MOBILE5a March 26, 1993 This file describes the "corrected" version of the MOBILE5.0 mobile source emission factor model, originally released on December 4, 1992. This new version fixes some of the errors discovered since the release of the model. Otherwise, this version of MOBILE5 runs identically to the original release and, except where corrections were made, provides similar results. The relevant files needed to use MOBILE5 are: M50A.EXE Contains executable application. M50AEX.EXE Contains some example inputs and outputs. M50UG.ZIP or M50UGWP.ZIP Contains sections from the User Guide. All of these files are self-extracting compressed files. Simply put the file into the directory where you want the files and execute the filename (i.e. enter the command "M50A.EXE"). The files will automatically decompress. The FORTRAN source code for MOBILE5a is available at the web site: http://www.epa.gov/OMSWWW/gopher/Models/Mobile5/ COMPRESSED FILES DECOMPRESSED FILES CONTAINED WITHIN COMPRESSED FILES: ---------- ----------------------------------------------------- M50A.EXE MOBILE5A.EXE Executable application program M50A.EXE F77L3.EER Error message data file M50A.EXE TECH12.D I/M data file (old vehicles) M50A.EXE IMDATA.D I/M data file (new vehicles) M50A.EXE M5.ICO MOBILE5 Microsoft Windows icon M50A.EXE M5.PIF MOBILE5 Microsoft Windows program information file M50AEX.EXE *.IN Example input files M50AEX.EXE *.OUT Example output files M50AEX.EXE M5BAT. Example batch file to run all examples MOBILE5 requires that the two I/M credit files (IMDATA.D and TECH12.D) be kept available if I/M runs are to be done, since the MOBILE5 code now no longer contains any default I/M credits. The F77L3.ERR file is helpful if there are runtime errors and should be kept available also. The User Guide sections have been updated since the original release. They are in a Wordperfect 5.1 format. Before printing, the document may require some reformatting for your particular printer if the intended page numbering and table formatting is to be retained. The document was originally written using Times-Roman and Helvetica type fonts. To run MOBILE5, simply type the command MOBILE5A. The model will ask if you would prefer interactive input (not recommended) or if you wish to use a "batch" mode. The batch mode requires the user to prepare a file listing the input and output filenames you wish to have MOBILE5 read and create. If the user indicates no (enter "N" for each prompt), then the model assumes that the user has prepared a single MOBILE5 input file and prompts for it's file name and the file name for the program output. March 29, 1993 To all MOBILE5 Users and Recipients: Since the release of MOBILE5 (December 4, 1992), a new proposal for reformulated gasoline and the final rulemaking for the revised evaporative emission system test procedure have been published in the Federal Register. Also, MOBILE5 has been found to contain a number of minor errors that can affect the emission factors calculated by the model under certain conditions. For these reasons, the Office of Mobile Sources (OMS) has developed a corrected release of MOBILE5, which is called MOBILE5a (March 26, 1993). These updates and corrections do not affect emission factors calculated for calendar year 1990 except for a few specific areas, as detailed below. This memorandum serves to transmit to your office one copy of the program diskette and the accompanying user documentation. The MOBILE5a program and documentation files have been installed on the OAQPS Technology Transfer Network Bulletin Board System (BBS), as part of the CHIEF bulletin board. An information sheet on the CHIEF BBS and how to access MOBILE5a is attached. Attached to this memo are two additional documents that should be distributed with each copy of MOBILE5 and the User's Guide, "MOBILE5 Microcomputer System Requirements," which outlines the hardware and software requirements for installing and running MOBILE5 on desktop computers, and "MOBILE5 Available Cutpoint Combinations," which lists the inspection and maintenance (I/M) program cutpoint combinations that are currently available to be used with MOBILE5. These are also available on the CHIEF BBS. None of the updates or corrections to be made to MOBILE5 affect the emission factors calculated for calendar year 1990, with a narrow exception described below (5th bullet in list of updates and corrections). However, MOBILE5a is now the official EPA model for estimating highway vehicle emission factors for post-1990 analyses. Hence the projection year and adjusted base year emission inventories for State Implementation Plans (SIPs) should now be developed using MOBILE5a. Updates and corrections to the model. The updates and corrections that have been made since the December 4, 1992 release of MOBILE5 are briefly described below: o The recently promulgated start date and phase-in period of the new evaporative emission system test procedure have changed from the projection made for the release of MOBILE5. The revised start date and phase-in period from the final rule are included in MOBILE5a. This reflects a delay in the implementation of the new standards and a change in the phase- in schedule, and results in slightly higher evaporative emissions after 1994. o The effects of reformulated gasoline (RFG) were estimated based on preliminary estimates. These estimates have been updated as of the February 26, 1993 Federal Register Notice of Proposed Rulemaking (58 FR 11722). This change increased the benefits (emission reductions) of reformulated gasoline slightly for the Phase 1 period. o The 4.0 g/bhp-hr emission standard for oxides of nitrogen (NOx) from heavy-duty diesel vehicles (HDDV) was incorrectly coded as model year 2001; the correct start date is model year 1998. NOx emission factors for calendar years 1998 and later, for HDDVs and for the composite (all vehicle) fleet, are slightly lower as a result of this correction. o There was an error in the application of the observed pass/fail rates for evaporative emission control system pressure/purge tests and the interaction of these rates with the tampering rates. This error caused evaporative emission rates to increase when there were I/M programs. This error is corrected for the future period in which the effect of the error becomes significant, resulting in lower estimates of evaporative emissions in future years. o There were two problems with the effective start dates for inspection and maintenance (I/M) programs. When a biennial inspection frequency is specified, MOBILE5 gave too much credit in the first year of operation. (This inaccuracy was also true in any earlier versions of the MOBILE model.) Second, an error in the logic for I/M implementation allowed full credit for I/M programs on their start date. Instead, I/M credits should gradually increase from the start date of the program at zero credit, to full credit following a full cycle of inspections. Since benefits calculated for July 1 emission factors are determined by interpolation, this error allowed for partial credit for an I/M program for the year immediately preceding the start year of an I/M program. Correction of these errors appropriately reduces the credit for I/M programs evaluated within 6 months of the I/M start date for annual programs, and within 18 months of the I/M start date for biennial programs. Thus, areas which prepared 1990 emission inventories based on January 1, 1990 emission factor output must recalculate the 1990 base year emission inventory if an annual I/M program with a start date of 1/1/90 or a biennial I/M program with a start date of 1/1/89 or 1/1/90 was also included in the emission factor calculations. Areas which prepared 1990 emission inventories based on July 1, 1990 emission factor output (internally interpolated from 1/1/90 and 1/1/91 emission factors) must recalculate the 1990 base year emission inventory if (a) an annual I/M program with a start date of 1/1/90 or 1/1/91, or (b) a biennial I/M program with a start date of 1/1/89, 1/1/90, or 1/1/91 was also included in the emission factor calculations. o The standard I/M credits estimated for Federal Tier 1 vehicles were not consistent with the pre-Tier 1 vehicles. Correction of the Tier 1 credits increases the benefit of standard I/M programs applied to Tier 1 vehicles. o A problem occurs in the first year (model year 1994) of the standard phase-in schedule for the California low-emitting vehicle (LEV) program. This problem caused the 1994 model year emission estimate to be too low if the user specifies California LEV standards. Fixing this error resulted in an increase in emissions for the 1994 model year (all calendar years 1994 and later affected). o There was an error in the calculation of tampering rates which depends on the user input of anti-tampering and I/M program start dates. Depending on the user input, correction of this error reduces the benefit of anti-tampering programs in future years. o There was an error in the determination of diurnal emissions for carbureted vehicles with properly operating evaporative emission control systems (passing vehicles). This error caused higher than intended evaporative emissions for some combinations of RVP and temperature. Generally, the error occurs when the fuel RVP is low. Eliminating this error will result in lower evaporative emissions in future years for these conditions. What's next. User documentation, in the form of an updated version of Chapter 2 of the MOBILE5 User's Guide, is also provided with today's release of the model. This document has also been installed on the CHIEF BBS with the MOBILE5a program files. Chapter 2 is the only portion of the User's Guide that is necessary to run the model. It describes all of the input requirements of the model and discusses all new and revised model features. A complete User's Guide, including detailed discussion of the model revisions, model output, and computer requirements, will be released as soon as it is available. The complete User's Guide will also be installed on the CHIEF BBS, and hard copies will be sent to each Regional Office. Attachments MOBILE5a (March 26, 1993) Inspection and Maintenance Program Available Cutpoint Combinations The following combinations of cutpoints are included in the set of I/M credits made available with this release of MOBILE5. All combinations are available for both annual and biennial cases. Other combinations may be made available if requested. HC CO NOx Test Procedure (ppm) (%) (N/A) (Units) 220 1.2 999. Idle Test 220 1.2 999. 2500/Idle Test (g/mi) (g/mi) (g/mi) (Units) 0.8 15.0 999. IM240 Test 0.8 20.0 999. IM240 Test 0.8 15.0 1.5 IM240 Test 0.8 20.0 1.5 IM240 Test 0.8 15.0 2.0 IM240 Test 0.8 20.0 2.0 IM240 Test 0.8 15.0 2.5 IM240 Test 0.8 20.0 2.5 IM240 Test 0.8 15.0 3.0 IM240 Test 0.8 20.0 3.0 IM240 Test 0.6 10.0 999. IM240 Test 0.6 12.0 999. IM240 Test 0.6 15.0 999. IM240 Test 0.6 20.0 999. IM240 Test 0.6 10.0 1.5 IM240 Test 0.6 12.0 1.5 IM240 Test 0.6 15.0 1.5 IM240 Test 0.6 20.0 1.5 IM240 Test 0.6 10.0 2.0 IM240 Test 0.6 12.0 2.0 IM240 Test 0.6 15.0 2.0 IM240 Test 0.6 20.0 2.0 IM240 Test 0.6 10.0 2.5 IM240 Test 0.6 12.0 2.5 IM240 Test 0.6 15.0 2.5 IM240 Test 0.6 20.0 2.5 IM240 Test 0.6 10.0 3.0 IM240 Test 0.6 12.0 3.0 IM240 Test 0.6 15.0 3.0 IM240 Test 0.6 20.0 3.0 IM240 Test 1.2 20.0 999. IM240 Test 1.2 20.0 1.5 IM240 Test 1.2 20.0 2.0 IM240 Test 1.2 20.0 2.5 IM240 Test 1.2 20.0 3.0 IM240 Test MOBILE5 Microcomputer System Requirements (March 26, 1993) The changes in the MOBILE model since MOBILE4.1 have increased the size of the executable code such that it will no longer run within the DOS 640k memory limit. This requires that the program be run on a machine capable of using extended/expanded memory. In addition, the FORTRAN compiler now available to our office which can produce a version of the MOBILE model that will run in extended/expanded memory can only produce executable code which requires both a machine which uses a 80386 microprocessor and that has a math coprocessor chip installed. If the computer is using DOS Version 5.0, there is a command "MSD" that will show the system hardware. If it shows a 80837 chip, then there is a math coprocessor installed. As a result, with the given understanding of the limitations of the compiler and the size of the program, MOBILE5 will require, at minimum, the following microcomputer hardware configuration for DOS machines: o IBM compatible 80386 or better (such as 80486). o At least two (2) megabytes of RAM memory. o Math coprocessor chip (such as Intel 80387) Microcomputers using the 80286 microprocessor will not be able to run the MOBILE5 model. In addition to the hardware requirements, the FORTRAN compiler also makes use of a memory manager to access the RAM memory in excess of 640k. This sometimes conflicts with existing memory managers installed on these machines. The following sections will discuss how to configure your machine to avoid these conficts. Users with Apple Macintosh systems should not experience any new problems with the new MOBILE model as long as sufficient RAM memory (at least 2 megabytes) is available. Since some of these system requirements are a result of the particular FORTRAN compiler that was used, users with FORTRAN compilers may want attempt to compile the source code themselves to have greater control over the characteristics of the final executable application. Memory Managers --------------- Most systems with expanded or extended memory use a memory manager (such as EMM386.COM) to access the RAM in excess of 640k. This memory manager is configured in the CONFIG.SYS file. When using MOBILE5 from DOS, this memory manager must define at least 2meg (2,048 Kbytes) of expanded memory. You should refer to the user guide for your system in order to determine exactly how this must be done. The MOBILE5 model does contain it's own memory manager, so if conflicts remain, the memory manager configuration can be removed altogether or commented out in the CONFIG.SYS file. MOBILE5 will then run in expanded memory using it's own built in memory manager. Windows ------- MOBILE5 can be run within the standard mode of Microsoft Windows 3.x if certain steps are taken. First, any memory managers defined in the CONFIG.SYS file must be removed or commented out. Windows can be used to control memory allocation. Next, a program information file (PIF) must be created to define the memory space in which to run MOBILE5. For example, the DOS prompt can be accessed from Windows by executing the COMMAND.COM application. This PIF must be created for standard mode and allocate 2 meg (2,048 Kbytes) to the COMMAND.COM application. MOBILE5 will only run with Windows using standard mode. This PIF is then associated with the DOS prompt icon in the Windows Program Manager. To start Windows in the standard mode, use the /S option when executing the WIN.COM command. The DOS command would appear: WIN /S Double-clicking on the icon associated with the PIF described above would drop the user into DOS. From DOS, MOBILE5 can be run as usual. Typing the command, EXIT, returns the user to Windows. A PIF can also be set up to access shell programs directly, if the user prefers, as a method to run MOBILE5.