[Federal Register Volume 64, Number 38 (Friday, February 26, 1999)]
[Notices]
[Pages 9500-9507]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-4828]


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ENVIRONMENTAL PROTECTION AGENCY

[FRL-6304-9]


Retrofit/Rebuild Requirements for 1993 and Earlier Model Year 
Urban Buses; Approval of a Certification of Equipment

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of certification of equipment.

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SUMMARY: The Agency received an application with cover letter dated 
December 8, 1997 from the Detroit Diesel Corporation (DDC) with 
principal place of business at 13400 Outer Drive, West, Detroit, MI 
48239-4001 for certification of urban bus retrofit/rebuild equipment 
pursuant to 40 CFR 85.1404-85.1415. The equipment is applicable to 1985 
through 1993 model year federal and California certified 6V92TA DDEC 
engines originally

[[Page 9501]]

manufactured by Detroit Diesel Corporation (DDC). This includes all 
DDEC II engines, DDEC I engines (1985 through 1987), and methanol-
fueled engines (manufactured from 1991 through 1993). On March 20, 1998 
EPA published a notice in the Federal Register (63 FR 13662) that the 
notification had been received and made the notification available for 
public review and comment for a period of 45 days. EPA has completed 
its review and the Director of the Vehicle Programs and Compliance 
Division has determined that it meets the requirements for 
certification, conditioned on the terms discussed below in section IV. 
The effective date of certification is discussed below under DATES.
    The equipment complies with the 0.10 gram per brake horsepower-hour 
(g/bhp-hr) particulate matter (PM) standard for the engines for which 
it is certified (see below). Certification of the DDC equipment, as it 
applies to engines of model years 1985 through 1993, is conditioned 
upon DDC complying with the terms discussed below in section IV.

ADDRESSES: The DDC application, as well as other materials specifically 
relevant to it, are contained in Public Docket A-93-42, Category XXIV-
A, entitled ``Certification of Urban Bus Retrofit/Rebuild Equipment''. 
Docket items may be inspected from 8:00 a.m. until 5:30 p.m., Monday 
through Friday. As provided in 40 CFR part 2, a reasonable fee may be 
charged by the Agency for copying docket materials.

DATES: Today's Federal Register notice announces the Agency's decision 
to certify the DDC equipment, as described below. The effective date of 
certification was established in a letter dated October 2, 1998, from 
the Director of the Vehicle Programs and Compliance Division to DDC 
Corporation. (A copy of the letter is in the public docket, which is 
located at the address noted above.) This certified equipment may be 
used immediately by urban bus operators, subject to the condition in 
Section IV.

FOR FURTHER INFORMATION CONTACT: Anthony Erb, Engine Programs and 
Compliance Division (6403J), U.S. Environmental Protection Agency, 401 
M St. SW, Washington, DC 20460. Telephone: (202) 564-9259.

SUPPLEMENTARY INFORMATION:

I. Background and Equipment Identification

    In a notification of intent to certify signed December 8, 1997, DDC 
applied for certification of equipment under the urban bus program. The 
notification is clarified and the equipment further described in 
letters from DDC dated July 28, 1998, and August 20, 1998. The 
equipment is referred to as the DDC rebuild kit, and is applicable to 
1985 through 1993 model year Detroit Diesel Corporation 6V92TA diesel 
engines equipped with Detroit Diesel Electronic Control (DDEC).
    The notification states that the DDC rebuild kit is designed to 
update all electronically controlled DDC 6V92TA DDEC engines that are 
either 253 or 277 horsepower (hp). The DDC kit utilizes components from 
DDC's certified engine upgrade kit, modified fuel injectors, conversion 
to DDEC IV engine control system, and a converter/muffler (previously 
certified to reduce particulate matter by 25 percent and manufactured 
by either Engine Control System Ltd, Engelhard Corporation, or Nelson 
Industries).
    The original test data provided with the certification was based on 
testing performed on an upgraded engine using a DDEC III system. In a 
letter dated July 28, 1998, DDC stated that since the kit was 
originally configured and tested, the DDEC IV system was released for 
all EPA certified on-highway Series 50 and 60 engines. DDC requested 
that the retrofit rebuild kits be modified to include the DDEC IV 
system. DDC stated that the DDEC IV system uses the same software as 
the DDEC III units so engine calibrations developed using the DDEC III 
system can be used in the DDEC IV system with no changes to the 
calibration. DDC stated that the DDEC IV system provides additional 
memory, increased processing speed and communication capability with 
the other vehicle/transmission computer systems and has no effect on 
engine performance or emissions. Based on the statements provided by 
DDC, EPA finds that the PM emission test results from testing performed 
using the DDEC III system presented in Table 1 below would not be 
affected by the use of the DDEC IV system in the retrofit kit. 
Additional discussion to the use of the DDEC IV system can be found in 
the response to comments section of this notice.
    The equipment to be certified is included in three constituent 
kits. The three constituent kits included in this submission are as 
follows:
    Engine Rebuild Kit--Newly Manufactured Parts: This kit is comprised 
of newly manufactured parts and consist of a gasket kit, air inlet 
hose, blower drive gear (2.05 to 1), blower by-pass valve assembly, 
cylinder kits (piston assemblies and cylinder liners), new electronic 
unit fuel injectors and DDEC IV conversion kits.
    Engine Rebuild Kit--Reliabilt Parts: This kit includes 
Reliabilt remanufactured parts, including camshafts, blower 
assembly, turbocharger and head assemblies.
    Converter/Muffler Kits: In order to provide the greatest 
flexibility to transit operators by providing several catalytic 
converter/muffler options, DDC plans to include the converter/mufflers 
provided by three suppliers: Engelhard Corporation, Engine Control 
Systems Ltd, and Nelson Industries. Transit operators will be able to 
select a converter/muffler from any one of the suppliers which will be 
packaged as a direct replacement for the vehicle muffler and which will 
accommodate the installation requirements of the various engine/vehicle 
combinations. Certification of the Engelhard CMXTM 
converter/muffler is described in a Federal Register notice of May 31, 
1995 (60 FR 28402). The Engine Control Systems' converter/muffler is 
described in a Federal Register notice of January 6, 1997 (62 FR 746). 
Nelson Industries' converter/muffler is described in a Federal Register 
notice of November 26, 1997 (62 FR 63159).
    One of each type of constituent kit is required for the rebuild of 
an engine. The engine rebuild kit usage is based on the required engine 
power rating (253 and 277 horsepower are available), engine rotation 
direction and orientation (43 degree tilt, 15 degree tilt, and 
upright). The notification includes parts lists. The converter/muffler 
kit usage is based on the operator's choice of converter supplier and 
the engine/vehicle combination.
    DDC states that standard procedures, as described in the service 
manual of 92 Series engines, are to be used when rebuilding the base 
engine using the candidate kit and will also provide specific 
conversion instructions with each kit. Additionally, there are no 
differences in service intervals or maintenance practices for the base 
engine associated with the installation of the kit. The converter/
muffler requires no regularly scheduled maintenance, only an occasional 
cleaning if the maximum back pressure of the exhaust system is 
exceeded. The engines also receive an upgraded control program for the 
electronic control module.
    Using engine dynamometer testing conducted in accordance with the 
Federal Test Procedure (FTP) for heavy-duty diesel engines, DDC 
documented in its December, 1997 notification, PM emissions below the 
0.10 g/bhp-hr level.
    DDC presents exhaust emission data that were developed for the 
engine configuration rated at 277 horsepower.

[[Page 9502]]

Testing of the candidate kit was conducted using each of the three 
converter/mufflers with the upgraded engine configuration. The test 
data indicate that the emissions of hydrocarbon (HC), carbon monoxide 
(CO), oxides of nitrogen (NOX), and smoke measurements for 
the engine equipped with the candidate equipment are less than exhaust 
emissions standards applicable to 1993 model year urban buses when 
tested over the Federal Test Procedure (FTP). The test data is 
summarized in Table 1.

                                 Table 1.--Exhaust Emissions From 6V92TA DDEC II
                                                    [277 hp]
----------------------------------------------------------------------------------------------------------------
      Gaseous and particulate  g/bhp-hr          Smoke  percent opacity
---------------------------------------------------------------------------                Comment
   HC       CO      NOX       PM      BSFC a     ACC       LUG      PEAK
----------------------------------------------------------------------------------------------------------------
1.3....     15.5      5.0   b 0.10        20    15        50      1993      Urban Bus Standards.
0.3....      1.0      4.8     0.08     0.516     1.7       1.2       3.0    Converter/Muffler A.
0.1....      0.2      4.7     0.08     0.506     2.2       1.9       2.9    Converter/Muffler B.
0.2....      0.5      4.9     0.095    0.517     1.6       1.3       2.7    Converter/Muffler C.
----------------------------------------------------------------------------------------------------------------
a Brake specific fuel consumption in units of pounds of fuel per brake-horsepower-hour.
b Non-compliance penalties are available up to 0.25 g/bhp-hr.

    No life cycle costs information has been submitted by DDC. DDC does 
not intend certification of this equipment to trigger program 
requirements for the applicable engines and no new requirements are 
triggered by this certification. The certification testing document a 
PM emissions level of 0.08 to 0.095 g/bhp-hr depending upon the 
catalyst installed, and also show that emissions of hydrocarbon (HC), 
carbon monoxide (CO), oxides of nitrogen (NOX), and smoke 
are within the applicable standards when tested over the FTP.
    Based on the testing demonstration, EPA believes that all DDC-
equipped engines will meet the 0.10 g/bhp-hr PM standard because 
installation of the kit upon engine rebuild results in the replacement 
of all emissions related parts with a specific set of parts, the 
combination of which results in a documented PM level of 0.08 to 0.095 
g/bhp-hr.
    The fuel consumption of the DDC kit ranged between 0.506 to 0.517 
pounds of fuel per brake-horsepower hour in the testing results 
provided.
    The DDC equipment is certified to a PM emission level of 0.10 g/
bhp-hr for all 1985 through 1993 DDC 6V92TA DDEC urban bus engines 
using either diesel fuel #1 or #2 (including engines originally 
certified, or rebuilt, to meet California emissions standards. This 
includes all DDEC II engines, DDEC I engines (1985 through 1987), and 
methanol-fueled engines (manufactured from 1991 through 1993).
    Table 2 lists the applicable engine models and certification levels 
associated with the certification announced in today's Federal 
Register.

                                        Table 2.--Certification PM Levels
----------------------------------------------------------------------------------------------------------------
     Applicable models \1\             Engine code                               PM level
----------------------------------------------------------------------------------------------------------------
1988-1993 Detroit Diesel 6V92TA  ALL (including those    0.10 g/bhp-hr.
 DDEC II.                         certified or rebuilt
                                  to meet California or
                                  50-state emissions
                                  standards).
1985-1987 Detroit Diesel 6V92TA
 DDEC I
1990-1993 Detroit Diesel 6V92TA
 Methanol Fueled DDEC Engines
----------------------------------------------------------------------------------------------------------------
\1\ Conditional certification applies to all model year engines. See discussion in section IV.

    DDC is required to provide a 100,000 mile defect warranty and 
150,000 mile emissions performance warranty for the components of the 
kit.

II. Summary and Analysis of Comments

    Comments were received from five parties in response to the Federal 
Register notice (63 FR 13660; March 20, 1998): Engelhard Corporation 
(Engelhard), Johnson Matthey, Incorporated (JMI), Chicago Transit 
Authority of Chicago, IL (CTA), Pierce Transit of Tacoma, Washington 
(Pierce), and the King County Metro of Seattle, Washington (Metro). 
Engelhard and JMI both have applied for certification of equipment to 
meet the 0.10 g/bhp-hr standard under the urban bus program for 6V92TA 
DDEC engines. The Engelhard equipment was approved for certification 
for the 1988 to 1993 6V92TA DDEC engines on July 1, 1998. The CTA, 
Pierce and Metro are operators of urban bus fleets in areas to which 
the Urban Bus Rebuild Requirements apply.
    Comments and issues generally fell into the following categories: 
(a) emissions testing; (b) equipment durability and in-service 
concerns; (c) installation instructions; (d) kit components; (e) life 
cycle cost; (f) kit supply options and labeling; and, (g) 
NOX increases. These are discussed in the sections below.
    Copies of the complete comments and other documentation are 
available in the public docket, which is located at the address stated 
above.

a. Emissions Testing

    JMI commented that the engine selected by DDC and used for 
certification testing was a brand new engine built specifically for 
urban bus rebuild development and certification testing. JMI commented 
that in order to demonstrate emissions reductions on an engine that is 
representative of the in-use engines in the transit industry, the EPA 
should require DDC to re-test their 0.1 DDEC kit on an existing, in-use 
engine procured from typical transit service. JMI commented that based 
on statements made in the notification the test engine information is 
not clear as to whether the test engine was manufactured per the build 
requirements for a previously certified 1996 model year 6V92TA engine 
or

[[Page 9503]]

whether it was a 1992-1993 engine or a 1996 engine. Engelhard asked 
what type of certification was the test engine certified to in 1996, is 
the parts list the same as a pre-1994 engine and are the block and all 
internal components the same. JMI commented that DDC presents emissions 
data from the certification testing of three converter mufflers. JMI 
notes that two of the converter mufflers in combination with the 
additional parts kits attain PM emission levels of 0.08 g/bhp-hr and 
that this would allow for some level of engine deterioration and 
catalyst deterioration over the 150,000 mile performance requirement. 
However, testing with converter/muffler C attains a PM emission level 
of 0.1 g/bhp-hr which is the standard and does not allow for any engine 
or catalyst deterioration over the 150,000 mile performance period. JMI 
commented that converter/muffler C should be eliminated from 
consideration in this certification package.
    In response to the JMI comment that the EPA should require DDC to 
re-test their 0.1 DDEC kit on an existing in-use engine procured from 
typical transit service, Section 85.1406 (a)(2)(iv) specifically allows 
the use of a new engine to demonstrate compliance with the 0.1 g/bhp-hr 
PM requirement. In regard to JMI's and Engelhard's questions concerning 
the build specifications of the test engine, DDC states in section 
05.02.01 of the Notification of Intent to Certify, that the test engine 
was built in June 1997. The test build configuration was not previously 
sold or certified so the engine cannot be identified with a model year 
designation. DDC states that the reference in section 05.02.04 to the 
1996 model year was intended only to indicate the test engine used a 
DDEC III engine control system. The conversion kit as certified will 
convert all in-service engines to virtually the same configuration as 
the test engine.
    With regard to JMI's comment that converter/muffler C should be 
eliminated from consideration because it does not allow for any 
deterioration over the 150,000 mile performance period, DDC has 
responded that it does not expect any catalyst or engine deterioration 
over the 150,000 performance period. DDC explained that the actual PM 
emissions results with catalyst C were 0.095 g/bhp-hr. This was 
reported as 0.10 g/bhp-hr using the specified rounding convention. DDC 
notes that the system utilizing catalyst C has a 10% margin for 
deterioration before the 0.10g/bhp-hr standard would be exceeded. EPA 
does not believe it would be appropriate to withhold this certification 
for catalyst C based on the emission results presented.

b. Equipment Durability and In-service Concerns

    The CTA asked whether DDC had performed thorough field service 
reliability testing to ensure that these upgraded kits will have equal 
operating performance and useful life in comparison to the original 
design. The CTA commented that the EPA certified catalytic converters 
used by CTA during the last two years have had very high failure rates 
that were both structural and functional in nature. Structural failures 
that CTA encountered on the converters were cracking or breakages of 
the wall material on the exhaust side of the converters. Functional 
failures were manifested by lack of engine power and high engine 
exhaust back pressure due to severe clogging and/or restriction of the 
catalytic converters. The CTA commented there is no documented 
information as to how the catalyst is working after being in service 
for an extended period of time. The CTA also commented that catalytic 
converter manufacturers should provide standard guidelines and/or 
procedures for evaluating or assessing the condition of a used 
catalytic converter.
    Engelhard commented that DDC included new prototype aftermarket 
injectors in the upgrade kit with no durability or service information. 
Engelhard asked what the maintenance interval is for the new injector, 
and whether it will last 150,000 miles. Engelhard commented that DDC 
has not provided any data demonstrating that the injectors will last 
150,000 miles and not cause an emissions shift, and will not require 
additional maintenance. Engelhard also noted that the injectors used in 
the DDC certification were ``pre-production parts'' and asked what 
assurance there is that the production parts produced with production 
tolerances will meet the standard. Engelhard noted that the kit 
contains an upgraded electronics package including new sensors. 
Engelhard asked if the new sensors require additional maintenance or 
replacement.
    Pierce commented that it has experienced shortened engine life, in 
the order of 120,000 miles between engine overhauls since 1995, 
compared to the original engine life of 280,000 miles before the first 
engine overhaul. Pierce noted that two significant events occurred 
during this time period. First, Pierce notes that it began using 15W/40 
engine oil in its DDC sub-fleets as a result of successes achieved in a 
two-year test. Second, between 1990 and 1995, DDC made significant 
changes to the cylinder kits, including a part number change. Pierce 
noted that the 15W/40 engine oil performance came into question only 
after re-manufacture with new cylinder kits approved after 1995. Engine 
problems related to liner scuffing of the #1 and #2 cylinders on the 
right bank began in 1995. Pierce expressed its concern with the 
durability of the DDC engine components offered in the retrofit/rebuild 
kit.
    Metro operates a fleet of 1,112 motor buses which includes 236 
Breda dual-mode buses used primarily for commuter service and which 
operate as diesels on freeways and other roads and operate as trolley 
buses in the downtown tunnel. The Breda buses were delivered in 1989-
1991 and are fitted with DDC 6V-92TA DDEC engines rated at 330 
horsepower. Metro commented that the original engine life of these 
engines was 131,000 miles. Since mid-1995 the fleet has suffered 
shortened engine life on the order of 28,000 miles between overhaul. 
Metro noted two significant events occurred during this time period. 
First, catalytic converter mufflers were installed in all buses when 
engines were rebuilt after March 1995. Second, between 1990 and 1995, 
DDC made significant changes to the cylinder kit, including the part 
number (changed in May 1995). This product has not been durable in 
Metro's application. Converter plugging has been a problem from the 
beginning with no discernible difference between Engelhard and Johnson 
Matthey equipment. Metro notes that the average converter life has been 
less than 19,000 miles. Metro also commented that the engine problems 
have centered on liner scuffing of the #1 and #2 pistons on the right 
bank of cylinders. Metro commented that it is concerned with the 
durability of the engine components offered for retrofit/rebuild and 
that DDC has not been able to provide Metro with cylinder kits with a 
demonstrated life anywhere near that of the original engine. JMI 
commented that while it recognizes that demonstration of durability is 
not a requirement of the urban bus retrofit/rebuild program, based on 
the cost of a 0.10 retrofit/rebuild kit, it would be prudent to have 
some demonstration of durability on typical engines in revenue service 
fitted with a trial kit. JMI commented that EPA should require DDC to 
provide a demonstration of durability of the proposed equipment before 
any decision is made concerning certification.
    In regard to the CTA comments, DDC has responded that it has not 
completed a field test with the proposed kit. With

[[Page 9504]]

regard to improvements to the design of the converter mufflers, DDC 
responded that it is aware that some converter/muffler failures have 
occurred as a result of excessive torsional stresses caused by a rigid 
mounting of the exhaust system. DDC stated its understanding that this 
problem was unique to a particular bus design and has been eliminated 
by modifying the converter/muffler mounting design. With regard to 
CTA's comment that catalytic converter manufacturers should provide 
standard guidelines and/or procedures for evaluating or assessing the 
condition of a used catalytic converter, DDC responded that a simple 
visual inspection for leaks, dents or structural damage to the catalyst 
core is usually sufficient to assess the condition of a used converter. 
EPA recommends that transits contact the catalyst manufacturers 
directly for updated information on procedures for evaluating catalyst 
condition if further information is desired or needed. EPA knows of no 
method for accurately testing PM performance of a catalyst in the 
field. However, to the extent a catalyst is mechanically clogging, use 
of the defect warranty may be an appropriate remedy.
    In regard to the Engelhard comments on the use of new prototype 
injectors in this kit and concerns regarding maintenance and 
durability, DDC has responded that the fuel injector does not require 
any scheduled maintenance. The diagnostic and repair procedures for the 
new injector are the same as for other DDC electronic injectors. DDC 
states that the fuel injectors that will be provided with the proposed 
kits are the same fundamental design that DDC has used since DDC first 
introduced electronic injectors in 1985. Diesel Technology Corporation, 
DDC's regular injector supplier, will manufacture these injectors using 
the same production processes and quality standards used for all DDC 
injectors. DDC stated that the only functional difference between the 
candidate injectors and the standard 1993 model year urban bus engine 
injector is that the number of spray orifices has been reduced from ten 
to nine with a corresponding increase in injection pressure. Secondary 
design changes were made to ensure injector life is maintained. DDC and 
Diesel Technology Corporation are conducting laboratory tests to 
demonstrate the durability of the design.
    In regard to Engelhard's comments on the upgraded electronics 
package (DDEC III as included in the original notice), DDC has 
requested that the DDEC IV system be included in the kit in place of 
the DDEC III system that was tested. The retrofit kit was originally 
described as updating the DDEC I and II systems to DDEC III. DDC states 
that as DDEC IV ECM production increases, it will eventually be used on 
all new engine production. DDC states that the DDEC IV control system 
to be used in this retrofit kit is an evolutionary advancement over 
prior generations of the DDEC engine control systems including the DDEC 
III kit that was installed during the FTP. DDEC IV contains the same 
software as DDEC III and calibrations developed for DDEC III will be 
used in the DDEC IV with no effect on engine performance or emissions 
according to DDC. DDEC IV provides additional memory capability for 
additional storage of engine codes and will identify all codes with the 
engine hour and date when they occur. All diagnostic capabilities 
available with DDEC III will remain available, but the information 
stored will be expanded and be available for analysis by newer computer 
systems. DDC states that the DDEC IV system also includes a coolant 
level sensor and associated diagnostics which were not available with 
DDEC II. DDC states that although the DDEC IV has more capabilities 
than previous DDEC systems, it is not more complicated and is not more 
difficult to operate or maintain. The added sensors in the DDEC IV 
system do not require more maintenance or replacement than previous 
systems. DDEC IV was introduced in September 1997 and has been shown to 
be durable and reliable according to DDC. DDC does not anticipate any 
problems with the use of the DDEC IV system in the retrofit kit.
    In response to the Pierce comments, DDC states that it has 
experienced increased cylinder kit failure rates at Pierce and other 
transits since 1995. DDC agrees that Pierce's use of 15W/40 oil may 
contribute to shortened engine life. For two stroke engines, DDC 
recommends straight 40 weight oil and does not recommend the use of 
multi-viscosity oils unless they have been CF2 approved. DDC states 
that the cylinder kits included in the original notification for this 
certification used the same components as the cylinder kits used in 
DDC's urban bus rebuild/retrofit kits certified to provide a 25% 
particulate reduction on 6V92 DDEC engines. DDC has recently made 
several changes to improve durability. This will result in a new 
cylinder kit which is virtually identical to the kits used in 1990. DDC 
believes these kits will provide the same durability as the kits 
provided to customers prior to 1995. These changes include a groove in 
the fire ring face to provide improved lubrication of the ring surface, 
changes to the oil rings and skirt to facilitate oil drain back to the 
crankcase and modifications to the cylinder liner manufacturing 
technique, but not to the cylinder liner itself.
    In a letter dated September 15, 1998 DDC provided information on 
the expected effect of this cylinder change on PM emission for the 
urban bus engine rebuild kit. DDC performed an engineering analysis 
demonstrating that the emission effects are small and that the emission 
standards will continue to be met using the revised cylinder kits. The 
grooved fire ring will carry more oil to the cylinder walls and 
increase oil consumption and, has the potential to increase volatile 
particulate emissions derived from the lubricating oil. DDC states that 
because the exhaust catalyst is very efficient in oxidizing volatile 
particulate, the net effect of any increase in engine out volatile 
components of the PM is substantially reduced. The soot and fuel 
derived volatile components of the PM are not expected to be affected. 
DDC also provided information on the breakdown of particulate emissions 
obtained during certification testing prior to revising the cylinder 
kit. Also shown is a particulate breakdown without any converter 
installed. DDC also provided data on the results of 100 hour oil 
consumption tests run at DDC to assess the impact of the cylinder kit 
revisions. The data shows that the cylinder kit revisions increased oil 
consumption by 21 percent. Based on the 21 percent oil consumption 
increase, DDC estimated the effect of the cylinder kit revisions on 
particulate matter exhaust emissions. DDC's analysis shows that the 
average PM increase with the three catalysts is 0.002 g/bhp-hr (the 
maximum increase was 0.0025 g/bhp-hr) and that the 0.10 g/bhp-hr 
standard will be met with each of the three catalysts. EPA finds that 
based on the analysis provided by DDC, the revised cylinder kit is 
acceptable for inclusion in the rebuild kit. A copy of DDC's letter and 
analysis has been placed in the public docket.
    In response to the Metro concerns, DDC comments that Metro is 
correct in stating that DDC made a number of changes to bus engine 
cylinder kits in the 1990-1995 time frame. Changes to the cylinder kits 
included piston-to-liner clearance, compression ring gap, oil ring 
expander tension, and cylinder liner honing. DDC states that the 
position of the top fire ring was never changed. DDC notes that it uses 
different cylinder kit designs for urban bus engines rated at 253 and 
277 horsepower and, the higher horsepower ratings typically used in 
truck

[[Page 9505]]

applications. As described above in response to the Pierce comments, 
DDC is modifying the cylinder kits provided with the certified kit to 
improve durability. DDC comments that these cylinder kits will be very 
similar to the kits used in 1990 which Metro suggests had superior life 
to overhaul. DDC commented that the retrofit/rebuild kit, will apply 
only to engines with 253 or 277 horsepower ratings. Consequently, it 
would not be applicable to the 330 horsepower engines in the Metro 
fleet.
    EPA appreciates JMI's comments concerning a durability 
demonstration and understands that transit operators are concerned with 
the durability of retrofit/rebuild equipment, and subsequent additional 
costs or engine damage that potentially could result from premature 
equipment failure. However, EPA notes that the urban bus retrofit/
rebuild regulations do not require a durability demonstration as a 
condition of certification. Rather, those certifying equipment, 
including DDC, are required pursuant to 40 CFR 85.1409 to provide a 
100,000 mile equipment defect warranty and a 150,000 mile emissions 
performance warranty.
    EPA believes that equipment suppliers will evaluate the durability 
of their equipment in order to minimize their liability resulting from 
the emissions defect and performance warranties. EPA believes that the 
available information does not indicate a durability concern with the 
equipment certified in today's notice, and therefore, does not provide 
sufficient basis to deny certification on these grounds. EPA will 
continue to monitor problems with this, and other certified equipment, 
and encourages transit operators to provide specific, detailed 
information regarding in-service problems with certified equipment.
    The equipment certifier is responsible for the emissions 
performance of the engine through the 150,000 mile emissions 
performance warranty period, if the transit properly installs and 
maintains equipment in accordance with the equipment manufacturer's 
instructions. The transit operator is responsible for proper 
installation and use of certified equipment, and is responsible for the 
emissions performance of equipment operated beyond the 150,000 miles 
emissions warranty period. Also, the retrofit/rebuild program does not 
obviate compliance with any state or local emission requirements, such 
as inspection/maintenance (I/M) or smoke testing programs.

c. Installation Instructions

    JMI comments on the DDC statement that the standard procedures 
described in the service manual for the 92 series are sufficient for 
rebuilding base engines using the proposed equipment. JMI notes that 
the service manual in their possession dated October 1988 contains no 
information on how to install DDEC III equipment. For transits that 
have older DDEC engines without DDEC III information, this would be a 
burden. JMI commented that EPA should require DDC to supply specific 
instructions on how to install a DDEC III conversion.
    While, as noted earlier, DDC is modifying the kit contents to use 
DDEC IV instead of DDEC III, the point of JMI's comment is still 
relevant. DDC states that the conversion will not be burdensome and 
will require less than three hours. DDC will provide detailed 
conversion instructions with each kit. DDC has provided EPA a sample 
copy of the instructions as an attachment to a letter to EPA from DDC 
dated September 24, 1998. A copy of these instructions has been placed 
in the public docket.

d. Kit Components

    JMI asked that EPA require DDC to explain why installation of the 
system does not alter or render inoperative any feature of the on-board 
diagnostic system incorporated by the engine manufacturer in view of 
the fact that the conversion to the DDEC III increases diagnostic and 
data logging capability. JMI also asks if there are any components or 
ancillary parts that are required which are not included in the parts 
lists of the kit. JMI comments that the parts lists in the DDC 
application do not include the appropriate ECM certification word codes 
(CWC's) for the listed parts combinations. JMI commented that to avoid 
confusion, EPA should require DDC to identify the correct CWC for each 
parts list. If the ECM needs to be changed to incorporate a different 
CWC, the EPA should require DDC to explain how this is done.
    As noted above, DDC plans to use DDEC IV operating systems in the 
rebuild kits. All necessary conversion hardware will be supplied with 
the kit. DDC states that the change to DDEC IV per se will have no 
effect on engine performance or emissions. All diagnostic capabilities 
available with DDEC II will remain available with DDEC IV. The only 
changes to the diagnostic system with DDEC IV are the additions of 
memory that allows engine hour, time, and date information to be stored 
with each engine code to assist in troubleshooting, and the addition of 
a coolant level sensor, and associated diagnostics according to DDC. 
DDC will provide in the kits the parts necessary to convert to DDEC IV. 
In regard to the CWC's, DDC states that the CWC used depends on the 
engine rating, engine rotation and the operators choice of #1 or #2 
diesel fuel. Because the appropriate parts list is selected based on 
different criteria, engine rotation and tilt angle, DDC finds it is not 
appropriate to include the CWC in the parts lists 1-3. Attachment 9 of 
DDC's notification lists the twelve CWC's (six for right hand rotation 
engines and six for left hand rotation) and identifies when each is to 
be used. DDC will supply an unprogrammed DDEC IV ECM with each kit. 
Local DDC distributors will program the ECM with the operator specified 
CWC at the time of installation.

e. Life Cycle Cost

    CTA asked about the total cost of these upgrade kits be to fleet 
operators. JMI commented that EPA should require DDC to provide cost 
data in order for transits to fairly and objectively evaluate and 
compare the various 0.10 technologies. JMI asks about the labor costs 
associated with the conversion and whether there is a cost to a transit 
if a change to the ECM CWC program is necessary. JMI also asked about 
the impact of the DDC DDEC III technology on fuel consumption.
    Engelhard commented that DDC has not included a baseline test for 
comparison with the proposed retrofit kit and that this data is 
necessary to verify that the equipment being installed on the engine 
does not affect engine performance or fuel economy. Engelhard commented 
that DDC has not provided life cycle cost data for this retrofit 
equipment and that the retrofit equipment should not be approved 
without providing the fuel economy penalty, installation costs, and 
additional maintenance.
    As noted earlier, DDC has not provided cost information in this 
notification. The regulations do not require certifications that are 
not trigger technology to include cost data. However, EPA will provide 
a limited response to this comment, based on the cost information 
provided in the notification. Section 1403(b)(1)(ii) describes those 
items which must be considered when analyzing life cycle cost of 
equipment, including equipment purchase price, incremental fuel cost, 
maintenance costs and costs of any fuel additives required.
    The price of the kit is not provided in the notification. This 
pricing information will obviously be provided

[[Page 9506]]

to the operator for consideration prior to purchase. The cost to 
program the CWC will be included in the price charged to the transit 
operator for the kit. Further, DDC responded that the conversion to the 
DDEC IV version will require approximately three additional hours of 
labor. Incremental fuel costs are based on a comparison with a baseline 
test. Since baseline test data was neither required nor provided in 
this notification, incremental fuel costs cannot be provided. However, 
based on the DDC data provided the brake specific fuel consumption 
(BSFC) in units of pounds of fuel per brake-horsepower-hour (lb/bhp-
hr), fuel usage during the FTP testing provided BSFCs of 0.506, 0.516 
and 0.517 lb/bhp-hr dependent upon which of the three catalysts was 
tested in conjunction with the kit. DDC responds that there will be no 
additional maintenance costs associated with this kit. No fuel 
additives are required or specified.

f. Supply Options and Labeling

    JMI comments that it is unclear how DDC intends to supply the 
converter/muffler kits and asked how the kits would be stocked, 
supplied, delivered, labeled, serviced and warranted.
    DDC states that complete rebuild kits, including converter/
mufflers, will be supplied by DDC through DDC's normal parts 
distribution system. Adequate supply will be maintained to assure 
timely distribution, of complete rebuild and any replacement parts that 
users may require. The complete kits will be warranted by DDC. DDC will 
provide the label within each kit.

g. Adverse Impact on NOX Emissions

    Engelhard questioned whether, if DDC is upgrading the control ECM 
from DDEC I and DDEC II to DDEC III, there will be a significant 
difference in the engine control maps. Engelhard also asked if this 
conversion would actually increase on-road NOX emissions. 
Engelhard requested that DDC verify that there will be no increase in 
NOX emissions under normal operating conditions.
    As noted earlier, DDC will use the DDEC IV system in place of the 
DDEC III system proposed in the original notification. DDC responds 
that the engine control strategies are the same as were used on 1991-
1993 DDC 6V-92 engines when originally manufactured. The control maps 
used during emission testing with the DDEC III system were modified 
slightly to meet emission requirements and achieve the same power/
torque rating with the modified fuel injector. No changes were made to 
the engine programming or control maps, which would have modified 
NOX emission characteristics during operation on or off the 
federal emission test cycle (FTP), compared to the 1991-1993 engine 
configurations. The 1991-1993 control maps and strategies, which were 
designed to meet the more stringent 5.0 g/bhp-hr NOX 
standard effective in 1991, should generally reduce NOX 
emissions for pre-1991 engines according to DDC. However, DDC commented 
that NOX emissions might conceivably increase in certain 
operating modes.
    As stated in section IV of this notice, EPA has placed conditions 
on the 1985-1993 model years engines covered by this certification 
because these engines will receive an upgraded electronic control 
module. EPA is concerned that electronically controlled engines may 
have been equipped by the original manufacturers with strategies 
designed to decrease fuel consumption during certain driving modes not 
substantially included in the FTP, with the effect of substantially 
increasing NOX during these modes. As a result, 
certification of the DDC kit, as it applies to 1985 through 1993 model 
year engines, is conditioned upon DDC demonstrating by March 1, 1999 
that any replacement engine control module (ECM) or ECM program used in 
conjunction with the certified kit will not adversely impact the 
emissions of NOX in comparison to the ECM or ECM program 
that is being replaced under conditions which may reasonably be 
expected to be encountered in normal vehicle operation and use, unless 
such conditions are substantially included in the Federal emission test 
procedure.

III. California Engines

    The NOX emission standard for new engine certification 
applicable to 1988 through 1990 model year engines sold in the State of 
California is 6.0 g/bhp-hr. For 1991 through 1993, the standard is 5.0 
g/bhp-hr. The emissions testing presented by DDC demonstrate a 
NOX emissions level that complies with the 5.0 g/bhp-hr 
standard. Therefore, today's certification of the DDC kit for DDEC 
engines applies to DDEC engines certified to meet California emissions 
standards, subject to the conditions discussed below.
    The equipment certified today may require additional review by the 
California Air Resources Board (CARB) before use in the State of 
California. EPA recognizes that special situations may exist in 
California that are reflected in the unique emissions standards, engine 
calibrations, and fuel specifications of the State. While requirements 
of the federal urban bus program apply to several metropolitan areas in 
California, EPA understands the view of CARB that equipment certified 
under the urban bus program, to be used in California, must be provided 
with an executive order exempting it from the anti-tampering 
prohibitions of that State. Parties interested in additional 
information should contact the Aftermarket Part Section of CARB, at 
(626) 575-6848.

IV. Certification and Conditional Certification

    EPA has reviewed this notification, along with comments received 
from interested parties, and finds the equipment described in this 
notification of intent to certify:
    (1) Complies with a particulate matter emissions standard of 0.10 
g/bhp-hr, without causing the applicable engine families to exceed 
other applicable emission requirements, subject to the conditions 
discussed below;
    (2) Will not cause an unreasonable risk to the public health, 
welfare or safety;
    (3) Will not result in any additional range of parameter 
adjustability; and
    (4) Meets other requirements necessary for certification under the 
Urban Bus Rebuild Requirements (40 CFR 85.1401 through 85.1415).
    With the following conditions, EPA hereby certifies this equipment 
for use in the Urban Bus Retrofit/Rebuild Program. As noted above, the 
equipment being certified today includes, for 1985-1993 model year 
engines, an upgraded control program for the electronic control module. 
EPA has recently become concerned that many electronically controlled 
engines may have been equipped by the original manufacturers with 
strategies designed to decrease fuel consumption during certain driving 
modes not substantially included in the federal test procedure, with 
the effect of substantially increasing NOX during these 
modes. Such electronic control strategies have the potential to be 
``defeat devices'' as defined at 40 CFR 86.094-22, and thus may violate 
40 CFR 85.1406 and 85.1408 if included in an urban bus retrofit 
application. The upgraded control program used for the 1985--1993 model 
year upgrade must therefore be reviewed for such violations.
    As a result, certification of the DDC kit, as it applies to 1985 
through 1993 model year engines, is conditioned upon DDC demonstrating 
by March 1, 1999 that any replacement engine control module (ECM) or 
ECM program used in conjunction with the certified kit will not 
adversely impact the emissions of NOX in comparison to the

[[Page 9507]]

ECM or ECM program that is being replaced under conditions which may 
reasonably be expected to be encountered in normal vehicle operation 
and use unless such conditions are substantially included in the 
Federal emission test procedure. The DDC equipment may be used 
immediately by transit operators in compliance with requirements of 
this program, subject to the above condition.

V. Transit Operator Responsibilities

    Today's Federal Register notice announces certification of the 
above-described Engelhard equipment, when properly applied, as meeting 
the 0.10 g/bhp-hr particulate matter standard of the Urban Bus Rebuild 
Program for urban bus engines certified as meeting both federal and 
California emissions standards. Affected urban bus operators who choose 
to comply with compliance program 1 may use this, or other equipment 
that is certified to meet the 0.10 g/bhp-hr particulate matter 
standard, for any engines listed in Table 2 which are rebuilt or 
replaced, subject to the condition of Section IV.
    Urban bus operators who choose to comply with compliance program 2 
may use the certified DDC equipment, and those who use this equipment 
may claim the respective particulate matter certification level from 
Table 2 when calculating their Fleet Level Attained (FLA), subject to 
the condition of Section IV.
    Urban bus operators must be aware of their responsibility for 
maintenance of records pursuant to 40 CFR 85.1403 through 85.1404. As 
stated in the program regulations (40 CFR 85.1401 through 85.1415), 
operators should maintain records for each engine in their fleet to 
demonstrate that they are in compliance with the Urban Bus Rebuild 
Requirements beginning on January 1, 1995. These records include 
purchase records, receipts, and part numbers for the parts and 
components used in the rebuilding of urban bus engines. Urban bus 
operators must be able demonstrate that all parts used in the 
rebuilding of engines are in compliance with program requirements. In 
other words, urban bus operators must be able demonstrate that all 
required components of the kit certified in today's Federal Register 
notice are installed on applicable engines.

    Dated: February 19, 1999.
Robert Perciasepe,
Assistant Administrator for Air and Radiation.
[FR Doc. 99-4828 Filed 2-25-99; 8:45 am]
BILLING CODE 6560-50-P