[Federal Register Volume 60, Number 159 (Thursday, August 17, 1995)]
[Notices]
[Pages 42881-42883]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-20423]



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ENVIRONMENTAL PROTECTION AGENCY
[FRL-5276-4]


Notice of Agency Completion of Study Regarding Heavy-Duty Engine 
Rebuilding Practices and Availability of Documents

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of completion of study and availability of documents.

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SUMMARY: EPA has completed a study of heavy-duty engine rebuilding 
practices as required by Section 202(a)(3)(D) of the Clean Air Act 
(CAA), and the results of that study are now available to the public.
    Based on this study, EPA takes the current view that regulations 
are not warranted to ensure that rebuilt current-technology heavy-duty 
engines meet the certification emission standards that applied to the 
engines when new. EPA retains broad authority under section 
202(a)(3)(D) of the CAA to impose requirements controlling heavy-duty 
engine rebuilding practices, and will continue to analyze whether 
requirements are warranted to protect public health or welfare.

FOR FURTHER INFORMATION CONTACT: Tom Stricker, Environmental Engineer, 
Manufacturers Operations Division (6405-J), U.S. Environmental 
Protection Agency, Washington, D.C. 20460, Telephone: (202) 233-9322. 
The available reports may be obtained by contacting the person 
identified above.

SUPPLEMENTARY INFORMATION:

I. Introduction

    Section 202(a)(3)(D) of the amended Clean Air Act (Act) requires 
the Administrator to study the practice of rebuilding heavy-duty 
engines (HDE's) and the impact rebuilding has on engine emissions. On 
the basis of that study and other information, EPA may prescribe 
requirements to control rebuilding practices, including emissions 
standards, ``* * * which in the Administrator's judgment cause, or 
contribute to, air pollution which may reasonably be anticipated to 
endanger public health or welfare taking costs into account.'' 42 
U.S.C. 7521(a)(3)(D). The required study has been completed and is now 
available to the public. The study findings are set forth in three 
documents: ``Heavy-Duty Engine Rebuilding Practices'', ``Heavy-Duty 
Engine Rebuilding Practices--Results of Emissions Testing'', and Heavy-
Duty Engine Rebuilding Practices--Executive Summary''.

II. Background

    EPA has long been aware that many HDE's, specifically heavy heavy-
duty diesel engines (HDDE's) and medium HDDE's, accumulate mileage far 
exceeding their statutory useful-life mileage 1, in large part due 
to engine rebuilding. Many heavy HDDE's accumulate up to one million 
miles or more before retirement. As a result, heavy HDDE's and medium 
HDDE's are unregulated for a large part of their actual lives.

    \1\ See 40 CFR 86.085-2 for useful-life definitions.
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    EPA conducted the statutorily required study in two phases 
described below:
    Phase I: Conduct a study of the current heavy-duty rebuild market, 
including identifying the key players in the rebuild industry, the 
current practices employed by rebuilders, the frequency of rebuilds and 
the types of engines being rebuilt. The primary data collection source 
utilized was a Request for Information published in the Federal 
Register.2 Phase I was completed in January 1992, and a report was 
circulated to various interested parties within government and 
industry.

    \2\ See ``Request for Information Concerning Heavy-Duty Rebuild 
Study'', 56 FR 13825 (Apr. 4, 1991).
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    Phase II: Using the findings of Phase I, conduct emissions testing 
of various rebuilt heavy-duty engines. EPA solicited comments from 
industry in the development of the final testing plan. A draft report 
was completed in May, 1994 and made available to various interested 
parties.

III. Phase I: Rebuild Study Findings

    EPA found a marked difference in rebuild practices among the 
various types of heavy-duty diesel engines. Heavy and medium heavy-duty 
diesel engines are usually rebuilt whereas light heavy-duty diesel 
engines and heavy-duty gasoline engines are seldom rebuilt.
    EPA determined that heavy HDDE's are rebuilt every 300,000-400,000 
miles. These large diesel engines are designed to be rebuilt, may 
undergo up to three or more rebuilds in a lifetime, and generally 
accumulate one million miles or more before scrappage.
    EPA estimates that 220,000-250,000 heavy HDDE's (out of a total 
heavy HDDE population of approximately 1.5 million) are rebuilt each 
year by fleets, independent garages, independent remanufacturing 
centers, original equipment (OE) dealers, OE remanufacturing facilities 
and others. Critical emissions components such as the fuel injection 
pump, fuel injectors, cylinder head, and cylinder kits (piston, rings 
and liner) are generally rebuilt, replaced or calibrated during a 
typical rebuild.
    EPA found that medium HDDE's are generally rebuilt only once, 
typically at around 200,000 miles. Significant mileage accumulation 
after rebuild is possible since most of these engines operate for about 
300,000 miles before scrappage.
    EPA estimates that approximately 67,000 medium HDDE's (out of a 
total medium HDDE population of approximately 900,000) are rebuilt each 
year by fleets, independent garages, independent remanufacturing 
centers, OE dealers, and OE remanufacturing facilities. As with heavy 
HDDE's, most critical emission components are serviced during rebuild.
    Due to the significant number of rebuilds performed on heavy HDDE's 
and medium HDDE's and the likelihood of significant mileage 
accumulation after rebuild, EPA determined quantitative emission data 
from these categories of engines were needed to effectively determine 
the impact of rebuilding on engine emissions.
    Light heavy-duty diesel engines and heavy-duty gasoline engines 
(HDGE's) are quite different from medium HDDE's and heavy HDDE's. EPA 
found that light HDDE's and HDGE's are not frequently rebuilt. Most 
engine manufacturers do not sponsor remanufacturing programs 

[[Page 42882]]
for these engines because of small market demand.
    EPA estimates that about 40,000 HDGE's are rebuilt each year out of 
a population of about four million (about 1 percent annually). EPA 
could not estimate the number of light HDDE rebuilds because so few of 
these engines are rebuilt that data were not available. Rebuilds on 
these two categories of engines generally result if engine failure 
occurs early in the life of the vehicle, and rebuilding the engine is 
financially advantageous compared to purchasing a new vehicle or 
engine. Once rebuilt, additional mileage accrued by these engines is 
generally limited by the vehicle life, which typically does not 
substantially exceed the statutorial useful-life of 110,000 miles. Due 
to the few number of rebuilds performed on these engines, no emissions 
data were generated by EPA.

IV. Phase II: Rebuilt Engine Test Findings

    EPA conducted emissions testing of rebuilt medium HDDE's and heavy 
HDDE's to determine the impact of rebuilding on engine emissions. Mack 
Trucks, Inc. (Mack) performed similar testing. The results of EPA and 
Mack testing are shown in Tables 1 and 2 below. A complete description 
of each test program is contained in an EPA report entitled ``Heavy-
Duty Engine Rebuild Study--Results of Emissions Testing''.
    Every engine tested, when rebuilt, demonstrated emissions of 
hydrocarbons (HC), carbon monoxide (CO), oxides of nitrogen (NOX) 
and particulate matter (PM) below the new engine certification 
standards applicable when each engine was new. Five engines emitted 
higher than the applicable standard for smoke. As discussed in the 
above referenced report, the smoke emissions measured by EPA are 
considered worst-case. In general, smoke emissions are becoming less of 
a concern as PM standards become more stringent.
    Based on the available data, no substantial difference in emissions 
performance was noted based on the party that rebuilt the engine--OE 
manufacturer, dealer, independent rebuild facility or fleet. Similarly, 
no significant emissions performance difference was noted between OE 
and aftermarket parts used to rebuild engines.

V. Advanced Diesel Engine Technologies

    Engines contained in this study ranged from model year 1983 through 
1990, inclusive. In general, heavy-duty diesel engines originally 
produced during this timeframe used mechanical fuel injection control, 
turbochargers and air-to-water or air-to-air aftercooling. Beginning in 
the late 1980's and early 1990's, advanced technologies such as 
electronic engine controls were incorporated into many engine designs 
to increase durability, reliability and emissions control (EPA tested 
one electronically controlled engine as part of this study). In 
addition to electronic controls, future engines may be equipped with 
other advanced control measures not present on most current engines, 
such as exhaust gas recirculation (EGR), aftertreatment (catalyst or 
particulate trap), advanced turbocharger geometry, and other engine 
modifications. At present, it is unknown how these future technologies 
will be addressed during rebuild and what affect rebuilding these 
components will have on engine emissions. Additionally, as future 
emission standards become more stringent, it may become more difficult 
for rebuilders to achieve the same ``like-new'' emissions levels 
demonstrated by the current-technology engines tested in EPA's study.

VI. Conclusion

    Based on the study findings, regulations to control rebuilding 
practices applicable to current-technology heavy-duty engines are not 
warranted to ensure that rebuilt engines meet the emission 
certification standards that applied to the engines when new. The study 
demonstrated that current-technology rebuilt engines generally emit 
below the standards applicable when such engines were new. While 
rebuilding extends the actual life of engines, it does not appear that 
the emissions characteristics of current engines deteriorate as a 
result of rebuild. Furthermore, most emissions critical components are 
currently replaced or adjusted during a typical engine rebuild.
    EPA retains broad authority to prescribe requirements to control 
heavy-duty engine rebuilding practices, and EPA will continue to 
analyze whether such requirements are warranted to protect public 
health or welfare.

    Dated: August 7, 1995.
Carol M. Browner,
Administrator.

                           Table 1.--Results of EPA Heavy-Duty Rebuilt Engine Testing                           
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                                                                                           Smoke*               
  Engine description      HC (g/       CO (g/      NOx (g/     Part. (g/  --------------------------------------
                          bhphr)       bhphr)       bhphr)       bhphr)       ``A''        ``B''        ``C''   
----------------------------------------------------------------------------------------------------------------
OE Remanufacture                                                                                                
 (After Rebuild):                                                                                               
    1987 Cummins NTC                                                                                            
     315.............        0.778        5.000        6.140        0.424         24.7         18.4         41.7
                             (1.3)       (15.5)       (10.7)         (na)         (20)         (15)         (50)
    1986 Caterpillar                                                                                            
     3406B...........        0.708        3.840        8.203        0.603         21.0         10.1         32.2
                             (1.3)       (15.5)       (10.7)         (na)         (20)         (15)         (50)
Fleet Rebuild (After                                                                                            
 Rebuild):                                                                                                      
    1990 Cummins NTC                                                                                            
     365.............        0.896        3.620        5.782        0.430          8.4         11.2         12.2
                             (1.3)       (15.5)        (6.0)        (0.6)         (20)         (15)         (50)
    1983 Cummins NTC                                                                                            
     400.............        0.597        4.540        4.835        0.476         18.7          6.8         26.6
                             (1.3)       (15.5)       (10.7)         (na)         (20)         (15)         (50)
    1986 Cummins                                                                                                
     LTA10...........        1.293        6.270        4.288        0.902         43.2         18.7         68.9
                             (1.3)       (15.5)       (10.7)         (na)         (20)         (15)         (50)
Simulated In-Frame                                                                                              
 Rebuild (After                                                                                                 
 Rebuild):                                                                                                      
    1989 Cummins NTC                                                                                            
     365.............        0.752        3.000        5.736        0.286         10.0         16.3         16.8
                             (1.3)       (15.5)       (10.7)        (0.6)         (20)         (15)         (50)
    1989 Detroit                                                                                                
     Diesel Series 60        0.370        3.810        8.697        0.329         15.4         10.1         24.5
                             (1.3)       (15.5)       (10.7)        (0.6)         (20)         (15)         (50)
    1986 Caterpillar                                                                                            
     3406B...........        0.180        2.680        5.988        0.407         19.2         11.7         36.6
                             (1.3)       (15.5)       (10.7)         (na)         (20)         (15)         (50)

[[Page 42883]]
                                                                                                                
Independent                                                                                                     
 Remanufacture (After                                                                                           
 Rebuild):                                                                                                      
    1987 General                                                                                                
     Motors 8.2T.....        0.823        2.100        7.280        0.451         12.5          8.6         24.8
                             (1.3)       (15.5)       (10.7)         (na)         (20)         (15)         (50)
    1987 Navistar                                                                                               
     DT466...........        0.559        2.560        7.435        0.343         10.6          9.2         17.8
                             (1.3)       (15.5)       (10.7)         (na)         (20)         (15)        (50) 
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 *``A'' = Acceleration; ``B'' = Lugging; ``C'' = Peak.                                                          
 Applicable standard shown in parentheses ( ) under each emission result.                                       
Italic type indicates emissions above applicable standard when such engine was new.                             



                    Table 2.--Results of Mack Trucks, Inc. Heavy-Duty Rebuilt Engine Testing                    
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                                                                                           Smoke*               
  Engine description      HC (g/       CO (g/      NOX (g/     Part. (g/  --------------------------------------
                          bhphr)       bhphr)       bhphr)       bhphr)       ``A''        ``B''        ``C''   
----------------------------------------------------------------------------------------------------------------
OE Remanufacture                                                                                                
 (After Rebuild):                                                                                               
    1987 Mack E6-350.         0.29         2.97         6.27         0.31         10.5          3.4         18.8
                             (1.3)       (15.5)       (10.7)         (NA)         (20)         (15)         (50)
    1985 Mack EM6-300         0.59         7.46         6.90         1.26         62.1          5.2         98.8
                             (1.3)       (15.5)       (10.7)         (NA)         (20)         (15)         (50)
    1987 Mack EM6-237         0.56         2.37         8.99         0.75         17.6         10.9         35.8
                             (1.3)       (15.5)       (10.7)         (NA)         (20)         (15)         (50)
Fleet Rebuild (After                                                                                            
 Rebuild):                                                                                                      
    1984 Mack EM6-300         0.21         1.56         8.27         0.37          8.1          3.6         14.8
                             (1.3)       (15.5)       (10.7)         (NA)         (20)         (15)         (50)
    1986 Mack E6-300.         0.16         2.69         8.82         0.23          9.1          3.1         17.0
                             (1.3)       (15.5)       (10.7)         (NA)         (20)         (15)         (50)
Simulated In-Frame                                                                                              
 Rebuild (After                                                                                                 
 Rebuild):                                                                                                      
    1987 Mack E6-350.         0.21         2.18         6.32         0.42         10.6         10.4         19.4
                             (1.3)       (15.5)       (10.7)         (NA)         (20)         (15)         (50)
    1984 Mack EM6-300         0.28         2.10         7.58         0.44         10.4          5.4         19.5
                             (1.3)       (15.5)       (10.7)         (NA)         (20)         (15)         (50)
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*``A'' = Acceleration; ``B'' = Lugging; ``C'' = Peak.                                                           
Applicable standard shown in parentheses ( ) under each emission result.                                        
Italic type indicates emissions above applicable standard when such engine was new.                             

[FR Doc. 95-20423 Filed 8-16-95; 8:45 am]
BILLING CODE 6560-50-P