In  its April 7,  1980  supplement  to its
 comments  on the high-altitude NPRM,  GM  reported  relevant  data on
 four of its 1977 high-altitude cars  which required  certification at
high  altitude.   One  car  that was tested at  Milford, Michigan

(950 feet) and  in an altitude chamber  (5,000  feet)  recorded a NOx
level 63 percent  higher  lower  at  Milford than at 5,000 feet, while
a  second  vehicle emitted 8  percent  less NOx  at  Milford  when com-
pared to its emissions  in  the  altitude  chamber.   The third vehicle
was tested at Milford and at Denver and recorded 1 percent higher
NOx emissions at  Milford.  A fourth  vehicle was  tested at Milford,
Denver,  and  in  an  altitude  chamber and  the  results were incon-
sistent.  The NOx emissions  at Milford  were 58 percent higher than
at  Denver  but 9  percent lower than in the altitude  chamber.   No
explanation was  given by GM for  this inconsistent  data.   It would
seem  from these  data which  represent  special  1977  high-altitude
vehicles  that  the NOx  emission  increases  for specially-designed,
high-altitude vehicles  at  lower  elevations  are  somewhat  lower and
less predictable than the MVMA data would indicate.   In conclusion,
EPA agrees  that  it  is  very probable that  1982/1983  high-altitude
vehicles certified  in Denver will have  somewhat  higher NOx levels
at high-altitude  elevations  nearer 4,000 feet; we would  expect the
increases to  average on the  order  of   10  to 20  percent.    This  is
unfortunate,  but we see no easy solution.  Similar situations exist
at low altitude; for example, a vehicle  certified at Ann Arbor (850
feet) would  emit greater NOx  levels when driven at or nearer sea
level.   But  these emissions  increases  are not excessive.   As the
LDV and LOT fleets become  dominated  by  three-way catalyst emission
control systems, such problems will disappear.

     With  regard to  vehicle performance  and/or driveability the
discussion is  somewhat  more straightforward.  Defining  acceptable
performance and driveability is the manufacturer's prerogative; EPA
does not  involve itself in  such  judgments.   Clearly, no manufac-
turer would  attempt  to  sell vehicles   at  4,200  feet  that  did not
have acceptable  performance  and driveability.  While the  change  in
altitude from 5,400  feet to 4,200  feet would indeed  cause leaner
combustion on non-altitude compensating  vehicles, we are  relatively
certain that  the effects on performance and driveability would  be
minor.   In  the  same  submission referenced  above,  regarding  its
special 1977 high-altitude vehicles,  GM  stated that  "in no case did
General Motors release  for production a high-altitude  engine which
we felt was commercially unacceptable  at sea level."  If GM found
no major  performance  or driveability problems with its 1977 high-
altitude vehicles  at  sea  level,  we would anticipate no problems
whatsoever with  1982/1983 high-altitude vehicles  at  4,200  feet.
It is true that  the emissions  standards have become more  stringent
since  1977,  but on  the other hand  emission control  systems  have
also become much more sophisticated.


     In view of the fact that EPA has already decided to  remove the
$40 maximum allowable charge,  it  is  recommended  that no  additional
action be taken.


N.   Issue;  Fuel Economy

Summary of Issue

     In the NPRM, EPA  did  not  claim  that  there would be any effect
of the high-altitude regulations on fuel economy.

Summary of Comments

     A  few commenters argued  that  it would  not be possible to
modify  certain high  fuel  economy vehicles  to meet  the  proposed
high-altitude  standards.    Others  commented that  to do  so  would
require major  modifications  which  could degrade  fuel economy,  and
because of the proposed $40 maximum  charge, such vehicles might be
prohibited from being  sold at both high and low altitudes.  Final-
ly, very few comments  (and almost no data) were received as to the
fuel  economy  effects of  the types of modifications which  EPA
expects to  be utilized   to  meet the  high-altitude standards.

Major Subissues

     1.   Modifiability of High  Fuel Economy Vehicles.   A  few
commenters argued that it  will not be possible to modify some high
fuel economy vehicles to meet  the proposed  high-altitude standards,
or else that such vehicles would require a major modification such
as an  axle ratio change.   Accordingly,  some high fuel economy
vehicles might be prohibited  from  sale  at  high altitude,  or  would
only be available  in slightly less  fuel efficient configurations.
In addition, because  of  the proposed $40 maximum modification
charge, many vehicles  requiring an axle  change  to comply  with  the
standards   might also  be prohibited  from sale  at  low altitudes as
well.   All  of these conditions would  lower  a  manufacturer's  cor-
porate average fuel  economy.

     2.   Effect of High-Altitude  Modifications on Fuel Economy in
General.  Many comments were received on  the  general  question of
the effect of  the  high-altitude regulations on fuel  economy.   In
other words,  given  that most  (or all) vehicles will be able to meet
the high-altitude standards without major design changes,  will  the
high-altitude  modifications   increase  or  decrease   fuel  economy?

Analysis of Comments

     1.   Modifiability of  High  Fuel  Economy Vehicles.   The .manu-
facturers  which claimed that  some  of their vehicles  could not  be
modified at  all,  or without  major  changes,  to meet  the  proposed
standards  did not supply data to support their positions.   Without
such data, it  is  impossible for EPA to  completely  evaluate  their

     First, examining  the  question of fuel economy  at high  alti-
tude,  as  discussed  elsewhere (see Technology  Issue)  EPA  has  con-
cluded  that most  types of  vehicles  now sold in  high-altitude

areas  are capable  of being modified to meet  the high-altitude
standards without  major modifications  (like axle  ratio  changes)
that might  negatively  impact  fuel  economy.   EPA  recognizes  that
there is a remote possibility that some high fuel economy vehicles
might  not be able  to comply with  the high-altitude standards,
but these are generally the  same  low-power  vehicles  which are not
now normally sold at high altitude due to performance limitations.
Thus,  EPA disagrees with  those  manufacturers  which  claimed  that
their  corporate  average fuel  economy  at high altitudes  would  be
negatively impacted by these  regulations.

     With respect  to the fuel  economy of manufacturers'  low-
altitude fleets,  EPA is convinced  that these  regulations  will
have no  effect  whatsoever.    The  availability  of  exemptions  for
certain   low-power vehicles will  enable  the  manufacturers  to
market  certain  high  fuel  economy vehicles  at  low  altitude  that
possibly could  not  certify  to  the high-altitude standards.
And  the  revocation  of the  $40 maximum charge  eliminates  the
possibility that a  manufacturer   would be prohibited from selling
vehicles at low altitude because of an excess  cost for high-
altitude modifications.

     2.   Effect of High-Altitude Modifications on Fuel Economy in
General.   Having dismissed the above  argument  that  major vehicle
modification or  availability problems would reduce  average  fuel
economy  at  either  high  or low altitude, the issue  remains as  to
whether  the types  of  modifications we  expect to  be used  to comply
with the high-altitude  standards  would  have a  zero  or  positive
effect  on fuel  economy.

     The  basic  parameter  of interest with respect to altitude
changes  is  the   air/fuel ratio  of the combustion  chamber  mixture
(determined  primarily by the carburetor  or  injection  pump  in the
gasoline-fueled  engine  and primarily by  the  injection pump  in the
diesel-fueled engine).   For  each vehicle,  the  manufacturer  iden-
tifies  the  optimum air/fuel  ratio for optimization  of emissions,
fuel economy, driveability,  performance,  etc.  As  the altitude  of
the vehicle  increases, and  the  atmospheric pressure decreases,  less
air will necessarily enter  the  combustion  chamber.    Unless  com-
pensated for, the  engine will  thus have  a lower  air/fuel  ratio  (a
"richer  mixture")  and will  suffer  higher hydrocarbon and  carbon
monoxide emissions, and  typically worse fuel economy.  As  discussed
elsewhere,  some  manufacturers  are  expected  to  utilize  three-way
catalytic converters  with  oxygen  sensor  feedback  systems  by  1982
which,  in varying degrees,  compensate for altitude  changes.   Other
manufacturers,  who  are  not  expected  to  use these  systems,  will
definitely need  to make minor  changes,  such as  the  addition  of
aneroid  carburetors,  adjustments  of  idle mixture,  spark  timing,
choke,  etc.   Spark timing,  in  particular,  can  have  an  important
effect  on fuel  economy.   At high altitudes, where NOx emissions are
naturally lower,  there exists the ability to advance  the  timing  to
improve fuel economy.

     Generally,  the  net results  of  the modifications which manu-
facturers are expected to adopt will  be an increase  in the air/fuel
ratio  (a "leaner mixture") to one that is as  close to  the optimized
air/fuel  ratio  as possible.   This would  be  expected to increase
fuel economy.   Again,  the manufacturers provided very little data
relevant to this issue. In fact, their written comments practically
ignored this issue and EPA had to rely on questioning  at the public
hearing  to  obtain the  opinions  of  several  manufacturers.   These
voluntary decisions  to  ignore the effects of  the proposed regula-
tions  on fuel  economy,  at  a  time  when  fuel economy is  such a
critical  issue  to the manufacturers  (both because  of rising fuel
economy standards and  because  of  market demand  for more  fuel
efficient vehicles) are, at the least, interesting.

     American Motors  Corporation (AMC) and General Motors (GM) were
two manufacturers  which ignored  this  issue  in their  written com-
ments but which were asked to  respond at  the  public hearings.  AMC
admitted that it was  possible that the addition of an aneroid (to
adjust  the  timing) would improve  fuel  economy.   GM  stated, "[I]f
you use the barometric sensor  to  adjust  the spark and timing, that
should result in a fuel economy advantage  to  the consumer."  Asked
to quantify the  fuel  economy benefit, they estimated  it to be 2.7
to 2.8 percent.    EPA  would  expect the  same  type  of  fuel economy
benefit due. to  fixed calibration  changes for high-altitude vehi-

     Ford also  declined to  comment   directly  on  this issue,  pre-
sumably because  they  predicted they  would need major  design modi-
fications to comply with the proposed  standards.  In  their written
comments  submitted  at  the  public hearing,  however, within the
context of  a  discussion of  octane requirements  at  high altitude,
Ford provides  a little  insight  into  their  position.   To quote:
"1979  truck  data indicate that  unique calibrations  using aneroid
fuel metering and spark advance devices improve driveability,
improve wide open throttle  acceleration times by  as much as  7
percent, and  improve  steady  state fuel economy by  as much as  16
percent versus  the non-aneroid system.   Nevertheless, the octane
quality of fuel  available  at high altitude caused the deletion  of
the 6°  [spark] advance feature.   This  resulted in a  2 percent loss
in performance and loss of most of the  fuel economy benefit of the
combined altitude  compensating devices"  (emphasis  added) .   Thus,
while  discussing  the problems  their engines  may have with lower
octane fuels, they  also pointed out  the possible  fuel  economy
benefits of aneroid  systems.   More evidence  of Ford's position  on
this issue has  been  found in  "A Special Message to  Ford Division
Dealership  Personnel"  dated  November,  1979.    In  discussing the
merits  of their  "Special High  Altitude  Performance  Package", which
features a  special altitude-compensating  carburetor,  they reported
that a series  of LOT tests at  altitudes  of 600,  1900, 5200, 8000,
and 14,200 feet  resulted in  an average  10.7 percent  improvement  in
fuel economy  at a steady  speed  of  55 mph with the  high-altitude
package.  It is clear from Ford's statements  in this  "message" that
they consider their high-altitude packages to  improve  fuel economy.

     Finally, EPA consulted the recent MVMA high-altitude baseline
program (draft  SAE  paper  by J.B, Edwards, et  al,  June 11, 1979).
Twenty-five  1970  vehicles were adjusted  to  manufacturers'  speci-
fications and tested  at  St Louis (elevation 520  feet),  tested at
Aurora, Colorado  (elevation 5490 feet)  as received  (thus,  still
calibrated  to  low-altitude conditions)  and  adjusted  to manufac-
turers' specifications and  tested  again at Aurora.   The relevant
comparison involves  the testing at Aurora before (which  could
represent a vehicle  calibrated  at low altitude but operated at high
altitude)  and  after  (which could  represent  a  "controlled"  high-
altitude  vehicle)  readjustment to  manufacturers'  specifications.
The average fuel economy  of the 25 vehicles was 2.4 percent greater
after readjustment to specifications than before,  again indicating
that high-altitude  modifications  which would tend  to recalibrate
engine  parameters  (especially  air/fuel ratio)  as  close  to  ideal
conditions as possible would likely  increase fuel economy.

     In conclusion,  it  appears that  there will  be a  slight  fuel
economy benefit  associated  with  these  regulations.  The  very
limited data available  to EPA  indicate that  the benefit might
be  in  the  2 to  3  percent range  for  vehicles which presently
have  no  altitude compensation.   But  many vehicles  already  have
some type of altitude compensation  or  else  altitude compensation
options,  so  the  fleetwide fuel economy benefit  would be  some
fraction of the range quoted above.   Based on the very limited data
base  and  the uncertainties involved,  EPA will not  enumerate  any
fuel economy benefit  and  will  not  credit any monetary savings to
better  fuel economy.  EPA does expect, however,  that there will be
a  small  fuel economy benefit  from  better high-altitude  emissions


     Although EPA does expect  a slight fuel  economy benefit  as  a
result of these regulations, it is recommended that EPA not attempt
to  quantify any  fuel economy  benefit nor any  resulting  monetary