Fuel Trends Report: 

Gasoline 1995 - 2005 
EPA420-R-08-002 

January 2008

Compliance and Innovative Strategies Division 

Office of Transportation and Air Quality 

U.S. Environmental Protection Agency

Fuel Trends Report: 

Gasoline 1995 - 2005 

NOTICE 

This technical report does not necessarily represent final EPA decisions or 

positions. It is intended to present technical analysis of issues using data 

that are currently available. The purpose in the release of such reports is to 

facilitate the exchange of technical information and to inform the public of 

technical developments.
Table of Contents

Executive Summary........................................................................................................................iii

Table of Acronyms........................................................................................................................ viii

Background Material.......................................................................................................................1

General Methodology ......................................................................................................................6

Summary of Average Estimates ...................................................................................................12

RFG Trends ....................................................................................................................................17

Conventional Gasoline Trends ......................................................................................................35

Sulfur .............................................................................................................................................41

Reid Vapor Pressure......................................................................................................................50

Oxygenates and Oxygen ...............................................................................................................60

Benzene .........................................................................................................................................88

Aromatics.......................................................................................................................................96

Olefins..........................................................................................................................................106

Distillation Parameters ...............................................................................................................112

Emission and Emission Performance .........................................................................................123

References ...................................................................................................................................139

Appendices ..................................................................................................................................140

Appendix to Sulfur Chapter ............................................................................................141

Appendix to RVP Chapter................................................................................................151

Appendix to Oxygenates and Oxygen Chapter ..............................................................159

Appendix to Benzene Chapter ........................................................................................174

Appendix to Aromatics Chapter......................................................................................184

Appendix to Olefins Chapter...........................................................................................194

Appendix to Distillation Parameters Chapter ................................................................203

Appendix to Emissions and Emissions Performance Chapter .......................................225

Regression Analysis ........................................................................................................250

PADD Level Analysis of Reporting Data .........................................................................256

Acknowledgments

The primary data analyst and author of this report is Stuart Romanow.
iii

Executive Summary

This report presents 1995-2005 clean fuel programs implementation data collected

and analyzed by the Environmental Protection Agency’s (EPA’s) Office of Transportation and

Air Quality. The data show that significant changes in gasoline composition during this

period resulted in emission reductions often substantially greater than regulatory

requirements. Future reports on fuel trends will be issued periodically.

Background

As a result of the Clean Air Act (CAA) of 1990, EPA adopted clean fuel programs for gasoline. In

1995, EPA implemented the Reformulated Gasoline (RFG) program, designed to reduce emissions of

ozone-causing volatile organic compounds (VOCs) and oxides of nitrogen (NOx), and air toxics such as

benzene and formaldehyde. At the same time, EPA implemented an anti-dumping program, to protect

the emission qualities of conventional gasoline (CG). In 2000, credit for early gasoline sulfur reduction

was provided by EPA’s Tier 2 gasoline sulfur program.

These clean fuel programs required gasoline refiners and importers to analyze gasoline, measure

certain emission-related parameters, and submit the data to EPA. These data have limitations, but in

many respects, provide an unparalleled source of information about gasoline property trends since 1995.1

Key Findings

 Gasoline Sulfur Decreases -- Average annual sulfur content in all gasoline dropped from about

300 ppm in 1997 to about 90 ppm in 2005.

 RFG NOx Reductions Exceed Requirements -- RFG exceeded applicable NOx performance

standards during both Phase I (1998-1999) and Phase II (2000 and beyond).

 RFG Toxics Reductions Exceed Requirements -- On average, Phase I RFG complied with

Phase II standards, and toxic performance still improved with the transition to Phase II

standards.

 Conventional Gasoline NOx and Toxics Emissions Decreased -- Between 1998 and 2005,

the summer NOx emissions of conventional gasoline were reduced by 5.7 percent, while summer

exhaust toxics were reduced by 4.7 percent.

 Ethanol Use in RFG Increased and MTBE Use Decreased -- In the summer of 1996, about

11 percent of the RFG sold contained ethanol while virtually all the remainder contained MTBE.

By the summer of 2005, the ethanol share increased to about 53 percent, with corresponding

decreases in MTBE.

Gasoline Sulfur Decreases

As Figure 1 demonstrates, average annual sulfur content in all gasoline dropped from about 300

ppm in 1997 to about 90 ppm in 2005. Early decreases in overall gasoline sulfur content were primarily

due to decreases in RFG sulfur content linked to the phase-in of increasingly stringent RFG NOx emission

performance standards. These NOx emission performance standards did not mandate sulfur reduction,

but lowering sulfur content was one of several property changes important to meeting the RFG NOx

standards. Post-2000 decreases were also due to early Tier 2 sulfur reductions, applicable to both RFG

1

EPA lacks information about certain properties, and has only partial information on others. One important

limitation of the trend analyses in this report is that, with the exception of certain oxygen and oxygenate analyses,

they do not include California gasoline.
iv

and CG. Phase-in of Tier 2 sulfur reductions began in 2004, but credit generation for early sulfur

reduction was allowed beginning in 2000.

Figure 1

RFG NOx Reductions Exceed Requirements

As Figure 2 demonstrates, RFG exceeded applicable NOx performance standards during both

Phase I (1998-1999) and Phase II (2000 and beyond). The summer NOx performance of Phase I RFG

exceeded the standard by as much as 3.5 percent, while the summer NOx performance of Phase II RFG

exceeded the standard by as much as 4.1 percent.

Annual Average Gasoline Sulfur Content - (parts per million)

Estimated from EPA Reporting System Data

0

50

100

150

200

250

300

350

1997 1998 1999 2000 2001 2002 2003 2004 2005

Year

Sulfur (ppm)

All Gasoline

RFG

CG
v

Figure 2

RFG Toxics Reductions Exceed Requirements

RFG also exceeded toxics performance standards. As Figure 3 demonstrates, the summer toxics

performance of Phase I RFG exceeded the standard by as much as 15.1 percent, while the summer toxics

performance of Phase II RFG exceeded the standard by as much as 12.8 percent. Winter RFG toxics

performance also exceeded standards (See Figure 9 in the RFG Trends section). On average, Phase I

RFG complied with Phase II standards, and toxic performance still improved with the transition to Phase

II standards.

Figure 3

NOx Performance of Summer RFG-Estimated from EPA Data

(Based on Phase II Complex Model)

0

2

4

6

8

10

12

1998 1999 2000 2001 2002 2003 2004 2005

Year

% Emission Reduction (from baseline gasoline)

Retail Avg.

Reporting Avg.

Phs II Averaged Std

Phs I Averaged Std *

*Phase I standard is an

approximation

based on the Phase II

complex model

Toxics Performance of Summer RFG - Estimated from EPA Data

(Based on Phase II Complex Model)

0

5

10

15

20

25

30

35

40

1998 1999 2000 2001 2002 2003 2004 2005

Year

% Emission Reduction (from baseline gasoline)

Retail Avg.

Reporting Avg.

Phs II Averaged Std

Phs I Averaged Std *

*Phase I standard is an

approximation

based on the Phase II

complex model
vi

Conventional Gasoline NOx and Toxics Emissions Decreased

As Figures 4 and 5 demonstrate, between 1998 and 2005, the summer NOx emissions of

conventional gasoline were reduced by 5.7 percent, while summer exhaust toxics emissions were reduced

by 4.7 percent. Winter emissions also decreased during this period (See Figures 3 and 5 in the

Conventional Gasoline Trends section). These reductions were not required by EPA regulations; instead,

they were a byproduct of Tier 2 sulfur regulation.

Figure 4

Figure 5

NOx Emissions of Summer CG

Estimated from EPA Reporting System Data

1200

1220

1240

1260

1280

1300

1320

1340

1998 1999 2000 2001 2002 2003 2004 2005

Year

Milligrams per Mile

Exhaust Toxics Emissions of Summer CG

Estimated from EPA Reporting System

Data

66

67

68

69

70

71

72

73

74

75

1998 1999 2000 2001 2002 2003 2004 2005

Year

Milligrams per Mile
vii

Ethanol Use in RFG Increased and MTBE Use Decreased

The CAA required that RFG contain two percent oxygen by weight. MTBE and ethanol were the

primary oxygenates used. Figure 6 shows the increasing use of ethanol in RFG and the decreasing use of

MTBE through 2005. In the summer of 1996, only about 11 percent of the RFG sold contained ethanol

while virtually all the remainder contained MTBE. By the summer of 2005, the ethanol share increased to

about 53 percent, with corresponding decreases in MTBE use.

% of Summer RFG Oxygenated with Ethanol and Ethers (Including Federal RFG Areas in CA)

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Ethanol 11% 10% 11% 12% 12% 15% 18% 37% 54% 53%

MTBE TAME other 89% 90% 89% 88% 88% 85% 82% 63% 46% 47%

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005

Figure 6

Gasoline oxygen content has been a topic of considerable interest. Concerns over groundwater

contamination from MTBE resulted in various state laws banning or phasing out its use in gasoline. The

Energy Policy Act of 2005 included a renewable content requirement for gasoline and eliminated the RFG

oxygen content requirement. RFG data for 2006, while not analyzed for this report, show that RFG

suppliers continued to use oxygen in RFG even after the requirement was removed in May of 2006, and

that virtually all of this RFG was ethanol-oxygenated. MTBE use in RFG is currently at near zero levels.

EPA finalized Renewable Fuel Standard program regulations in April 2007 to implement the Energy Policy

Act renewable content requirement. Like RFG, these regulations include new recordkeeping and

reporting requirements designed to track the volume of renewable fuel, including ethanol.
viii

Table of Acronyms

Acronym Definition

ASTM ASTM International- a voluntary standards development organization

(formerly, American Society for Testing and Materials)

CAA Clean Air Act

CFR Code of Federal Regulations

CG Conventional Gasoline

E200 Percent evaporated at 200 degrees F

E300 Percent evaporated at 300 degrees F

EPA US Environmental Protection Agency

ETBE Ethyl tertiary-Butyl Ether (an oxygenate)

FR Federal Register

MSAT Mobile Source Air Toxics

MTBE Methyl tertiary-Butyl Ether (an oxygenate)

NOx Oxides of nitrogen

PADD Petroleum Administration for Defense District (PADD I - East Coast, PADD II -

Midwest, PADD III-Gulf Coast, PADD IV- Rocky Mountain, PADD V-West

Coast)

RBOB Reformulated gasoline blendstock for oxygenate blending (i.e. the RFG

blendstock to which an oxygenate is added)

RFG Federal Reformulated Gasoline

RFS Renewable Fuels Standard

RVP Reid Vapor Pressure

T50 50 percent evaporation temperature (degrees F)

T90 90 percent evaporation temperature (degrees F)

TAME Tertiary-Amyl Methyl Ether (an oxygenate)

VOC Volatile Organic Compound
1

Background Material

EPA has developed and implemented several regulatory programs addressing air quality and

motor vehicle emissions which have significant impacts on gasoline properties and composition. Portions

of these regulations imposed data-related obligations on gasoline refiners, importers and other entities,

requiring that they analyze gasoline to measure certain emission-related parameters, and submit these

data to EPA. Refiners and importers must also submit gasoline volume data. These data, although

intended for compliance evaluation, also provide a unique source of information about trends in emissionrelated gasoline properties and performance. This report analyzes these data to quantify trends, and to

examine how these trends relate to regulatory requirements. This chapter includes a brief description of

these regulatory programs, and the data collected and analyzed in this report.

Reformulated Gasoline Program

Reformulated gasoline (RFG) is gasoline blended to burn cleaner and reduce smog-forming and

toxic pollutants. In ‘211(k) of the 1990 Amendments to the Clean Air Act (CAA 1990), Congress required

RFG to be sold in cities with the worst ozone non-attainment problems. In addition, other cities with

significant smog problems may choose to use RFG. RFG is currently used in 17 states and the District of

Columbia. About 30 percent of gasoline sold in the U.S. is reformulated.

In the 1990 Amendments, Congress also required that non-RFG, or conventional gasoline (CG),

sold in the rest of the country become no more polluting than gasoline sold in 1990. This requirement

ensures that refiners do not "dump" into conventional gasoline fuel components that are restricted in RFG

and that cause environmentally harmful emissions.

EPA introduced the RFG program in 1995, as required by the CAA. 2The RFG program

establishes emissions performance standards for volatile organic compounds (VOCs), nitrogen oxides

(NOx), and toxics. These standards are based on percent reductions from the average emissions of these

pollutants in 1990 model year vehicles operated on a specified baseline gasoline. The RFG program also

establishes a maximum benzene standard of 1.0 volume percent, and an oxygen minimum standard of

2.0 weight percent. (The Energy Policy Act of 2005 repealed the oxygen content requirement.) For

conventional gasoline, the program establishes emissions standards for exhaust toxics and NOx designed

to ensure that an individual refinery's or importer's gasoline will not have higher levels of these pollutants

than the refinery's or importer's 1990 gasoline. These standards for conventional gasoline are called the

anti-dumping standards. 3EPA has implemented the RFG program in three phases; the ASimple Model@

program began in 1995 and ended in 1997, the Phase I "Complex Model" RFG program began in 1998

and ended in1999, and the Phase II RFG program began in 2000. Phase II RFG is designed to result in

greater reductions of VOCs, NOx, and toxics emissions.

Refiners and importers of RFG are allowed to comply with each RFG standard either on a pergallon or annual average basis. Refiners and importers of conventional gasoline must comply with their

anti-dumping standards on an annual average basis. Refiners of RFG must comply with the RFG

standards separately for each refinery. Refiners of conventional gasoline may comply separately for each

refinery, or they may aggregate their refineries. Importers comply with both the RFG and conventional

gasoline standards for the aggregate of the gasoline they import during the year.

2 Regulations pertaining to the RFG program are in Subpart D-Reformulated Gasoline, 40 C.F.R. pt. 80

3

Subpart E-Anti-Dumping, 40 C.F.R. pt. 80
2

The emissions performance of gasoline is calculated using a model, called the Complex Model, which

predicts the emissions level of each regulated pollutant based on the measured values of certain gasoline

properties. These properties are: aromatics, olefins, sulfur, Reid Vapor Pressure (RVP), benzene, oxygen

and distillation points. Refiners and importers are required to measure these properties in each batch of

gasoline they produce or import, using a prescribed regulatory test method, and calculate the emissions

level of each pollutant in each batch of gasoline using the Complex Model. The actual emissions level of

each regulated pollutant in the refiner=s or importer's gasoline is compared to the emissions standard for

that pollutant to determine if the gasoline is in compliance.

Content Limits for Sulfur in Gasoline

In addition to the emissions requirements for RFG and conventional gasoline under the RFG

program, EPA established limits on the amount of sulfur that may be present in gasoline nationwide

beginning in 2004. 4 These gasoline sulfur limits are part of a major program designed to significantly

reduce the emissions from new passenger cars and light trucks. This program, called the "Tier 2”

program, is a comprehensive regulatory initiative that treats vehicles and fuels as a system, combining

requirements for cleaner vehicles with requirements for much lower levels of sulfur in gasoline.

The Tier 2 program phases in a single set of tailpipe emission standards that apply to all

passenger cars and light trucks. To achieve these standards, very clean vehicle emission control

technology is employed. Gasoline with reduced sulfur levels is required under the Tier 2 program to

enable this very clean vehicle emission control technology to be effective. In addition to its beneficial

effects on vehicle emission control systems, the reduction in gasoline sulfur levels required under the Tier

2 program will contribute directly to cleaner air. The Tier 2 program included an initial phase-in period in

which gasoline refiners and importers were required to comply with a company-wide annual average

sulfur standard of 120 parts per million (ppm) in 2004 and 90 ppm 2005. In 2005, refineries and

importers began complying with a 30 ppm annual average sulfur standard. 5 The program also limited

the amount of sulfur that may be present in any gallon of gasoline to 300 ppm in 2004 and 2005, and 80

ppm thereafter.

Under the Tier 2 program, refiners and importers were allowed to generate sulfur "credits" prior

to 2004 for reductions from refinery sulfur baselines established under the Tier 2 regulations. Beginning

with 2004, they were allowed to create sulfur credits if they over-complied with the annual average sulfur

standard by producing or importing gasoline with a sulfur level that is lower than the applicable standard.

Refiners and importers that create credits may use them to comply with the sulfur standard in a

subsequent year or they may trade the credits to another refiner or importer who may need them to

meet the sulfur standard.

Mobile Source Air Toxics Program

In addition to the RFG and sulfur programs, EPA=s Mobile Source Air Toxics (MSAT) program

establishes requirements for refiners and importers designed to ensure that the average level of toxic air

emissions from gasoline does not increase.6This program requires refiners and importers to establish an

individual toxics baseline, separately for RFG and conventional gasoline, based on the average toxics

4 40 C.F.R. ‘80.195

5

This 30 ppm standard applies to individual refineries and importers. As noted in the subsequent paragraph,

the regulations allow generation and trading of sulfur credits which may be used to meet this standard.

6

Subpart J-Gasoline Toxics, 40 C.F.R. pt 80
3

performance of their gasoline during the baseline period 1998 to 2000. Refiners and importers also must

establish a total baseline volume based on their volume of gasoline production or imports during the

baseline period. The volume of gasoline produced or imported during the year, up to the refiner's or

importer's baseline volume can be no more polluting than the refiner=s or importer's MSAT baseline level

for that type of gasoline (RFG or conventional). Any volume produced or imported in excess of the

refiner's or importer's individual MSAT baseline volume can be no more polluting than the RFG toxics

standard or the refiner's or importer's conventional gasoline anti-dumping toxics baseline level, as

applicable.

Refiner/Importer Compliance Reports

EPA has required refiners and importers of RFG to submit compliance reports on a quarterly

basis. 7These reports include information on the volume, properties, and emissions performance for

VOC, NOx and toxics of each individual batch of gasoline produced or imported during the quarter. In

addition, refiners and importers who comply with an RFG standard for a particular pollutant on an annual

average basis must submit an annual report which calculates the refinery's or importers annual average

emissions for that pollutant.

In addition, refiners and importers of conventional gasoline are required to submit an annual

averaging report. 8This report includes information on the volume, properties exhaust toxics, and NOx

emissions of each batch of gasoline produced or imported during the annual averaging period, and a

calculation of the refinery=s or importer=s annual average for each pollutant. Refiners and importers of

conventional gasoline are allowed to compile composite gasoline samples up to one month for purposes

of batch reporting.

Beginning in 2004, all refiners and importers were also required to submit an annual average

sulfur compliance report, which demonstrates compliance with the gasoline sulfur standards. 9This report

must include data on each batch of RFG and conventional gasoline produced or imported during the

annual averaging period, including batch volume and sulfur content. The sulfur compliance report also

includes information on the amount of sulfur credits that were created or received during the averaging

period, used to demonstrate compliance, transferred to another party, or carried over to the next

averaging period.

Since most of the information required to be reported under the MSAT program is also required

under the RFG program, refiners and importers are not required to submit a separate MSAT compliance

report. The only additional information required to be reported under the MSAT program relates to the

toxics baseline volume and incremental volume of gasoline produced during the year by a refiner or

importer. Refiners and importers are required to include this information in their RFG and conventional

gasoline reports.

All refiners and importers of gasoline sold in the U.S. are required to comply with the reporting

requirements described above, except for refiners and importers of gasoline produced or imported for use

in California. Refiners and importers of California gasoline are exempted from the federal reporting

requirements, and certain other federal enforcement requirements, based on a determination by EPA that

California's emissions standards are as stringent as, or more stringent than, the federal emissions

7

40 C.F.R. ‘80.75

8

40 C.F.R. ‘80.105

9

40 C.F.R. ‘80.370
4

standards, and California's enforcement program is sufficient to ensure that refiners and importers of

California gasoline meet California's standards.

EPA's Fuel Data Base

The information provided by refiners and importers in the compliance reports described above is

retained in a data base by EPA's Office of Transportation and Air Quality. This OTAQ data base is a

unique repository of information regarding gasoline production and importation in the U.S. 10 Much of the

information provided in the individual refiner and importer reports is deemed to be confidential business

information (CBI), which the Agency may not make available to the public. However, the raw data in

EPA's data base may be collectively analyzed to provide statistics on various aspects of gasoline

production and importation, such as the number and distribution of refiners, refineries and importers;

gasoline production and import volumes; gasoline properties; and emissions levels of various pollutants.

For example, this report includes analyses of gasoline property data to show RFG and CG property

averages by year and season, and property levels by gasoline volume percentile.

The information contained in this report relating to temporal and geographic trends in gasoline

properties, emissions performance, and production and import volumes is based on an analysis of the

collective data obtained from the refiner and importer compliance reports contained in EPA's data base.

This data is not available from other sources. The information and analyses contained in this report,

therefore, provides a unique picture of gasoline production and imports in the U.S.

RFG Surveys

Under the CAA, areas required to use RFG are called RFG "covered areas". Gasoline meeting RFG

emissions standards is required to be sold in each covered area. The most straightforward way to meet

this requirement would be to require that the contribution of each refinery to the gasoline supply of each

covered area would meet the RFG standards, on average. However, such an approach is unworkable in a

fungible gasoline distribution system -- one in which a refiner pumps his product into a pipeline where it

mingles with other refiners product in unknown proportions before reaching the various covered areas.

Gasoline is supplied to many covered areas in this manner.

10 It should be noted that EPA's database does not contain information on the production of gasoline by

California refiners for use in California nor on the importation of gasoline into California. Within this report, when we

speak of U.S. gasoline, we refer to non-California gasoline as explained in the preceding statement

As a result, the RFG program provides for a system of "refinery gate averaging", in which each

refiner is responsible only for the compliance, on average, of its own product as it leaves the refinery.

This approach, however, has the potential for geographical skewing, where one covered area receives

very clean gasoline while another gets very dirty gasoline, or temporal skewing, where a covered area

receives clean gasoline for part of the year, but gets dirty gasoline for another part of the year.
5

To ensure that such skewing does not occur, the RFG program requires refiners and importers to

conduct surveys of gasoline quality in RFG covered areas.11 These surveys are conducted by an industry

association according to a statistical sampling plan approved by EPA and involve sampling gasoline at

retail gasoline stations. If the gasoline in an area fails to meet the RFG standard for a particular RFG

pollutant, the standard for that pollutant is made more stringent and the number of surveys that must be

conducted in the following year is increased.

Under the RFG survey program, gasoline samples are taken at retail stations according to the

statistical sampling plan, the samples are tested for the relevant gasoline properties, and the emissions

performance of the gasoline is calculated to determine if the gasoline complies with the RFG standards.

Therefore, the survey data provides much information regarding the quality of gasoline sold at retail

gasoline stations in RFG covered areas. The information contained in this report relating to trends in

gasoline properties and emissions performance at retail gasoline stations is based on the data obtained

from the RFG surveys. As with the RFG and sulfur program reporting data, the RFG survey data is not

available from other sources. This report, therefore, provides a unique picture of gasoline quality at retail

stations in RFG covered areas. 12

11 The requirement to conduct surveys is at 40 C.F.R. ‘80.67(a) and compliance survey requirements are

contained in 40 C.F.R. ‘80.68

12 In addition to the RFG survey analyses presented in this report, EPA posts survey-based summary

information on RFG properties and emissions performance by area and season at

http://www.epa.gov/otaq/regs/fuels/rfg/properf/rfgperf.htm
6

General Methodology

Certain gasoline properties affect vehicle emissions, and these properties are regulated directly

through content standards or limits, and/or indirectly through standards controlling the emissions

characteristics of gasoline. EPA collects data on these emission-related parameters for compliance

purposes and, to verify compliance, reviews the data from individual refineries, import facilities and (for

RFG only) geographic areas. In addition to their intended compliance function, these data provide a

means to examine how gasoline has changed over time with respect to these emission-related

parameters. This “Trends” report includes year-by-year analyses of these data, in aggregate, rather than

on a facility-specific basis. EPA analyzed the “batch data” RFG and CG property information that refiners

and importers submit to EPA, as well as the retail property data collected in RFG surveys that are

conducted as a requirement of EPA’s regulations.

While these data, in many respects, provide an unparalleled source of information about gasoline

property trends, EPA's data collection is limited to information needed to evaluate compliance with its

regulations. As a result, EPA lacks information about certain properties, and has only partial information

on others. One important limitation of the trend analyses in this report is that, with the exception of

certain oxygen and oxygenates analyses; they do not include California gasoline. EPA regulations

exempted refiners, importers and oxygenate blenders from reporting requirements for this gasoline, and

limited RFG compliance survey requirements to oxygen and oxygenate sampling.

Report Structure

Individual chapters are devoted to a specific emission-related parameter (e.g. gasoline sulfur

content) or to groups of related parameters (e.g. distillation curve properties or Complex Model emissions

calculation outputs). Each of these parameter chapters provides background information and separate

RFG and CG data analyses for the pertinent parameter(s). The parameter chapters each have an

appendix with further graphical and tabular data summaries. Additionally, the report contains overview

chapters summarizing major trends in RFG and CG. In general, material presented in the overview

chapters is expanded upon in individual parameter chapters. Some graphical analyses presented in the

overview chapters are repeated in the parameter chapters and appendices for completeness and

consistency.

Aggregation of Data and Limitations of Analyses

EPA separately analyzed RFG and CG data. EPA further categorized RFG and CG data from each

reporting or survey year as “Summer” or “Winter”, and separately analyzed these data. (The "Winter"

data in each reporting or survey year includes gasoline produced or sold before and after the "Summer"

season.) Although certain EPA standards and requirements apply to RFG and CG on an annual basis,

emission-related regulations as well as vehicle performance needs impose seasonal requirements which

substantially affect gasoline composition. RFG intended for sale during the summer ozone season must

meet VOC emission performance standards and was required to meet more stringent NOx emission

performance standards. CG intended for sale during the summer season must meet RVP standards

intended to limit evaporative VOC emissions.

These data can be further split and/or aggregated in various other ways to provide potentially

useful analyses, and, to an extent, this was done. Tabular estimates of volume-weighted annual

parameter averages for each product type, and for RFG and CG combined are presented in a summary

chapter following this chapter. Ideally, this "Trends" report would contain exhaustive analyses of the

available data, providing the best available information to a variety of users with diverse interests and

needs. However, there were some significant limitations to the scope and extent of the analysis that EPA

was able to conduct and present in this report. In part, time and resource constraints limited these

analyses. Additionally, the parties that submit these data to EPA have claimed that the data are
7

confidential business information (CBI), and these data may be protected by CBI regulations. In order to

avoid potential CBI issues, EPA has not included any analyses where gasoline properties or volumes could

be strongly associated with individual companies, facilities or brands.

Time Span of Data for Trend Analyses

EPA analyzed “Summer” and “Winter” RFG and CG for each year in which “good” data were

available, through 2005. The earliest year may be 1995, 1997 or 1998, and is dependent on the season

and type of gasoline (RFG or CG), as well as the data set (reporting or surveys) and the specific gasoline

property. This initial year is variable largely because the data submission requirements that EPA imposes

are limited to information needed to determine compliance with regulations and standards. EPA began

collecting certain data in 1995 and, for 1998 and later years, the data requirements changed. RFG

surveys began in 1995, as well, and EPA’s analysis includes survey-based property estimates from 1995

when data for a given property were collected. While refinery/importer reports on RFG and CG were

submitted from 1995 on, only data from the more mature data management system that was in place for

1997 and later reports has been analyzed here.

Furthermore, although EPA has compared the properties and emissions qualities of conventional

and reformulated gasoline within this data-analysis time span to those of 1990 baseline gasoline, it is not

extrapolating backwards to extend the trend analysis back to1990. This report draws no conclusion about

how well 1990 baseline gasoline represented gasoline supplied in 1990.

Although the report is not intended to forecast trends, EPA has, in various chapters, identified

statutory or regulatory changes that have affected or will affect gasoline properties and emission qualities

beyond 2005.

Interpretation of Results

Year-to-year changes in gasoline properties can occur for a variety of reasons; however factors

associated with EPA’s regulatory requirements are likely to be the dominant influences on gasoline

property trends in recent years. The federal RFG program, which affected more than 25 percent of the

gasoline sold outside of California, was expected to have a substantial impact on gasoline properties.

Because of the scope of the RFG program, RFG requirements could potentially affect CG properties as

well (and EPA’s regulations include “Anti-Dumping” standards applicable to CG designed to preserve the

emission-related qualities of CG after these RFG standards were implemented.) The Tier 2 Gasoline sulfur

program, which affects both CG and RFG not only controls gasoline sulfur levels but could affect other

gasoline property trends as well. While this report is largely devoted to providing quantitative estimates

of gasoline parameters and how they changed over time, EPA also attempted to identify factors which

affect these parameter values and which may be responsible for trends or changes. This latter analysis

was not intended to extensively evaluate all possible reasons for trends or changes.

The analyses in this report and the interpretation of results are, for the most part, linked to EPA’s

regulatory perspective. Although the majority of gasoline is CG, EPA has emphasized analysis and

interpretation of RFG data because it collects both production and geographic-based retail data and

because the changes in RFG properties over time are likely to be the direct result of EPA regulations.

EPA’s analysis of RFG data pays particular attention to the changes that occurred between 1999 and 2000

with the transition from Phase I to the current Phase II standards. EPA’s analysis also focuses on

differences between RFG properties in 2000, the first year of Phase II standards, and 2005, the last year

of data included in this report. In addition to looking at overall trends in parameter averages during this

2000 to 2005 period, EPA has also looked at differences in parameter values between 2000 and 2005 on

an area-specific basis. Although differences between these two years could be due to non-regulatory
8

factors, the Tier 2 sulfur requirements as well as changes in oxygenate use could cause or contribute to

differences not only in sulfur and oxygenates, but in other parameters.

The data analysis in this report is predominantly descriptive. Quantitative results are presented

in graphical and tabular format. Determinations that the data display a trend or patterns are largely

based on subjective judgment and identification of a likely cause for the putative change or pattern.

However, EPA has made limited use of linear regression analysis to provide a more objective means of

evaluating and interpreting its estimates. For example, EPA looked at its estimates of RFG parameter

averages to determine if these estimates indicate a statistically significant shift between 1999 and 2000

distinguishable from year-to-year fluctuations and any overall linear trend. EPA also looked at estimates

of CG parameter averages to determine if there was evidence of any shift between 1999 and 2000.

(Such shifts could, but do not necessarily indicate that CG properties changed as a result of RFG standard

changes.) These regression analyses are discussed in an appendix to this report and results are cited in

the body of the report.

Consistency with Other Data and Analyses

EPA based the trend analyses in this report solely on data that it collected. Furthermore, these

analyses were conducted independently from other published analyses. As a result, parameter value and

volume estimates in this report may not always agree perfectly with comparable values published

elsewhere. Several specific consistency-related discussions are included in the report, and EPA found the

trends report estimates to be in reasonably good agreement with other data and analyses. Reasons for

minor differences between reporting system parameter averages published on EPA’s website and

reporting system averages contained in this report are identified in the “Summary of Average Estimates”

chapter. The “Oxygenates and Oxygen” chapter compares ethanol and MTBE volume estimates in this

report with estimates that EPA published in support of the Renewable Fuels Standard regulations. The

“PADD Level Analysis of Reporting Data” appendix includes some comparisons of EPA reporting system

gasoline volume totals with publicly-available Energy Information Administration volume data.

Data Analysis Specifics

Data Screening

Regulatory requirements, such as independent sampling and testing of some samples, help to

ensure the quality of the RFG and Anti-Dumping reporting data that refiners and importers submit to EPA.

Instances of missing, incomplete or incorrect RFG and Anti-Dumping batch reporting data have been

detected and corrected over the course of the data collection program. Furthermore, the reporting

system had been in place for over three years when the 1997 data were submitted and ten years when

the 2005 data were submitted, providing ample time for the industry to gain a thorough understanding of

its requirements.

Based on EPA's review of the data prior to analysis for this report, data errors are believed to

affect only a small proportion of the total data. Thus, data errors were not expected to have a critical

effect on the analysis. However, some additional data screening was performed as part of the analyses

for this report.

In general, data were eliminated from the analyses in two ways. For estimation of most

seasonal average parameter values, data were excluded on a parameter-specific basis. For each

parameter, a rule was established to determine if the data was missing from a batch record. This was

not entirely straightforward, because, for some parameters a value of zero is possible. For these

properties, a blank or null value might indicate a true "zero" value, rather than missing data. It is also
9

possible that zeros may have been used to represent missing data. For some parameters, additional

parameter-specific exclusion criteria were sometimes added to remove values that were clearly impossible

(e.g. when a parameter value reported as a volume percentage substantially exceeded 100 percent).

EPA applied more stringent screening for certain analyses, including estimation of average "Complex

Model" emissions or emissions performance and determination of parameter value distributions by

gasoline volume percentile. For this more stringent screening, in addition to the parameter-specific data

screens, CG, RFG and RBOB batches were flagged if they had "outlier" values for any parameter and

eliminated from an analysis even if the analysis was for a different parameter. For many parameters,

the limits were set at 10% beyond the acceptable range limits for the Complex Model. For some

parameters, RFG and CG have different acceptable range limits. RFG range limits are considered as

standards applicable to every RFG batch. However, the intent was not to exclude non-complying or "high

emissions" batches from these analyses, but to identify batches where one or more parameters were

likely to have been mis-reported or a batch mis-labeled (e.g. CG identified as RFG, CG blendstock

identified as CG.)

These additional screens excluded only a small proportion of the data from most of the analyses.

The additional data screens for this report removed some erroneous data items, although valid data may

also have been removed. The level of screening did not have much effect on the averages, suggesting

that over-screening did not substantially bias the results. Removal of extreme values for certain

parameters visibly affected the tails of parameter value distributions by volume for the parameters, but

had little effect on median values. Removal of data on a batch basis rather than a parameter basis for

some of these analyses probably removed some erroneous data values for parameters, even when the

parameter value did not meet the outlier criteria for that parameter.

The RFG Survey data which were analyzed are also subject to regulatory requirements which help

ensure the quality of the data submitted to EPA. Additionally, EPA has a Quality Assurance Project Plan in

place for the survey program. The survey regulations provide for exclusion of samples from a specific

parameter average if a sample exceeds a per gallon minimum or maximum standard for that parameter

plus an enforcement tolerance. These violations are rare and do not have much effect on survey

averages. EPA did not apply any further data screening criteria to the survey data for this report,

although several surveys were totally excluded from the analyses.

The analyses excluded a survey conducted in St. Louis, MO beginning March 20, 2000, because a

waiver issued as a result of a pipeline break allowed sale of conventional gasoline. EPA also excluded all

one-week RFG surveys conducted between September 2, 2005 and September 15, 2005 from the

analyses in this report since these summer surveys potentially included a mix of summer and winter

gasoline. EPA allowed early use of winter gasoline in a Hurricane Katrina-related waiver issued August

31, 2005, and property averages from these surveys may not have been representative of RFG intended

for sale during the summer ozone season. 13 Although hurricane-related waivers issued in September,

2005 allowed conventional gasoline use in certain RFG areas, the respective timing of these waivers and

surveys made it unlikely that surveys were significantly affected. No surveys were excluded from trends

report analyses in response to these waivers.

Estimation of Average Parameter Values

In order to develop estimates of property averages from these data, measurements from

individual samples must be combined. These measurements represent different quantities of gasoline,

consequently volume-weighting of both reporting and survey data is appropriate.

13 Ten surveys were excluded from 2005 averages; one in each of 10 areas (see

http://epa.gov/otaq/regs/fuels/rfg/properf/rfgperf.htm)
10

Although the reporting system was intended to evaluate the compliance of individual facilities

with standards, rather than to determine seasonal property averages for RFG and CG this is a fairly

straightforward process for reporting data. The volume of each batch is reported so that

volume-weighted property averages can be computed from batch reports.

Developing seasonal property average estimates for all RFG based on individual surveys

conducted in different RFG areas throughout the year is more complex. The individual surveys are

designed to give accurate estimates of average RFG properties in a given area during a given one-week

time period. Surveys are categorized as “Summer” if they are conducted between June 1 and September

15, and “Winter” if they are conducted before or after this period. Each area surveyed is surveyed a

minimum of two times during the summer and two times during the winter. EPA has determined

property averages for each survey, and averaged survey averages to estimate seasonal property

averages for each area.

These seasonal area averages do not represent equal volumes of gasoline so an arithmetic

average of these area averages may not accurately estimate an overall seasonal RFG average.

Consequently, EPA has weighted the area averages by estimates of annual gasoline sales in each of the

survey areas in each of the years. These gasoline volume estimates are provided to EPA in the survey

plan that the RFG Survey Association submits each year. These gasoline volume estimates are included

in the survey plan for purposes other than for combining area averages, but EPA believes that they are

accurate enough (even without further adjustment to estimate area-specific seasonal volumes) to ensure

that areas are not substantially misrepresented in the seasonal average computations.

Individual surveys are designed to sample proportionally to gasoline grade within each area.

Thus, each survey property average was expected to represent the grade mix within each area.

However, this “Trends” report includes estimates of seasonal RFG averages by grade based on survey

data. In order to generate these averages, EPA used area-specific estimates of grade percentages

(included in the survey plans), along with gasoline volume estimates in order to estimate gasoline

volumes by grade. EPA also computed individual survey averages by grade, combined them into

seasonal area averages by grade, and used these estimates of gasoline volume by grade as weighting

factors to compute seasonal averages by grade.

Clearly, estimation of average RFG property trends from survey data is more involved than

estimation of average trends from reporting data and requires assumptions and approximations which

affect the accuracy of the estimates. Also, the survey data are statistical samples while the reporting

data are a census. Thus, errors inherent in statistical sampling affect the precision and accuracy of

survey-based estimates. However, both estimates are included in this report because there may be real

differences between retail and reporting property averages (e.g. due to certain downstream blending

operations or downgrading of product) and the potential for some inaccuracies in reporting as well as

retail estimates. Although both data sets were used for RFG trend analyses, in part, because there could

be differences between production and retail gasoline properties, EPA expected that such differences

would be small. Consequently, EPA believes that when the two estimates are in close agreement, it

corroborates the quality of the data and the reliability of the estimates. (In most cases, the two

estimates agree quite well. Issues pertaining to disparities between survey and reporting-based

estimates are discussed in several chapters.) It is obvious that the RFG Survey data provide important

geographic property information and geographic-based analysis of these retail data are included in this

report. There is no comparable source of such information for CG, so CG analysis is generally limited to

seasonal aggregations of reporting data and, for most properties, averages by premium or regular grade

and season. Some PADD-specific analyses of 2004 and 2005 reporting data are included for both CG and

RFG.
11

Estimation of Parameter Distributions by Volume Percentile

In addition to estimates of property averages, this report includes analysis of the distributions of

property values by gasoline volume percentile for both CG and RFG, generated from batch reporting data.

Graphical and tabular distribution analyses are included in the appendix to each parameter chapter and,

in some chapters, in the body of the chapter, as well.

As previously noted, data used in these distribution analyses were screened for missing data and

outliers. Additionally, certain CG batches were excluded from the distribution analyses because they were

blendstock batches, rather than finished gasoline. These batches were included in computations of

average parameter values because it was assumed that the finished gasoline that would have resulted

from blending may not have also been reported. Inclusion of blendstock batches in CG average

computations could reasonably be expected to improve the accuracy of parameter average estimates

(and inclusion or exclusion has only minor effects on most estimates). However, inclusion of CG

blendstock batches in property distributions by volume is likely to make them less representative of

finished gasoline. Some properties of certain CG blendstock batches, which can be such things as

oxygenates and butane, differ substantially from finished gasoline (e.g., the RVP of butane is more than

50 psi). Thus, it is probably more appropriate and useful to exclude blendstock batches from these

distribution analyses.

RFG blendstock for oxygenate blending (RBOB) batches not removed for missing data or outliers

were included in the distribution analyses because these batches are Ahand blended@ with oxygenates

before properties are measured. Although these batch properties may sometimes differ from the

properties of the actual blend, they are representative of finished RFG.

Estimation of Complex Model Emissions and Emissions Performance Trends

Certain RFG and CG standards are based on Complex Model emissions calculations. The gasoline

property data that EPA collects are the inputs to this model, and EPA also receives certain model outputs

with these data. The current standards, applicable since 2000, are based on the Phase II version of this

model. Standards applicable for 1998 and 1999 were based on the Phase I version of the model. The

CG and RFG reporting and RFG Survey data which EPA received for 1998 and 1999 included emissions

calculations based on the Phase I model. Trend analyses based on a combination of Phase I and Phase

II model calculations would provide little information on changes in the emissions qualities of gasoline

since they would show the effects of the model version change as well as the effects of actual property

changes on emissions. EPA based all analyses on the Phase II model. EPA calculated Phase II Complex

Model results for each 1998 or 1999 batch or survey sample included in these analyses. EPA calculated

average performance by averaging the performance of individual batches or survey samples. Emissions

calculations using average property values for each year, season and gasoline type would probably

provide good approximations of average emissions or emissions performance with significantly less

computational effort. However, EPA's analysis may give slightly different and, arguably, better estimates

because there are some non-linear terms in the complex model equations. Calculating the Phase II

model performance of individual batches also allowed EPA to present emissions distribution by volume

information for 1998 and 1999 batches that can be directly compared to distributions for later years.

EPA ‘s analyses did not include calculated emissions performance for a subset of these batches

representing about three percent of 1998 and 1999 reported RFG and RBOB volume because of omitted

oxygenate information needed for Complex Model input. (In most cases, EPA regulations allowed these

omissions.)

The gasoline data that EPA collected for years prior to 1998 did not include the full set of

property inputs for the Complex Model. Consequently, this report does not include these years in

emissions or emissions performance trend analyses.
12

Summary of Average Estimates

The tables in this chapter summarize certain gasoline parameter estimates contained in this

report and aggregate Summer/Winter and RFG/CG reporting system estimates. As explained in the

General Methodology Chapter:

 The primary trend analyses separated the data into Summer RFG, Winter RFG, Summer CG and

Winter CG.

 Data were screened on a parameter-specific basis when calculating RFG and CG seasonal

averages.

The gasoline volumes contained in the tables are the total volumes for the batches in each

category, prior to data screening. In some cases, due to data-screening, these volumes differ from the

total volume of the batches used to calculate the volume-weighted average for a given parameter in a

given year and season. The seasonal volumes shown in the tables, rather than parameter-specific

screened volumes, were used to aggregate seasonal averages into the annual and RFG + CG combined

averages.

These tables are presented here without discussion. They are intended as a quick reference, as

well as an aid to those who may want to examine aggregate trends. These tables do not show specific

oxygenates for RFG or CG, and do not show CG oxygen content. The tables do not contain all of the

information summarized in this report. The reader should refer to individual chapters for more detailed

quantitative as well as qualitative information.

The reporting system parameter averages and gasoline volumes in this report, in some cases,

differ from reporting system averages and volumes published on EPA’s website. 14 Generally, the

differences are small enough to be of no significance for most purposes. EPA believes that such

differences are not due to computational error but are primarily due to the dynamic nature of the

reporting system database and to slightly different assumptions regarding the inclusion or exclusion of

data.

Even after reporting data for a given year have been received and entered, the reporting system

data for that year may change due to resubmitted and corrected data. These changes can occur some

time after the end of the reporting period. Results generated for this report and for the web posting may

differ in part because they were based on “snapshots” of the data taken at different times.

Different analysts performed the computations for the trends report and web posting and used

slightly different screening and analysis assumptions. For example, although California refineries report

their non-California production, the web posting analyses excluded these data while the trends report

analysis did not. This may well explain why the “unscreened” CG volumes given in this chapter are

slightly higher than the volumes posted on the website.

The tables posted on the website include oxygen and oxygenate concentration averages for CG.

These results may appear inconsistent with some of the CG oxygen and oxygenate analysis in this “trends

report”. However, the web analysis computed oxygen and oxygenates averages only for the batches

with an oxygen value greater than zero. The “trends report” analyses included CG batches with zero or

blank oxygen/oxygenate values in any CG oxygen/oxygenate averages. The report noted the uncertainty

and probable error associated with any oxygen/oxygenates analysis of CG reporting data.

14 See http://epa.gov/otaq/regs/fuels/rfg/properf/rfg-params.htm and

http://epa.gov/otaq/regs/fuels/rfg/properf/cg-params.htm
13

RFG Reporting - Summer

1997 1998 1999 2000 2001 2002 2003 2004 2005

Oxygen (wt%) 2.13 2.13 2.11 2.24 2.21 2.25 2.30 2.56 2.48

Benzene (Vol%) 0.66 0.67 0.71 0.59 0.62 0.59 0.61 0.59 0.66

Olefins (Vol%) 12.0 10.9 11.4 10.6 11.8 10.8 11.0 11.3 11.9

Aromatics (Vol%) 22.4 22.8 22.1 19.3 20.1 20.4 20.1 20.1 20.9

E200 (%) 48.8 49.2 47.7 47.5 47.5 47.9 47.9 48.8

E300 (%) 82.6 82.8 84.7 84.4 84.4 84.4 83.4 84.1

RVP (psi) 7.60 7.60 7.60 6.78 6.79 6.80 6.83 6.87 6.91

Sulfur (ppm) 289 202 205 126 127 124 110 79 69

Volume (gal) 12,522,261,326 12,837,419,615 13,005,827,782 12,983,168,478 13,230,634,977 13,847,971,634 13,587,633,643 14,243,059,617 14,092,489,036

RFG Reporting - Winter

1997 1998 1999 2000 2001 2002 2003 2004 2005

Oxygen (wt%) 2.21 2.22 2.16 2.12 2.11 2.09 2.15 2.38 2.36

Benzene (Vol%) 0.63 0.65 0.65 0.65 0.64 0.64 0.64 0.63 0.67

Olefins (Vol%) 11.3 10.8 11.3 11.8 12.3 11.2 11.0 11.1 11.0

Aromatics (Vol%) 19.2 19.9 19.5 19.0 19.2 19.4 19.4 19.1 19.6

E200 (%) 56.0 56.0 56.3 55.9 55.9 56.0 56.2 56.3

E300 (%) 84.9 84.6 86.1 85.8 85.5 85.1 84.9 85.3

RVP (psi)

Sulfur (ppm) 251 203 214 200 185 184 164 101 80

Volume (gal) 14,942,199,473 15,091,302,974 15,085,096,147 15,831,074,709 15,792,238,105 16,494,453,697 16,679,773,135 17,194,370,899 18,046,671,196

RFG Reporting - Annualized

1997 1998 1999 2000 2001 2002 2003 2004 2005

Oxygen (wt%) 2.17 2.18 2.14 2.18 2.15 2.16 2.22 2.46 2.41

Benzene (Vol%) 0.64 0.66 0.67 0.62 0.63 0.62 0.63 0.61 0.67

Olefins (Vol%) 11.6 10.8 11.3 11.3 12.1 11.0 11.0 11.2 11.4

Aromatics (Vol%) 20.7 21.2 20.7 19.1 19.6 19.9 19.7 19.6 20.1

E200 (%) 52.7 52.9 52.4 52.0 52.0 52.4 52.4 53.0

E300 (%) 83.8 83.8 85.5 85.1 85.0 84.8 84.3 84.8

RVP (psi)

Sulfur (ppm) 268 203 210 167 158 156 139 91 75

Volume (gal) 27,464,460,799 27,928,722,589 28,090,923,929 28,814,243,187 29,022,873,082 30,342,425,331 30,267,406,778 31,437,430,516 32,139,160,232

Table 1
14

Table 2

RFG Surveys - Summer

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005

Oxygen (wt%) 2.19 2.18 2.24 2.26 2.26 2.31 2.30 2.32 2.41 2.65 2.60

Benzene (Vol%) 0.67 0.68 0.68 0.68 0.72 0.60 0.64 0.62 0.65 0.65 0.72

Olefins (Vol%) 10.3 10.8 9.4 10.3 10.8 10.9 10.9 10.8

Aromatics (Vol%) 24.3 24.8 25.5 26.0 24.9 19.5 20.2 20.5 20.1 21.2 21.1

E200 (%) 49.4 49.8 47.9 47.5 47.7 48.0 48.1 48.8

E300 (%) 82.7 83.1 84.9 84.5 84.1 84.0 83.3 84.3

RVP (psi) 7.61 7.64 7.62 7.65 7.62 6.77 6.77 6.79 6.82 6.87 6.92

Sulfur (ppm) 190 204 127 122 117 106 78 69

RFG Surveys - Winter

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005

Oxygen (wt%) 2.42 2.28 2.38 2.42 2.32 2.31 2.24 2.24 2.35 2.61 2.62

Benzene (Vol%) 0.59 0.69 0.67 0.65 0.68 0.65 0.65 0.66 0.69 0.69 0.70

Olefins (Vol%) 9.4 10.0 10.0 10.7 10.6 10.8 10.5 9.5

Aromatics (Vol%) 20.0 20.7 20.8 21.1 21.2 18.1 18.5 19.3 19.1 19.4 18.9

E200 (%) 56.9 56.6 56.6 56.5 56.8 56.6 56.8 56.9

E300 (%) 85.1 84.6 86.1 86.1 85.7 85.6 84.9 85.6

RVP (psi)

Sulfur (ppm) 207 215 192 182 183 167 102 80
15

CG Reporting - Summer

1997 1998 1999 2000 2001 2002 2003 2004 2005

Oxygen (wt%)

Benzene (Vol%) 1.13 1.12 1.14 1.13 1.15 1.09 1.13 1.13 1.19

Olefins (Vol%) 12.3 11.5 11.7 11.7 12.6 12.0 11.8 11.1 11.8

Aromatics (Vol%) 27.4 27.5 27.6 28.4 28.3 28.1 27.9 28.1 27.8

E200 (%) 44.6 45.0 45.0 45.1 44.9 45.2 45.1 45.6

E300 (%) 80.8 81.1 80.5 81.1 80.6 80.7 80.6 81.6

RVP (psi) 8.31 8.29 8.26 8.25 8.25 8.29 8.29 8.29

Sulfur (ppm) 316 297 301 308 295 290 295 114 102

Volume (gal) 39,709,732,667 39,993,052,895 39,702,111,855 38,879,882,521 39,517,397,838 41,639,053,732 44,550,506,550 44,009,126,002 42,849,893,176

CG Reporting - Winter

1997 1998 1999 2000 2001 2002 2003 2004 2005

Oxygen (wt%)

Benzene (Vol%) 1.12 1.07 1.07 1.07 1.12 1.06 1.08 1.07 1.13

Olefins (Vol%) 12.3 11.2 11.4 12.0 12.4 11.7 11.4 11.2 11.5

Aromatics (Vol%) 25.0 24.8 25.0 24.8 25.3 25.0 24.9 24.6 24.7

E200 (%) 49.9 49.9 50.2 49.7 49.9 50.3 50.6 50.7

E300 (%) 83.2 83.0 83.4 83.2 83.1 82.8 83.3 84.1

RVP (psi) 12.13 12.04 12.01 11.91 11.99 12.11 12.17 12.06

Sulfur (ppm) 309 281 298 284 286 286 250 117 95

Volume (gal) 44,979,608,785 46,926,442,568 48,323,290,875 49,012,746,434 49,737,646,274 50,639,522,581 48,852,848,576 48,333,969,089 49,467,392,607

CG Reporting - Annualized

1997 1998 1999 2000 2001 2002 2003 2004 2005

Oxygen (wt%)

Benzene (Vol%) 1.12 1.09 1.10 1.10 1.14 1.08 1.11 1.10 1.16

Olefins (Vol%) 12.3 11.3 11.5 11.9 12.5 11.9 11.6 11.2 11.7

Aromatics (Vol%) 26.1 26.0 26.1 26.4 26.6 26.4 26.3 26.2 26.1

E200 (%) 47.5 47.7 47.9 47.7 47.7 47.8 48.0 48.3

E300 (%) 82.1 82.1 82.1 82.3 82.0 81.8 82.1 82.9

RVP (psi) 10.4 10.4 10.3 10.3 10.3 10.3 10.3 10.3

Sulfur (ppm) 312 288 300 295 290 288 272 116 98

Volume (gal) 84,689,341,452 86,919,495,463 88,025,402,730 87,892,628,955 89,255,044,112 92,278,576,313 93,403,355,126 92,343,095,091 92,317,285,783

Table 3
16

RFG & CG Combined Reporting - Summer

1997 1998 1999 2000 2001 2002 2003 2004 2005

Oxygen (wt%)

Benzene (Vol%) 1.02 1.01 1.03 1.00 1.02 0.97 1.01 1.00 1.06

Olefins (Vol%) 12.3 11.3 11.6 11.4 12.4 11.7 11.6 11.2 11.8

Aromatics (Vol%) 26.2 26.4 26.2 26.1 26.2 26.1 26.1 26.1 26.1

E200 (%) 45.6 46.1 45.6 45.7 45.5 45.8 45.8 46.4

E300 (%) 81.3 81.5 81.5 81.9 81.5 81.5 81.3 82.3

RVP (psi) 8.13 8.12 7.89 7.89 7.89 7.95 7.94 7.95

Sulfur (ppm) 310 274 278 262 253 248 251 106 94

Volume (gal) 52,231,993,993 52,830,472,510 52,707,939,637 51,863,050,999 52,748,032,815 55,487,025,366 58,138,140,193 58,252,185,619 56,942,382,212

RFG & CG Combined Reporting - Winter

1997 1998 1999 2000 2001 2002 2003 2004 2005

Oxygen (wt%)

Benzene (Vol%) 1.00 0.97 0.97 0.96 1.01 0.96 0.97 0.96 1.01

Olefins (Vol%) 12.0 11.1 11.4 11.9 12.4 11.6 11.3 11.2 11.4

Aromatics (Vol%) 23.6 23.6 23.7 23.4 23.9 23.6 23.5 23.1 23.3

E200 (%) 0 51.4 51.4 51.7 51.2 51.4 51.7 52.1 52.2

E300 (%) 0 83.6 83.4 84.1 83.8 83.7 83.4 83.8 84.4

RVP (psi)

Sulfur (ppm) 294 262 278 264 262 261 228 113 91

Volume (gal) 59,921,808,258 62,017,745,542 63,408,387,022 64,843,821,143 65,529,884,379 67,133,976,278 65,532,621,711 65,528,339,988 67,514,063,803

RFG & CG Combined Reporting - Annualized

1997 1998 1999 2000 2001 2002 2003 2004 2005

Oxygen (wt%)

Benzene (Vol%) 1.01 0.99 1.00 0.98 1.01 0.96 0.99 0.98 1.03

Olefins (Vol%) 12.1 11.2 11.5 11.7 12.4 11.7 11.5 11.2 11.6

Aromatics (Vol%) 24.8 24.9 24.8 24.6 24.9 24.7 24.7 24.5 24.6

E200 (%) 48.7 49.0 49.0 48.7 48.7 48.9 49.1 49.5

E300 (%) 82.5 82.5 82.9 83.0 82.7 82.5 82.6 83.4

RVP (psi)

Sulfur (ppm) 302 267 278 263 258 255 239 110 92

Volume (gal) 112,153,802,251 114,848,218,052 116,116,326,659 116,706,872,142 118,277,917,194 122,621,001,644 123,670,761,904 123,780,525,607 124,456,446,015

Table 4
17

RFG Trends

Changes in the properties and composition of RFG have occurred since RFG was first introduced

in 1995. These parameter changes were primarily due to regulatory requirements that were phased-in

over time. These changes and their regulatory causes are discussed below, grouped into two time

periods. The first period, from 1995 to 2000, begins with the introduction of the federal RFG program

and includes two RFG standard changes; one from 1997 to 1998 and the second from 1999 to 2000.

RFG standards were at their current Phase II level during the second period, from 2000 through 2005,

however other regulatory factors affected RFG properties and composition.

Changes in RFG from 1995 to 2000

When RFG was introduced in 1995, it was subject to oxygen minimum and benzene maximum

content standards, RVP limits for VOC-controlled (Summer ozone-season) RFG, and a toxics emission

performance standard. Emission performance refers to an emission reduction, in percent, relative to a

baseline gasoline, as determined by a mathematical model which estimates vehicle emissions based on

certain properties of the gasoline being used. The mathematical model which provided the basis for the

toxics performance standard is called the "Simple Model." The Simple Model considered the emissions

effect of four parameters: aromatics, benzene, oxygen (including, for some calculations, the individual

contribution of several specific oxygen-containing organic compounds called oxygenates), and RVP

(Summer only). The toxics emission performance standard along with the RVP, oxygen and benzene

requirements are called the Simple Model standards.

Beginning in 1998, "Complex Model" standards replaced the Simple Model standards. The

Complex Model standards included the same oxygen minimum and benzene maximum content standards

and, like the Simple Model standards, included a performance standard for toxics emissions. In addition,

the Complex Model standards included performance standards for NOx and VOC emissions. The Complex

Model considers the emissions effects of the four Simple Model parameters discussed above, and the

emissions effects of several additional gasoline parameters: sulfur, olefins, and two distillation points,

E200 and E300. The Complex Model standards were introduced in two phases: Phase I in 1998, and

Phase II, which requires more stringent emissions reductions, beginning in 2000.

EPA's evaluation of the RFG property and emissions performance changes is based on data that it

collects to determine compliance with its regulations. The gasoline parameter information that EPA

needed for compliance purposes changed in 1998, and this limits EPA's ability to compare RFG from 1995

through 1997 to RFG in 1998 and later years. (EPA has also restricted its production data analysis in this

report to 1997 and later years). EPA has collected data on the four Simple Model parameters (aromatics,

oxygen, benzene and RVP) since 1995, and there is no evidence of substantial changes in these

properties between 1997 and 1998, with the transition to the Complex Model standards. EPA also has

comprehensive production data on 1997 sulfur and olefin content, two of the four additional Complex

Model parameters. Based on these data, both sulfur and olefin content decreased between 1997 and

1998, and it is clear that the changes in sulfur content were substantial (figures 1 and 2). (See individual

parameter chapters for detailed graphical and tabular summaries of gasoline parameter values.)

According to the Complex Model, lowering gasoline sulfur content reduces NOx, exhaust toxics

and exhaust VOC emissions. Sulfur content has a substantial influence on NOx emission performance. It

is likely that refiners reduced the sulfur content of RFG from 1997 levels, in part, to meet the Complex

Model NOx emissions performance standard. However, it is unlikely that sulfur reductions of the

magnitude seen between 1997 and 1998 were solely due to the imposition of a NOx performance

standard, since Phase I Complex Model RFG was only required to have NOx emission performance equal

to baseline gasoline's with sulfur levels of 338 (Winter) and 339 (Summer) ppm. In addition, the RFG
18

regulations allowed refiners and importers to supply some RFG with NOx performance worse than

baseline gasoline if they complied on average with a slightly more stringent NOx performance

requirement.

The sulfur reductions in 1998 are attributable, at least in part, to a requirement that each

Complex Model input parameter be within specific range limits. These limits were intended to address

the validity of the model, and EPA=s regulations prohibit certification of RFG with properties outside of

these model limits (Limits of the model 40 C.F.R. ‘80.45(f)). The limit for sulfur is 500 ppm;

consequently each batch of RFG was required to have a sulfur content at or below this level beginning in

1998. Analysis of EPA=s reporting data shows that about 17% of Summer and 12% of Winter RFG refined

and imported in 1997 exceeded this limit (figures 3 and 4). Thus, even if 1997 RFG on average met

1998 NOx performance standards, a portion of that RFG would have required sulfur reductions to meet

the Complex Model range limit imposed in 1998. EPA did not calculate the average Complex Model

emission performance of its 1997 refiner/importer data since suppliers were not required to report the

E200 and E300 model inputs. However, as shown later in this chapter, EPA calculated the average

emission performance of 1998 and 1999 RFG. EPA found that the NOx performance of both Summer

and Winter RFG was significantly better than the standard, and presumes that average NOx performance

improved from 1997 to 1998. This over-compliance in 1998 and 1999 is likely partially, if not primarily,

due to sulfur reductions needed to comply with the sulfur range limit.

Presumably, the NOx performance standard and the Complex Model sulfur range limit were the

major factors influencing the 1997 to 1998 decrease in RFG's average sulfur content. However, since the

Complex Model recognized the toxics and VOC emissions benefits of sulfur reduction, reducing sulfur

levels below those needed to minimally comply with the NOx standard and sulfur range limit also may

have become an economically desirable option for some producer's by 1998. (As discussed below, the

more stringent standards applicable to Phase II RFG would result in additional sulfur reductions by year

2000.)

Figure 1
19

Figure 2

Figure 3
20

Figure 4

The transition from Phase I to Phase II Complex Model RFG occurred between 1999 and 2000.

The Phase II emission performance standards, particularly the more stringent standards applicable to

VOC-controlled (Summer) RFG caused significant changes in average values for most Complex Model

input parameters. Phase II RFG performance standards required greater reductions of VOC and NOx

emissions in VOC-controlled (Summer) RFG, and greater reductions in toxics emissions on an annual

basis. Figures 5 through 9 show RFG Complex Model performance and applicable performance

standards. Average Summer RFG performance improved between 1999 and 2000 even for toxics, where

Phase I RFG, on average, complied with the Phase II standards. The Winter NOx standard did not

become more stringent with Phase II and, on average, Phase I Winter RFG met Phase II standards for

Winter NOx and annual toxics performance. EPA's two data sources disagree somewhat about the

magnitude of the emissions performance changes for Winter RFG. While both data sources indicate

Winter performance improvements between 1999 and 2000, only the survey estimates suggest an abrupt

improvement. (The Phase II version of the Complex Model differs from the Phase I version. In this

report, to facilitate comparison of Phase I and Phase II RFG, Phase I RFG performance and standards are

estimated using the Phase II model.)

Figure 5
21

Figure 6

Figure 7
22

Figure 8

Figure 9
23

RFG producers adjusted several of the emission-related properties of their RFG blends to produce

Phase II RFG. Figures 10 through 12 show the composite effect of all (1999) Phase I to (2000) Phase II

property changes on Complex model emissions, using average property value estimates from RFG

surveys, as well as the individual effects of changing one property while holding all others constant. This

provides a good indication of the relative contribution of each property change to the overall Phase I to

Phase II emission performance change. (Because of the non-linear mathematical structure of the

Complex Model, the individual property effects do not precisely add up to the composite effect, and the

emission performance of this “average RFG” is not precisely the same as the average performance of all

RFG blends.) Since the performance standards, and consequentially, the emission-related properties

changed more substantially for Summer RFG, only Summer graphs are presented. Each bar is labeled

with the estimated average parameter values for 1999 and 2000.

Figure 10
24

Figure 11

Figure 12
25

RVP reductions were the primary means of meeting the more stringent Phase II VOC

performance standards. RVP effects on emissions are considered in the Summer version of the Complex

Model only. The Complex Model estimates both exhaust and non-exhaust VOC emissions and adds them

together. Although reducing RVP lowers exhaust VOC emissions, the RVP parameter primarily affects the

non-exhaust (i.e. evaporative emission) portion of the Complex Model, and is the only gasoline parameter

affecting its non-exhaust VOC estimates. Reductions in fuel aromatics and sulfur content, affecting

exhaust VOC emissions, contributed to total VOC reductions. (Figure 10 shows two sets of bars because

the non-exhaust portion of the Complex Model varies by geographic VOC Control Region. To simplify this

"property effects" analysis EPA used a single set of property averages based on data from both regions.)

Sulfur and aromatics reductions were the primary changes responsible for Phase I to Phase II

NOx performance improvements. Phase I to Phase II sulfur reductions were larger in Summer RFG, and

this sulfur reduction appears to be the most important single parameter contributing to Summer RFG NOx

performance improvement. However, it is clear that reductions in aromatics and olefin content had nonnegligible effects on Summer NOx performance improvement

Several parameter changes contributed to toxics performance improvements from Phase I to

Phase II. This analysis, based on property estimates from RFG Surveys indicates that reductions in

aromatics content were most important, but other parameter changes, such as sulfur and benzene

reductions, contributed significantly to toxics performance improvements. (Since the reporting system

data estimates a smaller 1999 to 2000 change in aromatics content but almost identical sulfur and

benzene changes it is possible that a similar analysis using reporting system data would conclude that the

aromatics content reduction was a significant but not primary contributor to toxics performance

improvement.)

The Complex Model estimates emissions of benzene, formaldehyde, acetaldehyde, 1,3-butadiene

and polycyclic organic matter and adds them together to produce a toxics emission estimate. Exhaust

benzene emissions are the largest component of Complex Model exhaust toxics, and exhaust benzene

reductions were the largest component of the 1999 to 2000 toxics emissions reductions (see the

Emissions chapter for this analysis.) The Summer model considers evaporative benzene emissions, as

well. As one would expect, both exhaust and non-exhaust benzene emissions are directly related to

gasoline benzene content, although other gasoline parameters also affect benzene emissions. There was

a sharp decrease in Summer RFG benzene content between 1999 and 2000, even though the benzene

content standard for RFG did not change (see the Benzene chapter). Additionally, RVP reductions, which

were necessary to meet the more stringent Phase II VOC standards, also contributed to Summer toxics

emission reductions because reducing RVP reduces evaporative benzene emissions.

The graph for parameter change effects on toxics emissions shows the oxygen contribution

change from individual oxygenates because, unlike VOC and NOx Complex Model calculations, toxics

calculations are a function of the type(s) of oxygenate used as well as the oxygen content of the gasoline

formulation. Oxygen and oxygenate changes between 1999 and 2000, and consequentially, their effects

on emissions, were very small.
26

Changes in RFG from 2000 to 2005

Additional regulatory requirements have been imposed on both RFG and conventional gasoline

since the beginning of the Phase II program in 2000. These requirements have and will influence the

properties, composition and emissions performance of RFG.

One direct change was made to the Phase II RFG performance standards. This change involved

a small relaxation in the VOC performance standards applicable to certain ethanol-oxygenated RFG

supplied to the Chicago and Milwaukee areas. While some decline in VOC performance in these areas

was expected as a result of this change the scope and magnitude of this change was limited and

influence on overall average RFG trends is small.

Figure 5, which estimates the overall VOC performance trend, suggests that RFG VOC

performance may have declined very slightly from 2000 to 2005. This estimate of a slight decline could

easily be attributable to imprecision or inaccuracy in the estimates. More areas declined in VOC

performance than improved, but the estimated performance changes in either direction were generally

small (Figure 13). However, it is apparent that the greatest performance declines occurred in the Chicago

and Milwaukee areas. Since VOC performance declines in these areas were expected as a result of the

standard change it is unlikely that the observed declines in VOC performance in these two areas are the

result of statistical or measurement error.

Figure 13
27

Perhaps the most significant post-2000 regulatory change is the Tier 2 gasoline sulfur program,

applicable to both RFG and conventional gasoline, which requires refiners to reduce sulfur levels

incrementally. In 2005 (with some exceptions), refiners and importers were required to comply with a 30

ppm annual average sulfur standard and a 300 ppm per gallon cap. The cap is reduced to 80 ppm for

2006 and later years. Both the RFG requirements and the Tier 2 gasoline sulfur requirements have

resulted in substantial reductions in gasoline sulfur levels. However, there is an important difference

between these sulfur reductions.

As indicated above, the RFG program did not mandate sulfur reductions, but set performance

standards based on the Complex Model. RFG producers, through their refining and blending processes,

are able to adjust various Complex Model input properties, including sulfur, in order to achieve the

required emission reductions. As previously noted, lowering gasoline sulfur content reduces NOx, exhaust

toxics and exhaust VOC emissions. Consequently, the more stringent Phase II performance standards for

these pollutants resulted in sulfur reductions from Phase I to Phase II RFG, especially in Summer RFG

(Figures 1 and 2).

The Tier 2 gasoline sulfur standards are required primarily for the purpose of enabling

technology. Gasoline with reduced sulfur content is necessary to enable the emission control systems in

Tier 2 vehicles to be fully effective. Phase-in of very stringent Tier 2 tailpipe emission standards,

applicable to all passenger cars and light trucks, began in 2004 along with a company-wide annual

average sulfur requirement of 120 ppm. The company-wide 120 ppm standard is comparable to the

average sulfur content in Phase II Summer RFG in 2000 and is substantially lower than the sulfur content

of Winter RFG. Thus, Tier 2 sulfur requirements have and will lower RFG sulfur content, and this trend is

apparent in the retail and production data averages shown in Figures 1 and 2. (Information on CG and

CG/RFG combined sulfur averages is available elsewhere in this report.)

Since the Tier 2 sulfur standards reduce sulfur levels below those needed to meet RFG

performance standards, and the Complex Model predicts that emission performance improves with lower

sulfur, the emissions performance of RFG could potentially improve as a result of the Tier 2 requirements.

Thus, emissions of these pollutants from older vehicles, as well as "Tier 2” vehicles could be lowered by

this sulfur reduction. However, RFG producers could also change their RFG formulations such that other

gasoline property changes would offset the Complex Model emission benefits of the required sulfur

reduction. This first effect clearly dominated RFG NOx emission performance, while the strongest

evidence of this latter effect is in RFG VOC performance. More generally, the interaction between the

RFG requirements and the Tier 2 sulfur reductions should be better understood as additional years of

data are analyzed.

The estimates of average NOx, VOC and toxics performance shown in Figures 5 through 9

indicate clear improvements in average NOx performance between 2000 and 2005, but do not show

improvements for VOCs. Summer and winter toxics changes were mixed, with a small decrease in

summer performance and a small increase in winter performance. Unlike VOC (with only a summer

standard) and NOx (where summer and winter standards differ), compliance with RFG toxics performance

standards and other toxics-related regulatory requirements is determined on an annual average basis.

Thus, improvements in Winter RFG toxics performance could have compensated for decreases in Summer

RFG toxics performance, and this may have been a factor influencing the directionally opposite seasonal

toxics performance trends.

EPA compared 2000 to 2005 RFG in the same manner as previously described for 1999 to 2000

RFG. Figures 14 through 18 show the composite effect of all 2000 to 2005 Phase II property changes on

Complex model emissions, using average property value estimates from RFG surveys, as well as the

individual effects of changing one property while holding all others constant.
28

Figure 14

Figure 15 Figure 16
29

Figure 17 Figure 18

Figure 14 shows that the VOC emission reduction benefits of lower sulfur (from 127 to 69 ppm)

and increased olefin content (which lower exhaust VOC) were offset by an increase in RVP (from 6.77 to

6.92 psi), which primarily increases evaporative VOC, and by other property changes which increase

exhaust VOC. Comparison of the scale of this chart with the chart showing 1999 to 2000 property effects

(figure 10) shows that, according to the Complex Model, the impact of any of the 2000 to 2005 property

changes on VOC emissions is very small compared to the overall Phase I to Phase II emission change,

which was primarily due to an RVP reduction (from 7.62 to 6.77 psi). The sulfur reduction between 2000

and 2005 may have facilitated some "trade off" between evaporative and exhaust VOC emission

reduction, but, through 2005, the Tier 2 regulation has not had a substantial effect on overall RFG VOC

performance (figure 5). Figure 14 also shows VOC reduction due to increase in RFG oxygen content.

This oxygen content increase is related to an increase in ethanol use. (This is discussed later.)

Figures 15 and 16 show that the Tier 2 sulfur requirements have clearly helped RFG's NOx

performance. As expected, the benefit is greater in Winter RFG because of the larger sulfur reduction

(192 to 80 ppm). Summer sulfur NOx benefits have also been offset to a greater extent by other

property changes. However, the overall trend shows improved NOx performance for both Summer and

Winter RFG between 2000 and 2005 and a substantial improvement in Winter performance between 2003

and 2005 (Figures 6 and 7). 15

Figures 17 and 18 show that the toxics reduction benefits of lower sulfur have been countered by

emission increases due to increased aromatics and benzene content, resulting in a slight decline in

15 Beginning in 2007, the NOx performance standards were, with some exceptions, eliminated for RFG

refiners and importers. The gasoline sulfur program will become the sole regulatory mechanism used to implement

gasoline NOx requirements. See 82 FR 8427.
30

Summer toxics performance and a slight improvement in Winter performance. As explained earlier, the

toxics graphs show oxygenate-specific effects because oxygenate type affects toxics emissions. These

graphs indicate that there is a toxics emission reduction associated with an increase in oxygen coming

from ethanol and a toxics emission increase associated with a decrease in oxygen coming from MTBE and

TAME. It is important to remember that all oxygenates have certain toxics emission reduction benefits

and that the increase in ethanol is related to the decrease in MTBE and TAME. The toxics emission

benefit lost from decreased use of these ethers in RFG is at least partially offset by the benefit gained

from increased use of ethanol in RFG.

Another post-2000 regulatory change affecting RFG (and conventional gasoline) is the Mobile

Source Air Toxic (MSAT) rule (2001). This rule requires refiners and importers to produce or import

gasoline with toxics emissions that are no greater than the toxics emissions of gasoline they produced or

imported during the period 1998-2000. Data collected by EPA indicates that RFG (and conventional

gasoline) often over-complied with toxics emission requirements. The MSAT rule is intended to preserve

this over-compliance in order to ensure that toxics emissions do not increase above current levels. Thus,

much RFG currently is subject to more stringent toxics emission performance requirements than the Phase

II RFG toxics emissions performance requirements. It would be difficult to isolate the effect of the MSAT

rule on changes in the properties and emission performance of RFG, but it is clear that the MSAT rule

could interact with other requirements and economic factors to affect the composition and performance of

RFG. 16

An additional regulatory requirement which has significantly impacted the composition of RFG is

the oxygen content requirement. The Clean Air Act (CAA) required that RFG contain 2 weight percent

oxygen, until the Energy Policy Act of 2005 [in ‘1504(a)] amended the CAA to remove this requirement. 17

This requirement was effective when RFG was introduced in 1995. RFG producers satisfied this

requirement by blending certain organic compounds, known as oxygenates into their gasoline. These

oxygenates fall into two general categories; ethers and alcohols. The most common ether used was

Methyl tertiary Butyl Ether (MTBE) although small quantities of other ethers, primarily tertiary-Amyl Methyl

Ether (TAME), were sometimes used. The only alcohol used in any significant quantity was ethanol.

16 EPA has finalized an "MSAT2” regulation to replace the current MSAT requirements with a 0.62 volume

percent average benzene requirement beginning in 2011. See 72 F.R. 8427

17 Removal of the oxygen requirement became effective with regulatory changes on April 24, 2006 for

California gasoline, and May 5, 2006 for gasoline nationwide. See 71 F.R. 8965 and 71 F.R. 26419.

Although the RFG oxygen content requirement did not change during the time

span considered in the report, it significantly affected composition of post-2000 RFG. A number of studies

have detected MTBE in ground water throughout the country; in some instances these contaminated

waters are sources of drinking water. While most of these detections have been well below levels of public

health concern, low levels of MTBE can make drinking water supplies undrinkable due to its offensive taste

and odor. In 1998, the EPA Administrator appointed a Blue Ribbon Panel to investigate the air quality

benefits and water quality concerns associated with the use of oxygenates in gasoline. The Panel, which

issued its report in September 1999, agreed broadly, but not unanimously, that in order to minimize

current and future threats to drinking water, the use of MTBE should be reduced substantially (Blue Ribbon

Panel, 1999). Subsequently, certain states have acted to ban or limit the use of MTBE in gasoline. This
31

has resulted in a decreased use of MTBE and an increased use of ethanol in RFG. This switch from MTBE

to ethanol affects the composition of RFG and potentially affects the Complex Model emissions

performance of RFG. (There are a number of issues relating to the overall emissions impact of ethanoloxygenated gasoline, and the ability of the Complex Model or other emission models to address these

impacts. A discussion of these issues is beyond the scope of this report, and, unless otherwise stated,

emissions performance refers to the Complex Model.)

Figures 19 through 22 show 2000 to 2005 changes in average ethanol and MTBE content (in

weight %), for the various RFG areas surveyed. In some areas where large changes occurred, the change

reflects a transition from all-ether to all-ethanol RFG. In other areas, the change reflects some ethanol

usage in 2000 and increased ethanol usage in 2005. In the case of the NY-NJ-Long Island-CT RFG area,

New York and Connecticut enacted MTBE bans, but New Jersey did not. The charts include several areas

in California where RFG was required under federal law. The federal oxygen content requirement, as well

as California=s gasoline requirements, applied to this gasoline.

Figure 19 Figure 20
32

Figure 21 Figure 22

The increased use of ethanol has resulted in a higher percentage of RFG being oxygenated with

ethanol, a larger fraction of total oxygen in RFG being supplied by ethanol and an increase, on average, in

the total oxygen content of RFG. Figures 23 through 26 show estimates of the fraction of RFG oxygenated

with ethanol, by year and season, through 2005. Figures 27 through 30 show estimates of the total

oxygen (in weight %) in RFG, and the amounts of this oxygen supplied by ethanol and other oxygenates.

The total oxygen content has increased along with the ethanol share because most ethanoloxygenated RFG supplied outside of California contains about 10 volume percent ethanol, providing about

3.5 weight percent oxygen, even though RFG was only required to have only 2 weight percent oxygen.

This occurred, in part, because, until a recent legislative change (American Jobs Creation Act, 2004), a

federal excise tax exemption available to ethanol was greatest when ethanol was blended at 10 volume

percent and pro-rated for blending at 5.7 or 7.7 volume percent (see the Oxygenates chapter).

Additionally, MTBE must be used at around 11 volume percent in order to provide the required 2 weight

percent oxygen. Thus, when ethanol is used to replace MTBE, blending at 10 volume percent replaces

much of the lost MTBE volume.
33

Figure 23 Figure 24

Figure 25 Figure 26
34

Figure 27 Figure 28

Figure 29 Figure 30
35

Conventional Gasoline Trends

EPA used the gasoline property data that it received from conventional gasoline (CG) refiners and

importers to investigate property trends. EPA's CG analysis covered the period between 1997 (or 1998

for some properties) and 2005. As noted in the General Methodology chapter, while EPA receives retail

survey as well as refiner/importer data for RFG, it receives only refiner/importer data for CG.

Consequently, the CG analysis in this report is less extensive than its RFG analysis.

EPA's Anti-Dumping regulations, affecting CG, and its Mobile Source Air Toxics regulations

affecting both CG and RFG, limited or prevented CG deterioration, but did not necessarily force

substantial changes in CG's emission-related properties or improvements in CG's emission qualities. The

Anti-Dumping standards changed between 1997 and 1998, with the transition to the Complex Model, and

the model for CG exhaust toxics and NOx emission calculations needed to determine CG compliance

changed in 2000 with the transition to the Phase II Complex Model. However, in sharp contrast to

simultaneous changes in RFG requirements that caused significant RFG composition changes, these CG

changes apparently had minor impacts on CG composition. Moreover, the Anti-Dumping regulations

apparently performed as intended, since CG emissions did not show significant or sustained increases

when the more stringent Phase II RFG regulations took effect.

The Tier 2 gasoline sulfur regulations applicable in 2004 and later years impose the same sulfur

content requirements on CG and RFG. However, CG sulfur content decreased more precipitously since

other regulatory factors affecting RFG had already resulted in sulfur reductions.

To summarize, EPA's analysis shows that certain CG gasoline properties have fluctuated from

year-to-year within the time period addressed in this report. These fluctuations may be linked to both

regulatory and non-regulatory factors. Specific instances where regulatory factors may have influenced

CG properties or emission qualities are identified in various chapters within this report. However, the

sulfur reduction requirement was the only regulatory factor that clearly exerted a large influence on CG

during this time period.

Figure 1 shows EPA's CG gasoline sulfur content estimates for each year between 1997 and 2005.

The large change from 2003 to 2004 is due to the Tier 2 gasoline sulfur requirements and, as explained

in the Sulfur chapter, these requirements may also have motivated some sulfur reductions prior to 2004.

Figure 1
36

Figures 2 through 5 show CG exhaust toxics and NOx average emission levels from 1998 through

2005 calculated with the Phase II Complex Model. CG must comply with Complex-model based exhaust

toxics and NOx "milligram per mile" emission standards. While sulfur reductions were required to enable

new technology vehicles to meet Tier 2 emission standards, the reductions also result in "cleaner" CG

because these sulfur reductions result in lower Complex Model emission levels. This is evident in the

2003 to 2004 emission improvements that occurred concurrent with the large sulfur decreases. This

suggests that CG sulfur reductions have and will reduce emissions in older vehicles as well. 18 These

Complex Model emission calculations are not intended to be accurate estimates of the overall emissions

rates or emissions changes that have occurred in each year as a result of gasoline property changes.

They are indicators of changes in the emissions qualities of gasoline over time without considering

changes in vehicle technology or emission standards.

Comparison with 1990 Statutory Baseline Gasoline

19

18 Beginning in 2007, NOx emission standards were, with some exceptions, eliminated for CG refiners and

importers. The gasoline sulfur program will become the sole regulatory mechanism used to implement gasoline NOx

requirements. See 82 FR 8427.

19 The properties of the Summer Baseline gasoline were specified in the Clean Air Act. EPA regulations

specified the properties of Winter Baseline gasoline. The term statutory baseline gasoline is used here to refer to

both the Summer and Winter .

Since the standards applicable to CG exhaust toxics and NOx are facility-specific and largely

depend on individual 1990 baselines, these graphs do not show CG standards. Instead, the graphs show

the Complex Model emissions rate of the seasonally-appropriate 1990 statutory baseline gasoline to

provide some basis for comparison. These statutory baseline gasoline properties and emission levels

were intended to be representative of the gasoline supplied in 1990. They are used to determine

compliance for refiners and importers without individual baselines, and also factor into CG compliance

determinations for individual refineries and importers supplying CG in excess of their 1990 gasoline

volumes.

The exhaust toxics and NOx emission levels in each season and year are lower than the 1990

baseline levels. Although the 1990 statutory baseline gasoline properties were intended to be

representative of the gasoline supplied in 1990, EPA does not have comprehensive data on CG properties

in 1990 comparable to the data collected in its Anti-Dumping reporting system. EPA has compared

properties and emission values of 1990 statutory baseline gasoline's to its CG estimates here and

elsewhere in this report to provide some frame of reference. While EPA’s Anti-Dumping regulations did

not mandate substantial changes in CG composition or emissions characteristics these comparisons are

insufficient to establish that these statutory baseline gasoline properties were or were not representative

of 1990 gasoline. Regulatory changes other than the Anti-Dumping regulations, including volatility

requirements and winter oxygenated gasoline program requirements certainly impacted CG composition

between 1990 and 1997, the earliest year for which CG data were analyzed in this report. Various states

have adopted specific gasoline requirements (e.g., low RVP, low sulfur) and these "boutique" fuels are

included in EPA's CG data. Non-regulatory factors may also have caused changes in conventional

gasoline during this time period.
37

Figure 2

Figure 3
38

Figure 4

Figure 5
39

Comparison with RFG

The data that EPA collects allow a comparison of CG and RFG Complex Model emissions on a

year-by-year basis. This is particularly interesting since CG emissions performance has improved as a

result of Tier 2 sulfur reduction requirements, and the sulfur levels in CG and RFG are converging. While

CG average sulfur levels in 2005 were still higher than RFG levels in that year, they were much lower than

the sulfur levels typically needed to comply with Phase II RFG emissions performance standards.

Figures 6 through 10 compare RFG and CG in several ways using the "percent reduction"

emission performance measures normally applied to RFG. EPA calculated both CG and RFG VOC, total

toxics and NOx emission reductions from 1990 statutory baseline gasoline. CG reductions from baseline

can be compared to RFG reductions from baseline and to RFG performance standards which are specified

as reductions from these 1990 baselines. (Each graph shows the "averaged" RFG performance standard.)

Summer VOC and Summer total toxics calculations and RFG standards depend on a geographic VOC

control region specification. For these two parameters, EPA compared CG to VOC Control Region 2 (i.e.

"Northern") RFG, and calculated CG emissions using the Region 2 version of Complex Model. RFG

emission reductions were also calculated relative to average CG emissions in each year. These results,

shown as dashed lines in each graph, allow direct comparison of RFG with its contemporary CG.

These graphs show that while CG emissions performance is improving relative to RFG, RFG

emission performance remained superior for each pollutant and season combination. Summer CG's VOC

performance has improved because sulfur reductions lower exhaust VOC emissions. (Sulfur reductions

do not lower non-exhaust VOC's, which are directly related to the Reid Vapor Pressure (RVP) parameter.)

Winter CG has met RFG's Winter NOx standard in each year analyzed. Summer CG is approaching RFG's

Summer NOx standard.

Figure 6
40

Figure 7 Figure 8

Figure 9 Figure 10
41

Sulfur

Background

Sulfur in gasoline originates in the crude oil used to produce the gasoline, and the sulfur content

of crude oil varies substantially. (Crude oil with low sulfur content is classified as “sweet crude”.)

Historically, high sulfur content in gasoline has been considered undesirable for reasons unrelated to

vehicle emissions. Sulfur oxides formed during combustion may be converted to acids that promote

corrosion of engine parts and exhaust systems. ASTM Standard D4814, first published in 1988, limited

sulfur content in unleaded gasoline to 0.10 mass percent (equivalent to 1000 parts per million) to protect

against engine wear, deterioration of engine oil and corrosion of exhaust system parts.

More recently, gasoline sulfur content has been a concern because of emission-related effects.

Sulfur affects gasoline vehicle emissions primarily because it adversely affects catalytic converters.

Reductions in gasoline sulfur content can reduce NOx, exhaust toxics and exhaust VOC emissions in the

A1990 technology@ vehicles used to develop the Complex Model. The phase-in of stringent Tier 2 tailpipe

emission standards began in 2004, along with the phase-in of the Tier 2 gasoline sulfur regulations.

Vehicles designed to meet these standards are particularly sensitive to sulfur and gasoline with reduced

sulfur content is necessary to enable the emission control systems in these vehicles to be fully effective.

Emission-related regulatory requirements have resulted in substantial sulfur reductions.

Gasoline is produced by blending several components, produced from different processes within a

refinery. The component from the Fluid Catalytic Cracking (FCC) unit typically has much higher sulfur

content than other components used in gasoline blending unless it is treated to remove sulfur. In the

past, refineries have largely relied on a process called hydro treating to reduce sulfur, when necessary.

However, conventional hydro treating results in a substantial loss of octane in the FCC gasoline. EPA's

Tier 2 sulfur reduction requirements have helped spur the development and implementation of

modifications or alternatives to conventional hydro treating. These processes allow removal of sulfur

while minimizing economically adverse consequences such as octane or volume loss.

Regulatory Limits on Sulfur Content

EPA's RFG and Anti-Dumping regulations have imposed both direct and indirect limits on gasoline

sulfur content. The Tier 2 gasoline sulfur regulations also impose direct gasoline sulfur limits on RFG and

CG. The regulatory requirements that have affected gasoline sulfur content are discussed below.

RFG Sulfur Limits

The Simple Model, which was the basis for RFG emission performance standards through 1997,

did not consider the effect of sulfur on emissions, nor did it evaluate NOx emissions performance, which is

sensitive to gasoline sulfur content. However, the annual average level for sulfur was not allowed to

exceed a refinery's or importer's 1990 baseline level. Hence, although the RFG regulations prior to 1998

neither required nor rewarded sulfur reduction, the regulations prevented any substantial increase in

sulfur levels in RFG.

Between 1997 and 1998, EPA transitioned from the Simple Model to the Phase I Complex Model

for assessing the emission performance of RFG. This transition introduced several factors that affected

RFG sulfur content:

 RFG was subject to NOx and VOC performance standards, as well as a toxics performance standard

and the new model recognized that lowering gasoline sulfur reduced emissions of all of these

pollutants.
42

 Each RFG batch was required to have a sulfur content at or below a 500 ppm model range limit.

Phase II RFG, introduced in 2000, required additional NOx, toxics and VOC emission reductions.

EPA only required Phase I RFG to meet, on a per-gallon basis, the NOx performance of 1990 baseline

gasoline's with sulfur levels of 338 ( Winter) and 339 (Summer) ppm. However, for Phase II, EPA

required Summer RFG to have NOx emission performance 5.5 percent better on a per gallon basis, (or

6.8 percent better on average), than this Summer baseline gasoline. It is generally accepted that this

more stringent Phase II NOx performance standard necessitated a reduction in average Summer RFG

sulfur levels.

CG Sulfur Limits

Prior to 1998, EPA prohibited the annual average sulfur level in CG from exceeding 125% of a

refinery's or importer's 1990 baseline. For 1998 and later, EPA prohibited annual average exhaust toxics

and NOx emissions from exceeding the refiner or importer's 1990 baselines for these emissions.

Additionally, the annual average CG sulfur levels were not allowed to exceed the greater of 1000 ppm

(the model range limit for CG) or the refiner or importer's 1990 sulfur baseline.

All Gasoline

The Tier 2 sulfur reduction standards, applicable to both RFG and CG, require a phased reduction

in gasoline sulfur content beginning in 2004. The standards applying to most refiners and importers for

2004 are a 120 ppm corporate pool average and a 300 ppm per gallon cap. In 2005, the standards

include a refinery or importer average of 30 ppm as well as a 90 ppm corporate pool average and a 300

ppm per gallon cap. Since 2006, the standards include a 30 ppm refinery or importer average with an 80

ppm per gallon cap. The Tier 2 requirements contain certain exceptions to the above requirements for

small refiners and for Ageographic phase-in A areas, so the full impact of the regulation on gasoline sulfur

levels will not be realized until later than 2006. However, the gasoline sulfur regulations also contain

various Averaging Banking and Trading (ABT) provisions, including mechanisms for credit generation for

sulfur reductions which occurred as early as year 2000. Thus, the Tier 2 requirements potentially

impacted sulfur levels prior to the phase in of the standards.

In summary, the Tier 2 requirements will result in substantial reductions in gasoline sulfur

content. The Tier 2 company-wide annual average sulfur requirement of 120 ppm, applicable in 2004, is

comparable to the average sulfur content in Phase II Summer RFG in 2000, before the impact of the Tier

2 sulfur regulations, and substantially lower than the sulfur content of Winter RFG. The Tier 2 sulfur

reduction requirements are more stringent than the sulfur reductions generally needed to comply with

RFG emission performance standards or with Anti-Dumping program regulations applicable to CG. 20

Consequently, the Tier 2 requirements became the dominant federal constraint on gasoline sulfur levels

by 2004. (California's gasoline requirements and a few other state regulatory requirements applicable to

specific localities do restrict sulfur more tightly than the 2004 Tier 2 standards.)

EPA's Sulfur Data

Sulfur data for both RFG and CG are currently necessary to determine compliance with EPA's

regulations. Thus, refiners and importers have been required to submit this information to EPA's

RFG/Anti-Dumping reporting system for each batch of gasoline refined or imported. Additionally, since

1998, EPA has received RFG Survey data on the sulfur content of RFG sold at gasoline stations. (Since

sulfur was not part of the Simple Model, Compliance was not needed with survey standards until 1998)

20 In fact, beginning in 2007 the NOx emission performance and emission requirements were eliminated, with certain

exceptions, for RFG and CG since the mandated sulfur reductions made them unnecessary. See 82 FR 8427.
43

Sulfur Trends

Overview-Reformulated Gasoline

Volume-weighted average RFG Sulfur levels, by year, are shown in Figures 1 (Summer) and 2

(Winter). Both reporting system estimates, by reporting year, and survey-based retail estimates, by

survey year are shown. Summer and Winter RFG sulfur levels exhibit clear downward trends. Both

Summer and Winter sulfur levels declined sharply between 1997 and 1998 with the transition from Simple

Model to Complex Model RFG. As noted, the need to comply with a 500 ppm sulfur limit, and the

introduction of new performance standards along with a model that considers the emission effect of sulfur

influenced this decline. EPA determined that about 17% of Summer and 12% of Winter RFG refined and

imported in 1997 exceeded the 500 ppm sulfur limit applicable in 1998 and later years, with some

batches exceeding 1000 ppm. Although EPA did not quantify the extent to which 1997 RFG exceeded the

NOx standard applicable to 1998 RFG, it is reasonable to assume that the 1998 NOx standard contributed

to the need for these 1997 to 1998 sulfur reductions. (Since sulfur has such a strong influence on

Complex Model NOx calculations, the effects of the range limit and the NOx standard on this sulfur

reduction are likely hard to separate.)

Figure 1

Figure 2
44

Summer RFG shows a second sharp sulfur decline between 1999 and 2000 with the transition

from Phase I to Phase II RFG. Although Winter RFG sulfur levels declined as well, the change was much

smaller. The Summer sulfur decrease is largely attributable to the more stringent NOx performance

standard. Since the Winter NOx performance standard did not become more stringent, winter sulfur

declines may not have been driven by the need to comply with NOx performance standards. However,

NOx performance did improve, in part, as a result of these sulfur reductions (see the RFG Trends

chapter.)

Both Summer and Winter RFG show decreasing sulfur levels between 2000 and 2004. The first of

the phased-in Tier 2 sulfur standards necessitated sulfur reductions by 2004. Since the Tier 2 regulation,

through credit generation, provided some incentive for sulfur reduction as early as 2000, it may also have

affected sulfur levels in each of the interim years.

Figures 1 and 2 separately analyze changes in sulfur levels, by reporting and survey year, for

Summer and Winter gasoline. Regardless of the production date reported for a batch, a batch was

categorized as Summer gasoline if it was designated VOC-controlled, and Winter gasoline if it was

designated non-VOC-controlled. Survey data were categorized as Summer for surveys conducted

between June 1 and September 15, and Winter for surveys conducted before or after that date. Thus,

for any year, the Winter RFG in this analysis is largely a mix of gasoline produced before and after each

VOC season.

Quarterly averages more precisely show how sulfur levels varied with time. Figure 3 presents

reporting system average sulfur levels calculated by calendar quarter based on the production date

reported for each batch.

Figure 3

The lowest line, representing the RFG averages, shows that, for the years 1997 and 2003, 4th

quarter sulfur averages were lower than 1st quarter, indicating that sulfur reductions needed to comply

with standard changes in 1998 and 2004 were implemented, in part, during the year preceding the

standard change. The timing of these sulfur reductions was likely influenced by concerns about

"downstream" compliance (i.e., compliance at locations in the distribution system subsequent to the
45

refinery or import facility). The Complex Model sulfur range limit, which drove the 1997 to 1998 sulfur

reduction, was potentially enforceable as a downstream standard since it applied to every batch of RFG,

although EPA exercised enforcement discretion in this matter. Since the Tier 2 regulations also included

various downstream standards for sulfur, refineries and importers may have chosen to reduce sulfur

levels during late 2003 to ensure compliance with these standards, as well as to generate sulfur credits.

Additionally, there was uncertainty associated with the desulphurization technologies which would be

needed to meet the Tier 2 standards economically. Thus, refiner's schedules for selection and

implementation of new desulphurization processes, which were not fully proven technology when the Tier

2 regulations were finalized in 2000, also affected the timing of these sulfur reductions. For example,

this may have made early sulfur reductions infeasible for some refineries even if the ABT program

provided some incentive for such reductions. On the other hand, refineries probably had some incentive

to get these processes operational earlier than needed for downstream compliance in order to ensure that

there were no technical problems.

Figure 3 also shows the cyclical effect of the more stringent Summer NOx emissions performance

standard on Phase II RFG sulfur levels, with quarters 2 and 3 lower than quarters 1 and 4 within each

year of the Phase II RFG program. Even though the Tier 2 requirements presumably limited the rise in

sulfur between the 3rd and 4th quarters of 2003, the cyclical effect is still apparent.

RFG Sulfur by PADD

Table 1 shows 2004 and 2005 reporting averages by PADD for PADD I, II and III refiners. These

averages were calculated from batch data, excluding importer batches (see “PADD Level Analysis”

appendix for additional information):

2004 & 2005 Reporting Average by PADD-RFG Sulfur (Refiner Batches Only)

2004 2005

Season PADD Average Value

(ppm)

Gasoline Volume

(gal)*

Average Value

(ppm)

Gasoline Volume

(gal)*

Summer I 91 4,792,114,891 73 4,430,958,220

II 78 1,740,499,436 64 1,844,913,833

III 73 5,890,920,167 78 5,690,766,967

Winter I 118 6,489,530,475 90 7,081,940,665

II 93 2,436,636,058 78 2,718,751,541

III 101 6,059,647,031 83 5,766,524,033

Annual I 107 11,281,645,366 84 11,512,898,885

II 87 4,177,135,494 72 4,563,665,374

III 87 11,950,567,198 81 11,457,291,000

*Volumes exclude batches with missing values for this parameter

Table 1
46

Figure 4

Figure 5

Additional Analysis and Observations-RFG

Data analyses pertaining to RFG sulfur are contained in the Appendix to this chapter. Several trends or

patterns are highlighted below:

 Average sulfur content in premium grade RFG has been consistently lower than in regular RFG. 21

21 As noted, removing sulfur from the FCC gasoline component could result in an octane loss.

Consequently, it may seem counter-intuitive that higher octane premium RFG had lower sulfur content than regular

grade. However, the lower sulfur content in premium RFG depends on the percentages of other blending

components used to meet octane requirements. For example, refiners typically choose to blend more reformate, a

high octane and low sulfur blending component, into premium gasoline.
47

 Average sulfur content of Summer and Winter RFG sold at retail outlets decreased between 2000 and

2005 in all areas surveyed in both years.

Overview-Conventional Gasoline

Volume-weighted average CG sulfur levels, by reporting year, are shown in Figure 6. Summer

and Winter averages are shown separately on the same graph. Both Summer and Winter sulfur levels

decreased from 1997 to 1998, with the transition from annual average sulfur content standards to

Complex Model-based annual average exhaust toxics and NOx emission standards. Although both

standards were derived from refinery and importer individual baselines, the 1998 standards may have

acted to reduce gasoline sulfur since they required emissions equal to the refinery or importer's

compliance baseline, while the 1997 standards allowed annual average sulfur content up to 125% of the

refinery or importer's baseline. Additional analysis would be needed to confirm this effect.

Figure 6

The Winter CG sulfur level decreased between 2002 and 2003, while the Summer level increased

slightly. This divergence of the Summer and Winter averages is a consequence of the timing of sulfur

reductions in advance of the Tier 2 standards. Similarly to RFG, the CG in this analysis was categorized

as Summer gasoline, regardless of production date, if it was designated as volatility-controlled, and

Winter gasoline if it was designated as non-volatility-controlled. Thus, Winter CG is largely a mix of

gasoline produced before and after each volatility control season. The need to comply with downstream

standards in 2004 would not have affected sulfur levels in volatility-controlled CG produced during 2003,

but would likely have affected sulfur levels in non-volatility-controlled gasoline produced late in 2003.

Figure 3 also shows average CG sulfur levels, by production quarter (upper line). CG sulfur content

dropped during 2003 with a large decrease between the 3rd and 4th quarters of 2003. Again, this is

consistent with the opportunity for sulfur credit generation, the existence of downstream standards under

the Tier 2 regulation and the need to implement new sulfur reduction technology.
48

CG Sulfur by PADD

Table 2 shows 2004 and 2005 reporting averages by PADD for PADD I, II and III refiners. These

averages were calculated from batch data, excluding importer batches (see “PADD Level Analysis”

appendix for additional information):

2004 & 2005 Reporting Average by PADD-CG Sulfur (Refiner Batches Only)

2004 2005

Season PADD Average Value

(ppm)

Gasoline Volume

(gal)*

Average Value

(ppm)

Gasoline Volume

(gal)*

Summer I 125 3,752,272,894 108 3,520,575,616

II 140 11,345,514,515 121 10,460,517,681

III 108 21,712,599,435 98 20,882,654,793

Winter I 138 3,480,957,004 110 4,040,674,006

II 135 13,169,031,421 117 13,447,545,074

III 115 23,618,950,103 86 22,432,331,959

Annual I 131 7,233,229,898 109 7,561,249,622

II 137 24,514,545,936 119 23,908,062,755

III 111 45,331,549,538 92 43,314,986,752

*Volumes exclude batches with missing values for this parameter

Table 2

Additional Analyses and Observations-CG

The sulfur content of Summer Baseline Gasoline, as specified in the Clean Air Act, is 339 parts

per million (ppm), and the sulfur content of Winter baseline gasoline, as specified by EPA's regulations, is

338 ppm. Data analyses pertaining to CG sulfur are contained in the Appendix to this chapter. These

data include tabular and graphical descriptions of CG sulfur content by volume and grade which show:

 In 1997, the first year for which sulfur reporting data were analyzed, the median Summer sulfur

content was 264 ppm and the 1990 baseline gasoline fell between the 60th and 65th percentile.

 In 2005, the last year for which sulfur reporting data were analyzed the median Summer sulfur

content was 76 ppm and the 1990 baseline gasoline fell above the 98th percentile.

 In 1997 the median Winter sulfur content was 253 ppm and the 1990 baseline gasoline fell between

the 60th and 65th percentile.

 In 2005 the median Winter sulfur content was 64 ppm and the 1990 baseline gasoline fell above the

98th percentile.

 The sulfur content of premium grade CG has been lower than that of regular grade in each year and

season.
49

Overview-All Gasoline

For the most part, this report has separately analyzed property trends by gasoline type and

season. The Tier 2 gasoline sulfur regulations do not distinguish between RFG and CG and make no

seasonal distinctions, but prescribe annual average standards. Consequently, it is appropriate to look at

sulfur trends in the entire gasoline pool and on an annual basis. Figure 3 shows quarterly averages for

RFG and CG combined (middle line). Figure 7 shows annual average sulfur levels for CG and RFG

combined. The only year-to-year increase in sulfur content occurred between 1998 and 1999, when both

RFG and CG sulfur content increased. There is no apparent regulatory explanation for these increases.

Figure 7

Aggregated sulfur content distributions by gasoline volume for 2005 are shown in Table 3, below:

Table 3

2005 Sulfur Content (ppm) by Volume

(from Batch Reports excluding CG blendstocks)

CG RFG/RBOB ALL

Volume %tile

minimum 0 0 0

5% 8 9 8

10% 16 18 16

15% 21 24 22

20% 25 29 26

25% 30 35 31

30% 36 41 38

35% 44 46 45

40% 52 51 51

45% 60 56 59

50% 70 61 67

55% 80 68 76

60% 93 74 87

65% 107 82 98

70% 125 91 112

75% 147 101 130

80% 172 114 152

85% 201 127 180

90% 233 147 215

95% 264 178 254

100% 478 371 478

Volume(gal): 90,897,009,258 32,128,092,630 123,025,101,888
50

Reid Vapor Pressure (RVP)

Background

RVP relates to gasoline's volatility, a gasoline=s ability to change from a liquid to a vapor. More

specifically, RVP is a measure of vapor pressure of gasoline at 100F, using a prescribed test method.

Gasoline volatility characteristics are important because they affect both vehicle performance and

emissions. RVP affects both exhaust and evaporative emissions; however, RVP is significant from an

emissions standpoint primarily because it directly relates to evaporative emissions of volatile organic

compounds (VOCs). VOC emissions are involved in the atmospheric chemical reactions that form ground

level ozone, an air pollutant, in the presence of sunlight and oxides of nitrogen. VOC emissions, hence

RVP, are of particular significance from an air quality standpoint during the Summer season. RVP is one

of the Complex Model input parameters used to calculate exhaust VOC emissions, and it is the only

parameter affecting the model's evaporative VOC calculations. Since RVP is important to vehicle

performance on a year-round basis, ASTM specifies RVP standards for gasoline.

Regulatory Limits on RVP

Several regulatory requirements indirectly or directly limit the RVP level in reformulated and

conventional supplied during late spring and summer when ozone is likely to be a problem. Because RVP

is an input parameter to the Complex Model, it is indirectly limited through Complex Model-based

emission standards. RVP is also directly limited through regulations which prescribe maximum levels for

RVP in gasoline (40 C.F.R. ‘80.27). The current volatility standards have been in effect since 1992,

predating the RFG and Anti-Dumping regulations.

The RVP limits prescribed in the volatility regulations are 9.0 psi or 7.8 psi, depending on the

location and specific month within the regulatory control period (May 1 to September 15 for refineries and

terminals, June 1 to September 15 for retail outlets). These volatility limits do not apply to gasoline sold

in Alaska, Hawaii and US territories, and gasoline containing between 9% and 10% ethanol by volume

may exceed the applicable standard by 1.0 psi.

Although the volatility regulations technically apply to RFG as well as CG, RFG regulations

effectively require RVP levels below those allowed under the volatility regulations. Under the RFG

regulations, refiners and importers must designate RFG produced or imported for use during the VOC

control period (the same period as the regulatory control period for volatility) as VOC-controlled, and all

other RFG as non-VOC-controlled. Different requirements, or "standards," apply to VOC-controlled RFG

depending on whether the gasoline is intended for use in VOC-Control Region 1 (VOC1), which generally

includes southern RFG areas, or VOC-Control Region 2 (VOC2), which includes northern RFG areas.

Refiners and importers must specify whether a VOC-controlled batch is intended for sale in VOC1 or

VOC2. The RVP in VOC-controlled RFG supplied prior to 1998 was directly controlled through specific RVP

standards. RFG for VOC1 was required to meet a 7.2 psi "per gallon" standard, or alternatively a 7.1 psi

"averaged" standard with a 7.4 psi per gallon maximum. RFG for VOC2 was required to meet an 8.1 psi

"per gallon" standard, or an 8.0 psi "averaged" standard with an 8.3 psi per gallon maximum.

Complex Model RFG requirements do not include RVP standards. However, the RVP in the

"Complex Model" VOC-controlled RFG supplied since 1998 is indirectly controlled through emissions

performance standards. RFG designated as VOC-controlled is required to meet certain VOC emission

reduction standards relative to a "statutory baseline" gasoline, representative of gasoline supplied in

1990, with different VOC standards for VOC Control Regions 1 and 2. 22 Although other gasoline

22 The Energy Policy Act of 2005 requires that EPA consolidate these separate standards.
51

parameters also affect Complex Model VOC emission performance, RVP reduction from the statutory

baseline level of 8.7 psi is the primary means to achieve these VOC reduction standards; hence these

VOC standards indirectly, but tightly, limit RVP in RFG. The VOC emissions reduction standards became

more stringent in 2000 with Phase II RFG. The "averaged" VOC standards specify per gallon minimum

VOC reductions as well as average reductions. As a result, the RFG emissions performance standards not

only constrain average RVP levels below those permitted by the volatility regulations, but generally

constrain maximum RVP levels as well.

As discussed above, CG RVP levels are directly limited by EPA's volatility regulations. CG supplied

since 1998 is also subject to refiner/importer baseline-specific anti-dumping exhaust toxics and NOx

emission requirements calculated by the Complex Model. However, while RVP affects both exhaust toxics

and NOx calculations to some extent, CG emission requirements for exhaust toxics and NOx may not have

a significant limiting effect on RVP.

In addition to the federal fuel regulations affecting RVP, certain states and localities have unique

gasoline specifications for RVP and/or other parameters. Such gasoline's have been referred to as

Aboutique@ fuels, and include gasoline subject to 7.0 psi or 7.2 psi RVP standards.

EPA's RVP Data

EPA collects RVP data in order to determine compliance with the RFG and Anti-Dumping

regulations. RVP values are necessary for the Summer Complex Model emission calculation for VOCcontrolled RFG. As a result, refiners and importers have been required, since 1995, to submit RVP data

for VOC-controlled RFG to EPA's RFG/Anti-Dumping reporting system for each batch of gasoline refined or

imported. Additionally, since 1995, EPA has received RFG Survey data on the RVP of RFG sold at retail

outlets during the VOC control period, June 1 to September 15. Refiners and importers are not required

to report the RVP for RFG designated as non-VOC-controlled. This is because the Winter version of the

Complex Model, used to determine compliance for non-VOC-controlled RFG, does not require the RVP of

the gasoline being evaluated as an input. As a result, EPA has only limited RVP data for Winter RFG.

Winter RFG Survey data reported to EPA also do not include RVP values. Since EPA has only limited

Winter RFG RVP data, this report does not include analysis of these data.

EPA's data collection requirements for CG have differed from RFG both temporally and seasonally.

Whereas RVP values have been required for determining RFG compliance since 1995, they were not

required for CG compliance calculations until 1998, with the introduction of Complex Model-based exhaust

toxics and NOx emission standards. Although these standards are for exhaust emissions only, the RVP

value is needed for the Summer Complex Model exhaust calculation. Therefore, the RVP value is needed

to determine compliance for Summer CG. As discussed above, the actual RVP of the gasoline is not used

in Winter Complex Model emission calculations. However, the RVP value is also needed to determine

compliance for Winter CG. EPA's regulations specify that the correct model (Summer or Winter) for

evaluating the emissions performance of CG depends on its RVP value. Therefore, the RVP of each batch

of CG is needed to verify that the correct model was used for the batch. As a result, refiners and

importers have been required, since 1998, to submit RVP data to EPA's reporting system for each CG

batch, whether or not the batch was produced or imported for use during the regulatory control period

specified in EPA's volatility regulations. Thus, this report includes analysis of both Summer and Winter CG

RVP data.
52

RVP Trends

Overview-Reformulated Gasoline

Figure 1 shows volume-weighted average Summer RFG RVP levels, by year. Both reporting

system estimates and survey-based estimates are shown. RVP levels were essentially unchanged with

the transition from Simple Model to Phase I Complex Model RFG standards between 1997 and 1998.

However, RVP decreased sharply between 1999 and 2000, with the transition from Phase I to Phase II

standards. This decrease in RVP was necessary in order to meet Phase II RFG's more stringent VOC

emission performance standards. Figure 2, using survey-based RVP estimates, shows that the Phase I to

Phase II RVP decrease was much greater for VOC Control Region 2 RFG than for VOC Control Region

RFG.

Figure 1

Figure 2
53

Figure 3 shows that the frequency distribution of RVP by volume for all Summer 1999 RFG is

bimodal; i.e. the ACombined@ distribution has two distinct peaks. Separate frequency distributions for

VOC1 and VOC2 RFG are also shown in Figure 3. They are clearly different with very little overlap in

range, explaining the bimodal nature of the combined distribution. This RVP difference is a result of a

more stringent VOC reduction standard applicable to VOC1 RFG during Phase I of the RFG program.

Figure 4 depicts the same analysis for Summer 2000 RFG. It is clear that there is little difference

between the RVP distributions for VOC1 and VOC2. Although VOC1 RFG still has a numerically greater

VOC emission reduction standard than VOC2 RFG, the difference is much smaller than in Phase I of the

RFG program. Furthermore, the Complex Model evaluates VOC1 and VOC2 evaporative emissions

differently. Since much of the apparent difference in VOC standards for the two regions is actually due to

this model effect (See the "Emissions" Chapter), the RVP distributions for the two regions are very similar.

Figure 3

The estimated average RVP levels in 2005 RFG are higher than in 2000 RFG. This increase is

small, slightly above 0.1 psi; however both survey and reporting estimates show an upward trend in

average RVP since 2000 (figure 1), and surveys show 2000 to 2005 increases in 21 of the 23 areas

surveyed in both years (see appendix to this chapter.) These RVP increases do not indicate

noncompliance; they are permissible as long as RFG continues to meet emissions performance standards.

The magnitude of the increase in RVP over this time period is small compared to the decrease in

RVP that occurred between Phase I and Phase II. Furthermore, there is no unquestionably clear causeeffect relationship between regulatory requirements and this RVP change, as there was with the transition

from Phase I to Phase II RFG where RVP reduction was the only feasible way to meet the VOC

performance standard.
54

Figure 4

Nevertheless, there are indications that a cause-effect relationship may exist between the

increase in RVP and the introduction of the mandated Tier 2 sulfur reduction requirements 23 A reduction

in sulfur content, all else constant, would improve VOC emissions performance by reducing Complex

Model exhaust VOC emissions estimates. An increase in RVP, all else constant, would hurt VOC emissions

performance by increasing Complex Model evaporative and exhaust VOC emissions estimates. Thus, VOC

emissions performance could remain unchanged if a sulfur decrease occurred concurrently with an RVP

increase. The existence of some cause-effect relationship between sulfur decreases and RVP increases in

RFG seems likely, particularly because VOC compliance margins have been small since 2000, (although

there has been substantial NOx and toxics over-compliance). This likely cause-effect relationship may be

due, to a large extent, to the way that refiners control gasoline RVP. It is often economically

advantageous for refiners to blend as much of the lighter hydrocarbons, particularly butane, as possible

into gasoline. However, butane raises RVP and, as a result, the need to comply with the VOC standard

limits the amount of butane that may be blended into summer RFG., Consequently, if sulfur reductions

provided additional VOC compliance margin, refiners may be motivated to offset it by raising RVP. The

data indicate an increase in RVP between 2000 and 2005, which is concurrent with a decrease in sulfur

content resulting from the Tier 2 sulfur requirements. As stated elsewhere in this report, these data do

not reflect the final Tier 2 sulfur requirement, and the interaction between the RFG requirements and the

Tier 2 sulfur reductions should be better understood as additional years of data are analyzed.

RFG RVP by PADD

Table 1 shows 2004 and 2005 reporting averages by PADD for PADD I, II and III refiners. These

averages were calculated from batch data, excluding importer batches (see “PADD Level Analysis”

appendix for additional information):

23 This is also discussed in the RFG Trends Chapter and in the Emissions Chapter.
55

2004 & 2005 Reporting Average by PADD-RFG RVP (Refiner Batches Only)

2004 2005

Season PADD Average Value

(psi)

Gasoline Volume

(gal)*

Average Value

(psi)

Gasoline Volume

(gal)*

Summer I 6.83 4,792,114,891 6.88 4,431,080,230

II 6.98 1,740,499,436 6.95 1,844,913,833

III 6.88 5,890,920,167 6.93 5,690,766,967

*Volumes exclude batches with missing values for this parameter

Table 1

Figure 5 shows estimates of average levels by PADD in retail RFG. These averages are volume-weighted

averages of the seasonal averages for each area, using gasoline volume estimates supplied in the survey

plans. In 2005, RFG surveys were conducted in 18 PADD I areas, five PADD II areas and two PADD III

areas. Prior to 2000, VOC control region was the primary factor contributing to geographic differences in

RVP. PADD I is a mix of control region 1 and 2 areas. PADD 2 was entirely control region 2 areas until

St. Louis (included in the 1999 surveys) opted into the RFG program. Both PADD 3 survey areas

(Houston and Dallas, TX) are in control region 1. As expected, the PADD to PADD RVP differences

diminished in 2000. The post-2000 upward RVP trend is apparent in each PADD.

Figure 5

Additional Analyses and Observations-RFG

Data analyses pertaining to RFG RVP are contained in the Appendix to this chapter. Several trends or

patterns are highlighted below:

 Twenty-one of twenty-three areas surveyed in both years had higher average RVP levels in 2005 than

in 2000.

 An upward shift in RVP since 2002 can also be seen in the distribution trend graph in the appendix.
56

Overview-Conventional Gasoline

Volume-weighted average Summer and Winter CG RVP levels are shown in figure 6. These RVP

values have varied little from year to year since 1998. These averages estimate RVP from

refiner/importer sampling, and could differ from the average RVP of gasoline sold at retail outlets for

various reasons, including downstream blending operations. For example, the volume-weighted CG

averages reported here include batches which are blendstocks such as ethanol intended for blending

downstream of refineries, as well as certain all-hydrocarbon blendstocks which do not contain oxygen.

The implicit assumption in a volume-weighted property average is that the property blends linearly with

volume, and this assumption is inaccurate for RVP when ethanol is blended into an all-hydrocarbon

blendstock. Although inclusion of blendstocks in the RVP averages could introduce some error, exclusion

of blendstocks from the average calculations does not necessarily provide a better estimate of the

average RVP of all conventional gasoline. (This is less of an issue in analysis of RFG data since reporting

requirements differ from CG requirements, and since retail RFG data are available as well.)

Figure 6

Figure 7 compares the RVP distributions by volume of Summer 1998 and Summer 2005 CG,

showing that the distribution as well as the average has changed little. The distributions are multi-modal

with peaks just to the left of the vertical lines marking 7.8 and 9.0 psi, the two federal volatility

standards. The distributions drop sharply at 7.8 and 9.0 psi suggesting that CG is often blended to meet

one of these two standards with only a small compliance margin. Blendstocks have been excluded from

the CG distribution data.

There is an additional smaller and more rounded peak at about 6.8 RVP, probably due to certain

boutique fuels. These boutique fuels are reported as CG, and EPA's reporting system does not distinguish

them from other conventional gasoline. Consequently, "boutique fuel" volume share cannot be explicitly

determined from EPA's data. (This "boutique fuel" portion of the distribution does not represent all

gasoline with unique specifications. Notably, California gasoline has unique fuel specifications affecting

RVP and other parameters, but gasoline intended for sale in California is exempt from EPA's reporting

requirements.) Readers who wish to determine what portion of gasoline volume falls within a specific

RVP range should refer to the percentile curves contained in the appendix to this chapter.
57

The distributions show a small volume of gasoline with RVP greater than 9.0 psi. This does not

necessarily represent noncompliant gasoline, but could include gasoline intended for Alaska, Hawaii and

US territories not subject to EPA volatility regulations. The distributions also contain some ethanoloxygenated gasoline eligible for a 1.0 psi RVP allowance. (Ethanol is typically blended downstream of

refineries, so ethanol oxygenated gasoline is under-represented in these CG distributions.) Additionally,

refiners and importers did not always identify their CG batches as volatility-controlled or not. (Current

instructions require that they do so.) In the absence of a designation, a batch produced or imported

between April and September was assumed to be volatility-controlled, and some non-volatility-controlled

CG batches may have been included in the Summer data.

Figure 7

Figure 8 compares the RVP distributions by volume of Winter 1998 and Winter 2005 CG, again

showing little difference between the two years. These distributions have a number of peaks. These

multi-modal distributions occur because gasoline, even outside of the volatility control season, is produced

to meet certain vapor pressure specifications. These specifications, described in ASTM Standard D 4814,

define six vapor pressure classes, specifying a maximum vapor pressure for each class. The vapor

pressure class limits are shown as vertical lines and labeled across the top axis. The ASTM standard also

defines vapor pressure class requirements by location and month. Outside of the EPA volatility-control

season these requirements are intended primarily to ensure adequate vehicle performance (e.g. a

gasoline used in Maine in January would require a higher RVP than a gasoline used in Florida in January

to ensure adequate cold-start performance.)

For several of the vapor pressure classes, the Winter CG distributions show a peak just to the left

of the class limit, with a sharp drop at the limit. As with the Summer CG, this suggests that refiners and

importers often supply gasoline which meets a vapor pressure class maximum with only a small

compliance margin. The winter distributions, however, also show peaks at points other than immediately

before a volatility class limit. Most notably, both distributions show a peak at about 12.5 psi, midway

between two class limits.
58

Figure 8

In summary, EPA's reporting system data indicate that both Summer and Winter CG RVP levels

show little change since 1998. However, reporting system RVP data for CG may not completely and

accurately reflect all downstream RVP changes. EPA's volatility regulations and ASTM standards appear

to be the major factors controlling CG RVP. While Tier 2 sulfur reductions could theoretically affect

Summer CG RVP levels through CG's Complex Model-based exhaust toxics and NOx standards, the

significance of this effect would depend on the extent to which refiner/importer individual compliance

baselines for these pollutants, rather than volatility standards, limit CG RVP.

CG RVP by PADD

Table 2 shows 2004 and 2005 reporting averages by PADD for PADD I, II and III refiners. These

averages were calculated from batch data, excluding importer batches (see “PADD Level Analysis”

appendix for additional information). As noted, the primary geographic factors limiting summer CG RVP

are emission-related EPA volatility and state “boutique fuel” regulations. Winter gasoline RVP is related

to location because of ambient temperature-associated drivability concerns. Thus, it is not surprising to

find lower average RVP levels in PADD III production than in PADDs I and II.

2004 & 2005 Reporting Average by PADD-CG RVP (Refiner Batches Only)

2004 2005

Season PADD Average Value

(psi)

Gasoline Volume

(gal)*

Average Value

(psi)

Gasoline Volume

(gal)*

Summer I 8.40 3,744,548,926 8.31 3,547,001,722

II 8.46 11,453,187,269 8.46 10,554,125,517

III 8.19 21,722,168,035 8.22 20,889,312,566

Winter I 12.66 2,891,701,318 12.31 3,504,605,534

II 13.31 9,805,826,594 13.25 8,565,282,585

III 11.77 20,865,873,542 11.73 18,781,652,701

Annual I 10.26 6,636,250,244 10.30 7,051,607,256

II 10.70 21,259,013,863 10.61 19,119,408,102

III 9.94 42,588,041,577 9.88 39,670,965,267

*Volumes exclude batches with missing values for this parameter

Table 2
59

Additional Analyses and Observations-CG

The RVP of Summer Baseline Gasoline, as specified in the Clean Air Act, is 8.7 psi, and the RVP of Winter

baseline gasoline, as specified by EPA's regulations, is 11.5 psi. 24 Data analyses pertaining to CG RVP

are contained in the Appendix to this chapter. These data include tabular and graphical descriptions of

CG RVP by volume which show:

 In 1998, the first year for which RVP reporting data were analyzed, the median Summer RVP was

8.52 psi and the 1990 baseline gasoline fell between the 65th and 70th percentile.

 In 2005, the last year for which RVP reporting data were analyzed, the median Summer RVP was

8.55 psi and the 1990 baseline gasoline fell between the 65th and 70th percentile.

 In 1998 the median Winter RVP was 12.39 psi and the 1990 baseline gasoline fell between the 30th

and 35th percentile.

 In 2005 the median Winter RVP was 12.21 psi and the 1990 baseline gasoline fell between the 35th

and 40th percentile.

24 The 11.5 psi winter baseline value is specified in EPA=s regulations even though a default value of 8.7 psi is

used in Complex Model evaluations of winter gasoline in order to "zero out" the effect of RVP on Winter exhaust

emissions.
60

Oxygenates and Oxygen

Background

Oxygenates are compounds used in gasoline blending that contain carbon, hydrogen and oxygen.

There are two main classes of oxygenates; ethers and alcohols. Methyl tertiary-butyl ether (MTBE) was

the predominant ether used in gasoline blending. Other ethers, primarily tertiary-Amyl methyl ether

(TAME), were sometimes used, often in combination with MTBE. In the United States, ethanol is the

only alcohol currently used in any significant quantity in gasoline blending, and ethers are no longer used

in significant quantities.

Oxygenates have been blended into gasoline in order to comply with regulatory requirements

intended to reduce air pollutant emissions from gasoline vehicles and engines. The Clean Air Act

required that reformulated gasoline (RFG) contain 2.0 weight percent oxygen. RFG was intended to

reduce emissions of toxics and ozone-forming pollutants. Oxygenates provided direct toxics and exhaust

VOC emission reduction benefits through the effect of oxygen on combustion, as well as indirect benefits

through dilution of, or partial substitution for gasoline blendstocks containing sulfur, aromatics or benzene

(constituents which can adversely impact emissions). Oxygen also directly reduces carbon monoxide

(CO) emissions through its effect on combustion. The Clean Air Act required that states adopt

oxygenated fuel programs for carbon monoxide non-attainment areas during the portion of the year

(typically winter) in which the area is prone to high ambient CO concentrations.

Oxygenates are also used in gasoline blending for reasons unrelated to emission reduction. Both

ethers and alcohols have a high blending octane value, making them at times economically attractive

blending component choices. Ethanol is a renewable fuel which, in the United States, is primarily

produced from corn. Federal tax incentives

have encouraged the use of ethanol in gasoline. These incentives included an excise tax exemption

available for gasoline alcohol blends. The amount of the exemption depended on the ethanol content of

the blend, with the maximum exemption available for 10% by volume ethanol blends and pro-rated

amounts for 7.7% and 5.7% blends (based on 190 proof or 95% pure ethanol). Additionally, blenders

receive a tax credit for blending ethanol into gasoline. The American Jobs Creation Act of 2004, signed

on October 22, 2004 changed the way the excise tax exemption operates. The amount of the exemption

is no longer based on these three blend levels.

The Energy Policy Act of 2005, repealed the RFG oxygen content requirement, effective

immediately in California and 270 days after enactment elsewhere. 25 It added a gasoline renewable fuel

content requirement of 4 billion gallons in 2006, incrementally increasing to 7.5 billion gallons in 2012. 26

These recent legislative changes will clearly impact the composition of future RFG and CG.

Regulatory Limits on Oxygen and Oxygenates

As a prelude to a discussion of this topic, it is useful to review the various units used to express

gasoline oxygen and oxygenate content, and the relationship between these units. Gasoline oxygen

content is expressed as a weight percentage of the gasoline-oxygenate blend. Gasoline oxygenate

content may expressed as either a weight or volume percentage of the gasoline-oxygenate blend. In

25 Removal of the oxygen requirement became effective with regulatory changes on April 24, 2006 for

California gasoline, and May 5, 2006 for gasoline nationwide. See 71 F.R. 8965 and 71 F.R. 26419.

26 EPA finalized a regulation to implement the Renewable Fuel Standard Program on May 1, 2007. See 72 FR

23900.
61

order to provide gasoline meeting a specific oxygen content requirement, oxygenates such as MTBE or

ethanol are blended into a hydrocarbon blendstock. As noted, oxygenates contain hydrogen and carbon

as well as oxygen, and different oxygenates contain different amounts of oxygen. For example, a pound

of pure MTBE contains about 0.18 pounds of oxygen, while a pound of pure ethanol contains about 0.35

pounds of oxygen. Therefore, it would be necessary to blend about 11 pounds of MTBE with 89 pounds

of non-oxygenated blendstock to produce 100 pounds of 2.0 weight percent oxygenated gasoline, which

would contain 11% MTBE, by weight. Alternatively, it would be necessary to blend about 5.7 pounds of

pure ethanol with 94.3 pounds of non-oxygenated blendstock to produce 100 pounds of 2.0 weight

percent oxygenated gasoline, which would contain 5.7% ethanol, by weight.

Since gasoline and oxygenates are liquids, oxygenate concentrations are more commonly

expressed as volume percentages rather than weight percentages. There are no universal weight percent

to volume percent conversion factors because each gasoline blend is a different mixture of hydrocarbons.

In order to convert exactly between a weight and volume oxygenate concentration it is necessary to

know the density of the gasoline-oxygenate blend, which varies from blend to blend. (There are

procedures to measure the density of a gasoline-oxygenate blend and these measurements are included

in the reporting system data submitted to EPA.) However, even if the density of the specific gasolineoxygenate blend is not known, a reasonably accurate weight to volume or volume to weight conversion

can be made because the densities of these blends vary over a fairly narrow range. 27 A 5.7 weight

percent pure (anhydrous and 200 proof) ethanol blended gasoline would typically contain slightly less

than 5.7 volume percent of pure ethanol. However, a 5.7 volume percent ethanol concentration is often

nominally associated with a 2.0 weight percent oxygen concentration, 7.7 volume percent ethanol with

2.7 weight percent oxygen and 10 volume percent ethanol with 3.5 weight percent oxygen. The 2.0%

and 2.7% oxygen weights and the 10 volume percent ethanol content have significance with respect to

Clean Air Act requirements and EPA regulations.

As noted, (prior to the effective date of the repeal of this provision by the 2005 energy

legislation) the Clean Air Act required that RFG contain 2.0 weight percent oxygen. EPA's regulations

allowed refiners, importers and oxygenate blenders to meet this requirement through compliance with a

2.0 weight percent Aper gallon@ standard, or a 2.1 weight percent “averaged standard” and a 1.5 weight

percent per gallon minimum. The per gallon minimum applicable to certain suppliers was adjusted as a

consequence of RFG Survey failures for oxygen content, and for 2005 remained at 1.6 weight percent for

certain suppliers and covered areas. These RFG oxygen requirements applied throughout the year. The

Clean Air Act also required an oxygen credit program; i.e. parties using more than the required amount of

oxygen in RFG generate credits which may be transferred to other parties for use in meeting the oxygen

standard.

The Clean Air Act's oxygenated fuel requirements (Section 211(m)) are intended to address CO

non-attainment. States may also have “maintenance” programs. These oxygenated fuel programs are

seasonal and state-specific. The Clean Air Act specified that the oxygen content for the non-attainment

areas requiring such programs be at least 2.7 weight percent. While some areas currently have winter

oxygenated fuel programs a number of areas, including several areas in the RFG program, at one time

had programs but no longer implement them.

27 EPA received RFG Survey oxygenate concentrations as weight percentages and Reporting System

concentrations as volume percentages. For this report, EPA made approximate weight to volume or volume to weight

conversions assuming a specific gravity of 0.745 for Summer RFG and 0.730 for Winter. The specific gravities of

MTBE, ethanol and TAME published in ASTM D4814 are 0.7460, 0.7939and 0.7758, respectively. To convert a weight

percent oxygenate to a volume percent oxygenate multiply the weight percent oxygenate by the gasoline blend

specific gravity and divide by the oxygenate specific gravity.
62

In addition to the requirements for oxygen use, there are several restrictions on the maximum

oxygen content and maximum amount of certain specific oxygenates that can be used. Both the Simple

Model and Complex Model have valid range limits of 4.0 weight percent for oxygen. However, these

range limits had little effect on the maximum oxygen content of gasoline since other requirements, in

place long before the RFG and Anti-Dumping programs, were as restrictive or more restrictive.

The Clean Air Act (‘211(f)(1)) prohibits fuel and fuel additive manufacturers from first introducing

into commerce, or increasing the concentration in use of any fuel or fuel additive for general use in light

duty motor vehicles which is not substantially similar to that utilized in the certification of motor vehicles

or engines under section 206 of the Act. A manufacturer may apply for a waiver of this provision for a

fuel or fuel additive which is not substantially similar. The Act, however, does not define “substantially

similar”, consequently EPA defined "substantially similar" as it applies to unleaded gasoline in an

interpretive rule, last revised in 1991 (56 FR 5352). 28

EPA's "substantially similar" definition allows certain alcohols (other than methanol) and ethers

including ethanol and MTBE, provided that the oxygen content does not exceed 2.7 weight percent. This

oxygen weight allows approximately 15% MTBE by volume, but the exact volume of MTBE allowed under

this definition is blend-specific. However, a waiver has also been granted which, under some conditions,

allows 15% MTBE by volume even if the oxygen content weight limit is exceeded. This oxygen weight

percent limit would only allow ethanol blending up to about 7.7 volume percent. However, the

“gasohol” waiver allows use of up to 10% by volume pure ethanol. This waiver is particularly significant

since ethanol is often blended at about 10 volume percent in order to take full advantage of the tax

incentives. This waiver allows approximately 3.7 weight percent oxygen, but again, this is blend-specific.

The definition and several waivers also allow use of methanol as an oxygenate, but the conditions for

methanol use are much more restrictive. Unless it is used with other oxygenates, methanol can only be

used at 0.3% by volume (about 0.16 weight percent oxygen). Additionally, health effects testing

requirements apply to methanol blends containing oxygen at 1.5 weight percent or greater. (Trace

quantities of methanol were often found in MTBE-oxygenated gasoline since methanol was used to

produce MTBE.) A document summarizing 211(f) waiver requests and EPA decisions is available on EPA's

website (EPA, 1995).

EPA's Oxygenate and Oxygen Data

Oxygen and oxygenate content data have always been necessary to determine compliance with

RFG standards. The weight percent oxygen content requirement applies to RFG for all years considered

in this report. Additionally, both the Simple and Complex models require the amount of oxygen coming

from specific oxygenates as inputs in order to calculate toxics emissions. Since 1995, RFG refiners and

importers have been required to report weight percent oxygen as well as MTBE, ethanol, ETBE, TAME, tbutanol and methanol content. (These oxygenates are reported as volume percentages and volume to

weight conversions can be made as needed since the density of each batch is also reported in units of

API gravity.)

28 "Substantially similar" information is available at http://www.epa.gov/otaq/additive.htm

One complication with this reporting is that ethanol blending typically does not occur at refineries,

but downstream at terminals. (This is necessary because gasoline is often shipped via pipeline and there

are problems associated with pipeline shipment of ethanol-blended gasoline due to ethanol's affinity for

water, which is present to some extent in pipelines.) Although this is less common, MTBE and other

ethers may also be blended downstream of the refinery. Thus, refiners generally produce and ship

reformulated blendstock for oxygenate blending (RBOB) rather than finished ethanol-oxygenated RFG.
63

Refiners must also designate the type(s) and amount(s) of oxygenates that may be added to the RBOB.

For compliance purposes, a refiner or importer must estimate the properties of the RFG that will be

produced from an RBOB batch by blending the specified type and amount of oxygenate into a sample of

the RBOB and analyzing the sample. The property and volume data which are reported to EPA for RBOB

batches are based on these Ahand blends@ rather than on analysis of the RFG produced by the actual

blending operations. There are a number of regulatory requirements associated with RBOB and

downstream blending of oxygenates. For example, RFG oxygenate blenders are also required to report

the type and amount of oxygenate added. These regulations are intended to ensure that the RFG

produced from RBOB meets all applicable standards. However, even if these requirements are precisely

and rigorously adhered to, "hand blend" properties may differ from final RFG properties. In certain

instances, the amount of oxygen added downstream may be greater than the amount of oxygen assumed

for reporting purposes. In fact, unless a refiner or importer of RBOB meets certain contractual and

quality assurance requirements addressing downstream blending, EPA=s regulations require that such

assumptions be made.

In addition to the reporting system data, EPA receives RFG Survey data which includes total

oxygen content in weight percent as well as concentrations of specific oxygenates, including several not

included in the reporting data. (These oxygenates have been reported to EPA as weight percentages.

Prior to 2004, EPA did not receive density information for each sample.) Until the repeal of the RFG

oxygen requirement, survey sampling for oxygen and oxygenates included RFG sold in federal RFG areas

in California. This RFG is not included in EPA's reporting system data. California RFG surveys sampled

for oxygen and oxygenates only and are no longer conducted. Surveys conducted outside of California

continue to sample for oxygen and oxygenates because they are input parameters for the Complex

Model.

The Anti-Dumping standards applicable to CG do not include an oxygen content standard.

However, Complex Model CG is subject to NOx and exhaust toxics emissions standards, and oxygen and

oxygenate data are necessary to calculate these emissions. Thus, since 1998, refiners and importers

have been required to report CG oxygen and oxygenate data. The CG reporting procedures and

requirements differ from those of RFG. CG blendstocks for oxygenate blending as well as some

oxygenate batches are included. However oxygenates added downstream of the refinery or import

facility may be included in compliance calculations only if the refiner can show that they were added to

the gasoline or blendstock, and thus may not be reported. Additionally, refiners and importers do not

create "hand blends" of blendstocks and oxygenates to determine properties, but report the pre-blend

properties of the blendstocks.

In summary, downstream oxygenate blending, particularly ethanol blending, contributes to

differences between gasoline leaving the refinery or import facility and gasoline sold at retail. This

affects the analysis and interpretation of the data considered in this report, not only for oxygen and

oxygenates, but for other properties as well since they will change with the addition of an oxygenate.

The effect on RFG data is expected to be small because of the requirement to create "hand

blends", and because of other regulatory requirements. (EPA's analyses of RFG batch reporting data in

this chapter and in other chapters include data for both RFG batches and RBOB batches.) Additionally,

EPA has a second source of data from the RFG surveys, which directly measures retail properties.

Consequently, even though ethanol is widely used in RFG, EPA believes its data provide good estimates of

the oxygenate content and the other properties of the RFG that is used in vehicles. Additionally, EPA

believes that it can make credible, although approximate, estimates of various measures of oxygenate

"market share" (e.g. as in the RFG Trends chapter) and of the volume of oxygenates used in RFG.
64

It is possible that a significant amount of the ethanol added to CG is not included in the AntiDumping reporting data submitted to EPA. Although EPA has analyzed these data to estimate oxygen

and oxygenate content, the results probably underestimate of the oxygenate content of CG sold at retail,

and may not accurately reflect trends in CG oxygenate use. However, even if CG oxygenate use is

significantly under-reported, the volume percentage of oxygenates in CG is believed to be small (certainly

in comparison to RFG). Therefore, EPA does not believe that downstream oxygenate blending has

caused estimates of other CG parameters from reporting system data to be substantially unrepresentative

of CG sold at retail.

The General Methodology chapter explained that, for each parameter analysis in this report, a

rule was established to determine if the data was missing from a batch record. It is worth noting that

the decisions pertaining to oxygen and oxygenate data are somewhat unique. Since the RFG considered

in this report was subject to an oxygen content requirement, and the oxygen could come from any of

several reported oxygenates, a zero or blank value for any oxygenate was treated as a zero if there was a

non-zero value for one or more of the other oxygenates; otherwise it was treated as missing data. For

example, a blank ethanol value would be averaged as a zero for batches reporting MTBE, ETBE, TAME or

T-Butanol content, but excluded from an average if these other oxygenates were also reported as blanks

or zero. Since CG may or may not contain oxygen, a reported oxygen or oxygenate value of zero was

treated as zero, and a blank value was treated as a zero if at least one other non-zero property value was

reported (e.g. a blank MTBE value would be assumed zero if sulfur was greater than zero); otherwise it

was treated as missing data.

Oxygen and Oxygenate Trends

Overview-Reformulated Gasoline

Since this topic has also been discussed in the RFG Trends chapter, reference will be made to

material contained therein. Readers, particularly those who are unfamiliar with the issues pertaining to

oxygenate use, may wish to read the relevant portion of that chapter before continuing. (Additionally,

some of the oxygen and oxygenate-related graphical and tabular data analysis in the RFG Trends chapter

is not repeated here.)

Although the RFG oxygen content requirement did not change between 1995 and 2004, average

RFG oxygen content increased during that period. During this period the average ethanol content of all

(i.e. ethanol and ether oxygenated) RFG increased while the average MTBE and TAME content of all RFG

decreased.

Figures 1 and 2 show estimates of average RFG oxygen content in Summer and Winter RFG

Both reporting system estimates, by reporting year, and survey-based retail estimates, by survey year,

are shown. The survey estimates exclude California data and, as for other parameters, California

gasoline is exempted from oxygen and oxygenate reporting requirements. The averages shown are

volume-weighted estimates. (See also Figures 25 through 32 in the RFG Trends chapter. These graphs

provide additional information and also include survey-based estimates which include federal RFG areas in

California.) Figures 1 and 2 show that oxygen content estimates from reporting and survey data are

close, but that survey-based estimates of oxygen content have been consistently higher by small

amounts. The direction of these differences suggests that the amount of oxygen added downstream is,

on average, slightly greater than that assumed for refiner and importer compliance calculations. As

noted, this is allowable and consistent with EPA's regulations. EPA's data screening to exclude batches

with missing oxygen or oxygenate data also contributed to lower average oxygen and ethanol content

estimates from the reporting system. The majority of batches with missing data were RBOB; thus likely
65

to be ethanol-oxygenated and also likely to be oxygenated at about 3.5 weight percent oxygen. (RBOB

refiners and importers are not required to report their "hand blend" oxygen and oxygenate content.

Although the majority of RBOB batch reports contained this information, a significant number in each year

did not.) EPA believes that the reporting data analysis probably underestimates average oxygen (and

ethanol) content. However, other factors could have caused or contributed to the differences between

reporting and survey-based estimates, including statistical sampling error or errors in the estimates of

gasoline volumes for individual survey areas.

Figure 1

Figure 2
66

Both graphs show higher oxygen content in 2004 than in any of the preceding years. Average

oxygen content increased due to the increased use of ethanol which, outside of California, was often

blended at 10 volume % to take full advantage of tax incentives, and to replace much of the lost volume

where ethanol replaced ethers as an oxygenate. Figures 3 through 8 shows that average ethanol content

increased substantially from 2003 to 2004, with corresponding decreases in ether content. These changes

were primarily due to MTBE bans in New York and Connecticut which took effect in 2004. Transitions from

ether-oxygenated to ethanol-oxygenated RFG occurred in other areas, as well, at various times within the

period covered by these trend charts. (Figures 21 through 24 in the RFG Trends Chapter identify areas

where large oxygenate use changes occurred between 2000 and 2004). Ethanol content estimates from

surveys are higher than reporting data estimates, and MTBE estimates lower, again consistent with

downstream ethanol blending in excess of the amount assumed for compliance calculations and the

probable bias resulting from screening for missing oxygenate data in batch reports. (The previously stated

caveats relating to comparison of survey and reporting estimates apply. Additionally, reporting data

volume concentrations were converted to weight concentrations to be directly comparable with survey

estimates, and the conversion calculations were approximations using average density values.)

Figure 3

Figure 4
67

Figure 5

Figure 6
68

Figure 7

Figure 8

Winter oxygenated gasoline requirements were superimposed on RFG requirements in several

areas including portions of Pennsylvania, New Jersey, Washington, DC, Maryland, Virginia, Massachusetts,

New York and Connecticut. Consequently, the oxygen content of some of the winter RFG sold in these

areas was higher than necessary to meet the federal RFG requirement. These areas were re-designated

to CO attainment at various times between 1996 and 2000, and winter oxygenated programs were

eliminated, except, in some cases, as contingency measures (EPA, 2005). The elimination of these

programs contributed to the downward trend seen over a portion of the Winter MTBE and Winter oxygen

content trend lines. Since these areas used little or no ethanol-oxygenated RFG, it is unlikely that ethanol

trends were affected.
69

Transitions from ethers to ethanol, elimination of winter oxygenate programs in RFG areas and

RFG program opt-ins/opt-outs affected specific areas at specific times. Only some RFG refiners, importers

and oxygenate blenders were affected. However, some of the areas affected were major markets, so

these localized changes at times materially affected overall trends. Tables contained in the appendix to

this chapter show seasonal oxygen weight percent, ethanol weight percent and MTBE weight percent

averages estimated from RFG surveys by area and year. The reader can determine where and when

significant changes in oxygen and oxygenate usage occurred.

Although the above factors are likely to have influenced RFG oxygen and oxygenate trends,

additional factors influencing oxygen and oxygenate use should be mentioned. This discussion is not

intended to be an in-depth analysis of the movements of RFG oxygen and oxygenate content over time

and the factors influencing these movements. Rather, it is intended to identify certain factors which

could be considered in such an analysis.

Compliance with averaged standards, and the use of oxygen credits contributed to the wide

range of oxygen content averages in RFG areas. The highest RFG area averages for each year-season

combination with the exception of 1995 occurred in areas where the preponderance of the gasoline was

ethanol blended at about 10 volume percent. The lowest area averages for each year-season

combination occurred in areas where all or virtually all gasoline was ether-oxygenated, primarily MTBEblended. Suppliers who blended this high oxygen content ethanol RFG generated credits which could be

made available to producers of ether-oxygenated RFG. These producers, in turn, could use credits to

help meet the 2.1 weight percent averaged oxygen content standard. This sometimes produced a

situation where the average oxygen content in one or more RFG areas dropped below 2.0 weight percent,

the Clean Air Act requirement for RFG. Figures 1 and 2 show that this occurred on a seasonal basis.

This sometimes occurred on an annual basis, as well, triggering RFG Survey failures. EPA's regulations

allowed adjustment of the per gallon minimum oxygen content standard applicable to certain suppliers

and RFG areas in the event of such failures. As previously noted, EPA did, in certain instances, "ratchet”

this standard. Per gallon minimum oxygen requirements became as high as 1.7 weight percent for some

areas and suppliers. However, even when a small oxygen shortfall did occur, the RFG sold in the

affected area met or exceeded all emissions performance requirements. Consequently, EPA elected not

to adjust per gallon minimum standards in response to oxygen survey failures occurring in 1998 and later

years. In accordance with EPA's regulations, a ratchet automatically became less stringent by 0.1 weight

percent if a ratcheted area passes surveys in two consecutive years. As of 2005, ratchets to a 1.6%

minimum were still in place in the Norfolk, VA and Washington, DC areas. Although the ratchets applied

to specific areas, the effects were not as localized as transitions from ether to ethanol or elimination of

winter oxygenated gasoline programs, but were likely to have applied to much of the total RFG supply

(see ‘80.41(q)). However, while the ratchets applied to a significant quantity of RFG, they may well have

had only a minor or negligible effect on oxygen or oxygenate content since the ratchets did not affect the

average oxygen content standard.

Comparison of Figures 1 and 2 shows that winter oxygen content levels were higher than

summer levels prior to 2000, but that summer levels were equal or higher in 2000 and later years.

Although there may have been other seasonal influences, the winter oxygenated fuel programs in effect

in several areas contributed to higher winter oxygen levels during the initial years of the RFG program.

As these programs were eliminated, other factors were able to influence seasonal oxygen content

differences. Since this seasonal high low reversal coincided with the transition from Phase I to Phase II

RFG, it is possible that the reversal is related to differences between Phase I and Phase II RFG.

The timing of localized changes not only affected these trend lines but probably affected the

variability of oxygen content within a reporting or survey year. For example, MTBE bans took effect in

New York and Connecticut in 2004, but RFG Surveys indicate that the transition from MTBE to ethanol
70

took place at the end of 2003. As noted throughout this report, the winter data for a given year include

RFG produced and/or sampled both before and after the Summer VOC control season, and differences

between gasoline produced before and after the Summer season may have been exacerbated by these

transitions.

Figure 9 shows fluctuations in average RFG oxygen content by production quarter, based on the

production date reported for each batch. Batches produced during the 1st and 4th quarters are

predominantly Winter RFG, while batches produced during the 2nd and 3rd quarters are predominantly

Summer RFG.

Figure 9

Figures 10 and 11 show the frequency distribution of oxygen concentrations for reporting year

2005 RFG (and RBOB) batches. For both distributions, the portion representing ethanol-oxygenated RFG

and RBOB blended (or assumed blended) at about 10 volume percent is clearly evident between about

3.3 and 4 weight percent oxygen. Very little RFG or RBOB was reported with oxygen content between

approximately 2.7 weight percent, the "substantially similar" upper limit exclusive of any waivers, and

about 3.3 weight percent. Virtually all of the remaining volume fell between approximately 1.5 weight

percent, the per gallon minimum allowed with averaged standards, and approximately 2.7 weight

percent. The batches in this oxygen content range are predominantly ether-oxygenated, however some

ethanol-oxygenated RBOB batches also fall within this range. Both distributions show a peak below 2.0

weight percent.

Several factors contributed to the variability of oxygen content within this 1.5 to 2.7 weight

percent range. Most RFG producers chose to comply with oxygen content standards on an average

rather than per gallon basis. The regulations permitting compliance on average and the use of credits to

meet the oxygen standard provided flexibility in the amount of oxygen a refiner or importer might use in

an individual batch as well as in total. In some cases, refiners and importers may have chosen to

produce some or all of their RFG with a relatively low oxygen content, using credits, while in other cases

they may have chosen to produce higher oxygen content ether-oxygenated RFG, hence not requiring or
71

even creating credits. Additionally, refiners and importers may have chosen to blend MTBE or other

oxygenates in amounts greater than needed to meet the oxygen content requirement because

oxygenates are a good source of octane. Even if a producer did not, on average, exceed the oxygen

content requirement, the producer may have blended premium gasoline with higher oxygen or oxygenate

content than regular grade. EPA's data analyses indicate that, in aggregate, this was true for MTBE.

Table 1 shows volume-weighted average MTBE content (in volume percent), calculated for

regular and premium grade RFG (and RBOB if any) batches where MTBE content was greater than zero

and ethanol content equal to zero. It shows that higher levels of MTBE were used in premium RFG than

in regular RFG in each year and season. These averages may not precisely represent the actual MTBE

levels, by grade, found in retail MTBE-oxygenated RFG for various reasons (e.g. a portion of regular and

premium production is blended at points downstream of refineries to produce mid-grade gasoline.) RFG

Survey data analysis, presented in the appendix to this chapter, also estimates higher MTBE levels in

premium RFG than in regular or mid-grade. Since the survey-based MTBE averages include ethanoloxygenated RFG with no MTBE content, the averages underestimate the level of MTBE in MTBEoxygenated RFG.

Average MTBE Content (volume %) By Grade for RFG Batches with MTBE but no Ethanol

Season Grade 1997 1998 1999 2000 2001 2002 2003 2004 2005

Summer PRM 11.08 10.96 10.65 11.06 11.19 10.99 10.97 11.65 11.69

REG 9.78 9.87 9.70 10.08 9.99 10.41 10.57 10.85 10.16

Winter PRM 11.52 11.26 10.72 10.08 10.31 10.11 10.33 10.87 10.67

REG 9.86 10.15 9.68 9.67 9.54 9.54 9.67 9.98 9.67

Table 1

Figure 10
72

Figure 11

Since the "substantially similar" waiver for gasohol allows ethanol blending at any level up to 10

volume percent, an ethanol-oxygenated RFG batch could have contained any amount of oxygen between

approximately the per-gallon minimum and approximately the 4.0 weight percent Complex model

maximum. Analysis of the 2005 reporting data indicates that virtually no batches fell within a portion of

this range. Although downstream oxygenate blenders may in some cases have blended and distributed

RFG with oxygen content within the "empty" portion of the reporting data distribution, analysis of RFG

Survey data confirms that very little of the RFG sold during that period contained oxygen greater than 2.7

weight percent and less than 3.3 weight percent. In comparison to the reporting data analysis, the

survey data analysis also estimates a slightly larger fraction of the total RFG volume containing 3.3 or

more weight percent oxygen, and a slightly smaller fraction containing 2.7 percent or less oxygen. This

last finding is consistent with other indications that more ethanol is blended downstream than is assumed

for refiner and importer RFG compliance reporting.

There are several additional factors which contribute to the shape of the distributions pictured,

and in particular, explain why very little volume falls between about 2.7 and 3.3 weight percent. As

noted, the excise tax incentive as structured until a recent legislative change favored 10 volume percent

ethanol blending and was tied to three discrete volume concentrations (10%, 7.7% and 5.7%) with 7.7%

nominally equivalent to 2.7 weight percent oxygen. EPA's RFG regulations also, in certain circumstances,

provided incentives for using ethanol at 10 volume percent. These incentives included a relaxed VOC

performance standard applicable to 9-10 volume percent ethanol-blended Summer RFG sold in the

Chicago and Milwaukee areas and the oxygen credit program (i.e. the most credits would be generated

when ethanol is blended at around 10 percent). Additionally, when ethanol is blended into a

hydrocarbon blendstock to make gasoline, an RVP increase occurs which does not occur if MTBE or other

ethers are blended to make gasoline. Consequently, low volatility RBOB is needed to produce ethanoloxygenated RFG during the Summer to ensure that the finished RFG will meet VOC performance

standards. Thus refining the blendstock needed to produce ethanol-oxygenated RFG is sometimes more

costly than refining the blendstock needed to produce ether-oxygenated RFG. However, the blendstock

needed to produce 10 percent ethanol-oxygenated RFG may not be more expensive to refine than the

blendstock needed to produce 5.7 volume percent ethanol-oxygenated RFG, or RFG with any intermediate

ethanol content. Lastly, EPA's RFG regulations pertaining to downstream oxygenate blending limit the
73

amount of oxygen that refiners or importers can claim to 2.0 weight percent, and in certain circumstances

requires that a refiner or importer assume that only 4.0 volume percent ethanol (about equivalent to the

1.5 weight percent oxygen per gallon minimum) will be blended downstream, unless they meet certain

contractual and quality assurance requirements (see ‘80.69). While it would normally have been

advantageous for refiners and importers to claim as high an oxygen content as possible in their

compliance calculations, there would have been some trade-off between the benefits of claiming an

oxygen content equivalent to 10 volume percent ethanol, and any costs associated with meeting these

blender oversight requirements. If a refiner or importer elected not to meet these requirements, the

amount of oxygen assumed would be 2 weight percent or less and if he elected to meet these

requirements, he would in all likelihood have chosen to claim an oxygen content equivalent to 10 volume

percent ethanol. Presumably, if refiners or importers produced RBOB for ethanol blending, there was

little economic motivation to claim an ethanol content greater than that required to meet the 5.7 volume

percent threshold but substantially less than 10 volume percent.

The appendix to this chapter contains tabular and graphical percentile (i.e., cumulative

distribution) data for oxygen content, ethanol content and MTBE content based on reporting data. The

ethanol percentile charts clearly show that ethanol content falls into discrete ranges, as would be

expected from the above discussion. An additional factor contributing to the total absence of gasoline

volume in a portions of this distribution is that ethanol is seldom reported as used in combination with

other oxygenates. The MTBE percentile charts show that there are some batches that contain MTBE in

amounts significantly greater than zero but at a concentration insufficient to meet a 1.5 weight percent

per-gallon minimum oxygen standard (about 8 volume percent MTBE). This occurred because it is not

unusual to find MTBE in combination with other oxygenates such as TAME in a given batch of gasoline.

Since there is interest in the absolute volume of oxygenates in gasoline, EPA has included

estimates of non-oxygenated hydrocarbon and oxygenate volume for federal RFG. Table 2 shows volume

estimates calculated from the batch volumes and oxygenate volume percent concentrations contained in

refiner and importer batch reports.

EPA believes that these totals, in general, provide good, but imperfect, estimates of the volumes

of oxygenates used in federal RFG outside of California. 29 Although some reporting errors and omissions

exist, the impact on overall totals, with the exception of the ethanol volume, is likely to be small.

Reliance on the refiner and importer batch data to estimate ethanol volumes is likely to be a more

significant source of error in the ethanol volume estimates, for two reasons. First, as previously

explained, the amount of ethanol blended downstream may exceed the amount assumed by refiners and

importers. Second, although most RBOB refiners and importers report the oxygenate type and volume

percent concentrations used in their "hand blends", some parties omit this data. EPA's regulations

require that refiners and importers include the oxygenate volume in the volume reported for each RBOB

batch but do not explicitly require that they submit the oxygenate type and volume percent

concentration. Thus, EPA's oxygenate volume calculations in table 2 would not have included the

oxygenate volumes for these batches. Consequently, the ethanol volumes contained in the above table

are virtually certain to be lower than the actual volume of ethanol in RFG.

EPA's regulations require that RFG oxygenate blenders report oxygenate volume data. While

these data provide an alternative means to develop an RFG ethanol volume estimate, blenders complying

29 The oxygenate volume estimates in this report are based on analysis of data and information submitted to

EPA for purposes other than tracking the absolute volume of oxygenates used in gasoline. Although, in some cases,

the calculated volume estimates are shown to the nearest gallon this level of precision and accuracy is not implied;

these estimates are approximate. EPA has not determined that these volume estimates are the best available

published information on this topic. Readers should be aware that the Department of Energy’s Energy Information

Administration collects and publishes official energy statistics from the US government (see http://www.eia.doe.gov/).
74

with the per gallon oxygen content standard do not submit batch reports, complicating analysis of these

blender data. In lieu of blender data analysis, EPA has performed other analyses which quantify the

sensitivity of ethanol and total volume estimates to downstream blending.

Table 3 compares the estimates of ethanol and total RFG volume calculated directly from refiner and

importer batch reports with two alternatives (shown in bold font). The first alternative assumed that

each batch that did not contain oxygenate type and volume percent concentration data was oxygenated

with 4.0 volume percent ethanol. (This "minimum value" assumption has a regulatory basis under

certain circumstances; however in this analysis EPA applied this value to all "omitted data" batches

regardless of batch type or other information.) The amount of ethanol attributed to these omitted data

batches was added to the amount directly calculated from reported volumes and concentrations. The

second alternative assumed that all batches containing at least 3.8 volume percent ethanol and all

batches with omitted oxygenate data were oxygenated with 10 volume percent ethanol. Although this

had a small effect on ethanol totals, it also assumed batches with less than 3.8 volume percent ethanol

contained the directly calculated ethanol volume. The assumptions in the second alternative also have

an effect on the volume for certain batches, and the table also shows the effect on the total RFG volume.

Since the “10 volume %” assumption is more consistent with survey data and other information

than the “minimum value” assumption. EPA expects that the lower reporting-based estimates are

virtually certain to have underestimated actual ethanol usage in RFG. However, while the higher based

estimates are expected to be closer to actual usage, they may possibly overestimate ethanol volume.

RFG survey sampling occasionally found samples outside of California where ethanol was present in

concentrations significantly lower than 10 volume percent. Additionally, even when ethanol is blended at

a nominal 10 volume percent, the actual ethanol concentration is usually slightly less than 10 percent

because the ethanol blended into gasoline is denatured; i.e. it contains a small amount of an impurity

making it unfit for human consumption.

Non-reporting, reporting errors and omissions as well as violation of EPA's regulatory limits on

ethanol in gasoline could have resulted in RFG ethanol volume outside of the estimated ranges.

However, EPA believes that the actual ethanol volume in RFG, in each year, while almost certainly above

the lower reporting-based estimate, would not have significantly exceeded the higher reporting-based

estimate. To further investigate this assumption, EPA also estimated ethanol volume in each year using

the average RFG ethanol content estimates derived from RFG Survey data together with the annual RFG

volume estimates that the RFG Survey Association provides in its survey plans. EPA assumed that 45%

of this volume is VOC-controlled Summer RFG and 55% Winter RFG, since these are approximately the

ratios seen in the reporting data. These survey-based estimates of RFG ethanol volume are also

summarized in Table 3. In each year through 2004 the survey-based estimates fell between the high and

low reporting-based estimates, closer to the higher reporting estimate. In 2005 the survey-based

estimate exceeded the higher reporting-based estimate by less than three percent. These survey-based

approximations, in general, indicate that the actual RFG ethanol volume in each year probably fell

between the low and high reporting-based estimates. Although the 2005 survey-based estimate slightly

exceeded the upper reporting-based estimate, this does not strongly indicate that actual ethanol volume

exceeded the reporting-based estimate, given the approximate nature of these calculations.

As part of the process leading to the finalization of regulations to implement the renewable fuels

program requirements of the Energy Policy Act of 2005, EPA published a Regulatory Impact Analysis

(RIA) addressing the emissions, air quality and economic impacts of the program. 30 The RIA contained

estimates of volumes for ethanol and MTBE use, based on historic data from various sources, to represent

baseline conditions. EPA derived the estimates of oxygenate volume in this “trends” report independently

from the analyses supporting its Renewable Fuels Standard (RFS) Regulations.

30 The RIA is available at http://epa.gov/otaq/renewablefuels/420r07004.pdf
75

Given the significance of the RFS program it is appropriate for this “trends report” to include

some comparison of estimates to identify any significant disparities. Examination of comparable results

indicates that they are in reasonably good agreement with respect to RFG oxygenate volumes.

Specifically, estimates of oxygenate use in 2004 federal RFG contained in this report can be compared

with 2004 base year estimates in the RFS RIA.

Ethanol volume totals in Table 3 of this chapter can be compared to the sum of the 2004 PADD 1,

2 and 3 RFG ethanol consumption estimates in the RFS regulatory impact analysis (1,230 million gallons).

31 The ethanol volume estimates in the trends report are intended to estimate the volume of ethanol

without considering the volume of any denaturant that may be present in the ethanol. For various other

purposes, including compliance with the RFS, and Internal Revenue Service excise tax regulations, the

volume of denaturant is included. Assuming that 5% of the ethanol consumption estimate in the RFS RIA

is denaturant, it is appropriate to compare the trends report volume estimates to 95% of the RFS

estimate (1,169 million gallons). The comparable trends report ethanol volume estimates are about 78%

(916 MM gallons-low reporting), 93% (1,090 MM gallons-surveys) and 96% (1,120 MM gallons - high

reporting) of this volume. The upper reporting system-based estimate, which assumed that ethanol is

blended into RBOB at the 10 volume % limit, agrees well with both the survey-based estimate in the

trends report and the estimate in the RFS RIA.

Estimates of 2004 RFG MTBE volume shown in table 2 of this chapter can be compared with 2004

estimates in the RFS RIA. The trends report estimate (2,135 MM gallons) can be compared with the total

RFG MTBE volume (1,878 MM gallons) given in the RFS RIA. 32 This latter total included 19 MM gallons

used in PADD5, where Arizona’s “Cleaner Burning Gasoline” fuel regulations impose requirements similar

to those of federal and California RFG programs in the Phoenix area.

Refiners and importers are required to report volume percent MTBE content and batch volume for

each RFG batch. MTBE was typically blended at the refinery, rather than at terminals, and there is no

requirement to add a denaturant to MTBE. Consequently, calculation of MTBE volume from these batch

report concentrations and volumes should provide a reasonably accurate estimate of the MTBE volume in

non-California gasoline produced as RFG in a given year. California banned MTBE use after January 1,

2004, so reporting system MTBE estimates for 2004 and 2005, unlike prior year estimates, should reflect

nationwide MTBE usage in RFG. The reporting system estimate exceeds the 2004 estimate in the RFS

RIA by less than 14 percent. The RFS RIA noted that the Energy Information Administration reported

2004 MTBE usage in RFG as 2.0 billion gallons, but the RFS RIA analysis reduced this to 1.9 billion

gallons.33 Although the RFS RIA estimate is lower than the trends report estimate, the RIA estimate is

characterized as a “consumption” estimate while the trends report estimate is a refiner/importer estimate,

and MTBE consumption in RFG areas could have been smaller than the MTBE content in gasoline

produced as RFG since some RFG could have been marketed outside of RFG areas. Since EPA’s

reporting-based MTBE volume estimates are expected to closely estimate actual MTBE use in RFG, the

trends report does not include a table of survey-based MTBE volume estimates, as it does for ethanol.

However, using the same basic assumptions, the survey-based MTBE use estimate for 2004 RFG is about

2.0 billion gallons.

EPA has a limited basis for estimation of oxygenate volumes in the RFG sold in federal RFG areas

in California. (These are areas where RFG is mandated by the Clean Air Act and federal regulations,

based on ozone air quality.) EPA's regulations (40 CFR 80.81), which exempt refiners importers and

oxygenate blenders of California gasoline from many of the reporting requirements applicable to gasoline

sold outside of California, provided for oxygen surveys in these areas to ensure that the federal RFG

oxygen content standard was met.

31 See RIA table 2.2-5 page 63

32 See RIA table 2.2-3 page 59

33 See footnote 26 page 57 of the RIA.
76

Estimated Gallons of RFG Oxygenates and Hydrocarbons based on Refiner/Importer Batch Reports (Excludes California)

Table 2

Season Data 1997 1998 1999 2000 2001 2002 2003 2004 2005

Summer MTBE 1,071,597,101 1,125,469,361 1,089,183,554 1,135,416,556 1,154,011,408 1,199,903,109 1,175,062,810 1,017,763,982 970,917,488

Ethanol 116,719,792 126,671,140 135,612,567 144,765,712 140,950,792 173,837,314 186,597,775 418,865,421 392,714,925

ETBE 163,905 57,783 76,521 529,920 550,207 211,833 777,507 124,041 1,417,282

TAME 96,796,209 97,298,332 109,093,183 119,311,611 115,382,581 102,443,754 109,992,263 57,917,198 59,781,098

T_butanol 1,852,929 1,662,098 2,129,311 2,306,023 2,700,257 3,191,915 2,769,361 3,302,839 2,879,387

Methanol 2,409,022 1,842,350 1,366,976 942,867 2,006,367 939,210 950,143 1,123,509 816,929

Hydrocarbons w/o

oxygen

11,209,230,173 11,484,418,551 11,665,634,998 11,579,895,788 11,814,114,444 12,367,444,499 12,108,710,985 12,733,380,559 12,663,961,928

Total Volume 12,498,769,130 12,837,419,615 13,003,097,110 12,983,168,478 13,229,716,057 13,847,971,634 13,584,860,845 14,232,477,549 14,092,489,036

Winter MTBE 1,247,140,935 1,287,536,349 1,234,898,146 1,256,617,034 1,249,894,911 1,269,523,975 1,224,289,829 1,116,862,067 1,121,563,294

Ethanol 176,044,353 182,154,056 172,692,564 188,289,969 179,198,097 207,787,969 264,607,450 425,217,760 458,144,406

ETBE 163,829 404,759 145,423 722,267 2,353,316 1,857,791 176,153 285,687 4,288,669

TAME 102,918,788 102,954,626 118,188,700 113,252,505 108,920,290 93,243,310 59,626,275 51,860,959 46,435,024

T_butanol 2,525,600 2,322,076 2,740,995 2,202,582 2,538,465 2,829,843 2,839,813 2,673,376 2,788,917

Methanol 2,165,515 1,417,924 1,861,992 1,073,472 1,915,335 1,758,366 1,469,656 798,214 1,007,389

Hydrocarbons w/o

oxygen

13,400,206,530 13,507,944,631 13,553,712,580 14,268,916,880 14,238,183,530 14,856,998,466 15,126,763,959 15,596,672,836 16,410,604,358

Total Volume 14,931,165,550 15,084,734,421 15,084,240,402 15,831,074,709 15,783,003,943 16,433,999,720 16,679,773,135 17,194,370,899 18,044,832,058

Annual MTBE 2,318,738,035 2,413,005,710 2,324,081,700 2,392,033,591 2,403,906,319 2,469,427,084 2,399,352,639 2,134,626,049 2,092,480,782

Ethanol 292,764,145 308,825,195 308,305,131 333,055,681 320,148,888 381,625,284 451,205,225 844,083,182 850,859,331

ETBE 327,734 462,542 221,944 1,252,187 2,903,523 2,069,624 953,660 409,728 5,705,951

TAME 199,714,996 200,252,958 227,281,884 232,564,116 224,302,871 195,687,064 169,618,537 109,778,157 106,216,123

T_butanol 4,378,529 3,984,174 4,870,306 4,508,605 5,238,723 6,021,758 5,609,175 5,976,215 5,668,304

Methanol 4,574,536 3,260,274 3,228,969 2,016,339 3,921,702 2,697,576 2,419,800 1,921,723 1,824,318

Hydrocarbons w/o

oxygen

24,609,436,703 24,992,363,182 25,219,347,578 25,848,812,668 26,052,297,974 27,224,442,965 27,235,474,944 28,330,053,395 29,074,566,286

Total Volume 27,429,934,680 27,922,154,036 28,087,337,512 28,814,243,187 29,012,720,000 30,281,971,354 30,264,633,980 31,426,848,448 32,137,321,094
77

Reporting System Based Alternative Estimates of RFG Ethanol and Total RFG Volume

1997 1998 1999 2000 2001 2002 2003 2004 2005

Annual Ethanol Volumes (gallons)

Estimated from Batch

concentrations & volumes

292,764,145 308,825,195 308,305,131 333,055,681 320,148,888 381,625,284 451,205,225 844,083,182 850,859,331

All batches with unreported

oxygenate data assumed 4% EtOH

332,630,715 337,543,715 343,328,264 371,560,055 361,793,029 423,492,651 504,208,308 915,998,927 935,017,799

All batches with >= 3.8% ethanol

or unreported oxygenate data

assumed 10% EtOH

480,033,112 471,648,802 485,801,666 501,070,555 492,370,440 592,815,198 677,741,183 1,119,661,357 1,143,158,771

Total Gallons (from batch

volumes)

27,429,934,680 27,922,154,036 28,087,337,512 28,814,243,187 29,012,720,000 30,281,971,354 30,264,633,980 31,426,848,448 32,137,321,094

All batches with unreported

oxygenate data assumed 4% EtOH

27,429,934,680 27,922,154,036 28,087,337,512 28,814,243,187 29,012,720,000 30,281,971,354 30,264,633,980 31,426,848,448 32,137,321,094

All batches with >=3.8% ethanol

or unreported oxygenate data

assumed 10% EtOH

27,517,537,221 28,013,181,344 28,177,276,214 28,885,997,127 29,080,831,200 30,388,492,850 30,358,662,231 31,522,637,261 32,219,224,365

Survey-Based Estimates Annual Ethanol Volumes (gallons)

Estimated Average Ethanol WT%

Concentration-Summer

1.36 1.46 1.60 1.60 1.57 1.81 1.96 3.72 3.81

Estimated Approximate Ethanol

Vol% Concentration (assume blend

sg=0.745,etoh sg=0.7939)

1.28 1.37 1.50 1.50 1.47 1.70 1.84 3.49 3.58

Estimated Average Ethanol WT%

Concentration-Winter

1.83 1.68 1.85 1.96 1.81 1.95 2.52 3.97 4.20

Estimated Approximate Ethanol

Vol% Concentration (assume blend

sg=0.730,etoh sg=0.7939)

1.68 1.54 1.70 1.81 1.66 1.79 2.31 3.65 3.86

Estimated Annual RFG Total

Gallons-except CA (From RFG

Survey Plans)

28,352,970,000 28,759,802,000 29,506,498,000 28,922,480,000 29,046,358,000 29,273,367,000 29,979,353,000 30,460,161,000 31,483,686,000

Estimated Annual Ethanol Gallons

(assuming 45% Summer RFG/55%

Winter RFG)

424,864,889 420,987,795 475,895,074 483,112,058 458,271,047 511,926,099 629,712,996 1,090,058,001 1,175,055,482

Table 3
78

EPA has received both Summer and Winter oxygen survey data for three areas, Los Angeles, San

Diego and Sacramento, since 1997, and for San Joaquin since 2003. These survey data provide

estimates of oxygenate concentrations which can be applied to gasoline volume data to estimate

oxygenate volumes. EPA does not collect such volume data, however the RFG survey plans and other

survey-related documents submitted to EPA contain estimates of annual gasoline volumes for these as

well as non-California RFG areas. These estimates were derived from published population and percapita gasoline consumption data and were generated to determine the total number of RFG surveys that

are required in a calendar year. EPA has used these volume estimates throughout this report as

weighting factors when averaging survey data from different areas. The gasoline volume estimates for

the California areas have been used with the survey oxygenate concentration averages in order to

generate the oxygenate volume estimates shown in Table 4. These table values should be considered as

"ballpark" estimates, and more accurate estimates of ethanol use in these California areas may be

available elsewhere. The reader is also reminded that these estimates do not include oxygenate use in

California gasoline sold in areas outside of the federal RFG areas. While California's regulations did not

require oxygen in this gasoline, oxygenates were sometimes used.

Estimates of 2004 California RFG ethanol volume shown in table 4 of this report can also be

compared with estimates in the RFS RIA. 34 However, the trends report estimate (629 MM gallons)

included only the ethanol volume from RFG in the federally-mandated RFG areas in California where, in

2004, gasoline was required to contain oxygen as well as meet statewide California RFG standards. EPA,

for its statewide estimate in the RFS RIA (853 MM gallons) assumed, based on discussions with California

Air Resources Board staff, that all California gasoline contained 5.7% ethanol, by volume. These two

estimates differ primarily because the applicable areas differed.

Estimated Oxygenate Volumes (Millions of Gallons) In California's Federal RFG Areas *

1997 1998 1999 2000 2001 2002 2003 2004 2005

Estimated Ethanol

Volumes

Los Angeles, CA 0.0 0.0 0.0 0.0 57.9 55.0 364.4 404.7 397.2

Sacramento Metro, CA 0.0 0.0 0.0 0.0 5.4 8.1 45.2 70.5 59.5

San Diego, CA 0.0 0.0 0.0 0.0 5.5 6.0 55.3 68.3 68.0

San Joaquin, CA #N/A #N/A #N/A #N/A #N/A #N/A 42.3 85.2 85.7

Total 0.0 0.0 0.0 0.0 68.9 69.2 507.3 628.7 610.4

Estimated MTBE Volumes

Los Angeles, CA 717.8 749.8 796.0 800.3 670.5 658.9 44.0 0.0 0.0

Sacramento Metro, CA 99.5 103.6 105.3 106.1 90.6 119.2 46.1 0.0 0.0

San Diego, CA 124.6 128.6 137.9 142.1 134.6 122.0 24.9 0.1 0.0

San Joaquin, CA #N/A #N/A #N/A #N/A #N/A #N/A 82.8 0.0 0.0

Total 941.9 982.0 1039.2 1048.5 895.7 900.2 197.8 0.1 0.0

Estimated TAME Volumes

Los Angeles, CA 18.3 4.2 8.6 10.5 11.5 6.1 0.2 2.0 0.0

Sacramento Metro, CA 3.3 4.9 3.2 4.7 4.5 5.5 2.2 1.1 0.0

San Diego, CA 6.5 1.7 2.6 2.3 0.9 0.1 0.1 0.6 0.5

San Joaquin, CA #N/A #N/A #N/A #N/A #N/A #N/A 0.1 1.8 0.0

Total 28.2 10.8 14.4 17.6 16.9 11.6 2.5 5.5 0.5

* Estimates based on RFG Survey oxygenate measurements and survey plan estimates of gasoline volumes

Table 4

34 See RIA Table 2.2-3 page 59
79

RFG Oxygen and Oxygenates by PADD

Tables 5 through 8 show 2004 and 2005 reporting averages by PADD for PADD I, II and III

refiners. These averages were calculated from batch data, excluding importer batches (see “PADD Level

Analysis” appendix for additional information):

2004 & 2005 Reporting Average by PADD-RFG Oxygen (Refiner Batches Only)

2004 2005

Season PADD Average

Value (wt %)

Gasoline Volume

(gal)*

Average

Value (wt %)

Gasoline Volume

(gal)*

Summer I 2.59 4,726,753,777 2.50 4,224,319,396

II 3.48 1,390,108,766 3.50 1,515,851,939

III 2.36 5,818,619,897 2.25 5,620,100,245

Winter I 2.45 5,896,265,229 2.41 6,230,237,499

II 3.26 1,824,393,952 3.24 2,129,892,557

III 2.09 5,997,046,241 2.05 5,739,092,825

Annual I 2.51 10,623,019,006 2.45 10,454,556,895

II 3.35 3,214,502,718 3.35 3,645,744,496

III 2.22 11,815,666,138 2.15 11,359,193,070

*Volumes exclude batches with missing values for this parameter

Table 5

2004 & 2005 Reporting Averages by PADD-RFG Ethanol (Refiner Batches Only)

2004 2005

Season PADD Average

Value (vol %)

Gasoline Volume

(gal)*

Average

Value (vol %)

Gasoline Volume

(gal)*

Summer I 3.01 4,726,753,777 3.14 4,224,319,396

II 9.39 1,390,108,766 9.46 1,515,851,939

III 1.75 5,827,786,523 1.31 5,620,730,455

Winter I 3.00 5,896,265,229 3.02 6,227,516,269

II 8.61 1,824,393,952 8.63 2,129,892,557

III 0.98 5,997,046,241 0.91 5,739,092,825

Annual I 3.01 10,623,019,006 3.07 10,451,835,665

II 8.95 3,214,502,718 8.97 3,645,744,496

III 1.36 11,824,832,764 1.11 11,359,823,280

*Volumes exclude batches with missing values for this parameter

Table 6
80

2004 & 2005 Reporting Averages by PADD-RFG MTBE (Refiner Batches Only)

2004 2005

Season PADD Average Value

(vol %)

Gasoline

Volume (gal)*

Average Value

(vol %)

Gasoline

Volume (gal)*

Summer I 8.02 4,726,753,777 7.13 4,224,319,396

II 0.00 1,390,108,766 0.00 1,515,851,939

III 8.74 5,827,786,523 8.96 5,620,730,455

Winter I 7.11 5,896,265,229 6.82 6,227,516,269

II 0.00 1,824,393,952 0.00 2,129,892,557

III 8.52 5,997,046,241 8.53 5,739,092,825

Annual I 7.52 10,623,019,006 6.95 10,451,835,665

II 0.00 3,214,502,718 0.00 3,645,744,496

III 8.63 11,824,832,764 8.74 11,359,823,280

*Volumes exclude batches with missing values for this parameter

Table 7

2004 & 2005 Reporting Average by PADD-RFG TAME (Refiner Batches Only)

2004 2005

Season PADD Average Value

(vol %)

Gasoline

Volume (gal)*

Average Value

(vol %)

Gasoline

Volume (gal)*

Summer I 0.14 4,726,753,777 0.28 4,224,319,396

II 0.00 1,390,108,766 0.00 1,515,851,939

III 0.55 5,827,786,523 0.59 5,620,730,455

Winter I 0.05 5,896,265,229 0.09 6,227,516,269

II 0.00 1,824,393,952 0.00 2,129,892,557

III 0.68 5,997,046,241 0.53 5,739,092,825

Annual I 0.09 10,623,019,006 0.17 10,451,835,665

II 0.00 3,214,502,718 0.00 3,645,744,496

III 0.62 11,824,832,764 0.56 11,359,823,280

*Volumes exclude batches with missing values for this parameter

Table 8

Figures 12 through 17 show estimates of average oxygen, ethanol and MTBE levels by PADD in

retail RFG. 35 These averages are volume-weighted averages of the seasonal averages for each area,

using gasoline volume estimates supplied in the survey plans. (Oxygenate concentrations for these retail

data are in weight percent.) In 2005, RFG surveys were conducted in 18 PADD I areas, five PADD II

areas, two PADD III areas and four PADD V areas. It is obvious that virtually all PADD II RFG in more

recent years was ethanol-oxygenated. Increased ethanol use in PADDs I and V during the “trends report”

time period occurred primarily as a result of state MTBE bans. The survey averages show a small

amount of ethanol use in PADD I winter RFG even prior to these bans, but no ethanol use in summer

RFG. EPA regulations contained prohibitions against combining VOC-controlled ethanol-oxygenated RFG

with VOC controlled RFG produced using any other oxygenate during the January 1st through

September 15th period. Thus, limited ethanol use in predominantly MTBE-oxygenated RFG areas would

have been more feasible in winter than summer RFG.

35 Since TAME was always found in conjunction with MTBE but at much lower concentrations, PADD-specific

retail averages are not shown. Area-specific RFG Survey average oxygenate concentrations for TAME and other

oxygenates can be found at http://epa.gov/otaq/regs/fuels/rfg/properf/rfgperf.htm.
81

Figure 12

Figure 13
82

Figure 14

Figure 15
83

Figure 16

Figure 17

Additional Analysis and Observations-RFG

Data analyses pertaining to RFG oxygen and oxygenates are contained in the Appendix to this chapter.

Overview-Conventional Gasoline

For various reasons, analysis of EPA's CG data provides less information about oxygen and

oxygenates use than analysis of EPA's RFG data. As noted, refiners and importers do not always report
84

oxygenates added downstream of refineries and import facilities, so EPA's data are likely to

underestimate ethanol use in CG, possibly to a greater extent than in RFG, and may underestimate ether

use as well. Unlike downstream blenders who add oxygen to RBOB, CG oxygenate blenders are not

subject to reporting requirements. Additionally, since there is no nationwide oxygen content standard

applicable to CG as there was with RFG, EPA cannot determine if refiner and importer CG batch reports

with blank oxygen and oxygenate data fields represent batches with zero oxygen content or batches with

data omissions. Since there was no regulatory requirement for CG surveys as there was with RFG, EPA

does not have retail data to compare or contrast with CG reporting data.

Nonetheless, EPA has computed estimates of CG oxygenate and hydrocarbon volumes from

reporting data. These estimates are contained in Table 9. Since these data are likely to underestimate

oxygenate use, and EPA lacks retail data to corroborate trends, any conclusions regarding CG oxygenate

volumes or trends based on these data should be considered uncertain. Therefore, this report limits its

interpretation of CG oxygenate data to a few observations.

Reporting system ethanol volume estimates for 2004 CG can also be compared with values in the

RFS RIA. Based on batch reporting data, EPA estimated approximately 357 million gallons of ethanol in

CG. The RFS RIA estimate (Tables 2-9) is 1,149 million gallons in CG and 193 MM gallons in winter

oxygenated gasoline. This is consistent with the assumption in the trends report that EPA’s Anti-Dumping

reporting data significantly underestimates CG ethanol use.

In the trends report EPA estimated that about 410 MM gallons of MTBE were used in 2004 CG

production. For its 2004 base case analysis, the RFS RIA assumed that MTBE use outside of RFG could

be ignored. The trends report batch data analysis shows that the total MTBE volume used in 2004 CG

was about 19% of that used in RFG.
85

Estimated Gallons of CG Oxygenates and Hydrocarbons based on Refiner/Importer Batch Reports (Excludes California)

Season Data 1998 1999 2000 2001 2002 2003 2004 2005

Summer MTBE 252,881,317 263,857,150 239,812,977 249,459,785 261,046,445 303,540,761 220,336,203 156,726,080

Ethanol 68,787,726 103,158,524 104,005,119 93,305,613 122,469,291 123,138,938 151,645,217 158,885,968

ETBE 321,936 364,469 697,051 1,203,214 445,999 4,229,741 4,600,108 1,969,397

TAME 27,389,697 15,739,451 29,062,988 34,129,294 43,476,191 29,299,178 20,856,029 17,903,319

T_butanol 978,010 1,025,554 1,038,110 1,151,257 1,330,605 763,296 604,433 413,913

Methanol 1,469,751 440,993 677,409 1,051,256 1,218,595 635,660 494,447 213,725

Hydrocarbons w/o

oxygen

39,636,317,978 39,315,845,797 38,498,391,810 39,112,534,538 41,208,233,201 43,984,491,302 43,604,900,088 42,513,780,773

Total Volume 39,988,146,413 39,700,431,939 38,873,685,463 39,492,834,956 41,638,220,326 44,446,098,876 44,003,436,524 42,849,893,176

Winter MTBE 221,924,891 244,488,419 200,707,656 202,568,448 202,532,803 180,866,801 189,744,455 145,192,111

Ethanol 90,932,967 140,558,756 179,725,078 171,860,389 183,660,878 179,499,685 205,465,808 231,622,489

ETBE 232,124 82,274 724,484 1,351,462 496,032 1,034,938 1,645,897 4,744,327

TAME 25,929,645 15,370,098 21,838,185 23,721,415 37,451,523 20,716,356 18,822,251 18,436,905

T_butanol 679,657 680,049 685,072 837,127 958,779 656,387 555,308 262,795

Methanol 709,534 602,052 546,135 1,155,641 1,178,733 654,325 413,736 282,911

Hydrocarbons w/o

oxygen

46,584,731,037 47,915,978,752 48,602,598,915 49,333,020,314 50,204,198,335 48,288,412,977 47,906,967,487 49,058,601,515

Total Volume 46,925,139,854 48,317,760,399 49,006,825,526 49,734,514,796 50,630,477,083 48,671,841,470 48,323,614,941 49,459,143,051

Annual MTBE 474,806,208 508,345,569 440,520,633 452,028,233 463,579,248 484,407,562 410,080,658 301,918,191

Ethanol 159,720,692 243,717,280 283,730,197 265,166,002 306,130,168 302,638,623 357,111,024 390,508,457

ETBE 554,059 446,743 1,421,534 2,554,676 942,031 5,264,680 6,246,004 6,713,724

TAME 53,319,341 31,109,549 50,901,173 57,850,709 80,927,714 50,015,533 39,678,280 36,340,223

T_butanol 1,657,666 1,705,602 1,723,183 1,988,384 2,289,384 1,419,683 1,159,741 676,708

Methanol 2,179,285 1,043,045 1,223,544 2,206,898 2,397,328 1,289,985 908,183 496,635

Hydrocarbons w/o

oxygen

86,221,049,015 87,231,824,549 87,100,990,725 88,445,554,851 91,412,431,536 92,272,904,279 91,511,867,575 91,572,382,288

Total Volume 86,913,286,267 88,018,192,338 87,880,510,989 89,227,349,752 92,268,697,409 93,117,940,346 92,327,051,465 92,309,036,227

Table 9
86

Figure 18 shows that reported CG oxygenate volume is less than one percent of reported CG

volume. (RFG oxygenate volume has been about ten percent of RFG volume.) Based on analysis of

reported volumes and concentrations, MTBE volume percentage has decreased since 1998, while ethanol

volume percentage has increased. Decreases in MTBE volume share in CG may be partially attributable to

MTBE bans and phase-outs, which also affected some states or portions of states using CG. (The "nongeographic" analysis presented here is insufficient to confirm a direct relationship between MTBE bans and

the MTBE volume decrease.) The increase in ethanol volume share estimated from reported volumes and

concentrations suggests increased use of ethanol in CG.

Figure 18

CG Oxygen and Oxygenates by PADD

Tables 10 through 13 show 2004 and 2005 reporting averages by PADD for PADD I, II and III refiners.

These averages were calculated from batch data, excluding importer batches (see “PADD Level Analysis”

appendix for additional information).

As with aggregate CG oxygen and oxygenate data, it is likely that oxygen and ethanol are under-reported:

2004 & 2005 Reporting Average by PADD-CG Oxygen (Refiner Batches Only)

2004 2005

Season PADD Average Value

(wt %)

Gasoline

Volume (gal)

Average Value

(wt %)

Gasoline

Volume (gal)

Summer I 0.44 3,752,272,894 0.34 3,547,001,722

II 0.34 11,456,437,187 0.34 10,566,219,165

III 0.17 21,722,608,623 0.13 20,889,546,279

Winter I 0.37 3,484,116,076 0.30 4,064,064,814

II 0.40 13,323,919,987 0.33 13,589,333,929

III 0.14 23,628,091,025 0.11 22,443,420,127

Annual I 0.41 7,236,388,970 0.32 7,611,066,536

II 0.37 24,780,357,174 0.33 24,155,553,094

III 0.15 45,350,699,648 0.12 43,332,966,406

Table 10
87

2004 & 2005 Reporting Averages by PADD-CG Ethanol (Refiner Batches Only)

2004 2005

Season PADD Average Value

(vol %)

Gasoline

Volume (gal)

Average Value

(vol %)

Gasoline Volume

(gal)

Summer I 0.82 3,752,272,894 0.74 3,547,001,722

II 0.97 11,456,437,187 0.97 10,566,219,165

III 0.06 21,722,608,623 0.05 20,889,546,279

Winter I 0.83 3,484,116,076 0.68 4,064,064,814

II 1.16 13,323,919,987 0.92 13,589,333,929

III 0.05 23,628,091,025 0.07 22,443,420,127

Annual I 0.82 7,236,388,970 0.71 7,611,066,536

II 1.07 24,780,357,174 0.94 24,155,553,094

III 0.05 45,350,699,648 0.06 43,332,966,406

Table 11

Table 12

2004 & 2005 Reporting Average by PADD-CG TAME (Refiner Batches Only)

2004 2005

Season PADD Average Value

(vol %)

Gasoline

Volume (gal)

Average Value

(vol %)

Gasoline Volume

(gal)

Summer I -0.17 3,752,272,894 0.07 3,547,001,722

II 0.00 11,456,437,187 0.00 10,566,219,165

III 0.04 21,722,608,623 0.02 20,889,546,279

Winter I 0.03 3,484,116,076 0.05 4,064,064,814

II 0.00 13,323,919,987 0.00 13,589,333,929

III 0.02 23,628,091,025 0.02 22,444,880,341

Annual I -0.08 7,236,388,970 0.06 7,611,066,536

II 0.00 24,780,357,174 0.00 24,155,553,094

III 0.03 45,350,699,648 0.02 43,334,426,620

Table 13

2004 & 2005 Reporting Averages by PADD-CG MTBE (Refiner Batches Only)

2004 2005

Season PADD Average Value

(vol %)

Gasoline Volume

(gal)

Average Value

(vol %)

Gasoline Volume

(gal)

Summer I 0.70 3,752,272,894 0.39 3,547,001,722

II 0.00 11,456,437,187 0.00 10,566,219,165

III 0.76 21,722,608,623 0.60 20,889,546,279

Winter I 0.35 3,484,116,076 0.30 4,064,064,814

II 0.00 13,323,919,987 0.00 13,589,333,929

III 0.65 23,628,091,025 0.41 22,444,880,341

Annual I 0.53 7,236,388,970 0.34 7,611,066,536

II 0.00 24,780,357,174 0.00 24,155,553,094

III 0.70 45,350,699,648 0.50 43,334,426,620
88

Benzene

Background

Benzene is an organic compound found in gasoline. It is one of a family of compounds known as

aromatics. Benzene may occur in crude oil. Benzene and other aromatics are also produced in a refinery

process called reforming. While gasoline aromatics content, in total, is an important parameter affecting

emissions, gasoline benzene content is also considered separately because gasoline benzene content has a

direct effect on exhaust and evaporative benzene emissions. Benzene emissions are of concern because

benzene is a toxic air pollutant known to be carcinogenic.

Benzene is an important petrochemical. Its uses include manufacture of other compounds used to

make plastics, nylon, dyes and detergents. Some refineries producing gasoline may also extract benzene.

The demand for benzene as a petrochemical, as well regulatory control of gasoline benzene content for

emissions purposes is likely to affect gasoline benzene content trends.

Regulatory Limits on Benzene Content

Several regulatory requirements directly or indirectly limit the benzene content in reformulated and

conventional gasoline. RFG benzene content is directly limited through benzene content standards. CG

benzene content is directly limited, but less strictly, through Anti-Dumping standards. RFG requirements

were intended to create a gasoline that was superior, in emissions performance, to the gasoline that was

supplied in 1990. CG "Anti-Dumping" requirements were intended to prevent the quality of CG from

deteriorating as a result of the RFG requirements. Consequently, both RFG and CG are subject to

regulations designed to limit toxics emissions. Since benzene emissions, which are the largest component

of these toxics emissions, increase with increasing gasoline benzene content, limits on toxics emissions

indirectly limit gasoline benzene content. These regulatory requirements are discussed in more detail

below.

RFG must meet a 1.00 volume percent Aper gallon@ maximum benzene content standard, or

alternatively, on an annual basis, a 0.95 volume percent "averaged" standard with a 1.30 volume percent

per gallon maximum. These benzene content standards have been in effect since 1995. RFG benzene

content has also been indirectly limited through toxics emission performance (i.e. "percent reduction")

standards since 1995. However, the performance standards, unlike the benzene content standards, have

not remained constant.

The Simple Model, which was the basis for the RFG toxics performance standard from 1995

through 1997, included estimates of exhaust and (for Summer) evaporative benzene emissions in its toxics

performance estimate. The Phase I Complex Model determined emissions performance for RFG in 1998

and 1999. The Phase II Complex Model determines emissions performance for RFG in 2000 and beyond.

While there are differences between the Phase I and Phase II Complex Models, both models include

exhaust and, for Summer, evaporative benzene in their toxics estimates. Importantly, Phase II RFG is

required to meet more stringent toxics reduction standards than Phase I RFG. As with the Simple Model,

the Complex Model considers benzene content as one of several gasoline parameters affecting benzene

emissions. The Complex Model also considers the emissions effects of several parameters, such as sulfur

content, which are not included in the Simple Model. Thus, although other factors are involved, the toxics

performance standard limits benzene content

CG benzene content is also both directly and indirectly limited. Annual average benzene levels

may not exceed the greater of the refiner's or importer's 1990 baseline for benzene or the Complex

Model's 4.9 volume percent benzene "acceptable range" maximum limit specified in EPA's regulations. CG

supplied from 1995 through 1997 was required to have annual average exhaust benzene emissions, as

calculated by a mathematical model, no greater than the refiner's or importer's compliance baseline for
89

exhaust benzene emissions (i.e. refiners and importers must meet individualized standards for CG, rather

than generalized standards, as for RFG.) This exhaust benzene emissions model estimated exhaust

benzene as a function of gasoline benzene and aromatics content. CG supplied subsequent to 1997 is

required to have exhaust toxics emissions, based on the Complex Model, which do not exceed the refiner's

or importer's exhaust toxics compliance baseline. These emissions include other exhaust toxic pollutants

in addition to benzene, and several gasoline parameters in addition to benzene affect the benzene portion

of these Complex Model toxics emissions. Again, although other factors are involved, the emission

requirement indirectly limits CG benzene content.

EPA's Mobile Source Air Toxics (MSAT) regulations have imposed additional requirements on both

RFG and CG. These regulations do not regulate benzene content directly or require additional toxic

emission reductions. Rather, the MSAT regulations required refiners and importers, beginning on January

1, 2002, to produce or import gasoline with toxics emissions that are no worse than the toxics emissions of

gasoline they produced or imported during the period 1998 through 2000. EPA's data indicate that some

refiners and importers had over-complied with toxics emissions requirements. The MSAT rule is intended to

preserve this over-compliance to ensure that toxics emissions do not increase above current levels. 36

EPA's Benzene Data

36 EPA has finalized an "MSAT2” regulation to replace the current MSAT requirements with a 0.62 volume

percent average benzene requirement beginning in 2011. See 72 F.R. 8427

Since gasoline benzene content data has been and is currently necessary to determine RFG and

CG compliance, refiners and importers have been required, since 1995, to submit this information to EPA's

RFG/Anti-Dumping reporting system for each batch of gasoline refined or imported. Additionally, since

1995, EPA has received RFG Survey data on the benzene content of RFG sold at gasoline stations. EPA

has analyzed reporting system benzene data from 1997 through 2005, and RFG Survey data from 1995

through 2005.

Benzene Trends

Overview-Reformulated Gasoline

Figures 1 and 2 show Summer and Winter volume-weighted average RFG benzene content levels,

by year. Both the reporting system estimates, by reporting year, and the RFG Survey-based estimates, by

survey year, are shown. The decrease in benzene content between Summer 1999 and Summer 2000 RFG,

as estimated by both data sets, is greater in magnitude than any prior or subsequent year to year change.

The change in benzene content between Summer 1999 and Summer 2000 is also obvious from the

frequency distribution comparison shown in Figure 3, and in the distribution trend chart in the appendix to

this chapter.

It is clear that Summer RFG benzene content changed concurrently with the transition from Phase

I to Phase II RFG. (Regression analysis confirms the subjective conclusion-see "Regression Analysis"

appendix). Although the RFG benzene content standard did not change from Phase I to Phase II RFG, as
90

discussed above, the toxics performance requirement became more stringent with Phase II RFG. It is likely

that the more stringent Phase II toxics performance requirement is partially, if not primarily responsible for

the benzene content reduction, since benzene content affects Complex Model toxics emission performance

calculations. Benzene content does not directly affect Complex Model NOx or VOC emission estimates,

however, benzene content may also have been collaterally affected by refining and blending changes

made in order to comply with Phase II NOx and VOC standards.

The timing of the benzene content shift and the relationship between benzene content and toxics

emissions provide strong circumstantial evidence of a cause-effect relationship between the transition to

Phase II RFG and the shift in benzene content. The analysis presented in this report is, however, more

equivocal in supporting this relationship than in supporting other cause-effect relationships. Analysis

presented in the RFG Trends chapter suggests that benzene reduction was not the primary reason for

Phase I to Phase II toxics performance improvement and also shows that, although Summer toxics

performance improved with Phase II, on average, Phase I RFG complied with Phase II toxics requirements.

In contrast, similar analyses suggest that RVP reduction and sulfur reduction were, respectively, the

primary reasons for VOC and NOx performance improvements, and that, on average, Phase I RFG did not

comply with Phase II VOC or Summer NOx performance standards. Moreover, the demand for benzene as

a petrochemical would need to be considered in any rigorous analysis to explain gasoline benzene content

trends.

Figure 1
91

Figure 2

Figure 3

The RFG toxics performance standard applies to all RFG and is met on an annual average basis.

However, there was little change in benzene content between Winter 1999 and Winter 2000 RFG, and pre2000 Winter benzene content levels are comparable to those in 2000 and beyond. A possible explanation

for this lack of change in Winter benzene content is that benzene reduction is more valuable as toxics

emission reduction strategy when producing Summer RFG, since both exhaust and non-exhaust benzene

emissions are considered in Summer toxics performance. Another hypothetical "regulatory" explanation is

that, if benzene content changes were largely a collateral effect of refining and blending changes made to

meet Phase II VOC and NOx standards, Winter RFG benzene content may not have been affected. VOC

standards do not apply to Winter RFG and the Winter NOx standard did not become more stringent.

Comparison of Figures 1 and 2 shows that for Phase II RFG, Winter benzene levels have been

consistently higher than Summer levels, while prior to 2000, Summer levels have generally been higher.

The survey standard is a 1 percent annual average and, while in some years an RFG area may have

approached or even exceeded this level on a seasonal basis, there have been no survey failures.
92

Both the survey-based and reporting estimates of average benzene concentration indicate

increases between 2000 and 2005. After 2000, both summer and winter survey-based estimates have

been higher than corresponding reporting estimates. It is not apparent why retail benzene concentrations

would be higher than production benzene concentrations. This divergence may be the result of statistical

or other errors inherent in the use of the geographic survey data to estimate overall averages.

RFG Benzene by PADD

Table 1 shows 2004 and 2005 reporting averages by PADD for PADD I, II and III refiners. These

averages were calculated from batch data, excluding importer batches (see “PADD Level Analysis”

appendix for additional information):

2004 & 2005 Reporting Averages by PADD-RFG Benzene (Refiner Batches Only)

2004 2005

Season PADD Average Value

(vol %)

Gasoline Volume

(gal)*

Average Value

(vol %)

Gasoline Volume

(gal)*

Summer I 0.55 4,787,247,511 0.62 4,430,366,230

II 0.84 1,740,499,436 0.86 1,844,913,833

III 0.54 5,890,920,167 0.60 5,690,766,967

Winter I 0.65 6,488,981,913 0.69 7,081,608,319

II 0.79 2,437,732,174 0.81 2,718,751,541

III 0.54 6,059,647,031 0.57 5,771,776,973

Annual I 0.61 11,276,229,424 0.66 11,511,974,549

II 0.81 4,178,231,610 0.83 4,563,665,374

III 0.54 11,950,567,198 0.59 11,462,543,940

*Volumes exclude batches with missing values for this parameter

Table 1

Figures 4 and 5 show estimates of average levels by PADD in retail RFG. These averages are

volume-weighted averages of the seasonal averages for each area, using gasoline volume estimates

supplied in the survey plans. In 2005, RFG surveys were conducted in 18 PADD I areas, five PADD II

areas and two PADD III areas. Survey averages show consistently higher benzene levels in PADD II, as

do the reporting averages for the two years analyzed.

Figure 4
93

Figure 5

Additional Analysis and Observations-RFG

Data analyses pertaining to RFG benzene are contained in the Appendix to this chapter.

These include estimates of grade specific averages which show that average benzene content in premium

grade RFG has been consistently lower than in regular RFG.

Overview-Conventional Gasoline

Volume-weighted average CG benzene content levels, by reporting year, are shown in Figure 6.

Summer and Winter averages are shown separately on the same graph. Based on inspection, these

averages do not suggest a clear trend in either the Summer or Winter data, although the 2005 averages

were the highest for the 1997-2005 period. Summer CG benzene content levels have been higher than

winter CG benzene content levels since 1998. The direction of year to year change in Summer and Winter

benzene content levels has been the same between 1999 and 2003, suggesting that the same factors might

be influencing the year to year changes in both.

It is unclear whether regulatory changes have had a substantial influence on year to year changes

in CG benzene content. A change in CG toxics emission requirements occurred between 1997 and 1998

with the transition to a Complex Model-based standard. CG was required to comply with the MSAT toxics

requirements beginning in 2002. While reductions in average benzene content occurred concurrently with

these changes, neither of these regulatory changes was explicitly intended to require a sharp reduction in

toxics emissions. There was little change in CG benzene content between 1999 and 2000 even though RFG

benzene declined, consistent with the intent of the Anti-Dumping regulations. Given the relatively small

changes in benzene content at these transitions and the observed fluctuations in benzene content, it would

be inappropriate, without further evidence and analysis, to ascribe any cause-effect relationship between

these regulatory changes and changes in CG benzene content.
94

Figure 6

CG Benzene by PADD

Table 2 shows 2004 and 2005 reporting averages by PADD for PADD I, II and III refiners. These averages

were calculated from batch data, excluding importer batches (see “PADD Level Analysis” appendix for

additional information):

2004 & 2005 Reporting Averages by PADD-CG Benzene (Refiner Batches Only)

2004 2005

Season PADD Average Value

(vol %)

Gasoline

Volume (gal)*

Average Value

(vol %)

Gasoline

Volume (gal)*

Summer I 0.96 3,721,549,054 1.12 3,517,507,894

II 1.38 11,327,130,611 1.41 10,437,087,141

III 0.98 21,712,599,435 1.07 20,884,656,303

Winter I 0.93 3,451,551,536 1.18 4,025,985,850

II 1.32 13,133,321,322 1.25 13,416,981,375

III 0.89 23,618,108,969 1.01 22,432,331,959

Annual I 0.95 7,173,100,590 1.15 7,543,493,744

II 1.35 24,460,451,933 1.32 23,854,068,516

III 0.93 45,330,708,404 1.04 43,316,988,262

*Volumes exclude batches with missing values for this parameter

Table 2

Additional Analyses and Observations-CG

The benzene content of Summer baseline gasoline, as specified in the Clean Air Act, is 1.53

volume percent, and the benzene content of Winter baseline gasoline, as specified by EPA's regulations, is

1.64 volume percent.

Data analyses pertaining to CG benzene are contained in the Appendix to this chapter. These data include

tabular and graphical descriptions of CG benzene content by volume and grade which show:
95

 In 1997, the first year for which benzene reporting data were analyzed, the median Summer benzene

content was 0.95 volume percent and the 1990 baseline gasoline fell between the 70th and 75th

percentile.

 In 2005, the last year for which benzene reporting data were analyzed, the median Summer benzene

content was 1.06 volume percent and the 1990 baseline gasoline fell between the 70th and 75th

percentile.

 In 1997 the median Winter benzene content was 0.88 volume percent and the 1990 baseline gasoline

fell between the 75th and 80th percentile.

 In 2005 the median Winter benzene content was 0.98 volume percent and the 1990 baseline gasoline

fell between the 80th and 85th percentile.

 The benzene content of premium grade CG has been lower than that of regular grade in each year and

season.

All Gasoline

Although this report has analyzed benzene trends separately by season and gasoline type,

benzene is regulated on an annual average basis for both RFG and CG. Since the MSAT2 regulations will

eventually supersede both the RFG and Anti-Dumping benzene and toxics requirements, some readers

may also be interested in analyses combining RFG and CG data. Aggregated reporting data averages are

available, in tabular form, in the “Summary of Average Estimates” chapter of this report. Aggregated

benzene content distributions by gasoline volume for 2005 are shown in Table 3, below:

2005 Benzene Content (vol %) by Volume

(from Batch Reports excluding CG blendstocks)

CG RFG/RBOB ALL

Volume %

minimum 0.00 0.01 0.00

5% 0.36 0.30 0.33

10% 0.47 0.37 0.42

15% 0.53 0.41 0.48

20% 0.60 0.45 0.54

25% 0.66 0.48 0.59

30% 0.73 0.51 0.64

35% 0.79 0.54 0.69

40% 0.86 0.58 0.74

45% 0.94 0.61 0.80

50% 1.01 0.64 0.86

55% 1.10 0.67 0.92

60% 1.20 0.70 1.00

65% 1.29 0.74 1.09

70% 1.39 0.78 1.19

75% 1.49 0.82 1.32

80% 1.61 0.86 1.44

85% 1.77 0.91 1.60

90% 2.01 0.98 1.84

95% 2.43 1.07 2.25

100% 5.20 1.68 5.20

Volume (gal): 90,872,058,197 32,132,421,234 123,004,479,431

Table 3
96

Aromatics

Background

Aromatics are a family of hydrocarbon compounds with chemical properties similar to benzene.

In addition to benzene, other aromatic compounds such as toluene and xylenes are found in gasoline, and

aromatics other than benzene constitute the bulk of the aromatics volume in most gasoline. The main

source of aromatics in gasoline is reformate, a blending component produced in a refinery process units

called reformers. Reformate is a high octane, low sulfur blending component. While these are desirable

characteristics, reformate, with its high aromatics content, also has some undesirable emissions

characteristics. The Complex Model indicates that certain toxics, NOx and exhaust VOC increase with

increasing gasoline aromatics content.

Benzene and other aromatics are petrochemicals which are used for various purposes such as in

the manufacture of plastics and as solvents. Aromatics produced at refineries are sometimes extracted

and marketed as petrochemicals. Thus, the demand for these aromatics as petrochemicals will, to an

extent, affect the aromatics content of gasoline.

Regulatory Limits on Aromatics Content

The primary regulatory constraints on gasoline aromatics content have been and currently are

indirect limits resulting from model-based emission standards. Prior to 1998, RFG was subject to a toxics

emission performance standard based on the Simple Model. According to this model, exhaust benzene

emissions, one of several toxic emissions incorporated in this standard, increase with gasoline aromatics

content as well as gasoline benzene content. (While benzene is an aromatic compound, benzene content

is also considered as a separate gasoline parameter and additional regulations address gasoline benzene

content. See the Benzene Chapter in this report.) CG supplied from 1995 through 1997 was required to

have annual average exhaust benzene emissions, as calculated by a formula considering both aromatics

and benzene content, no greater than the refiner=s or importer=s compliance baseline for exhaust benzene.

In 1998 and subsequent years standards based on the Complex Model applied to both RFG and

CG. Complex model RFG is subject to toxics, NOx and VOC emission performance standards. CG

exhaust toxics and NOx emissions cannot exceed the refiner's or importer's compliance baseline for these

emissions. Gasoline aromatics are generally associated with toxics emissions, and gasoline toxics emission

requirements, including the current MSAT requirements, are expected to have a limiting effect on

aromatics content. The Complex Model predicts that aromatics reduction lowers exhaust benzene

emissions. Although it predicts that emissions of certain other toxics may increase slightly with reduced

aromatics, the exhaust benzene emission reduction more than offsets these increases, resulting in a net

toxics emission reduction with an aromatics content reduction.

Toxics emission standards may not have been the only standards limiting aromatics content

Analysis presented in the RFG Trends chapter suggests that aromatics reductions may have helped

significantly to meet the more stringent Phase II RFG Summer NOx performance standard, as well as to

provide some additional VOC reduction. While NOx emission requirements may have, in the past, had

some limiting effect on the aromatics content of RFG and CG, the Tier 2 sulfur reductions, with consequent

substantial NOx emission reductions and over-compliance for both, clearly reduced the limiting effect, if

any, of NOx emission requirements on aromatics content. 37

37 As noted elsewhere, NOx emission requirements were generally eliminated in 2007 and toxics emission

requirements will generally be eliminated in 2011, removing most of the regulatory constraints on aromatics content.
97

Complex Model acceptable range limits directly limit gasoline aromatics content. The acceptable

range limit for RFG is 50 volume percent and the acceptable range limit for CG is 55 volume percent. For

RFG, this range limit is applicable to each batch. For CG, the annual average aromatics level cannot

exceed 55 volume percent or the refiner=s or importer=s 1990 baseline for aromatics, whichever is greater

EPA's Aromatics Data

EPA collects aromatics data in order to determine compliance with the RFG and Anti-Dumping

regulations. Refiners and importers have been required, since 1995, to submit aromatics content data for

each batch of CG and RFG refined or imported. Additionally, since 1995, EPA has received RFG Survey

data on the aromatics content of RFG sold at retail outlets.

Aromatics Trends

Overview-Reformulated Gasoline

Analysis of aromatics data from EPA's two data sources shows that a decrease in average

aromatics content occurred with the transition from Phase I to Phase II standards. Decreases in aromatics

content for both Summer and Winter RFG are consistent with a more stringent Phase II annual average

toxics emission performance standard. However, estimates from these two sources have been in better

agreement for most other properties, particularly in quantifying Phase I to Phase II changes.

Consequently, there is additional uncertainty in any conclusions regarding aromatics trends. While it is

reasonable to expect some difference in estimates from the two data sources the estimates appear to

differ in a systematic fashion.

Figure 1
98

Figure 2

Figure 1 shows Summer averages calculated from reporting system and survey data. Both data

sets show a decrease in aromatics content from 1999 to 2000 greater than any of the other year to year

changes, although the production data indicate a 2.9 volume percent reduction in aromatics content, while

the survey data indicate a 5.4 volume percent reduction. While the survey-based and reporting systembased averages are in close agreement in 2000 and subsequent years, the survey-based estimates were

higher than reporting system estimates in 1999 and in the two preceding years.

Figure 2 shows Winter averages calculated from the two data sets. While the survey data show a

1999 to 2000 decrease in aromatics content of 3.1 volume percent, clearly greater than any of the other

year-to-year changes, the production data show only a 0.5 volume percent decrease in aromatics content

between 1999 and 2000. As with the Summer estimates, survey-based average estimates were higher

than reporting system estimates in 1999 and in the two preceding years.

Although estimates from the two data sources clearly differ, there is little doubt that an atypical

change in Summer RFG aromatics content occurred concurrent with the transition from Phase I to Phase II

standards. For both data sets, the 1999 to 2000 decrease in aromatics is, subjectively, large compared to

other year-to- year changes. More objectively, regression analysis of both sets of estimates indicates that

a statistically significant shift in aromatics content occurred (see Regression Analysis Appendix). The

timing and magnitude of the decreases do not, in themselves, establish a cause-effect relationship, but

toxics, NOx and VOC Summer RFG emission performance standards all became more stringent, and

aromatics reductions can improve emission performance for all of these pollutants. Analysis presented in

the RFG chapter, based on survey data, confirms that Summer RFG emission performance improved

between 1999 and 2000, and identifies aromatics content reduction as the primary factor for toxics

performance improvement, and as the secondary factor for NOx and VOC improvement.

While estimates from both data sets indicate a reduction in Winter RFG aromatics content between

1999 and 2000, only the survey-based estimates indicate that a statistically significant shift in aromatics

content occurred concurrent with the transition to Phase II standards. Average toxics performance
99

during Phase I, as estimated from both data sets substantially over-complied with the Phase II toxics

performance standard. Thus, while some refineries and importers may have needed to reduce aromatics

and improve winter toxics performance to meet the Phase II toxics standard (EPA's aggregate analysis did

not address this), the more stringent Phase II toxics standard may not have had a large impact on average

Winter RFG aromatics content. The Winter NOx performance standard did not become more stringent

with Phase II, and average Phase I NOx performance substantially over-complied with the Phase II

standard, so it is unlikely that this standard would have caused a change in Winter RFG aromatics content.

Consequently, evidence supporting a cause-effect relationship between this transition and an aromatics

content change is more equivocal.

The General Methodology Chapter explains why EPA analyzed both RFG survey and reporting data

to estimate overall RFG property trends even though survey-based trend estimation required more

approximations and assumptions. The analysis presented here suggests that, for aromatics, there were

some systematic differences between the two estimates prior to 2000, with good agreement in 2000 and

subsequent years. Consequently, the two data sets differ somewhat in their estimate of the magnitude of

the change in aromatics content between Phase I and Phase II RFG. Arguably, there is some rationale for

rejecting survey-based trend estimates in favor of reporting-based estimates if there is any substantial

disparity. However, EPA has not identified a clear problem with either data set and believes that both sets

of aromatics estimates must be considered. There are several reasons for this view:

It appears unlikely that the differences between the survey-based and reporting system estimates

of average aromatics content are solely attributable to some combination of statistical sampling error and

imprecise sales volume estimates. For Summer RFG, the most notable difference between the two

estimates is that the reporting system averages in 1997, 1998 and 1999 fell close to or below the lowest

seasonal average in any of the areas sampled. Thus, even extremely inaccurate estimates of sales

volume, by themselves, would not explain the difference between the two averages. The mandatory RFG

areas, which, in general, would be heavily weighted in the average calculation because of their large sales

volumes were also the most frequently sampled in each survey year with multiple one week surveys during

the June 1-September 15 Summer period. (e.g. In 1998 each of the non-California mandatory areas were

surveyed between six and eight time during this period). Thus, the areas that most heavily influenced the

volume-weighted average calculation would also likely have the most accurate seasonal area average

estimates. For Winter RFG, the most notable difference is that the reporting system estimate showed

only a 0.5 volume percent decrease in aromatics content between 1999 and 2000, while the survey-based

estimate indicates a 3.1 volume percent decrease. Area-specific seasonal survey averages for both

Summer and Winter RFG show that aromatics content decreased in each of the 23 areas surveyed in both

1999 and 2000. For Winter RFG, the area-specific survey average decreases ranged from about 1.2 to 5.9

volume percent. Since these paired area data from the surveys strongly indicate a decrease in Winter

aromatics between 1999 and 2000, it is difficult to dismiss the survey data entirely, and conclude with a

high degree of certainty that there was little change in Winter aromatics between 1999 and 2000. 38

Although the reporting data are not a statistical sample, the reporting system averages are also

subject to error. A number of different parties of varying capabilities collect and analyze reporting system

samples and submit reports to EPA. Although EPA's regulations include mechanisms to help ensure the

quality of the data, such as record keeping and independent laboratory sampling and analysis

requirements, these mechanisms cannot totally eliminate reporting data errors. In addition to errors in the

sense of mistakes such as incorrect reporting of data or omitting a data item, there are precision and

accuracy issues associated with the measurement of any gasoline parameter ( i.e., even when a gasoline

38 It should be noted that sample sizes in individual one-week surveys are smaller in Winter than in Summer,

and in some areas fewer surveys are scheduled during the Winter season. This may result in less precision and

accuracy in Winter than Summer seasonal average estimates based on survey data.
100

sample is carefully analyzed using the correct methods and procedures measured property values can

differ from the "true" property values). A detailed discussion of these issues is beyond the scope of this

report, however it is worth noting that there are some additional aromatic-specific factors that could affect

the quality of the aromatics data from both data sets. EPA's regulations have allowed two methods for

measurement of gasoline aromatics content; Gas Chromatography/Mass Spectrometry (GC-MS) designated

as ASTM standard method D 5769, and Flourescent Indicator Adsorption (FIA), designated as ASTM

standard method D 1319.39

EPA's regulations designated GC-MS as the method for determining aromatics content, but allowed

use of D 1319 if the result is correlated with the designated method. In its "RFG Questions and Answers"

guidance document (EPA 2003) EPA has characterized D 1319 as "highly operator-dependent" and having

"relatively large reproducibility". "Reproducibility" is a term referring to the difference in test results from

two different operators measuring the same material at two different laboratories or using two different

instruments. Survey samples were analyzed for aromatics using D 1319, but in each year all or most of

these analyses were done at a single laboratory (although not necessarily with the same operator and

instrument), and this laboratory was used since the inception of the RFG Survey program. A larger

number of laboratories analyzed reporting system samples, and the data do not identify which of these

two methods was used to determine the aromatics content of each batch. (Consequently, it would be

difficult to determine if measurement-related issues are important in explaining the difference between

reporting system and survey aromatics estimates.)

39 From time to time ASTM revises its standards and the complete standard number includes a suffix

indicating the revision (e.g. D1319-02a). EPA regulations specifying test methods (40 CFR 80.46) reference specific

versions of these test methods. Although EPA from time to time updates these regulations to reflect revisions to

ASTM standards, these regulations do not always specify the "active" standard (see http://www.astm.org).

Additionally, there may be actual differences between the average properties of gasoline sold at

retail and the average of properties in the gasoline and blendstock that refiners and importers consider for

compliance determination. (These differences can occur as a result of allowable practices such as

downgrading of RFG to CG, downgrading of Summer RFG to Winter RFG, or blending of oxygenates in

amounts greater than assumed for compliance reporting.) Differences may be even more apparent when,

as in this report, gasoline properties are analyzed and compared on a seasonal basis, particularly when

there are large Summer to Winter variations in a property. EPA does not know if real differences between

retail and reporting properties were a major cause for differences in aromatics estimates. However, since

the true retail averages could differ from the true reporting averages, and since both are of interest, it is

generally appropriate to consider RFG data from both sources in trend analyses.
101

Figure 3

Regardless of which data estimates are used, comparison of Figures 1 and 2 shows that aromatics

levels in Summer RFG are generally higher than aromatics levels in Winter RFG. Gasoline composition

varies seasonally because of regulatory emission requirements, as well as vehicle performance

("drivability") requirements associated with gasoline's volatility and distillation characteristics. The need to

meet these seasonal requirements has resulted in a clear seasonal variation in aromatics content for both

RFG and CG. This variation can be seen in Figure 3, which shows average RFG and CG aromatics content,

estimated from reporting system data, by production quarter. Although this yearly cyclical variation in RFG

aromatics diminished with the transition to the Phase II RFG standards in 2000, it is still apparent.

RFG Aromatics by PADD

Table 1 shows 2004 and 2005 reporting averages by PADD for PADD I, II and III refiners. These

averages were calculated from batch data, excluding importer batches (see “PADD Level Analysis”

appendix for additional information):

2004 & 2005 Reporting Averages by PADD-RFG Aromatics (Refiner Batches Only)

2004 2005

Season PADD Average Value

(vol %)

Gasoline Volume

(gal)*

Average Value

(vol %)

Gasoline Volume

(gal)*

Summer I 21.2 4,792,114,891 21.9 4,431,080,230

II 18.9 1,740,499,436 19.1 1,844,913,833

III 18.7 5,890,920,167 19.2 5,690,766,967

Winter I 20.4 6,489,530,475 20.7 7,081,940,665

II 17.3 2,438,403,544 18.4 2,718,751,541

III 17.9 6,059,647,031 18.0 5,766,524,033

Annual I 20.7 11,281,645,366 21.2 11,513,020,895

II 18.0 4,178,902,980 18.7 4,563,665,374

III 18.3 11,950,567,198 18.6 11,457,291,000

*Volumes exclude batches with missing values for this parameter

Table 1
102

Figures 4 and 5 show estimates of average levels by PADD in retail RFG. These averages are volumeweighted averages of the seasonal averages for each area, using gasoline volume estimates supplied in

the survey plans. In 2005, RFG surveys were conducted in 18 PADD I areas, five PADD II areas and two

PADD III areas. For Phase II RFG, survey data generally showed the highest aromatics concentrations in

PADD I RFG, as did reporting data for the two years analyzed.

Figure 4

Figure 5
103

Additional Analyses and Observations-RFG

Data analyses pertaining to RFG aromatics content are contained in the Appendix to this chapter. Several

trends or patterns are highlighted below:

 Average aromatics content of premium grade RFG has been higher than aromatics content in regular

or (from survey data) mid-grade RFG in each year and season40

 Analysis of retail data shows that aromatics content decreased from 1999 to 2000 for each gradeseason combination

Overview-Conventional Gasoline

Figure 6 shows Summer and Winter average CG aromatics levels, by reporting year. Summer and

Winter average aromatics levels peaked in 2000 and 2001 respectively. The largest year-to-year change in

Summer aromatics content occurred between 1999 and 2000, when average aromatics increased by more

than 0.8 volume percent, and the largest Winter change occurred between 2000 and 2001, when average

aromatics increased by more than 0.5 volume percent. Notably, although Summer averages decreased in

each succeeding year through 2003, averages in 2000 and subsequent years were higher than averages in

1997 through 1999. Regression analysis also indicates that a shift in Summer CG aromatics content

occurred between 1999 and 2000. This sustained Summer CG aromatics increase concurrent with a

sustained Summer RFG Phase I to Phase II aromatics decrease suggests, but does not establish that the

transition to Phase II RFG influenced CG aromatics content. Figure 3, which also shows CG aromatics

averages by production quarter, illustrates that average aromatic levels have been consistently highest

during the 2nd quarter of production, where the majority of production volume is Summer gasoline, and

these 2nd quarter averages in 2000 and succeeding years were higher than in each year prior to 2000.

40 The RFG Survey sampling plan estimates the grade market share in each area to ensure that grades are

properly represented in each survey. Errors in estimating the grade mix may contribute to inaccuracies in individual

survey estimates of property averages and, in turn, contribute to inaccuracies in survey-based estimates of overall

average property values. EPA does not believe that incorrect estimates of grade mix are the major cause of

differences between survey-based and reporting system based aromatics estimates, since the same directional

differences are apparent when 1997 through 1999 regular and premium grade survey averages and reporting

averages are compared on a grade by grade basis (see appendix).
104

Figure 6

Although EPA has no CG data from a second source comparable to the RFG Surveys, the disparity

between RFG Survey and reporting system-based estimates of aromatics raises the level of uncertainty in

conclusions about CG trends based on reporting system data. Since EPA cannot explain why these

differences occurred, and since the differences appear to be somewhat systematic, EPA cannot rule out

the possibility that this is indicative of an issue with the reporting system data that may affect both RFG

and CG.

CG Aromatics by PADD

Table 2 shows 2004 and 2005 reporting averages by PADD for PADD I, II and III refiners. These

averages were calculated from batch data, excluding importer batches (see “PADD Level Analysis”

appendix for additional information):

2004 & 2005 Reporting Averages by PADD-CG Aromatics (Refiner Batches Only)

2004 2005

Season PADD Average Value

(vol %)

Gasoline Volume

(gal)*

Average Value

(vol %)

Gasoline Volume

(gal)*

Summer I 28.4 3,721,549,054 28.9 3,520,575,616

II 28.7 11,333,095,661 28.6 10,443,353,793

III 27.3 21,712,599,435 27.0 20,882,654,793

Winter I 24.0 3,455,187,610 24.6 4,011,434,950

II 25.1 13,146,020,260 24.5 13,428,549,183

III 24.1 23,618,763,665 24.5 22,432,331,959

Annual I 26.2 7,176,736,664 26.6 7,532,010,566

II 26.8 24,479,115,921 26.3 23,871,902,976

III 25.6 45,331,363,100 25.7 43,314,986,752

*Volumes exclude batches with missing values for this parameter

Table 2
105

Additional Analysis and Observations-CG

The aromatic content of Summer Baseline Gasoline, as specified in the Clean Air Act, is 32.0 volume

percent, and the aromatic content of Winter baseline gasoline, as specified by EPA's regulations, is 26.4

volume percent. Data analyses pertaining to CG aromatics are contained in the Appendix to this chapter.

These data include tabular and graphical descriptions of CG aromatics content by volume and grade which

show:

 In 1997, the first year for which aromatics reporting data were analyzed, the median Summer

aromatics content was 26.9 volume percent and the 1990 baseline gasoline fell between the 75th and

80th percentile.

 In 2005, the last year for which aromatics reporting data were analyzed, the median Summer

aromatics content was 27.4 volume percent and the 1990 baseline gasoline fell between the 75th and

80th percentile.

 In 1997 the median Winter aromatics content was 24.3 volume percent and the 1990 baseline gasoline

fell between the 60th and 65th percentile.

 In 2005 the median Winter aromatics content was 24.2 volume percent and the 1990 baseline gasoline

fell between the 65th and 70th percentile.

 The aromatics content of premium grade CG has been higher than that of regular grade in each year

and season.
106

Olefins

Background

Olefins are a class of hydrocarbons found in gasoline. Olefins content, in volume percent, is an

input parameter for the Complex Model. The gasoline blending component from the Fluid Catalytic

Cracking (FCC) unit often has a high olefin concentration. Olefins are desirable gasoline constituents

because of their octane characteristics but, according to the Complex Model, NOx and exhaust toxics

emissions increase with olefin content. The model predicts that exhaust VOCs will decrease as olefin

content increases.

Regulatory Limits on Olefin Content

EPA's RFG and Anti-Dumping regulations have imposed both direct and indirect limits on gasoline

olefin content. The Simple Model, applicable to RFG through 1997, did not consider the effect of olefins

on emissions. However, the annual average olefin content was not allowed to exceed a refinery's or

importer's 1990 olefins baseline level. Currently, the olefin content of RFG is directly limited by a 25.0

volume percent maximum Complex Model range limit intended to ensure the validity of the model's

emission performance estimates. The olefin content of RFG and CG was indirectly limited through

Complex Model-based limits on RFG and CG emissions since Complex Model NOx and exhaust toxics

increase with increasing gasoline olefin content. Regulatory changes eliminating these emission limits

have or will remove these indirect constraints.

Prior to 1998, the annual average olefins level in CG was not allowed to exceed 125% of a

refinery's or importer's 1990 baseline. For 1998 and later, CG was required to have annual average

Complex Model emissions of exhaust toxics and NOx that did not exceed the refiner or importer's 1990

baselines for these emissions. Additionally, annual average CG olefins levels were not allowed to exceed

the greater of the Complex Model valid range limit for CG olefins (30.0 volume %) or the refiner or

importer's 1990 olefins baseline.

EPA's Olefins Data

Olefins data for both RFG and CG have been and are currently necessary to determine compliance

with EPA's regulations. Refiners and importers have been required, since 1995, to submit this information

to EPA's RFG/Anti-Dumping reporting system for each batch of gasoline refined or imported. Additionally,

since 1998, EPA has received RFG Survey data on the olefins content of RFG sold at gasoline stations.

(Since olefins content was not part of the Simple Model, it was not needed to determine compliance with

survey standards until 1998).

Olefins Trends

Overview-Reformulated Gasoline

Figures 1 and 2 show Summer and Winter volume-weighted average RFG olefins, by year.

Although the reporting-based production and survey-based retail trendlines are somewhat different, EPA

has not identified any pervasive problem with either set of olefins data. As with the aromatics estimates,

EPA believes that estimates from both sets of data must be considered unless a clear problem can be

identified in one or the other data sets.
107

Figure 1

Figure 2

The reporting system data show decreases in average olefin content between 1997 and 1998 for

both Summer and Winter RFG. The 1997 Summer average is higher than in any of the succeeding years

while the 1997 Winter average is not. Although EPA analyzed only a single year of Simple Model RFG

olefins data, there is some basis for concluding that these decreases were in response to EPA's Complex

Model requirements. Close to four percent of both Summer and Winter RFG supplied in 1997 would not

have meet 1998 requirements because it did not meet the Complex Model's 25 volume percent olefin

content range limit restriction, applicable to each RFG batch. (The graphical and tabular data in the

appendix to this chapter show shifts in both "RFG olefins by gasoline volume" distributions between 1997

and 1998.)

Additionally, the Complex Model recognized the emission benefits of olefin reduction, and some
108

suppliers may have reduced olefins in order to meet 1998 NOx and toxics performance standards. The

transition from Simple Model to Complex Model standards affected sulfur content in a similar but much

more substantial manner. (While Summer and Winter olefins content decreased by about 11% and 5%,

sulfur content decreased by about 30% and 19%, respectively.) In addition to the parallel regulatory

factors cited above, olefin reductions may also have occurred as a result of refining and blending processes

used to reduce sulfur content. As noted in the Sulfur Chapter, refineries have, in the past, largely relied on

a process called hydro treating to reduce sulfur, when necessary. In addition to lowering sulfur content,

hydro treating may also have reduced olefins.

The survey-based estimates of Summer olefin content suggest that a downward shift occurred

between 1999 and 2000 with the transition from Phase I to Phase II, superimposed on an upward trend.

Although the reporting data also show a decrease in olefin content between 1999 and 2000, it is not

distinguishable from other year to-year changes. By contrast, EPA concludes that, for Summer RFG, both

data sets clearly show all other Complex Model parameters, except oxygen, shifted between 1999 and

2000. Neither of the Winter estimates suggest that olefin content changed in response to this transition.

Analysis based on RFG Survey property averages presented in the RFG Trends Chapter indicates

that, even for Summer RFG, the 1999 to 2000 olefin reduction provided only a small portion of the total

Phase I to Phase II RFG NOx and toxics emission reduction.

In summary, olefin content reductions apparently had a small role in meeting Phase II standards,

and conversely, the transition from Phase I to Phase II RFG probably had a limited effect on RFG olefins

content.

RFG Olefins by PADD

Table 1 shows 2004 and 2005 reporting averages by PADD for PADD I, II and III refiners. These averages

were calculated from batch data, excluding importer batches (see “PADD Level Analysis” appendix for

additional information):

2004 & 2005 Reporting Average by PADD-RFG Olefins (Refiner Batches Only)

2004 2005

Season PADD Average Value

(vol %)

Gasoline Volume

(gal)*

Average Value

(vol %)

Gasoline

Volume (gal)*

Summer I 13.0 4,792,114,891 13.3 4,431,080,230

II 5.3 1,740,499,436 4.7 1,844,913,833

III 11.2 5,890,920,167 12.5 5,690,766,967

Winter I 12.9 6,489,530,475 13.0 7,081,940,665

II 4.9 2,438,403,544 5.3 2,718,751,541

III 11.4 6,059,647,031 11.0 5,766,524,033

Annual I 12.9 11,281,645,366 13.1 11,513,020,895

II 5.0 4,178,902,980 5.1 4,563,665,374

III 11.3 11,950,567,198 11.7 11,457,291,000

*Volumes exclude batches with missing values for this parameter

Table 1

Figures 3 and 4 show estimates of average levels by PADD in retail RFG. These averages are volumeweighted averages of the seasonal averages for each area, using gasoline volume estimates supplied in
109

the survey plans. In 2005, RFG surveys were conducted in 18 PADD I areas, five PADD II areas and two

PADD III areas. The survey data show that olefins content is consistently lowest in PADD II RFG, as do

reporting data for the two years analyzed.

Figure 3

Figure 4

Additional Analysis and Observations-RFG

Data analyses pertaining to RFG olefins are contained in the Appendix to this chapter. Grade

specific analyses show that average olefins content in premium grade RFG has been consistently lower

than in regular RFG.
110

Overview-Conventional Gasoline

Figure 5 shows volume-weighted average CG olefins levels, by reporting year. These levels

decreased from 1997 to 1998, concurrent with the transition from annual average olefin content standards

to Complex Model-based annual average exhaust toxics and NOx emission standards. However, by 2001

both Summer and Winter olefin levels peaked above 1997 values, prior to decreasing through 2004. The

standard change described earlier probably represented an increase in stringency that could have

influenced the 1997 to 1998 olefin content decrease It is not readily apparent if, or how, the latter

movements in CG olefin averages relate to regulatory requirements.

Figure 5

CG Olefins by PADD

Table 2 shows 2004 and 2005 reporting averages by PADD for PADD I, II and III refiners. These averages

were calculated from batch data, excluding importer batches (see “PADD Level Analysis” appendix for

additional information):

2004 & 2005 Reporting Average by PADD-CG Olefins (Refiner Batches Only)

2004 2005

Season PADD Average Value

(vol %)

Gasoline Volume

(gal)*

Average Value

(vol %)

Gasoline Volume

(gal)*

Summer I 12.83 3,721,549,054 12.67 3,520,575,616

II 8.82 11,333,095,661 9.63 10,443,213,355

III 12.20 21,712,599,435 12.80 20,882,654,793

Winter I 15.66 3,455,187,610 14.78 4,035,235,552

II 8.60 13,155,255,287 9.45 13,434,249,988

III 12.18 23,618,763,665 12.07 22,432,331,959

Annual I 14.19 7,176,736,664 13.80 7,555,811,168

II 8.70 24,488,350,948 9.53 23,877,463,343

III 12.19 45,331,363,100 12.42 43,314,986,752

*Volumes exclude batches with missing values for this parameter

Table 2
111

Additional Analysis and Observations-CG

The olefin content of Summer Baseline Gasoline, as specified in the Clean Air Act, is 9.2 volume

percent, and the olefin content of Winter baseline gasoline, as specified by EPA's regulations, is 11.9

volume percent. Data analyses pertaining to CG olefins are contained in the Appendix to this chapter.

These data include tabular and graphical descriptions of CG olefins content by volume and grade which

show:

 In 1997, the first year for which olefins reporting data were analyzed, the median Summer olefin

content was 11.8 volume percent and the 1990 baseline gasoline fell between the 30th and 35th

percentile.

 In 2005, the last year for which olefins reporting data were analyzed the median Summer olefin

content was 11.4 volume percent and the 1990 baseline gasoline fell at approximately the 35th

percentile.

 In 1997, the median Winter olefin content was 11.7 volume percent and the 1990 baseline gasoline fell

between the 50th and 55th percentile.

 In 2005, the median Winter olefin content was 10.8 volume percent and the 1990 baseline gasoline fell

between the 55th and 60th percentile.

 The olefin content of premium grade CG has been lower than that of regular grade in each year and

season.
112

Distillation Parameters

Background

Gasoline is a mixture of hydrocarbons which have different boiling points. Consequently, as

gasoline is heated, portions of its volume evaporate at different temperatures. The relationship between

temperature and percent of volume evaporated is referred to as a distillation curve or profile, and a test

procedure (ASTM D86) is used to determine the distillation profile of a gasoline sample. Gasoline volatility

characteristics are important because they affect both emissions and vehicle performance. The

relationship between EPA's regulatory requirements and gasoline distillation characteristics will be

discussed later in this chapter. In addition to these emission-related requirements, there are ASTM

specifications that place restrictions on distillation parameters for vehicle performance purposes. ASTM

standard D4814 defines specifications for six different Vapor Pressure/Distillation classes of gasoline which

include limits on T10, T50 and T90 (the temperatures at which 10%, 50% and 90% of the gasoline

evaporates). This standard also specifies which class of gasoline is required for each state and month of

the year. In 1998 a specification was added for the “drivability index” (DI), a formula

(1.5*T10+3.0*T50+1.0*T90) that combines these three distillation points into a number which, if too high,

indicates that the gasoline might cause performance problems. A 2006 revision of the standard, D4814-

06a, amended the formula with an upward adjustment for ethanol content

(1.5*T10+3.0*T50+1.0*T90+2.4 °F*ethanol volume%).

Regulatory Limits on Distillation Parameters

Under the Simple Model standards which applied prior to 1998, the annual average T90 level for

RFG could not exceed the refinery's or importer's 1990 baseline level. The Simple Model, itself, did not

consider the effect of any distillation profile parameters on emissions. The Complex Model, however,

included two distillation parameters, E200 and E300. These parameters are, respectively, the percent of

gasoline evaporated at 200 degrees and 300 degrees Fahrenheit. There is a strong negative correlation

between T50 and E200 and between T90 and E300. These "E" parameters are determined from the same

distillation curve as the "T" parameters. E200 and E300, like other Complex Model parameters, have

acceptable range limits (30% to 70% for E200 and 70% to 100% for E300), which are applicable to each

batch of RFG. Since E200 and E300 are part of the Complex Model, RFG and CG emission requirements,

in theory, could constrain these parameters.

Simple Model CG standards limited the annual average T90 level to 125% of the refiner's or

importer's compliance baseline. For Complex Model CG, annual average E200 and E300 were limited to

the greater of the refiner’s or importer’s 1990 baseline or the Complex Model range limit. Since gasoline's

distillation characteristics depend on its composition, any changes to or limits on gasoline composition

necessary for compliance with emission requirements potentially affect or constrain these distillation

parameters. Changes to or trends in distillation parameters over time may indicate that such composition

changes occurred.

EPA's Distillation Property Data

EPA collects data in order to determine compliance with RFG and Anti-Dumping requirements.

EPA needed T90 data through reporting year 1997, and E200/E300 data in 1998 and subsequent years.

EPA's RFG/Anti-Dumping batch reporting forms have provisions for reporting T50, T90, E200 and E300 for

each gasoline batch, and some parties chose to report distillation parameter information beyond that

needed to determine compliance with standards. EPA has restricted its analysis of batch data distillation

parameters to those that were required for compliance determination. RFG Survey data prior to 1998 did
113

not include any distillation parameter information. For 1998 and later years, the data included not only

E200 and E300 but T50 and T90; consequently survey-based estimates for all four of these parameters will

be included for 1998 and subsequent years.

Distillation Parameter Trends

Overview-Reformulated Gasoline

Figures 1 through 4 show volume-weighted E200 and E300 averages, by year. Both the reporting

system estimates, by reporting year, and the RFG Survey-based estimates, by survey year, are shown.

The reporting and survey based estimates both indicate that the largest year-to-year change in

average Summer E200 was a decrease between 1999 and 2000, concurrent with the transition from Phase

I to Phase II RFG. Regression analysis of both sets of estimates for years 1998 through 2004 indicates

that a statistically significant shift in E200 occurred at that time (see Regression Analysis Appendix).

There was little or no change in Winter E200 between 1999 and 2000.

The largest year-to-year changes in average Summer and Winter E300 were increases between

1999 and 2000, and regression analysis also indicates that statistically significant shifts in E300 occurred.

Additionally, according to both reporting and survey-based estimates, Summer and Winter E300 were

lower in 2005 than in 2000, although increases from 2004 to 2005 may indicate reversal of apparent

downward trends. Regression analysis indicates statistically significant downward linear trends through

2004 in the Summer survey-based estimates, and in both Winter estimates.
114

Figure 1 Figure 2

Figure 3 Figure 4
115

Figures 5 and 6 show volume-weighted T50 averages, by year, estimated from RFG Survey data.

The largest year-to-year change Summer T50 was an increase between 1999 and 2000, and

regression analysis indicates that a statistically significant shift in T50 occurred. There was a much smaller

increase in Winter T50 between 1999 and 2000, and regression analysis does not indicate a statistically

significant shift. However, figure 6 shows that Winter T50 was lowest in 2004 and 2005, and regression

analysis through 2004 indicates a statistically significant downward linear trend.

Figures 7 and 8 show volume-weighted T90 averages, by year, estimated from RFG Survey data.

The largest year-to-year changes in both Summer and Winter T90 were decreases between 1999

and 2000, and regression analysis indicates that statistically significant shifts in T90 occurred. Additionally,

both Summer and Winter T90 increased between 2000 and 2004, and regression analysis indicates

statistically significant upward trends through 2004. Decreases from 2004 to 2005 may indicate reversal

of these upward trends.
116

Figure 5 Figure 6

Figure 7 Figure 8
117

In general, it is not surprising that changes in Summer RFG distillation parameters occurred

concurrent with the transition from Phase I to Phase II standards. The more stringent Phase II standards

applicable to Summer RFG necessitated a number of refining and blending changes, and these changes

may alter distillation profiles, even if it was not their intended purpose. In addition to the shifts in

distillation parameters, analyses of Summer RFG reporting and survey data concur that statistically

significant shifts in RVP, benzene, aromatics and sulfur occurred between 1999 and 2000.

Phase II requirements for Winter RFG, other than toxics performance, were not more stringent

than Phase I requirements, so there was probably less regulatory pressure for changes in composition, and

hence, less reason to expect significant changes in distillation properties. However, analysis of Winter

survey data indicates statistically significant shifts in E300, T90 and aromatics content between 1999 and

2000. Analysis of reporting data confirms the shift in E300, but does not confirm the shift in aromatics or

identify any other parameters that changed significantly between 1999 and 2000. (Reporting data were

not analyzed for T90 changes.)

Since the two data sets are in agreement with respect to E300 increase, there is little doubt that a

shift occurred between 1999 and 2000, possibly, but not necessarily, as a result of the transition to Phase

II standards. Since there is strong evidence of an E300 change, it is reasonable to assume that there was

some significant change in Winter RFG composition between 1999 and 2000, even if it was not captured in

EPA's data or identified in EPA's analysis (e.g. even if aromatics or olefins content did not change,

proportions of specific aromatics or olefins may have changed).

As noted, the analyses also indicate possible trends in distillation parameters between 2000 and

2004. As explained in the RFG Trends chapter, the major regulatory factors affecting RFG between 2000

and 2005 were the Tier 2 sulfur requirements, MSAT, and state bans on MTBE with consequent increased

use of ethanol. EPA has not undertaken a detailed analysis to identify possible causes for these apparent

trends.

RFG Distillation Parameters by PADD

Tables 1 and 2 show 2004 and 2005 reporting averages by PADD for PADD I, II and III refiners.

These averages were calculated from batch data, excluding importer batches (see “PADD Level Analysis”

appendix for additional information):

2004 & 2005 Reporting Averages by PADD-RFG E200 (Refiner Batches Only)

2004 2005

Season PADD Average Value

(% evaporated)

Volume (gal)* Average Value

(% evaporated)

Volume (gal)

Summer I 47.3 4,792,114,891 47.6 4,431,080,230

II 46.6 1,740,499,436 46.3 1,844,913,833

III 48.7 5,890,920,167 49.9 5,690,766,967

Winter I 55.4 6,489,530,475 55.6 7,081,940,665

II 58.4 2,438,403,544 56.5 2,718,751,541

III 55.8 6,059,647,031 56.7 5,766,524,033

Annual I 52.0 11,281,645,366 52.5 11,513,020,895

II 53.5 4,178,902,980 52.3 4,563,665,374

III 52.3 11,950,567,198 53.3 11,457,291,000

*Volumes exclude batches with missing values for this parameter

Table 1
118

2004 & 2005 Reporting Averages by PADD-RFG E300 (Refiner Batches Only)

2004 2005

Season PADD Average Value

(% evaporated)

Volume (gal)* Average Value

(% evaporated)

Volume (gal)*

Summer I 83.6 4,792,114,891 84.1 4,431,080,230

II 84.7 1,740,499,436 84.3 1,844,913,833

III 82.5 5,890,920,167 83.2 5,690,766,967

Winter I 85.1 6,489,530,475 85.7 7,081,940,665

II 85.7 2,438,403,544 84.7 2,718,751,541

III 83.7 6,059,647,031 84.5 5,766,524,033

Annual I 84.4 11,281,645,366 85.1 11,513,020,895

II 85.3 4,178,902,980 84.5 4,563,665,374

III 83.1 11,950,567,198 83.9 11,457,291,000

*Volumes exclude batches with missing values for this parameter

Table 2

Figures 9 through 12 show estimates of average E200 and E300 levels by PADD in retail RFG. These

averages are volume-weighted averages of the seasonal averages for each area, using gasoline volume

estimates supplied in the survey plans. In 2005, RFG surveys were conducted in 18 PADD I areas, five

PADD II areas and two PADD III areas.

Figure 9
119

Figure 10

Figure 11
120

Figure 12

Additional Analysis and Observations-RFG

Data analyses pertaining to RFG distillation parameters are contained in the Appendix to this chapter.

Overview-Conventional Gasoline

Figures 13 and 14 show volume-weighted E200 and E300 averages by year. As noted, changes in

distillation parameter averages are indicators of changes in gasoline composition which may or may not be

reflected in the data that EPA collects. EPA's analysis for this report did not extensively look for or identify

specific reasons for the observed changes in CG distillation parameters.

Figure 13
121

Figure 14

CG Distillation Parameters by PADD

Tables 3 and 4 show 2004 and 2005 reporting averages by PADD for PADD I, II and III refiners. These

averages were calculated from batch data, excluding importer batches (see “PADD Level Analysis”

appendix for additional information):

2004 & 2005 Reporting Averages by PADD-CG E200 (Refiner Batches Only)

2004 2005

Season PADD Average Value

(% evaporated)

Volume (gal)* Average Value

(% evaporated)

Volume (gal)*

Summer I 45.5 3,752,272,894 45.1 3,547,001,722

II 46.6 11,456,335,295 47.5 10,565,279,667

III 44.6 21,716,635,879 44.8 20,889,312,566

Winter I 51.5 3,482,171,831 51.0 4,063,455,417

II 52.6 13,313,565,716 52.7 13,578,145,833

III 49.7 23,627,111,420 49.3 22,444,499,833

Annual I 48.4 7,234,444,725 48.2 7,610,457,139

II 49.8 24,769,901,011 50.4 24,143,425,500

III 47.2 45,343,747,299 47.1 43,333,812,399

*Volumes exclude batches with missing values for this parameter

Table 3
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2004 & 2005 Reporting Averages by PADD-CG E300 (Refiner Batches Only)

2004 2005

Season PADD Average Value

(% evaporated)

Volume (gal)* Average Value

(% evaporated)

Volume (gal)*

Summer I 82.7 3,752,272,894 82.8 3,547,001,722

II 81.4 11,456,437,187 81.9 10,566,219,165

III 79.4 21,722,168,035 80.5 20,889,312,566

Winter I 84.4 3,482,279,645 84.4 4,063,455,417

II 84.1 13,313,789,786 84.6 13,583,692,059

III 81.8 23,627,111,420 82.6 22,444,499,833

Annual I 83.5 7,234,552,539 83.7 7,610,457,139

II 82.9 24,770,226,973 83.4 24,149,911,224

III 80.6 45,349,279,455 81.6 43,333,812,399

*Volumes exclude batches with missing values for this parameter

Table 4

Additional Analysis and Observations-CG

Data analyses pertaining to CG distillation parameters are contained in the Appendix to this chapter.
123

Emission and Emission Performance

Background

Both RFG and CG must meet certain emission-related standards tied to the Complex Model. This

model produces VOC, NOx and toxics emission estimates for "1990 technology" light duty gasoline vehicles

as a function of the gasoline parameters discussed throughout this report. The model is used to produce

two types of estimates; "milligrams per mile" emission estimates for a given gasoline formulation and

"percent reduction" emission performance estimates which compare the emissions of a given gasoline

formulation to the emissions of the 1990 "statutory" baseline gasoline whose properties are specified in

the Clean Air Act and/or in EPA's regulations. CG Anti-Dumping standards are intended to maintain the

NOx and exhaust toxics emissions qualities of the gasoline that each individual refinery or importer

produced in 1990. RFG standards require VOC (for Summer RFG), total toxics (including evaporative

benzene for Summer RFG) and NOx emission reductions from the specified 1990 baseline gasoline. The

"milligram per mile" Complex Model estimates are used to evaluate CG emission compliance and the

Apercent reduction@ estimates are used to evaluate RFG compliance.

Quantitative emissions and emissions performance estimates in this report are based on the

Complex Model. The standards applicable to gasoline in years 1998 and 1999 were based on the Phase I

version of this model, however all analyses in this report are based on the currently applicable Phase II

Complex Model. Trend analyses based on a combination of Phase I and Phase II model calculations would

provide little information on changes in the emissions qualities of gasoline since they would show the

effects of the model version change as well as the effects of actual property changes on emissions.

In addition to the Phase I and Phase II model difference, there are multiple versions of the Phase

II model. Different versions of the model as well as different baseline gasoline properties apply to

Summer and Winter gasoline. The Summer model produces different VOC and toxics estimates for VOC

Control Region 1 (Southern) and VOC Control Region 2 (Northern) RFG, because its calculation of the nonexhaust portion of these emissions varies by region. As with the gasoline property analyses, EPA

categorized data from each reporting or survey year as “Summer” or “Winter”, and separately analyzed

these data. However, while direct comparison of seasonal or regional gasoline properties is often

informative, direct comparison of emissions or emission reductions could lead to erroneous conclusions.

For example, it is incorrect to conclude that the differences between Summer and Winter model milligrams

per mile estimates in a given year are due solely or primarily to differences in the emissions characteristics

of Summer and Winter gasoline.

EPA's Complex Model was developed from several thousand emission tests collected from studies

designed to measure the effects of gasoline properties on vehicle emissions. In order to meet Clean Air

Act's RFG requirements this model was based on 1990 vehicle technology, and it has not been updated to

include newer technology vehicles. Although the model's developers used rigorous statistical analysis to

produce a sophisticated emission model, the Complex Model was intended to be used to determine if

gasoline blends complied with emission standards rather than to estimate fleet-wide emission changes

resulting from changes in gasoline.

Section 1506 of The Energy Policy Act of 2005, ("Analyses of Motor Vehicle Fuel Changes") which

amends Section 211 of the Clean Air Act, directs the Administrator of EPA to develop and finalize an

emissions model that reflects the effects of gasoline characteristics or components on emissions from

vehicles in the motor vehicle fleet during calendar year 2007. This section contains additional

requirements addressing the effects of fuel changes on emissions, including a "permeation effects" study

which will provide estimates of evaporative emission increases that could result from use of gasoline with

ethanol content in a motor vehicle. Fulfilling the requirements in this section of the Energy Policy Act

should provide analytical tools to better understand, prospectively and retrospectively, the emission

impacts of gasoline property changes.
124

In summary, the emissions and emissions performance analyses in this chapter and elsewhere in

this report provide some basis for comparing the emissions characteristics of production and retail gasoline

to standards. They are also indicators of changes in the emissions qualities of gasoline over time, without

considering changes in vehicles over time. Results allow some quantitative comparisons, and provide

some means of judging relative emissions qualities and trends. However, the "milligram per mile" and

"percent reduction" values presented here are not intended to and almost certainly do not provide an

accurate estimate of the overall emissions changes that have occurred as a result of gasoline property

changes.

Regulatory Limits on Emissions and Emissions Performance

As stated, RFG refineries and importers must meet VOC, total toxics and NOx emissions

performance standards. These standards are specified as percent reductions from emissions with a

Summer or Winter baseline gasoline (i.e. "statutory" baseline gasoline). Refiners and importers may

choose to comply with "per gallon" standards or with "averaged" standards. These averaged standards

require greater emission reductions than per gallon standards, but allow more batch to batch variability in

emissions performance. Suppliers who comply with the averaged VOC performance standard must also

meet a per-gallon minimum performance standard. There are no per-gallon minimums for toxics or NOx.

VOC standards, which are applicable only to Summer RFG, vary by VOC control region and suppliers much

designate the region for each batch. Slightly less stringent VOC standards apply to RFG containing10

volume percent ethanol supplied to the Chicago and Milwaukee areas.

Suppliers generally elect to comply with averaged standards. EPA's regulations required the RFG

surveys that generated the retail data analyzed in this report as a condition of compliance with averaged

standards. The survey regulations include requirements for VOC, toxics and NOx performance surveys,

and failure criteria for each type of survey.

Current and historic emission performance standards and requirements for RFG compliance are

contained in EPA's regulations (40 C.F.R. ‘80.41). Where relevant, averaged emission performance

standards are displayed in the graphical and tabular analyses in this report.

CG refineries and importers must meet "milligram per mile" exhaust toxics and NOx emission

standards on an annual average basis. Standards applicable to CG refineries and importers are facilityspecific and largely dependent on the Aindividual baseline@ properties and volumes of the gasoline they

supplied in 1990.

The Mobile Source Air Toxics regulations impose Aanti-backsliding@ toxics requirements on both

RFG and CG suppliers. RFG MSAT standards are total toxics performance standards and CG standards are

exhaust toxics emissions standards. Both the RFG and CG requirements are facility-specific.

EPA's Emission Data

Since 1998, refiner and importer batch reports for both CG and RFG included the Complex Model

outputs necessary for compliance determination, as well as the property information needed to determine

the Complex Model inputs. RFG Survey data submitted since 1998 has also included both Complex Model

outputs and input information. Prior to 1998 neither data source included the full set of Complex Model

input properties. Consequently, although estimates of Complex Model emission performance could have

been derived for earlier years with assumptions about the missing inputs, EPA has restricted the emissions

analyses in this report to 1998 and later.
125

EPA recalculated 1998 and 1999 Complex Model outputs for each batch and survey sample using

the Phase II model to provide a common basis for measurement of emissions trends. Additionally, both

to provide information for further analysis and to verify the accuracy of the reported results, EPA

recalculated Complex Model outputs for 2000 through 2005 CG and RFG batch data. Differences between

average estimates based on reported and calculated values were small. EPA chose to rely on calculated

emission values, rather than reported emission values for all CG analyses. However, EPA found that some

RFG blendstock (RBOB) batch reports did not contain information on the type (presumably ethanol) and

concentration of oxygenate. (While most parties report this information they are not required to do so.)

These batches contained other parameter information as well as reported emission performance values.

Since EPA could not correctly calculate emission performance for these batches but did not want to

exclude them from trend analyses, EPA used reported emission performance values for all batches in

overall RFG trend analyses. Some of the additional analyses in this chapter use calculated RFG emission

or emission performance results for the batches with complete parameter information. These results are

labeled "calculated from batch data".

The General Methodology chapter in this report notes that EPA screened the batch data in this

report and describes, in general, the procedures used to screen gasoline property data. EPA excluded

some data from the emissions analyses as well although the exclusion criteria were somewhat different.

As explained in that chapter certain batches with outlier values for one or more parameters were flagged

and excluded from distribution by volume analyses for all parameters, but not necessarily from average

calculations. Since the Complex Model has multiple parameter inputs, flagged batches were excluded from

average emission and emission performance calculations as well as distribution by volume analyses. EPA

also used maximum and minimum results from its calculated RFG emissions performance results to

estimate a range of reasonable values in order to flag emission outliers that are likely to be erroneous

values.

For gasoline property analyses, CG blendstock batches were included in averages but excluded

from property by volume distributions. CG blendstocks were excluded from all emission analyses. While

EPA's regulations include an "equivalent emissions performance" (EEP) procedure for calculating Complex

Model emissions for these blendstock batches, this procedure is for compliance purposes and inclusion of

these EEP batches in emissions analyses would not necessarily produce better trend estimates.

(Additionally, it would have been difficult for EPA to replicate these EEP calculations.)

Emission and Emission Performance Trends

Overview-Reformulated Gasoline

The VOC and NOx performance standards applicable to Summer RFG and the toxics standard

applicable to both Summer and Winter RFG became more stringent in 2000 with the transition from Phase

I to Phase II RFG standards. Analyses of both reporting and survey data confirmed improvements in

performance concurrent with this transition. Figures 1 through 3 show the Summer RFG performance

trend lines derived from both reporting and survey data. (These performance trend lines were also

presented in the "RFG Trends" chapter). Since Phase I Summer RFG, on average, did not meet either the

averaged or per-gallon Phase II VOC and NOx standards, an improvement in average performance was

necessary. Summer toxics performance clearly improved as well, even though Phase I RFG, on average,

over-complied with the Phase II standard. An analysis presented in the RFG Trends chapter illustrates

one probable reason for this toxics performance improvement. This analysis shows that certain of the RFG

property changes that reduced VOC and/or NOx emissions also reduced toxics emissions. Even if the

toxics standard had not become more stringent with Phase II, the more stringent VOC and NOx standards

would have forced certain property changes beneficial to toxics performance. RFG emission performance
126

standards applied on a refinery or importer-specific basis and, unlike oxygen and benzene content

standards, could not be met through the transfer of credits. Consequently, even though Phase I Summer

RFG on average, over-complied with the Phase II toxics standard, it is probable that performance also

improved because some refiners and importers did not meet Phase II toxics performance standards during

Phase I and would not have met the toxics performance standard solely through property changes

necessary for Phase II VOC and NOx compliance. EPA did not analyze the data on a facility-specific basis,

however EPA did determine that average benzene levels dropped with the transition to Phase II. Benzene

content reductions lower Complex Model toxics emissions but do not directly affect VOC or NOx emissions,

suggesting that some suppliers reduced benzene content in order to improve toxics performance. (See the

Benzene Chapter).

The Summer RFG trend lines also show, on average, significant over-compliance with the current

NOx and toxics performance standards, but very little VOC compliance margin. The survey data shows

the best NOx performance in 2005 and the reporting data in 2004, and the improvement in NOx

performance since 2000 is the result of the mandated Tier 2 gasoline sulfur reductions. 41 These

reductions were necessary to enable the emission control systems in "new technology" Tier 2 vehicles to

be fully effective. However, the improvement in Complex Model NOx emission performance suggests that

these sulfur reductions have reduced NOx emissions in older vehicles using RFG as well. Although sulfur

reductions, all else constant, also lower VOC and toxics emissions, the trend lines through 2005 do not

show any performance benefits. Analyses presented in the RFG Trends Chapter demonstrated that the

VOC and toxics emission benefits of sulfur reductions between 2000 and 2005 were offset by changes in

other properties that increased VOC and/or toxics emissions.

The data are more equivocal about Winter RFG performance. Figures 4 and 5 show that both

reporting and survey average estimates indicate better Winter NOx and toxics performance in 2000 than in

1999. However only the survey estimates suggest that the transition from Phase I to Phase II RFG

standards had a strong influence on Winter RFG emissions performance, since the reporting system

performance improvements concurrent with this transition are not markedly different from other year-toyear performance changes. These trend lines show that Phase I Winter RFG, on average, substantially

over-complied with Phase II Winter NOx and toxics emission Aaveraged@ performance standards.

Additionally, after adjusting the Phase I standards to the Phase II model, it is apparent that for Winter RFG

only the toxics standard, which is applicable on an annual average basis, became more stringent in Phase

II. Consequently, while EPA's aggregate data analysis did not rule out the need for Phase II performance

improvements in Winter RFG, it did not indicate that emission performance improvements were necessary.

The disparity between the reporting and survey estimates leaves some question about the effect

of the Phase II requirements on Winter RFG. Although there is some rationale for relying more heavily

on reporting data to estimate overall averages, there are also reasons to consider survey-based estimates

as well. The issue of disparity between reporting and survey estimates has been discussed in the chapter

on aromatics. Since aromatics content is an important parameter in Complex Model NOx and toxics

emissions calculations, differences between reporting and survey aromatics content estimates are likely to

be strongly related to differences in performance estimates.

While there is some divergence in the middle, the beginning and end-points of the reporting and

survey-based trend estimates are in better agreement for both NOx and toxics. Both NOx lines show

approximately the same performance improvement between 1998 and 2005. The increased rate of

improvement between 2003 and 2005 almost certainly resulted from the phased reduction in gasoline

41 A “ratchet” of the RFG NOx standards in 2002 and 2003, resulting from a 2001 NOx survey failure in Sussex

County, DE may have had a minor effect on overall post-2000 NOx performance. These more stringent (by 1%)

average NOx reduction standards applied to refineries that supplied RFG to this area.
127

sulfur standards beginning in 2004. Both toxics estimates concur that toxics performance in 2005 was

better than in 1998 and 1999, and that toxics performance improved from 2003 to 2005.

Figure 1

Figure 2
128

Figure 3

Figure 4
129

Figure 5

Additional Analyses and Observations-RFG

VOC Emissions and Emission Performance

Figure 6 shows the exhaust and non-exhaust components of Complex Model VOC emissions

expressed in milligrams per mile, rather than as percent reductions. The Phase II Complex Model

attributes about 69 percent of Phase I and about 72 percent of Phase II Summer RFG VOC emissions to

exhaust emissions. While both exhaust and non-exhaust emissions were reduced in order to meet Phase

II VOC standards, non-exhaust emission reductions accounted for about 63% of the total reduction. The

Complex Model estimates non-exhaust VOC emissions from gasoline RVP (and the VOC control region

specification). All Complex Model input parameters except benzene affect Complex Model exhaust VOC

emissions. In addition to producing the non-exhaust VOC reductions, RVP reductions contributed to

exhaust VOC reductions. Consequently, RVP reduction was critical to meeting Phase II VOC reduction

standards.

Figure 6
130

The emission estimates in Figures 1 and 6 reflect a composite of RFG designated for VOC Control

Region 1 and VOC Control Region 2. Figure 7 shows VOC emission performance, based on the VOC

control region specified for each batch, and calculated with the appropriate regional version of the Phase II

Complex Model. The Region 2 data include some "adjusted VOC" ethanol-oxygenated RFG supplied to

Chicago and Milwaukee, although this RFG may be under-represented because of data screening. This

graph correctly suggests that there was a substantial difference between Region 1 and Region 2 VOC

performance prior to 2000 and that both improved between 1999 and 2000, narrowing the gap. However,

as explained earlier, it is important to interpret region-to region emission comparisons correctly.

Figure 7

Since the Complex Model evaluates the non-exhaust portion of VOC emissions differently

depending on the VOC Control Region, these composite emissions reflect, to some degree, a geographic

effect related to temperature, as well as the effects of the gasoline properties on emissions. In order to

remove this geographic effect, non-exhaust VOC emissions for VOC Region 1 batches were recalculated

using the VOC Region 2 model. This allows a side-by-side comparison of the property-related VOC

emission differences between these two types of RFG. Figure 8 shows, on average, that the propertyrelated emission characteristics of these two types of RFG, which differed during Phase I primarily because

of non-exhaust emissions, became essentially the same after the Phase II standards took effect.

Figure 8
131

The Energy Policy Act of 2005 requires that EPA consolidate the RFG regulations applicable to VOC

Control Region 1 and VOC Control Region 2 by eliminating the less stringent requirements applicable to

VOC Control Region 2 and instead applying the more stringent requirements applicable to VOC Control

Region 1 (‘1504(c)). The VOC performance standard for VOC Control Region 1 (29.0 percent "averaged"

reduction) is numerically more stringent than the Region 2 standard (27.4. percent except for "adjusted

VOC" gasoline supplied to Chicago and Milwaukee). While there is an apparent 1.6 percent difference in

stringency between the two standards, in fact, as the above analysis suggests, there is little or no real

difference in stringency. To confirm this, EPA evaluated the Complex Model VOC performance of 4194

individual Summer RFG formulations reported in 2004 batch reports, using the Region 1 and Region 2

versions of the Complex Model. These batches were a mix of Region 1 and Region 2 RFG. When all

formulations were evaluated with the Region 1 model the average performance was 29.2 percent, and

when evaluated with the Region 2 model average performance was 27.7 percent. The 1.5 percent

difference between the two performance averages is nearly the same as the difference between the

Region 1 and the unadjusted Region 2 standards, demonstrating that most of this apparent difference in

stringency is due to differences between the Region 1 and Region 2 models.

Figure 9 shows exhaust, non-exhaust and total VOC milligram per mile emissions plotted as

differences from year 2000 emissions. Both exhaust and non-exhaust emissions changes between 2000

and 2005 are clearly very small compared to changes from 1999 to 2000. Exhaust emissions are lower in

2005 than in 2000, while non-exhaust emissions are higher in 2005 than in 2000. In particular, the

exhaust emission decreases between 2002 and 2005 were nearly offset by non-exhaust emission

increases.

Figure 9

These opposing movements in exhaust and non-exhaust VOC emissions provide tenuous evidence

of a trend because of their small magnitude and short duration. However, additional factors suggest that

they may represent something other than random fluctuations. The VOC emission performance trend

lines (Figures 1 and 6) show that VOC compliance margins are small especially when compared to NOx

and toxics compliance margins, indicating that RFG's VOC emission performance standards are more

constraining than these other RFG standards. It was suggested in the RVP chapter that suppliers would

strive to increase RVP in Summer RFG, but that RVP was constrained by the VOC performance standard.

Summer RFG sulfur levels decreased continuously from 2002 to 2005 as a result of the Tier 2 gasoline
132

sulfur requirements, and these sulfur reductions were partially responsible for exhaust VOC reductions.

Although these sulfur reductions could have provided additional VOC compliance margin, refiners may

have chosen to take back this additional compliance margin by raising RVP. This is generally consistent

with an analysis, based on 2000 and 2005 RFG Survey property estimates, presented in the RFG Trends

chapter. It showed that VOC emission reductions due primarily to sulfur decreases were offset by VOC

increases due primarily to RVP increases. This is also somewhat consistent with assumptions that EPA's

Mobile 6.2 model makes when modeling the impact of an RFG program. This model assumed an RVP

increase from 6.7 to 6.8 psi in RFG beginning in 2003 as a result of the Tier 2 gasoline sulfur program

(Brzezinski, 2001).

It is important to recognize that even if the Tier 2 reductions in sulfur content do interact with RFG

requirements in ways that affect how refiners meet RFG standards, the resultant property changes may be

small (e.g. RVP increased by slightly more than 0.1 psi between 2000 and 2005, and other factors, such as

the implementation of the Chicago/Milwaukee "adjusted VOC" standards contributed to this increase).

Moreover, even if the sulfur reductions do cause changes in RFG composition, it does not necessarily follow

that RFG's overall emissions impact would be adversely affected.

Toxics Emissions and Performance

The Complex Model estimates emissions of exhaust benzene, non-exhaust benzene, acetaldehyde,

formaldehyde, 1, 3 Butadiene and polycyclic organic matter (POM). It sums these estimates to estimate

total toxics and makes no adjustments for the different potencies of these toxic pollutants. The Winter

Complex Model assumes that non-exhaust benzene emissions are zero. Figures 10 and 11 show the

milligram per mile contribution of each of these toxic pollutants to RFG toxics emissions, and exhaust

benzene is the major contributor to both Summer and Winter toxics emissions.

Figures 12 and 13 show each toxics component and total toxics plotted as milligram per mile

changes from the 1998 estimates. The change in exhaust benzene emissions over time was the major

component of the toxics emission trends for both Summer and Winter RFG. Changes in several gasoline

parameters, including but not limited to gasoline benzene content, have had significant effects on RFG

benzene emissions. Analysis based on RFG Survey data presented in the RFG Trends chapter showed

that aromatics, sulfur, and benzene content reductions accounted for much of the Phase I to Phase II

toxics reduction in Summer RFG and that sulfur reductions produced further toxics reductions between

2000 and 2005. These content changes, all else constant, lower exhaust benzene emissions.

Figures 12 and 13 also show that recent increases in acetaldehyde emissions have partially offset

decreases in benzene emissions. These acetaldehyde emission increases probably resulted from

increased use of ethanol in place of MTBE. RFG ethanol use increased substantially between 2002 and

2005 concurrent with these acetaldehyde increases. (See the RVP Trends and Oxygenates chapters.)

The Complex Model, for toxics emissions calculations only, considers not only the amount of oxygen but

the specific oxygenate(s) used. According to the Complex Model, adding any oxygenate to gasoline, all

else constant, will reduce certain toxics, including exhaust benzene. Additionally, use of any oxygenate

may further reduce toxics emissions because of dilution of and/or substitution for gasoline components

that adversely affect toxics emissions. However, the Complex Model predicts that specific oxygenates will

have different effects on certain of the constituent toxics in the total toxics calculation. It predicts that

acetaldehyde emissions increase as ethanol content increases and also as MTBE content decreases. The

model indicates no relationship between ethanol and formaldehyde emissions, but predicts a positive

relationship between MTBE content and formaldehyde emissions. However, EPA's analysis did not find

formaldehyde emission decreases concurrent with the substantial decrease in MTBE use. This lack of

correlation between MTBE reduction and formaldehyde emission reduction can occur since all Complex

Model toxics are functions of multiple parameters.
133

Analyses in the Chapter Appendix

The chapter appendix contains additional RFG analyses which treat the Complex Model emission

performance parameters in the same manner as the gasoline property parameters addressed in other

chapters, including grade-to-grade and geographic comparisons. Since these emission performance

comparisons connote that some RFG is better than other RFG, some further discussion is warranted.

There are patterns in grade-to-grade emissions performance. For example, on average, premium

gasoline exhibited consistently better Summer and Winter NOx performance than regular or mid-grade

gasoline. This is probably largely due to lower sulfur and olefins levels in premium RFG (see the sulfur and

olefins chapters). These differences were largely due to refining and blending practices needed to meet

the octane requirements of each gasoline grade. Although the Complex Model may have identified

premium RFG as being, in certain respects, a "cleaner" gasoline than other grades of RFG, it does not

necessarily follow that significant environmental benefits would occur with increased use of premium

gasoline in vehicles that do not need premium gasoline

The grade-to-grade differences may have been affected, to an extent, by some refiner decisions to

market a low sulfur premium grade gasoline in advance of Tier 2 sulfur reduction standards. EPA's

analysis for this report did not isolate and compare the Complex Model emissions performance of gasoline

brand/grade combinations explicitly marketed as "cleaner" to that of other of the same grade. However,

it is quite possible that such produced lower emissions than other of the same grade.

RFG emissions performance varied geographically, even for RFG covered by the same regionspecific standards. Although some areas received better RFG than others, by various Complex Model

emission performance measures, EPA's regulations, in particular its RFG Survey requirements, ensured that

each area received Agood@ RFG.
134

Figure 10 Figure 11

Figure 12 Figure 13
135

Overview-Conventional Gasoline

Figures 14 through 17 show exhaust toxics and NOx emission trend lines for CG. Since CG

standards are facility-specific these graphs, unlike the RFG trend graphs, do not show standards.

However the graphs show the seasonally-appropriate 1990 baseline gasoline emission value, which

provides some basis for comparison. In all cases, average emission levels have been lower than these

baseline emission levels.

For each pollutant-season combination the lowest emission levels were in 2004 or 2005 and the

largest year-to-year changes were emission decreases between 2003 and 2004. These changes were

concurrent with the large gasoline sulfur reductions that resulted from the phase in of Tier 2 gasoline

sulfur standards. EPA's analysis did not investigate the extent to which individual emission parameters

influenced CG emissions, but it is virtually certain that these sulfur reductions were the primary cause of

CG emission reductions.

Additional Analysis and Observations-CG

The Phase II Complex Model exhaust toxics emission rate for 1990 Summer Baseline Gasoline is 80.10

milligrams per mile and the exhaust toxics emission rate for 1990 Winter Baseline Gasoline is 120.55

milligrams per mile. The appendix to this chapter includes tabular and graphical descriptions of CG

emission rates which show:

 In 1998, the first year for which Complex Model emissions were analyzed, the median Summer

exhaust toxics emission rate was 70.6 mg/mi and the 1990 baseline gasoline fell between the 80th and

85th percentile.

 In 2005, the last year for which Complex Model emissions were analyzed, the median Summer exhaust

toxics emission rate was 66.7 mg/mi and the 1990 baseline gasoline fell between the 85th and 90th

percentile.

 In 1998, the median Winter exhaust toxics emission rate was 107.5 mg/mi and the 1990 baseline

gasoline fell between the 80th and 85th percentile.

 In 2005, the median Winter exhaust toxics emission rate was 100.8 mg/mi and the 1990 baseline

gasoline fell between the 85th and 90th percentile.

The Phase II Complex Model NOx emission rate for 1990 Summer Baseline Gasoline is 1340.0 milligrams

per mile and the NOx emission rate for 1990 Winter Baseline Gasoline is 1540.0 milligrams per mile.

 In 1998, the first year for which Complex Model emissions were analyzed, the median Summer NOx

emission rate was 1323.5 mg/mi and the 1990 baseline. gasoline fell between the 55th and 60th

percentile.

 In 2005, the last year for which Complex Model emissions were analyzed, the median Summer NOx

emission rate was 1234.0 mg/mi and the 1990 baseline gasoline fell between the 85th and 90th

percentile.

 In 1998, the median Winter NOx emission rate was 1489.4 mg/mi and the 1990 baseline gasoline fell

between the 60th and 65th percentile.

 In 2005, the median Winter NOx emission rate was 1386.2 mg/mi and the 1990 baseline gasoline fell

between the 90th and 95th percentile.
136

Figure 14 Figure 15

Figure 16 Figure 17
137

Comparison of RFG and CG Emissions and Performance

To facilitate comparison of RFG and CG Complex Model emission qualities, EPA has evaluated RFG

exhaust toxics and NOx "milligram per mile" emissions, and CG VOC, total toxics and NOx Apercent

reduction@ emission performance. These results are presented in this chapter in tabular form, together

with the appropriate results for comparison. Graphical comparisons of CG and RFG emissions

performance are also presented in the Conventional Gasoline Trends chapter of this report. Since the

VOC Control Region specification, which is not provided for CG, affects Summer VOC and Summer total

toxics emissions calculations, all CG percent reduction calculations assumed VOC Control Region 2, and the

control-region dependent CG results are compared to VOC Control Region 2 RFG.

It is apparent from these tables that CG, at least since 1998, has been "cleaner" than 1990

baseline gasoline. RFG has provided substantial additional emission benefits relative to CG in each year

and season although improvements in CG emissions have narrowed the gap between RFG and CG

The largest improvements in Summer and Winter CG emission performance for all pollutants

occurred between 2003 and 2004, concurrent with the largest sulfur reductions. NOx performance is

particularly sensitive to sulfur content. However, even though CG sulfur levels in 2004 dropped to levels

comparable to or below those of Apre Tier 2” RFG, the average NOx performance of 2005 Summer CG was

slightly worse than the "averaged" standard for RFG. Winter CG, in each year since 1998, has met the

Winter RFG NOx 1.5% averaged performance standard.

It is not the intent of this report to extrapolate these data to estimate RFG or CG emission levels

when the Tier 2 sulfur reductions are fully implemented. However, CG NOx performance will likely

improve and the gap between RFG and CG NOx performance may decrease, but not necessarily disappear,

as further sulfur reductions occur. Although analysis or detailed discussion of the air quality benefits

associated with these emission reductions is also beyond the scope of this report, it is reasonable to expect

that any incremental RFG NOx reductions beyond the RFG standards or CG performance levels may

translate into tangible air quality benefits. This is clearly the case for Summer RFG in areas that need to

achieve additional NOx reductions in order to attain ambient ozone standards. Winter RFG overcompliance may also be important because NOx plays a role in secondary particulate formation.

Complex Model RFG and CG Exhaust Toxics and NOx Emissions in Milligrams Per Mile

(Calculated from Batch Data)

Summer

RFG

Summer

CG

Summer

RFG

Summer

CG

Winter

RFG

Winter

CG

Winter

RFG

Winter

CG

Year Exhaust toxics NOx Exhaust toxics NOx

1998 59.0 72.5 1273 1326 90.5 110.2 1446 1492

1999 59.1 73.0 1277 1331 90.8 110.9 1456 1502

2000 55.3 73.5 1218 1334 90.0 110.4 1450 1500

2001 56.0 73.6 1228 1333 89.8 112.4 1445 1509

2002 55.7 72.6 1221 1327 89.7 110.7 1436 1500

2003 55.5 73.0 1214 1325 89.5 109.6 1427 1483

2004 55.7 68.7 1202 1253 88.0 104.4 1392 1423

2005 56.3 69.1 1207 1250 88.0 104.8 1380 1410

1990 Statutory

Baseline

Emissions

80.1 1340 120.5 1540

Table 1
138

Complex Model CG and RFG Performance in Percent Reduction from 1990 Summer Baseline

(Calculated from Batch Data)

Summer CG Summer RFG Summer CG Summer RFG Summer CG Summer RFG

Year VOC (VOC

Region 2

Model)

VOC (VOC

Region 2

Model and

data)

Total toxics

(VOC Region

2 Model)

Total toxics

(VOC Region

2 Model and

data)

NOx NOx (all datasee note)

1998 5.8 16.2 11.0 28.9 1.1 5.0

1999 6.2 16.4 10.5 28.7 0.6 4.7

2000 5.8 27.8 9.9 33.5 0.5 9.1

2001 6.6 27.8 9.5 32.4 0.5 8.3

2002 6.2 27.5 11.0 32.8 0.9 8.9

2003 5.7 27.5 10.4 32.6 1.1 9.4

2004 7.9 27.5 15.4 32.2 6.5 10.3

2005 8.6 27.4 14.6 31.4 6.7 9.9

Phase II RFG

Averaged

Standards

27.4

VOC region 2

21.5

Annual

Standard

6.8

Table 2

Complex Model CG and RFG Performance in Percent Reduction from 1990 Winter Baseline

(Calculated from Batch Data)

Winter CG Winter RFG Winter CG Winter RFG

Year Toxics NOx

1998 8.6 25.0 3.1 6.1

1999 8.0 24.6 2.5 5.5

2000 8.4 25.3 2.6 5.9

2001 6.8 25.5 2.0 6.1

2002 8.2 25.6 2.6 6.7

2003 9.1 25.7 3.7 7.3

2004 13.4 27.0 7.6 9.6

2005 13.1 27.0 8.4 10.4

Phase II RFG Averaged

Standards

21.5

Annual Standard

1.5

Table 3
139

References

American Jobs Creation Act of 2004, Pub. L. No. 108-357, ‘301, 104 Stat 1418 (2004)

ASTM D 1319. Standard test method for hydrocarbon types in liquid petroleum products by fluorescent

indicator adsorption. ASTM International

ASTM D 4814. Standard specification for automotive spark-ignition engine fuel. ASTM International

ASTM D 5769. Standard test method for determination of benzene, toluene, and total aromatics in finished

by gas chromatography/mass spectrometry. ASTM International

Blue Ribbon Panel on Oxygenates in Gasoline (1999, September). Achieving clean air and clean water.

Brzezinski, D. (2001, April). Estimating emission effects of RFG gasoline in Mobile6. EPA Report: EPA420-R01-028, M6.FUL.005, Retrieved April 15, 2006, from

http://www.epa.gov/otaq/models/mobile6/r01028.pdf

Clean Air Act of 1990, Pub. L. No. 101-549, 104 Stat. 2399 (1990)

Energy Information Administration. (2005, June). Petroleum supply annual 2004, volume 1. Retrieved

June 20, 2006 from

http://www.eia.doe.gov/oil_gas/petroleum/data_publications/petroleum_supply_annual/psa_volum

e1/psa_volume1.html

Energy Policy Act of 2005, Pub. L. No. 109-58, 119 Stat 594 (2005)

Regulation of Fuels and Fuel Additives (2004, July). Code of Federal Regulations Title 40, Pt.80

U.S. Environmental Protection Agency (2007, April) Regulatory impact analysis: renewable fuel standard

program. EPA Report EPA420-R-07-004, Retrieved May, 2007 from

http://epa.gov/otaq/renewablefuels/420r07004.pdf

U.S. Environmental Protection Agency. (2005, November). State winter oxygenated fuel program

requirements for attainment or maintenance of CO NAAQS. EPA Report: EPA420-B-05-013,

Retrieved May 15, 2006, from http://www.epa.gov/otaq/regs/fuels/420b05013.pdf

U.S. Environmental Protection Agency. (2003, July). RFG questions and answers consolidated by topic

(Section 2: sampling and testing p.13). EPA Report: EPA420-R-03-039. Retrieved May 15, 2006,

from http://www.epa.gov/otaq/rfg_qa.htm

U.S. Environmental Protection Agency. (1995, August 22). Waiver requests under section 211(f) of the

Clean Air Act. Retrieved May 31, 2006, from

http://www.epa.gov/otaq/regs/fuels/additive/waiver.pdf
140

APPENDICES
141

Appendix to Sulfur Chapter

RFG Sulfur by Gasoline Volume

Figure 1

Summer RFG Sulfur Content (ppm) by Volume (from Batch Reports)

Reporting Year

Volume

%tile

1997 1998 1999 2000 2001 2002 2003 2004 2005

minimum 0 1 4 1 1 0 1 0 0

5% 29 35 42 25 30 26 18 10 6

10% 52 61 64 39 42 37 27 17 16

15% 74 79 82 51 51 45 37 24 22

20% 94 96 103 64 61 54 47 30 28

25% 111 113 121 74 71 62 55 37 33

30% 131 128 139 84 82 72 62 43 39

35% 150 145 153 94 90 80 71 48 44

40% 178 162 167 102 99 90 79 54 49

45% 204 176 180 112 109 99 89 60 52

50% 237 192 192 121 120 110 98 67 57

55% 265 206 207 130 129 119 107 74 62

60% 288 222 220 141 140 130 116 83 68

65% 313 237 237 149 149 140 127 91 75

70% 343 255 257 158 158 151 139 100 84

75% 387 277 278 167 169 163 150 110 93

80% 446 297 300 179 179 178 163 121 105

85% 541 321 328 191 195 197 179 132 120

90% 641 359 360 211 218 224 201 153 136

95% 793 410 413 242 253 268 239 184 164

100% 1204 499 500 479 488 472 469 331 313

Volume

(gal): 12,436,241,790 12,832,805,667 12,998,841,841 12,983,127,318 13,196,166,160 13,835,809,610 13,583,183,155 14,232,658,149 14,083,260,572
142

RFG Sulfur by Gasoline Volume (continued):

Figure 2

Winter RFG Sulfur Content (ppm) by Volume (from Batch Reports)

Reporting Year

Volume

%tile

1997 1998 1999 2000 2001 2002 2003 2004 2005

minimum 0 1 1 1 1 0 1 0 0

5% 29 33 36 33 29 29 23 14 11

10% 51 53 58 52 45 44 40 22 19

15% 69 72 81 69 61 59 54 29 25

20% 86 89 104 84 78 77 65 36 31

25% 101 106 121 99 91 97 79 43 37

30% 119 122 139 112 105 111 94 51 43

35% 137 139 155 129 117 123 108 60 49

40% 160 153 169 145 131 133 119 69 54

45% 179 168 183 163 144 145 127 79 60

50% 199 183 197 182 159 159 138 90 66

55% 219 197 214 201 174 174 150 101 72

60% 240 218 232 220 192 187 163 111 79

65% 267 239 249 240 213 209 179 125 88

70% 294 262 273 259 240 233 197 136 96

75% 328 290 297 281 266 259 220 146 107

80% 373 321 328 310 290 290 249 159 119

85% 440 353 358 343 323 321 287 173 134

90% 548 381 395 384 361 359 334 193 155

95% 717 426 429 430 417 404 390 223 192

100% 2912 499 511 496 500 499 500 337 371

Volume

(gal): 14,905,356,077 15,062,572,102 15,079,905,134 15,829,077,693 15,727,561,297 16,429,804,256 16,669,506,697 17,188,867,639 18,044,832,058
143

RFG Sulfur by Gasoline Volume (continued):

(Cumulative Distributions for Latest Year Data)

Figure 3

Figure 4
144

RFG Sulfur by Grade

Figure 5

Figure 6
145

RFG Sulfur By Grade (continued):

RFG Average Sulfur Content (ppm) and Volume (gal) by Year, Grade, and Season-from Reporting Data

Reporting Year

Grade Season Data 1997 1998 1999 2000 2001 2002 2003 2004 2005

PRM s Average 196 151 149 78 85 84 66 55 43

Volume 3,437,323,049 3,651,099,126 3,537,723,033 2,788,523,817 2,765,064,985 2,919,724,883 2,735,295,696 2,385,535,898 2,143,973,091

w Average 163 148 150 139 122 114 94 57 44

Volume 3,875,280,201 4,137,427,813 3,836,358,338 3,419,995,241 3,299,267,883 3,387,457,520 3,103,333,727 2,945,338,123 2,583,694,635

REG s Average 323 222 226 140 138 134 121 85 74

Volume 8,933,744,061 9,007,552,063 9,320,974,363 10,122,448,765 10,373,861,808 10,879,031,865 10,824,904,975 11,783,350,501 11,881,795,879

w Average 278 224 237 217 202 219 180 110 86

Volume 10,810,119,364 10,661,459,665 10,902,774,956 12,246,078,983 12,361,561,882 13,031,122,001 13,476,711,626 14,159,160,294 15,422,172,055

Users of these grade-specific property estimates calculated from RFG and Anti-Dumping data should be aware that grade-specific

estimates based on reporting data may differ from actual retail property values by grade. Although aggregate estimates from the reporting

system may also differ from actual retail property values, there are several additional reasons why these grade-specific estimates may differ. Midgrade gasoline is often blended from regular and premium gasoline at some point downstream of the refinery. Thus, some of the gasoline volume

reported and included in these tables as regular or premium would be marketed as mid-grade. Additionally, EPA's grade-specific average analysis

excludes some gasoline and blendstock that was included in aggregate average estimates. EPA has presented averages for batches labeled as

regular and premium gasoline only; excluding batches labeled as mid-grade (since these batches may not be a representative sample of gasoline

marketed as mid-grade), mix of grades, or without a grade label. EPA also excluded CG blendstock batches from grade-specific analyses even if

they had a grade designation.

The table shows the total volume, in gallons, for the batches used to calculate each grade average. In part, because of factors discussed

above these volumes are not expected to represent the actual volumes by grade of retail gasoline.
146

RFG Sulfur-Geographic

Figure 7 Figure 8
147

Conventional Gasoline

CG Sulfur by Gasoline Volume

Figure 9

Summer CG Sulfur Content (ppm) by Volume (from Batch Reports excluding Blendstocks)

Reporting Year

Volume

%tile

1997 1998 1999 2000 2001 2002 2003 2004 2005

minimum 0 0 0 0 0 0 0 0 0

5% 19 27 23 30 27 21 15 8 8

10% 41 49 44 54 47 43 30 15 17

15% 64 72 66 75 69 64 47 21 22

20% 89 100 92 97 92 85 63 27 26

25% 118 122 116 124 113 105 85 36 32

30% 150 145 146 149 135 130 117 46 38

35% 178 172 179 177 156 156 150 57 48

40% 203 204 211 203 178 182 179 68 57

45% 233 231 237 232 204 207 210 80 66

50% 264 254 264 261 232 232 240 94 76

55% 290 279 289 284 260 261 276 113 88

60% 318 308 319 311 289 294 306 129 100

65% 349 335 358 341 318 326 344 146 113

70% 385 368 393 379 353 367 379 161 132

75% 423 402 433 422 405 408 427 178 153

80% 487 449 476 490 463 466 484 198 176

85% 590 527 552 604 545 529 565 219 204

90% 725 631 669 724 680 637 678 239 233

95% 849 791 836 859 840 810 832 269 269

100% 1081 1084 1060 1081 1045 1089 1096 449 478

Volume

(gal): 39,315,348,774 39,013,838,890 37,130,899,033 36,366,550,602 38,566,421,725 40,811,809,360 43,223,878,447 43,512,526,323 42,196,228,805
148

CG Sulfur by Gasoline Volume (continued):

Figure 10

Winter CG Sulfur Content by Volume (from Batch Reports excluding Blendstocks)

Reporting Year

Volume

%tile

1997 1998 1999 2000 2001 2002 2003 2004 2005

minimum 0 0 0 0 0 0 0 0 0

5% 20 14 19 19 18 20 15 9 8

10% 42 38 43 40 39 40 26 17 15

15% 65 60 66 60 59 60 40 24 20

20% 89 80 87 80 80 79 57 30 25

25% 112 102 113 100 105 101 77 36 29

30% 136 123 138 123 134 128 98 46 34

35% 164 148 163 149 158 156 123 58 41

40% 194 172 187 176 178 182 146 72 49

45% 222 200 214 202 202 205 172 86 56

50% 253 229 238 226 227 227 199 100 64

55% 281 258 270 253 254 255 221 115 75

60% 311 289 302 284 286 279 246 133 87

65% 349 316 339 311 323 313 275 150 101

70% 388 353 381 353 364 350 309 168 118

75% 431 392 429 399 404 403 345 185 141

80% 489 438 485 449 457 458 395 204 168

85% 579 511 565 515 524 537 465 222 199

90% 704 617 660 644 617 650 586 244 232

95% 849 784 800 811 789 811 767 269 259

100% 1071 1083 1057 1086 1083 1079 1010 449 478

Volume

(gal): 44,568,243,930 46,189,100,491 47,577,145,369 47,958,091,470 48,807,540,198 49,661,093,570 47,455,096,094 47,651,820,292 48,700,780,453
149

CG Sulfur by Gasoline Volume

(Cumulative Distributions for Latest Year Data)

Figure 11

Figure 12
150

CG Sulfur-by Grade

CG Average Sulfur Content (ppm) and Volume (gal)by Year, Grade and Season-From Reporting Data

Reporting Year

Grade Season Data 1997 1998 1999 2000 2001 2002 2003 2004 2005

PRM s Average 134 120 118 114 100 85 97 51 51

Volume 6,908,485,473 6,600,159,963 6,231,165,137 4,955,635,124 4,996,778,324 5,177,600,571 5,143,196,797 4,635,507,910 4,138,979,931

w Average 117 103 110 108 101 98 81 50 44

Volume 8,304,496,529 8,193,379,471 7,668,490,252 6,627,924,003 6,554,918,975 6,568,341,755 5,507,050,392 5,077,869,493 4,508,926,779

REG s Average 368 345 361 357 337 332 334 119 107

Volume 28,005,415,849 28,380,712,680 26,617,451,271 27,335,453,049 28,964,605,205 30,992,801,780 33,051,938,207 34,605,072,844 33,851,903,439

w Average 367 330 346 329 330 330 283 123 100

Volume 32,127,505,321 32,117,523,489 33,273,916,900 35,151,238,087 35,939,854,456 36,931,713,041 35,948,070,047 37,501,622,970 39,121,167,000

Users of these grade-specific property estimates calculated from RFG and Anti-Dumping data should be aware that grade-specific

estimates based on reporting data may differ from actual retail property values by grade. Although aggregate estimates from the reporting

system may also differ from actual retail property values, there are several additional reasons why these grade-specific estimates may differ. Midgrade gasoline is often blended from regular and premium gasoline at some point downstream of the refinery. Thus, some of the gasoline volume

reported and included in these tables as regular or premium would be marketed as mid-grade. Additionally, EPA's grade-specific average analysis

excludes some gasoline and blendstock that was included in aggregate average estimates. EPA has presented averages for batches labeled as

regular and premium gasoline only; excluding batches labeled as mid-grade (since these batches may not be a representative sample of gasoline

marketed as mid-grade), mix of grades, or without a grade label. EPA also excluded CG blendstock batches from grade-specific analyses even if

they had a grade designation.

The table shows the total volume, in gallons, for the batches used to calculate each grade average. In part, because of factors discussed

above these volumes are not expected to represent the actual volumes by grade of retail gasoline.
151

Appendix to RVP Chapter

RFG RVP by Gasoline Volume

Figure 1

Summer RFG RVP Content by Volume (from Batch Reports)

Reporting Year

Volume

%tile

1997 1998 1999 2000 2001 2002 2003 2004 2005

minimum 6.03 5.95 6.18 6.34 6.19 6.19 6.35 6.34 6.33

5% 6.79 6.79 6.80 6.43 6.44 6.43 6.47 6.47 6.49

10% 6.90 6.90 6.94 6.48 6.49 6.49 6.53 6.53 6.57

15% 6.99 6.99 7.00 6.53 6.53 6.53 6.57 6.59 6.63

20% 7.05 7.05 7.05 6.56 6.57 6.57 6.62 6.65 6.69

25% 7.10 7.11 7.11 6.59 6.60 6.60 6.65 6.69 6.73

30% 7.18 7.19 7.18 6.63 6.64 6.65 6.68 6.72 6.76

35% 7.31 7.31 7.26 6.66 6.66 6.68 6.71 6.75 6.79

40% 7.49 7.57 7.45 6.69 6.70 6.72 6.73 6.78 6.83

45% 7.68 7.69 7.66 6.72 6.72 6.73 6.76 6.82 6.86

50% 7.76 7.77 7.76 6.73 6.74 6.76 6.79 6.85 6.89

55% 7.82 7.82 7.84 6.76 6.77 6.79 6.84 6.88 6.92

60% 7.88 7.87 7.89 6.79 6.81 6.82 6.86 6.91 6.96

65% 7.92 7.91 7.94 6.83 6.84 6.85 6.89 6.94 6.99

70% 7.96 7.95 7.98 6.86 6.88 6.89 6.92 6.98 7.02

75% 8.00 7.99 8.00 6.91 6.93 6.94 6.97 7.02 7.06

80% 8.04 8.03 8.04 6.94 6.98 6.99 7.02 7.06 7.11

85% 8.10 8.08 8.08 7.00 7.05 7.05 7.07 7.11 7.17

90% 8.16 8.13 8.14 7.07 7.11 7.11 7.13 7.18 7.24

95% 8.23 8.20 8.20 7.21 7.24 7.21 7.23 7.29 7.32

100% 9.22 8.41 8.65 7.75 7.75 7.76 7.69 8.96 9.95

Volume

(gal): 12,448,415,575 12,832,964,637 12,998,841,841 12,983,168,478 13,222,633,468 13,847,971,634 13,584,860,845 14,232,658,149 14,083,382,582
152

RFG RVP by Gasoline Volume (continued):

(Cumulative Distribution for Latest Year Data)

Figure 2

RFG RVP by Grade

Figure 3
153

RFG RVP by Grade

RFG Average RVP (psi) and Volume (gal) by Year, Grade – Summer only-From Reporting Data

Reporting Year

Grade Season Data 1997 1998 1999 2000 2001 2002 2003 2004 2005

PRM s Average 7.59 7.56 7.60 6.73 6.73 6.71 6.74 6.77 6.77

Volume 3,416,852,331 3,651,258,096 3,537,723,033 2,788,564,977 2,772,816,841 2,931,886,907 2,736,973,386 2,385,535,898 2,144,095,101

REG s Average 7.61 7.61 7.59 6.79 6.81 6.82 6.85 6.88 6.94

Volume 8,915,975,289 9,007,552,063 9,320,974,363 10,122,448,765 10,392,283,260 10,879,031,865 10,824,904,975 11,783,350,501 11,881,795,879

Users of these grade-specific property estimates calculated from RFG and Anti-Dumping data should be aware that grade-specific estimates based

on reporting data may differ from actual retail property values by grade. Although aggregate estimates from the reporting system may also differ from

actual retail property values, there are several additional reasons why these grade-specific estimates may differ. Mid-grade gasoline is often blended from

regular and premium gasoline at some point downstream of the refinery. Thus, some of the gasoline volume reported and included in these tables as

regular or premium would be marketed as mid-grade. Additionally, EPA's grade-specific average analysis excludes some gasoline and blendstock that was

included in aggregate average estimates. EPA has presented averages for batches labeled as regular and premium gasoline only; excluding batches

labeled as mid-grade (since these batches may not be a representative sample of gasoline marketed as mid-grade), mix of grades, or without a grade

label. EPA also excluded CG blendstock batches from grade-specific analyses even if they had a grade designation.

The table shows the total volume, in gallons, for the batches used to calculate each grade average. In part, because of factors discussed above

these volumes are not expected to represent the actual volumes by grade of retail gasoline.
154

RFG RVP-Geographic

Figure 4
155

Conventional Gasoline

CG RVP by Gasoline Volume

Figure 5

Summer CG RVP (psi) by Volume (from Batch Reports excluding Blendstocks)

Reporting Year

Volume

%tile

1998 1999 2000 2001 2002 2003 2004 2005

minimum 5.89 5.83 5.85 5.80 5.96 5.83 5.80 5.80

5% 6.94 6.99 6.96 6.88 6.89 6.89 6.87 6.82

10% 7.39 7.39 7.39 7.36 7.37 7.39 7.36 7.37

15% 7.52 7.50 7.52 7.51 7.52 7.52 7.51 7.53

20% 7.62 7.59 7.60 7.59 7.60 7.62 7.61 7.63

25% 7.73 7.67 7.68 7.67 7.68 7.69 7.69 7.72

30% 8.04 7.76 7.76 7.76 7.79 7.83 7.87 7.92

35% 8.27 8.12 8.05 8.05 8.07 8.17 8.19 8.21

40% 8.38 8.34 8.25 8.24 8.29 8.37 8.36 8.36

45% 8.46 8.44 8.39 8.37 8.40 8.47 8.46 8.46

50% 8.52 8.51 8.47 8.49 8.49 8.54 8.54 8.55

55% 8.58 8.58 8.54 8.55 8.57 8.61 8.60 8.59

60% 8.62 8.62 8.61 8.61 8.62 8.64 8.64 8.63

65% 8.66 8.66 8.65 8.65 8.67 8.69 8.68 8.68

70% 8.71 8.71 8.69 8.70 8.71 8.73 8.72 8.72

75% 8.75 8.74 8.74 8.75 8.75 8.76 8.76 8.76

80% 8.79 8.79 8.79 8.79 8.79 8.81 8.80 8.81

85% 8.84 8.83 8.82 8.84 8.85 8.85 8.85 8.85

90% 8.89 8.88 8.88 8.89 8.90 8.90 8.89 8.90

95% 8.94 8.94 8.95 8.95 8.95 8.95 8.95 8.95

100% 12.10 11.95 12.09 12.06 12.10 12.08 12.07 12.10

Volume

(gal): 39,091,550,524 37,194,647,473 36,395,981,388 38,566,835,643 40,819,234,602 43,243,575,045 43,509,104,037 42,196,228,805
156

CG RVP by Gasoline Volume (continued):

Figure 6

Winter CG RVP (psi) by Volume (from Batch Reports excluding Blendstocks)

Reporting Year

Volume %tile 1998 1999 2000 2001 2002 2003 2004 2005

minimum 5.54 5.57 5.40 5.48 5.39 5.35 5.32 5.40

5% 8.56 8.39 8.26 8.14 8.33 8.69 8.76 8.75

10% 9.49 8.89 8.81 8.74 8.82 9.81 10.07 9.81

15% 10.30 10.13 9.91 9.86 9.97 10.51 10.63 10.43

20% 10.82 10.71 10.71 10.52 10.66 10.88 10.93 10.79

25% 11.10 11.04 11.04 10.90 11.00 11.12 11.14 11.01

30% 11.32 11.26 11.23 11.14 11.21 11.29 11.31 11.23

35% 11.59 11.46 11.45 11.35 11.42 11.49 11.53 11.47

40% 11.96 11.87 11.89 11.61 11.76 11.87 11.88 11.79

45% 12.20 12.14 12.19 11.94 12.05 12.09 12.08 12.04

50% 12.39 12.35 12.40 12.20 12.26 12.27 12.23 12.21

55% 12.55 12.51 12.55 12.41 12.44 12.41 12.39 12.36

60% 12.71 12.69 12.71 12.58 12.62 12.58 12.53 12.50

65% 12.89 12.87 12.89 12.77 12.83 12.76 12.69 12.66

70% 13.10 13.07 13.09 12.99 13.04 12.99 12.89 12.83

75% 13.29 13.29 13.29 13.22 13.28 13.23 13.10 13.02

80% 13.46 13.44 13.45 13.41 13.44 13.40 13.30 13.24

85% 13.94 13.93 13.79 13.70 13.76 13.78 13.62 13.48

90% 14.29 14.31 14.25 14.24 14.26 14.26 14.25 14.07

95% 14.64 14.65 14.59 14.59 14.61 14.61 14.64 14.55

100% 16.30 16.00 15.94 16.20 15.78 16.00 15.50 15.35

Volume (gal): 46,061,502,458 45,842,624,362 41,249,911,572 48,563,137,130 48,898,338,201 41,635,803,399 39,996,766,942 38,557,421,343
157

CG RVP by Gasoline Volume (continued):

(Cumulative Distributions for Latest Year Data)

Figure 7

Figure 8
158

CG RVP by Grade

CG Average RVP (psi) and Volume (gal) by Year, Grade and Season-from Reporting Data

Reporting Year

Grade Season Data 1998 1999 2000 2001 2002 2003 2004 2005

PRM s Average 8.17 8.16 8.07 8.08 8.10 8.17 8.15 8.14

Volume 6,635,803,305 6,252,416,423 4,957,386,104 4,996,778,324 5,181,939,065 5,149,486,549 4,635,507,910 4,138,979,931

w Average 12.11 11.98 11.94 11.82 11.93 12.01 11.94 12.00

Volume 8,209,902,634 7,399,170,984 5,413,808,077 6,555,892,276 6,542,422,368 5,021,592,048 4,297,707,397 3,716,904,849

REG s Average 8.33 8.29 8.25 8.25 8.27 8.30 8.30 8.30

Volume 28,418,412,132 26,656,367,421 27,360,707,607 28,965,019,123 30,995,888,528 33,053,399,345 34,601,650,558 33,851,903,439

w Average 12.06 11.97 11.89 11.80 11.87 11.97 12.02 11.94

Volume 31,980,799,123 31,791,685,337 29,648,094,807 35,690,792,290 36,194,877,059 31,768,671,300 31,555,556,718 32,128,135,107

Users of these grade-specific property estimates calculated from RFG and Anti-Dumping data should be aware that grade-specific

estimates based on reporting data may differ from actual retail property values by grade. Although aggregate estimates from the reporting

system may also differ from actual retail property values, there are several additional reasons why these grade-specific estimates may differ. Midgrade gasoline is often blended from regular and premium gasoline at some point downstream of the refinery. Thus, some of the gasoline volume

reported and included in these tables as regular or premium would be marketed as mid-grade. Additionally, EPA's grade-specific average analysis

excludes some gasoline and blendstock that was included in aggregate average estimates. EPA has presented averages for batches labeled as

regular and premium gasoline only; excluding batches labeled as mid-grade (since these batches may not be a representative sample of gasoline

marketed as mid-grade), mix of grades, or without a grade label. EPA also excluded CG blendstock batches from grade-specific analyses even if

they had a grade designation.

The table shows the total volume, in gallons, for the batches used to calculate each grade average. In part, because of factors discussed

above these volumes are not expected to represent the actual volumes by grade of retail gasoline.
159

Appendix to Oxygenates and Oxygen Chapter

RFG Oxygen Weight Percent by Gasoline Volume (Excluding California)

Figure 1

Summer RFG Oxygen Content (wt%) by Volume (from Batch Reports)

Reporting Year

Volume

%tile

1997 1998 1999 2000 2001 2002 2003 2004 2005

minimum 1.20 1.50 1.50 1.50 1.51 1.43 1.44 1.45 1.44

5% 1.53 1.62 1.70 1.68 1.68 1.66 1.63 1.69 1.66

10% 1.58 1.67 1.72 1.73 1.72 1.74 1.71 1.76 1.72

15% 1.62 1.70 1.75 1.76 1.76 1.78 1.78 1.82 1.75

20% 1.68 1.74 1.77 1.80 1.79 1.82 1.84 1.88 1.78

25% 1.72 1.78 1.79 1.83 1.82 1.86 1.90 1.94 1.82

30% 1.78 1.82 1.81 1.88 1.85 1.89 1.94 2.00 1.87

35% 1.83 1.87 1.84 1.91 1.88 1.94 1.99 2.08 1.91

40% 1.90 1.91 1.87 1.95 1.93 2.00 2.05 2.17 1.98

45% 1.96 1.98 1.90 2.01 1.99 2.05 2.10 2.25 2.07

50% 2.00 2.02 1.93 2.07 2.05 2.10 2.15 2.35 2.19

55% 2.06 2.06 1.97 2.13 2.11 2.16 2.23 2.43 2.33

60% 2.10 2.09 2.01 2.20 2.17 2.21 2.29 2.50 2.43

65% 2.16 2.13 2.07 2.29 2.23 2.27 2.36 2.58 2.51

70% 2.25 2.17 2.13 2.37 2.31 2.35 2.42 3.31 2.67

75% 2.34 2.22 2.20 2.44 2.39 2.43 2.48 3.45 3.44

80% 2.44 2.32 2.30 2.52 2.47 2.51 2.54 3.49 3.51

85% 2.52 2.46 2.45 2.60 2.55 2.58 2.65 3.53 3.54

90% 2.65 2.64 2.62 3.42 3.31 3.40 3.48 3.57 3.59

95% 3.47 3.47 3.47 3.52 3.53 3.49 3.57 3.64 3.66

100% 3.91 3.96 3.82 3.78 4.10 4.00 4.02 3.91 3.95

Volume

(gal): 12,212,323,923 12,566,698,539 12,660,919,964 12,569,342,940 12,783,848,128 13,409,581,178 13,185,376,501 13,746,792,069 13,464,126,854
160

RFG Oxygen Weight Percent by Gasoline Volume (Continued):

Figure 2

Winter RFG Oxygen Content (wt%) by Volume (from Batch Reports)

Reporting Year

Volume

%tile

1997 1998 1999 2000 2001 2002 2003 2004 2005

minimum 1.44 1.36 1.50 1.50 1.43 1.45 1.25 1.37 1.46

5% 1.59 1.66 1.71 1.68 1.69 1.65 1.59 1.64 1.62

10% 1.64 1.70 1.74 1.73 1.72 1.70 1.64 1.70 1.68

15% 1.68 1.74 1.76 1.76 1.75 1.73 1.69 1.75 1.72

20% 1.72 1.77 1.78 1.79 1.78 1.76 1.73 1.78 1.75

25% 1.76 1.80 1.80 1.81 1.80 1.78 1.76 1.82 1.78

30% 1.80 1.83 1.82 1.83 1.82 1.80 1.79 1.85 1.81

35% 1.86 1.86 1.85 1.85 1.85 1.83 1.81 1.88 1.84

40% 1.93 1.90 1.88 1.88 1.87 1.85 1.84 1.91 1.88

45% 1.99 1.94 1.91 1.90 1.89 1.87 1.86 1.94 1.90

50% 2.04 2.00 1.95 1.93 1.91 1.90 1.90 1.99 1.94

55% 2.09 2.05 1.99 1.97 1.94 1.93 1.93 2.07 1.98

60% 2.14 2.13 2.03 2.00 1.98 1.97 1.97 2.16 2.06

65% 2.21 2.21 2.09 2.05 2.02 2.01 2.02 2.29 2.21

70% 2.31 2.32 2.16 2.10 2.08 2.07 2.09 2.44 2.39

75% 2.56 2.61 2.26 2.16 2.14 2.13 2.19 2.67 3.40

80% 2.70 2.72 2.40 2.26 2.23 2.21 2.35 3.53 3.53

85% 2.77 2.78 2.62 2.43 2.39 2.36 2.57 3.58 3.58

90% 2.87 2.89 2.82 2.64 2.58 2.66 3.53 3.64 3.65

95% 3.53 3.53 3.54 3.56 3.57 3.57 3.62 3.72 3.72

100% 3.99 4.02 3.85 3.81 4.02 3.94 4.00 4.04 3.97

Volume

(gal): 14,520,852,742 14,621,530,037 14,604,242,854 15,291,171,680 15,116,796,877 15,826,024,638 15,771,471,139 15,875,951,167 16,565,687,773
161

RFG Oxygen Weight Percent by Gasoline Volume (Continued):

Cumulative Distributions for Latest Year Data

Figure 3

Figure 4
162

RFG MTBE Content (Volume Percent) by Gasoline Volume

Summer RFG MTBE Content (Vol%) by Volume (from Batch Reports)

Reporting Year

Volume

%tile

1997 1998 1999 2000 2001 2002 2003 2004 2005

5%

10%

15% 4.95 5.11 4.42 5.66 5.18 0.20 0.06

20% 6.78 6.23 5.86 6.72 7.36 6.55 5.97

25% 8.21 8.05 7.30 8.17 8.41 8.34 7.91 0.05 0.04

30% 8.52 8.95 8.87 8.73 8.80 8.88 8.69 0.10 0.19

35% 8.72 9.13 9.36 9.05 9.11 9.17 9.01 6.30 7.68

40% 8.99 9.39 9.57 9.36 9.34 9.51 9.37 8.52 8.65

45% 9.27 9.67 9.70 9.60 9.58 9.77 9.79 9.13 9.03

50% 9.58 9.99 9.83 9.82 9.80 10.04 10.16 9.53 9.40

55% 9.94 10.35 9.99 10.10 10.09 10.34 10.55 9.92 9.62

60% 10.44 10.78 10.17 10.40 10.35 10.65 10.95 10.26 9.78

65% 10.90 11.11 10.39 10.68 10.74 11.08 11.39 10.77 10.03

70% 11.30 11.35 10.59 11.11 11.20 11.47 11.74 11.25 10.30

75% 11.59 11.57 10.89 11.56 11.64 11.83 12.19 11.81 10.65

80% 11.95 11.83 11.29 12.08 12.11 12.24 12.64 12.45 11.35

85% 12.57 12.08 11.75 12.92 12.68 12.76 13.04 13.05 12.20

90% 13.18 12.64 12.36 13.44 13.25 13.35 13.52 13.55 13.07

95% 13.81 13.75 13.52 14.02 13.74 13.91 13.98 14.00 13.72

100% 15.71 16.00 16.21 15.17 15.86 15.79 15.62 15.12 15.24

Volume

(gal): 11,977,238,567 12,553,324,899 12,608,377,199 12,574,035,936 12,783,848,128 13,409,581,178 13,168,085,773 13,749,448,485 13,464,757,064

Winter RFG MTBE Content (Vol%) by Volume (from Batch Reports)

Reporting Year

Volume

%tile

1997 1998 1999 2000 2001 2002 2003 2004 2005

5%

10%

15% 0.21 0.18 0.47 0.42 0.65 0.07

20% 5.06 5.24 5.42 5.55 5.59 5.23 0.14

25% 7.18 6.94 6.89 7.22 7.99 7.67 7.36 0.05 0.04

30% 8.34 8.68 8.72 8.40 8.59 8.56 8.36 0.28 0.20

35% 8.64 9.04 9.18 8.88 8.98 8.84 8.66 7.95 7.85

40% 8.89 9.30 9.38 9.20 9.24 9.10 8.89 8.56 8.45

45% 9.09 9.52 9.53 9.40 9.44 9.26 9.15 8.87 8.78

50% 9.33 9.74 9.67 9.60 9.60 9.41 9.37 9.15 9.03

55% 9.63 9.98 9.80 9.77 9.76 9.61 9.53 9.39 9.23

60% 10.14 10.24 9.97 9.91 9.92 9.77 9.70 9.62 9.44

65% 10.73 10.58 10.18 10.07 10.06 9.95 9.87 9.84 9.63

70% 11.21 11.09 10.42 10.24 10.24 10.15 10.04 10.06 9.85

75% 11.63 11.70 10.75 10.49 10.44 10.36 10.28 10.29 10.09

80% 12.22 12.16 11.16 10.83 10.74 10.67 10.56 10.79 10.29

85% 13.71 13.49 11.69 11.31 11.18 11.09 11.00 11.39 10.55

90% 14.52 14.58 12.66 11.89 11.63 11.55 11.52 12.12 11.09

95% 14.94 14.98 14.34 12.92 12.44 12.30 12.41 13.01 12.19

100% 16.93 16.86 16.10 15.63 15.30 15.62 15.02 15.13 15.79

Volume

(gal): 14,400,124,642 14,621,530,037 14,594,054,317 15,275,786,534 15,122,255,995 15,825,705,992 15,771,471,139 15,875,951,167 16,559,495,884
163

RFG MTBE Content (Volume Percent) by Gasoline Volume (Continued):

Cumulative Distribution for Latest Year Data

Figure 5

Figure 6
164

RFG Ethanol Content (Volume Percent) by Gasoline Volume

Summer RFG Ethanol Content (vol%) by Volume (from Batch Reports)

Reporting Year

Volume

%tile

1997 1998 1999 2000 2001 2002 2003 2004 2005

67%

68% 5.28

69% 5.56

70% 9.03 5.38

75% 9.34 9.32

80% 9.44 9.48

81% 9.45 9.50

82% 9.48 9.54

83% 0.01 9.49 9.56

84% 0.03 4.70 9.51 9.58

85% 5.09 5.23 9.54 9.60

86% 5.33 5.35 9.56 9.61

87% 4.81 5.50 9.10 9.59 9.63

88% 4.66 4.96 7.44 0.09 5.76 9.31 9.62 9.67

89% 5.18 4.87 5.15 8.95 8.59 9.07 9.37 9.64 9.70

90% 5.36 5.15 5.26 9.23 9.11 9.23 9.42 9.67 9.72

95% 9.40 9.45 9.47 9.51 9.56 9.45 9.65 9.88 9.92

100% 10.51 10.69 10.42 10.10 10.85 10.31 10.40 11.00 10.60

Volume

(gal): 11,977,238,567 12,553,324,899 12,608,377,199 12,574,035,936 12,783,848,128 13,409,581,178 13,168,085,773 13,749,448,485 13,464,757,064

Winter RFG Ethanol Content (vol%) by Volume (from Batch Reports)

Reporting Year

Volume

%tile

1997 1998 1999 2000 2001 2002 2003 2004 2005

66% 0.02

67% 0.02 0.02

68% 0.02 0.02

69% 0.02 0.08

70% 4.85 4.80

75% 5.65 9.13

76% 9.15 9.23

77% 9.26 9.31

78% 9.34 9.36

79% 0.08 9.40 9.40

80% 4.82 9.43 9.44

81% 4.90 9.46 9.47

82% 4.98 9.49 9.50

83% 4.52 5.03 9.51 9.53

84% 5.02 4.69 0.02 4.81 5.11 9.54 9.56

85% 5.21 4.86 4.60 4.92 4.53 4.90 5.29 9.56 9.59

90% 5.57 5.74 5.47 5.55 5.39 5.75 9.44 9.70 9.73

95% 9.38 9.42 9.45 9.48 9.53 9.50 9.67 9.90 9.93

100% 10.49 10.71 10.39 10.24 10.52 10.46 10.70 10.82 10.73

Volume

(gal): 14,400,124,642 14,621,530,037 14,594,054,317 15,275,786,534 15,122,255,995 15,825,705,992 15,771,471,139 15,875,951,167 16,559,495,884
165

RFG Ethanol Content (Volume Percent) by Gasoline Volume (Continued):

Cumulative Distribution for Latest Year Data

Figure 7

Figure 8
166

RFG Oxygen Content by Grade

Figure 9

Figure 10
167

RFG MTBE Content by Grade

Figure 11

Figure 12

These averages include RFG which did not contain MTBE.
168

RFG Ethanol Content by Grade

Figure 13

Figure 14

These averages include RFG which did not contain ethanol.
169

RFG Oxygen Content by Season and Survey Area (Except CA)

Average of oxygen (weight %) Year

Season Area 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005

Summer Atlantic City, NJ (1) 2.17 1.98 2.16 2.14 2.23 2.32 2.29 2.31 2.20 2.02

Baltimore, MD 2.07 1.87 1.94 1.96 1.99 2.06 2.01 2.06 2.07 2.12 2.03

Boston-Worcester, MA 2.18 2.12 2.15 2.08 2.01 2.17 2.10 2.09 2.08 2.14 2.07

Chicago-Lake Co., IL, Gary, IN 2.59 3.36 3.44 3.46 3.54 3.51 3.52 3.50 3.51 3.53 3.61

Covington, KY (3) 1.98 2.70 3.05 3.06 2.99 2.91 3.57 3.59 3.64

CT - remainder (3) 2.02 2.01 2.10 2.08 3.53 3.57

Dallas-Fort Worth, TX 2.09 1.91 2.01 2.07 2.01 2.03 2.07 2.08 2.21 2.21 2.01

Hartford, CT 2.13 2.03 2.02 2.04 2.02 2.13 2.10 2.12 2.13 3.54 3.59

Houston-Galveston, TX 2.17 1.87 1.95 2.04 2.00 2.11 2.08 2.15 2.20 2.13 2.05

Knox Co. and Lincoln Co., ME (2,3) 2.11

Lewiston-Auburn, ME (2,3) 2.22

Louisville, KY 2.05 1.98 2.30 2.36 2.27 2.27 2.25 2.05 3.50 3.56 3.60

Manchester, NH 2.08 2.08 2.11 1.96 2.18 2.17 2.18 2.13 2.06 1.96

Milwaukee-Racine, WI 2.61 3.42 3.42 3.45 3.51 3.49 3.44 3.49 3.50 3.51 3.58

Norfolk-Virginia Beach, VA 2.10 1.88 1.92 1.97 2.03 2.07 1.98 2.04 2.12 2.24 2.07

NY-NJ-Long Is.-CT 2.08 1.99 2.11 2.03 2.02 2.03 2.06 1.99 2.11 2.91 2.87

Phila.-Wilm, DE-Trenton, NJ 2.09 2.00 2.09 2.13 2.12 2.20 2.29 2.26 2.31 2.21 2.07

Phoenix, AZ (1,2) 1.89

Portland, ME (2) 2.23 2.07 2.10 2.18

Portsmouth-Dover, NH (3) 2.11 2.08 2.15 1.98 2.21 2.27 2.18 2.12 2.15 1.98

Poughkeepsie, NY (3) 2.10 2.08 2.02 2.03 2.04 2.06 1.99 2.01 3.56 3.58

Queen Anne Co.-Kent Co., MD (3) 2.06 2.10 2.20 2.10 1.93

Rhode Island 2.26 2.06 1.95 2.08 2.07 2.07 1.99 1.93 2.02 2.09 2.10

Richmond, VA 2.08 1.85 1.95 1.95 2.00 2.13 1.96 1.98 2.12 2.12 2.05

Springfield, MA 2.17 2.12 2.12 2.08 2.08 2.12 2.07 2.01 2.11 2.16 2.40

St. Louis, MO (1) 2.22 2.20 2.26 3.05 3.54 3.56 3.66

Sussex County, DE (1) 2.09 1.98 2.01 2.14 2.29 2.25 2.09 1.82

Warren County, NJ (1) 2.04 2.17 2.18 2.15 1.94

Washington, DC area 2.13 1.92 1.97 1.99 2.03 2.11 1.96 1.99 2.09 2.08 2.00

Winter Atlantic City, NJ 2.65 1.81 2.04 2.14 2.08 1.94 1.96 2.05 1.94 1.89

Baltimore, MD 2.30 1.83 1.93 1.90 1.95 1.98 1.98 1.92 1.96 1.98 1.88

Boston-Worcester, MA 2.10 1.98 1.96 2.06 2.10 2.14 2.11 2.05 2.05 2.04 2.03

Chicago-Lake Co., IL, Gary, IN 3.13 3.53 3.56 3.68 3.69 3.70 3.65 3.64 3.66 3.67 3.69

Covington, KY 2.03 3.32 3.14 3.02 2.99 3.34 3.72 3.90 3.70

CT - remainder 2.04 2.03 2.05 2.76 3.59 3.64

Dallas-Fort Worth, TX 1.97 1.87 1.91 1.97 1.94 1.99 1.99 1.93 1.97 1.95 1.99

Hartford, CT 2.20 2.06 2.17 2.06 2.10 2.12 2.06 2.01 2.37 3.60 3.66

Houston-Galveston, TX 2.00 1.83 1.92 1.97 1.99 2.04 2.06 2.04 2.08 2.03 2.06

Knox Co. and Lincoln Co., ME 2.25

Lewiston-Auburn, ME 2.26

Louisville, KY 1.98 2.04 2.19 2.16 2.40 2.24 2.25 2.90 3.71 3.72 3.68

Manchester, NH 2.11 1.95 2.10 2.10 2.04 2.15 2.06 2.08 2.01 1.92

Milwaukee-Racine, WI 2.95 2.91 2.52 3.53 3.55 3.65 3.51 3.61 3.69 3.65 3.69

Norfolk-Virginia Beach, VA 2.01 1.85 1.91 1.87 1.96 2.00 1.98 1.98 2.01 2.08 1.93

NY-NJ-Long Is.-CT 2.61 2.53 2.64 2.70 2.19 1.99 1.91 1.87 2.08 2.96 3.09

Phila.-Wilm, DE-Trenton, NJ 2.26 1.85 2.01 2.04 1.95 2.06 1.94 1.90 1.94 1.93 1.88

Phoenix, AZ 3.56

Portland, ME 2.20 2.12 2.11 2.26

Portsmouth-Dover, NH 2.11 1.91 2.15 2.12 2.24 2.12 2.05 2.04 2.15 1.92

Poughkeepsie, NY 2.45 2.41 2.52 2.25 2.12 1.91 1.90 2.74 3.68 3.65

Queen Anne Co.-Kent Co., MD 2.28 2.00 1.83 1.87 1.84

Rhode Island 2.25 1.95 1.96 2.05 2.08 2.20 2.04 1.86 1.93 2.03 1.89

Richmond, VA 2.20 1.86 1.88 1.91 1.98 1.94 1.94 1.95 1.95 1.99 1.88

Springfield, MA 2.13 1.94 2.00 2.09 2.18 2.22 2.03 2.11 1.97 2.20 2.38

St. Louis, MO 2.69 2.71 2.54 2.84 3.46 3.61 3.58

Sussex County, DE 2.11 1.89 2.00 1.98 1.96 1.87 1.80 1.77

Warren County, NJ 2.36 1.98 1.90 1.91 2.07

Washington, DC area 2.71 1.87 1.96 1.91 2.01 1.98 1.94 1.98 2.01 2.05 1.94

Reasons for no data in certain

years:

1 No data prior to opt-in to RFG

2 No data subsequent to opt-out of RFG

3 Not sampled in certain years (smaller

area)
170

RFG Oxygen Content by Season and Area (Federal RFG Areas in California)

Average of Oxygen (Wt%) Year

Season Area 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005

Summer Los Angeles, CA 2.05 2.05 2.04 2.20 2.01 2.07 2.11 2.02 2.08 2.12

Sacramento Metro, CA 2.12 2.04 2.11 2.13 2.18 1.99 2.13 2.05 2.05 2.14

San Diego, CA 2.03 2.09 2.06 2.19 2.09 2.17 2.07 2.09 2.08 2.11

San Joaquin, CA 2.11 2.13 2.19

Winter Los Angeles, CA 2.03 2.15 2.16 2.23 2.12 2.05 2.01 2.13 2.01

Sacramento Metro, CA 2.03 2.13 2.09 2.14 2.13 2.05 2.03 2.17 2.13

San Diego, CA 2.09 2.14 2.17 2.20 2.21 2.12 2.02 2.09 2.08

San Joaquin, CA 2.08 2.23 2.13
171

RFG MTBE Content (WT%) by Season and Survey Area (Except CA)

Average of MTBE (wt%) Year

Season Area 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005

Summer Atlantic City, NJ 11.12 10.67 11.49 11.44 11.47 12.31 12.27 12.31 11.77 10.80

Baltimore, MD 10.43 9.02 9.31 9.55 9.51 10.12 9.73 10.30 10.33 10.76 10.46

Boston-Worcester, MA 10.14 10.37 10.70 10.23 9.52 10.59 9.96 10.36 10.12 10.88 10.03

Chicago-Lake Co., IL, Gary,

IN

1.89 0.60 0.65 0.43 0.00 0.01 0.00 0.01 0.02 0.03 0.00

Covington, KY 7.67 5.63 2.52 3.49 3.44 3.29 0.00 0.00 0.00

CT - remainder 10.14 10.14 9.22 9.78 0.06 0.04

Dallas-Fort Worth, TX 9.23 8.93 9.93 9.87 10.31 10.16 10.38 10.48 11.26 11.12 9.89

Hartford, CT 10.40 10.29 10.39 10.38 9.08 9.21 9.60 9.27 9.24 0.06 0.03

Houston-Galveston, TX 10.79 8.84 9.27 10.45 10.26 11.01 10.42 10.95 11.39 11.13 10.57

Knox Co. and Lincoln Co.,

ME

11.42

Lewiston-Auburn, ME 11.70

Louisville, KY 4.80 7.87 8.12 7.19 7.81 8.16 7.40 7.65 0.00 0.00 0.00

Manchester, NH 10.37 10.52 11.03 10.24 11.11 11.11 11.23 11.17 10.47 10.18

Milwaukee-Racine, WI 1.49 0.38 0.45 0.34 0.00 0.00 0.00 0.00 0.01 0.01 0.02

Norfolk-Virginia Beach, VA 10.07 8.99 9.51 9.68 9.96 10.33 9.62 10.33 10.47 11.74 10.69

NY-NJ-Long Is.-CT 10.70 10.43 11.19 10.65 10.67 10.26 10.54 10.26 10.46 4.89 4.54

Phila.-Wilm, DE-Trenton, NJ 10.68 10.42 10.78 11.15 11.28 11.50 12.03 12.06 12.34 11.85 11.04

Phoenix, AZ 9.99

Portland, ME 11.84 11.28 11.23 11.58

Portsmouth-Dover, NH 11.06 11.21 11.27 10.57 11.82 11.75 11.40 11.14 11.36 10.67

Poughkeepsie, NY 10.90 10.98 10.76 10.43 10.21 10.54 10.13 9.59 0.20 0.05

Queen Anne Co.-Kent Co.,

MD

10.04 9.51 10.54 11.19 10.41

Rhode Island 11.37 10.22 10.04 10.32 9.96 9.53 9.65 9.93 9.99 11.44 10.29

Richmond, VA 10.25 8.94 9.21 9.68 9.72 10.53 9.93 10.12 10.74 10.99 10.54

Springfield, MA 10.61 10.82 11.03 10.62 9.68 9.90 9.80 9.34 9.74 11.07 7.82

St. Louis, MO 7.91 9.07 8.85 0.22 0.27 0.08 0.02

Sussex County, DE 9.63 8.05 9.11 9.74 10.19 11.51 11.46 9.99

Warren County, NJ 10.67 10.94 10.73 11.61 10.32

Washington, DC area 10.47 9.17 9.67 9.85 9.59 10.43 9.84 10.13 10.35 10.43 10.17

Winter Atlantic City, NJ 14.06 8.99 10.56 10.87 9.87 10.07 10.23 10.88 10.48 10.29

Baltimore, MD 11.72 8.21 9.51 9.71 9.50 9.58 9.39 9.61 9.84 10.15 9.70

Boston-Worcester, MA 9.60 9.13 9.20 9.57 8.96 9.80 9.54 9.98 10.40 10.07 9.98

Chicago-Lake Co., IL, Gary,

IN

2.22 0.60 0.48 0.07 0.00 0.00 0.00 0.01 0.01 0.00 0.00

Covington, KY 7.45 3.29 2.91 3.67 3.63 1.81 0.01 0.00 0.00

CT - remainder 9.98 9.68 8.85 5.21 0.11 0.07

Dallas-Fort Worth, TX 9.10 8.89 9.89 9.61 9.43 9.89 9.89 9.83 10.11 9.60 9.62

Hartford, CT 10.58 9.82 10.20 9.79 8.85 9.01 9.36 8.85 7.33 0.09 0.09

Houston-Galveston, TX 9.94 8.56 9.37 10.02 10.33 10.52 10.21 10.39 10.62 10.20 10.80

Knox Co. and Lincoln Co.,

ME

12.13

Lewiston-Auburn, ME 11.76

Louisville, KY 6.34 7.69 7.55 7.93 7.83 7.26 7.29 4.10 0.01 0.00 0.00

Manchester, NH 10.24 10.22 10.07 10.28 10.05 11.17 10.68 10.77 10.62 10.32

Milwaukee-Racine, WI 2.46 0.23 0.49 0.01 0.00 0.00 0.00 0.01 0.00 0.01 0.00

Norfolk-Virginia Beach, VA 9.78 8.69 9.42 9.47 9.92 9.91 9.91 9.97 10.19 10.88 9.54

NY-NJ-Long Is.-CT 12.88 12.95 13.32 13.93 11.23 9.87 9.85 9.68 8.55 3.99 3.24

Phila.-Wilm, DE-Trenton, NJ 11.16 9.01 9.99 10.68 10.24 10.34 9.87 9.87 10.18 10.57 10.25

Phoenix, AZ 0.17

Portland, ME 12.00 11.07 11.51 11.73

Portsmouth-Dover, NH 10.79 9.54 11.29 9.98 10.96 11.21 10.98 10.67 11.79 10.51

Poughkeepsie, NY 12.89 12.05 12.50 11.01 9.78 9.54 9.20 5.14 0.11 0.10

Queen Anne Co. Kent Co.,

MD

11.49 9.48 8.91 9.93 9.99

Rhode Island 10.30 9.09 9.39 10.12 9.25 9.81 9.62 9.31 9.53 10.59 9.45

Richmond, VA 10.74 8.42 9.12 9.81 9.53 9.43 9.61 9.83 9.70 10.29 9.62

Springfield, MA 9.52 9.08 9.77 9.95 9.02 9.39 9.59 9.27 8.93 8.91 7.25

St. Louis, MO 5.46 5.59 4.90 2.91 0.46 0.16 0.03

Sussex County, DE 9.78 8.90 8.12 8.04 8.80 10.05 9.87 9.76

Warren County, NJ 12.48 10.32 9.95 10.25 8.09

Washington, DC area 13.18 8.86 9.63 9.58 9.87 9.71 9.73 9.96 10.12 10.42 9.94
172

RFG MTBE Content (WT%) by Season and Area (Federal RFG Areas in California)

Average of MTBE (wt%) Year

Season Area 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005

Summer Los Angeles, CA 10.85 10.96 11.14 11.94 10.94 9.76 9.56 0.42 0.00 0.00

Sacramento Metro, CA 11.56 10.85 10.99 11.54 11.47 9.37 9.86 4.83 0.00 0.00

San Diego, CA 10.55 10.98 11.00 11.89 11.32 10.92 10.39 2.50 0.01 0.01

San Joaquin, CA 6.08 0.00 0.00

Winter Los Angeles, CA 10.63 11.37 11.82 12.12 9.66 9.86 0.79 0.00 0.00

Sacramento Metro, CA 10.85 11.25 11.12 11.34 10.04 9.59 2.73 0.00 0.00

San Diego, CA 10.78 11.51 11.71 11.96 11.21 10.54 1.68 0.00 0.00

San Joaquin, CA 5.28 0.00 0.00

RFG Ethanol Content (WT%) by Season and Survey Area (Except CA)

Average of Ethanol (wt%) Year

Season Area 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005

Atlantic City, NJ 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Baltimore, MD 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00

Boston-Worcester, MA 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.33

Chicago-Lake Co., IL, Gary,

IN

6.33 9.29 9.57 9.74 10.21 10.12 10.14 10.09 10.10 10.15 10.39

Covington, KY 1.45 4.83 7.46 6.95 6.78 6.64 10.29 10.34 10.49

CT - remainder 0.00 0.00 0.00 0.00 10.13 10.27

Dallas-Fort Worth, TX 0.03 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Hartford, CT 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 10.16 10.33

Houston-Galveston, TX 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Knox Co. and Lincoln Co.,

ME

0.00

Lewiston-Auburn, ME 0.00

Louisville, KY 1.36 1.45 2.32 3.01 2.40 2.21 2.54 1.78 10.05 10.25 10.36

Manchester, NH 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01

Milwaukee-Racine, WI 6.56 9.58 9.61 9.76 10.10 10.05 9.91 10.05 10.07 10.12 10.29

Norfolk-Virginia Beach, VA 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

NY-NJ-Long Is.-CT 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5.78 5.76

Phila.-Wilm, DE-Trenton, NJ 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.01

Phoenix, AZ 0.00

Portland, ME 0.00 0.00 0.00 0.00

Portsmouth-Dover, NH 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Poughkeepsie, NY 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 10.14 10.29

Queen Anne Co.-Kent Co.,

MD

0.00 0.00 0.00 0.00 0.00

Rhode Island 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.32

Richmond, VA 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Springfield, MA 0.00 0.02 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.36 2.47

St. Louis, MO 2.00 1.35 1.52 8.65 10.04 10.20 10.53

Sussex County, DE 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Warren County, NJ 0.00 0.00 0.01 0.00 0.01

Summer

Washington, DC area 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Winter Atlantic City, NJ 0.15 0.00 0.15 0.16 0.54 0.07 0.17 0.00 0.00 0.00

Baltimore, MD 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Boston-Worcester, MA 0.07 0.22 0.10 0.18 0.33 0.30 0.36 0.18 0.30 0.22 0.38

Chicago-Lake Co., IL, Gary,

IN

7.69 9.75 10.00 10.56 10.61 10.66 10.50 10.48 10.55 10.57 10.64

Covington, KY 1.72 7.85 7.49 6.76 6.69 8.65 10.71 11.22 10.63

CT - remainder 0.17 0.23 0.41 5.15 10.28 10.45

Dallas-Fort Worth, TX 0.02 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.01 0.00 0.00
173

Hartford, CT 0.22 0.35 0.51 0.35 0.41 0.43 0.27 0.45 2.72 10.33 10.48

Houston-Galveston, TX 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Knox Co. and Lincoln Co.,

ME

0.00

Lewiston-Auburn, ME 0.00

Louisville, KY 1.61 1.64 2.34 2.01 2.69 2.55 2.58 6.13 10.69 10.72 10.61

Manchester, NH 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.03 0.00 0.00

Milwaukee-Racine, WI 6.72 8.13 6.99 10.16 10.23 10.51 10.10 10.40 10.63 10.49 10.62

Norfolk-Virginia Beach, VA 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00

NY-NJ-Long Is.-CT 0.41 0.11 0.35 0.30 0.18 0.36 0.16 0.13 1.33 6.37 7.20

Phila.-Wilm, DE-Trenton, NJ 0.44 0.09 0.14 0.05 0.16 0.18 0.10 0.12 0.14 0.00 0.04

Phoenix, AZ 10.17

Portland, ME 0.00 0.00 0.00 0.00

Portsmouth-Dover, NH 0.00 0.16 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00

Poughkeepsie, NY 0.13 0.33 0.32 0.38 0.71 0.30 0.32 5.05 10.51 10.45

Queen Anne Co.-Kent Co.,

MD

0.00 0.00 0.00 0.00 0.01

Rhode Island 0.24 0.30 0.14 0.25 0.25 0.48 0.34 0.35 0.38 0.26 0.44

Richmond, VA 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Springfield, MA 0.37 0.35 0.21 0.22 0.36 0.72 0.27 0.50 0.59 1.44 2.99

St. Louis, MO 4.74 4.73 4.52 6.54 9.72 10.32 10.30

Sussex County, DE 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Warren County, NJ 0.00 0.01 0.00 0.00 1.67

Washington, DC area 0.09 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00

RFG Ethanol Content (WT%) by Season and Area (Federal RFG Areas in California)

Average of Ethanol (wt%) Year

Season Area 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005

Summer Los Angeles, CA 0.01 0.00 0.00 0.00 0.00 0.77 1.00 5.59 5.96 6.09

Sacramento

Metro, CA

0.00 0.00 0.00 0.00 0.00 0.61 0.77 3.38 5.90 6.12

San Diego, CA 0.00 0.00 0.00 0.00 0.00 0.49 0.52 4.71 5.94 6.02

San Joaquin, CA 2.90 6.10 6.25

Winter Los Angeles, CA 0.00 0.00 0.00 0.00 1.00 0.75 5.36 6.08 5.77

Sacramento

Metro, CA

0.00 0.00 0.00 0.00 0.63 0.65 4.24 6.08 5.97

San Diego, CA 0.00 0.00 0.00 0.00 0.48 0.57 4.94 5.99 5.92

San Joaquin, CA 3.21 6.25 6.07
174

Appendix to Benzene Chapter

RFG Benzene by Gasoline Volume

Figure 1

Summer RFG Benzene Content by Volume (from Batch Reports)

Reporting Year

Volume

%tile

1997 1998 1999 2000 2001 2002 2003 2004 2005

minimum 0.07 0.05 0.06 0.00 0.01 0.00 0.06 0.00 0.01

5% 0.25 0.24 0.29 0.29 0.27 0.25 0.27 0.28 0.30

10% 0.32 0.32 0.36 0.34 0.34 0.32 0.33 0.33 0.37

15% 0.37 0.38 0.40 0.37 0.38 0.36 0.36 0.37 0.41

20% 0.41 0.42 0.43 0.39 0.41 0.39 0.38 0.40 0.45

25% 0.44 0.47 0.48 0.42 0.44 0.42 0.41 0.43 0.48

30% 0.48 0.50 0.52 0.44 0.46 0.44 0.43 0.45 0.51

35% 0.51 0.53 0.57 0.47 0.48 0.47 0.46 0.48 0.54

40% 0.55 0.55 0.61 0.49 0.51 0.50 0.49 0.51 0.57

45% 0.58 0.59 0.65 0.51 0.53 0.52 0.52 0.54 0.60

50% 0.62 0.62 0.68 0.53 0.56 0.55 0.55 0.56 0.64

55% 0.67 0.65 0.71 0.55 0.59 0.57 0.59 0.59 0.67

60% 0.71 0.70 0.75 0.58 0.62 0.60 0.63 0.61 0.71

65% 0.75 0.76 0.80 0.61 0.66 0.63 0.66 0.64 0.74

70% 0.80 0.82 0.85 0.66 0.70 0.66 0.71 0.67 0.78

75% 0.84 0.88 0.90 0.70 0.76 0.70 0.75 0.71 0.82

80% 0.89 0.95 0.97 0.76 0.82 0.75 0.80 0.75 0.86

85% 0.95 1.01 1.02 0.83 0.89 0.81 0.86 0.80 0.90

90% 1.02 1.06 1.08 0.95 0.98 0.91 0.94 0.88 0.96

95% 1.13 1.13 1.15 1.05 1.10 1.04 1.08 1.01 1.06

100% 1.30 1.33 1.42 1.28 1.30 1.29 1.30 1.51 1.34

Volume

(gal): 12,435,941,155 12,831,030,495 12,996,112,177 12,982,665,444 13,222,175,920 13,847,238,818 13,584,238,237 14,227,790,769 14,082,668,582
175

RFG Benzene by Gasoline Volume (continued):

Figure 2

Winter RFG Benzene Content by Volume (from Batch Reports)

Reporting Year

Volume

%tile

1997 1998 1999 2000 2001 2002 2003 2004 2005

minimum 0.00 0.02 0.01 0.03 0.01 0.01 0.00 0.01 0.01

5% 0.21 0.23 0.27 0.28 0.28 0.27 0.27 0.26 0.30

10% 0.28 0.31 0.32 0.33 0.34 0.33 0.33 0.31 0.36

15% 0.33 0.36 0.36 0.37 0.38 0.37 0.36 0.35 0.40

20% 0.36 0.40 0.39 0.40 0.42 0.40 0.39 0.38 0.45

25% 0.40 0.43 0.42 0.43 0.45 0.44 0.43 0.42 0.48

30% 0.44 0.47 0.45 0.47 0.48 0.48 0.46 0.45 0.51

35% 0.47 0.50 0.48 0.50 0.51 0.51 0.50 0.49 0.55

40% 0.50 0.53 0.52 0.53 0.54 0.55 0.53 0.52 0.58

45% 0.54 0.56 0.56 0.56 0.57 0.58 0.57 0.56 0.61

50% 0.58 0.60 0.59 0.60 0.60 0.61 0.61 0.59 0.64

55% 0.63 0.65 0.63 0.64 0.63 0.65 0.64 0.62 0.67

60% 0.67 0.69 0.67 0.68 0.66 0.68 0.68 0.66 0.70

65% 0.72 0.74 0.72 0.72 0.70 0.71 0.72 0.71 0.74

70% 0.77 0.79 0.78 0.78 0.74 0.74 0.76 0.75 0.78

75% 0.82 0.84 0.83 0.83 0.79 0.78 0.80 0.79 0.82

80% 0.87 0.89 0.89 0.89 0.85 0.83 0.87 0.85 0.87

85% 0.93 0.95 0.96 0.95 0.93 0.89 0.93 0.91 0.92

90% 1.01 1.01 1.04 1.02 1.01 0.98 1.01 0.99 0.98

95% 1.11 1.09 1.13 1.11 1.10 1.09 1.11 1.09 1.08

100% 2.65 1.32 1.30 1.33 1.30 1.30 1.30 1.31 1.68

Volume

(gal): 14,914,492,944 15,066,250,612 15,082,593,974 15,826,525,899 15,733,483,045 16,429,447,508 16,675,657,569 17,189,415,193 18,049,752,652
176

RFG Benzene by Gasoline Volume (continued):

(Cumulative Distributions for Latest Year Data)

Figure 3

Figure 4
177

RFG Benzene by Grade

Figure 5

Figure 6
178

RFG Benzene by Grade (continued):

RFG Average Benzene Content (v%) and Volume (gal) by Year, Grade and Season – From Reporting Data

Reporting Year

Grade Season Data 1997 1998 1999 2000 2001 2002 2003 2004 2005

PRM s Average 0.60 0.60 0.63 0.53 0.52 0.48 0.50 0.50 0.58

Volume 3,433,830,960 3,649,323,954 3,537,270,189 2,788,061,943 2,772,653,293 2,931,154,091 2,736,350,778 2,384,807,492 2,143,381,101

w Average 0.57 0.59 0.61 0.54 0.55 0.52 0.50 0.52 0.56

Volume 3,876,199,245 4,139,145,511 3,839,047,178 3,419,795,153 3,305,189,631 3,387,100,772 3,102,938,885 2,944,118,191 2,583,362,289

REG s Average 0.68 0.70 0.73 0.61 0.65 0.62 0.63 0.62 0.68

Volume 8,933,744,061 9,007,552,063 9,318,697,543 10,122,448,765 10,392,283,260 10,879,031,865 10,824,904,975 11,779,211,527 11,881,795,879

w Average 0.64 0.67 0.66 0.68 0.67 0.67 0.68 0.65 0.69

Volume 10,818,337,187 10,663,420,477 10,902,774,956 12,243,727,277 12,361,561,882 13,031,122,001 13,483,257,340 14,160,927,780 15,427,424,995

Users of these grade-specific property estimates calculated from RFG and Anti-Dumping data should be aware that grade-specific estimates

based on reporting data may differ from actual retail property values by grade. Although aggregate estimates from the reporting system may also

differ from actual retail property values, there are several additional reasons why these grade-specific estimates may differ. Mid-grade gasoline is

often blended from regular and premium gasoline at some point downstream of the refinery. Thus, some of the gasoline volume reported and

included in these tables as regular or premium would be marketed as mid-grade. Additionally, EPA's grade-specific average analysis excludes

some gasoline and blendstock that was included in aggregate average estimates. EPA has presented averages for batches labeled as regular and

premium gasoline only; excluding batches labeled as mid-grade (since these batches may not be a representative sample of gasoline marketed as

mid-grade), mix of grades, or without a grade label. EPA also excluded CG blendstock batches from grade-specific analyses even if they had a

grade designation.

The table shows the total volume, in gallons, for the batches used to calculate each grade average. In part, because of factors discussed

above these volumes are not expected to represent the actual volumes by grade of retail gasoline.
179

RFG Benzene-Geographic

Figure 7 Figure 8
180

Conventional Gasoline

CG Benzene by Gasoline Volume

Figure 9

Summer CG Benzene Content by Volume (from Batch Reports excluding Blendstocks)

Reporting Year

Volume

%tile

1997 1998 1999 2000 2001 2002 2003 2004 2005

minimum 0.00 0.00 0.00 0.00 0.03 0.00 0.00 0.00 0.00

5% 0.26 0.27 0.26 0.34 0.35 0.34 0.36 0.35 0.37

10% 0.37 0.39 0.38 0.44 0.47 0.45 0.46 0.47 0.47

15% 0.44 0.46 0.47 0.51 0.55 0.50 0.53 0.55 0.54

20% 0.50 0.53 0.54 0.57 0.62 0.54 0.59 0.62 0.60

25% 0.57 0.59 0.60 0.62 0.68 0.60 0.65 0.68 0.67

30% 0.65 0.66 0.66 0.67 0.73 0.69 0.72 0.73 0.74

35% 0.73 0.73 0.73 0.74 0.79 0.76 0.78 0.79 0.80

40% 0.79 0.80 0.81 0.81 0.85 0.83 0.85 0.86 0.88

45% 0.87 0.88 0.87 0.87 0.92 0.88 0.92 0.93 0.98

50% 0.95 0.96 0.95 0.95 1.00 0.94 1.00 0.99 1.06

55% 1.05 1.06 1.03 1.03 1.08 1.01 1.08 1.08 1.15

60% 1.17 1.15 1.13 1.12 1.17 1.10 1.18 1.15 1.26

65% 1.29 1.26 1.24 1.22 1.27 1.19 1.27 1.24 1.37

70% 1.42 1.38 1.37 1.34 1.40 1.30 1.37 1.35 1.45

75% 1.55 1.52 1.51 1.47 1.54 1.42 1.49 1.49 1.55

80% 1.69 1.67 1.65 1.58 1.68 1.57 1.61 1.62 1.66

85% 1.85 1.85 1.84 1.74 1.83 1.76 1.77 1.72 1.85

90% 2.06 2.09 2.09 1.98 2.07 1.95 1.95 1.94 2.09

95% 2.43 2.39 2.43 2.36 2.37 2.28 2.30 2.30 2.45

100% 5.33 5.29 5.00 5.25 5.00 5.00 5.00 5.14 5.08

Volume

(gal): 39,313,521,046 39,075,503,909 37,192,482,168 36,393,283,808 38,566,604,576 40,819,234,602 43,235,647,755 43,503,138,987 42,188,895,941
181

CG Benzene by Gasoline Volume (continued):

Figure 10

Winter CG Benzene Content by Volume (from Batch Reports excluding Blendstocks)

Reporting Year

Volume

%tile

1997 1998 1999 2000 2001 2002 2003 2004 2005

minimum 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

5% 0.23 0.23 0.26 0.28 0.31 0.32 0.32 0.32 0.35

10% 0.34 0.35 0.39 0.39 0.42 0.43 0.44 0.42 0.46

15% 0.43 0.43 0.46 0.46 0.50 0.49 0.51 0.49 0.53

20% 0.49 0.48 0.52 0.52 0.56 0.55 0.57 0.55 0.60

25% 0.54 0.55 0.56 0.56 0.61 0.61 0.62 0.61 0.66

30% 0.60 0.60 0.61 0.61 0.67 0.66 0.68 0.67 0.72

35% 0.66 0.67 0.67 0.66 0.72 0.72 0.74 0.73 0.79

40% 0.74 0.72 0.73 0.73 0.79 0.78 0.81 0.79 0.85

45% 0.81 0.79 0.79 0.80 0.86 0.84 0.87 0.85 0.92

50% 0.88 0.90 0.87 0.88 0.93 0.91 0.94 0.92 0.98

55% 0.99 1.00 0.97 0.96 1.01 0.98 1.02 0.99 1.06

60% 1.10 1.10 1.07 1.05 1.10 1.06 1.10 1.08 1.15

65% 1.25 1.21 1.18 1.15 1.22 1.15 1.19 1.17 1.25

70% 1.40 1.33 1.30 1.25 1.34 1.23 1.28 1.27 1.34

75% 1.58 1.43 1.41 1.38 1.47 1.33 1.38 1.39 1.43

80% 1.74 1.56 1.56 1.53 1.60 1.45 1.52 1.51 1.54

85% 1.93 1.77 1.74 1.72 1.78 1.64 1.67 1.67 1.69

90% 2.19 2.01 2.02 1.98 2.09 1.91 1.89 1.92 1.94

95% 2.64 2.39 2.39 2.40 2.52 2.30 2.28 2.25 2.42

100% 5.23 5.00 5.34 5.28 5.00 4.88 5.22 5.00 5.20

Volume

(gal): 44,616,143,682 46,277,269,226 47,691,599,779 48,005,753,994 48,802,911,584 49,671,321,830 47,446,594,748 47,637,145,526 48,683,162,256
182

CG Benzene by Gasoline Volume

(Cumulative Distributions for Latest Year Data)

Figure 11

Figure 12
183

CG Benzene by Grade

CG Average Benzene Content (v%) and Volume (gal) by Year, Grade and Season-From Reporting Data

Reporting Year

Grade Season Data 1997 1998 1999 2000 2001 2002 2003 2004 2005

PRM s Average 0.95 0.95 0.92 0.83 0.94 0.85 0.87 0.85 0.89

Volume 6,847,436,919 6,631,452,976 6,252,416,423 4,957,386,104 4,996,778,324 5,181,939,065 5,144,650,585 4,629,542,860 4,132,713,279

w Average 0.83 0.86 0.89 0.86 0.96 0.86 0.87 0.84 0.94

Volume 8,297,352,383 8,231,582,167 7,674,529,390 6,623,696,787 6,552,510,604 6,571,003,043 5,505,637,848 5,063,677,945 4,498,577,769

REG s Average 1.12 1.13 1.14 1.10 1.15 1.08 1.13 1.11 1.18

Volume 28,060,742,477 28,406,715,846 26,654,202,116 27,358,010,027 28,964,788,056 30,995,888,528 33,050,308,019 34,601,650,558 33,850,837,227

w Average 1.15 1.09 1.09 1.05 1.11 1.06 1.08 1.05 1.12

Volume 32,178,466,105 32,165,391,015 33,356,627,836 35,197,390,669 35,933,948,416 36,930,102,215 35,937,081,377 37,501,139,752 39,113,050,332

Users of these grade-specific property estimates calculated from RFG and Anti-Dumping data should be aware that grade-specific estimates

based on reporting data may differ from actual retail property values by grade. Although aggregate estimates from the reporting system may also

differ from actual retail property values, there are several additional reasons why these grade-specific estimates may differ. Mid-grade gasoline is

often blended from regular and premium gasoline at some point downstream of the refinery. Thus, some of the gasoline volume reported and

included in these tables as regular or premium would be marketed as mid-grade. Additionally, EPA's grade-specific average analysis excludes

some gasoline and blendstock that was included in aggregate average estimates. EPA has presented averages for batches labeled as regular and

premium gasoline only; excluding batches labeled as mid-grade (since these batches may not be a representative sample of gasoline marketed as

mid-grade), mix of grades, or without a grade label. EPA also excluded CG blendstock batches from grade-specific analyses even if they had a

grade designation.

The table shows the total volume, in gallons, for the batches used to calculate each grade average. In part, because of factors discussed

above these volumes are not expected to represent the actual volumes by grade of retail gasoline.
184

Appendix to Aromatics Chapter

RFG Aromatics by Gasoline Volume

Figure 1

Summer RFG Aromatics Content (Vol%) by Volume (from Batch Reports)

Reporting Year

Volume

%tile

1997 1998 1999 2000 2001 2002 2003 2004 2005

minimum 0.2 2.6 0.4 1.9 3.1 0.0 1.9 0.4 2.0

5% 11.7 12.9 12.0 10.5 13.0 13.3 12.7 13.1 13.7

10% 13.9 14.7 13.8 13.2 14.4 14.6 14.1 14.5 15.0

15% 15.3 15.8 15.2 14.6 15.2 15.5 15.2 15.5 16.0

20% 16.4 16.9 16.1 15.3 16.0 16.2 16.1 16.3 17.0

25% 17.3 17.9 17.0 16.0 16.7 16.9 16.8 17.0 17.8

30% 18.1 19.2 18.0 16.5 17.4 17.6 17.4 17.7 18.6

35% 19.0 20.0 18.8 17.0 17.9 18.2 18.0 18.2 19.1

40% 20.0 20.8 19.9 17.5 18.5 18.7 18.5 18.7 19.5

45% 20.9 21.4 20.8 18.0 19.0 19.3 19.0 19.2 19.9

50% 21.8 22.1 21.6 18.6 19.5 19.9 19.6 19.7 20.3

55% 22.6 22.8 22.5 19.2 20.1 20.5 20.1 20.2 20.7

60% 23.5 23.5 23.4 19.8 20.7 21.2 20.7 20.8 21.3

65% 24.3 24.3 24.2 20.5 21.4 21.9 21.3 21.3 21.9

70% 25.1 25.3 25.3 21.2 22.1 22.6 21.9 21.9 22.7

75% 26.1 26.6 26.6 22.0 22.9 23.5 22.7 22.7 23.6

80% 27.3 28.1 27.8 23.0 23.8 24.3 23.7 23.5 24.7

85% 29.1 30.0 29.5 24.5 24.8 25.3 24.9 24.7 25.7

90% 32.1 32.4 31.3 26.5 26.3 26.4 26.3 25.9 27.0

95% 35.7 35.0 34.0 29.4 28.8 28.4 28.4 28.0 29.1

100% 52.4 50.6 48.4 47.8 42.3 48.9 46.4 40.1 41.8

Volume

(gal): 12,446,593,615 12,832,964,637 12,998,841,841 12,983,168,478 13,222,633,468 13,847,971,634 13,584,860,845 14,232,658,149 14,083,382,582
185

RFG Aromatics by Gasoline Volume (continued):

Figure 2

Winter RFG Aromatics Content by Volume (from Batch Reports)

Reporting Year

Volume

%tile

1997 1998 1999 2000 2001 2002 2003 2004 2005

minimum 0.0 1.0 0.6 0.9 0.9 1.4 0.6 0.7 0.2

5% 9.6 10.8 10.2 9.8 10.2 11.5 11.8 10.8 11.8

10% 11.6 12.5 12.1 12.0 12.2 13.1 13.3 12.7 13.7

15% 12.7 13.7 13.4 13.2 13.3 14.0 14.3 13.9 14.8

20% 13.7 14.5 14.3 13.9 14.2 14.8 15.0 15.0 15.6

25% 14.5 15.2 15.1 14.7 15.0 15.5 15.7 15.7 16.3

30% 15.3 16.1 15.8 15.3 15.6 16.1 16.4 16.4 16.9

35% 16.0 16.8 16.4 15.9 16.2 16.7 17.0 17.0 17.5

40% 16.7 17.6 17.1 16.5 16.9 17.2 17.6 17.5 18.1

45% 17.4 18.3 17.7 17.1 17.4 17.8 18.2 18.1 18.7

50% 18.1 18.9 18.5 17.7 17.9 18.5 18.7 18.6 19.2

55% 18.9 19.6 19.2 18.5 18.7 19.1 19.3 19.2 19.7

60% 19.7 20.4 19.9 19.3 19.4 19.9 19.9 19.7 20.2

65% 20.5 21.1 20.8 20.2 20.2 20.6 20.5 20.3 20.7

70% 21.5 22.0 21.8 21.2 21.1 21.3 21.2 21.1 21.3

75% 22.7 22.9 22.9 22.3 22.3 22.3 22.1 21.8 22.0

80% 24.0 24.5 24.3 23.7 23.6 23.3 23.1 22.8 22.9

85% 26.0 26.3 25.9 25.3 25.1 24.7 24.5 24.0 24.2

90% 28.8 29.1 28.5 27.5 27.8 26.7 26.3 25.7 25.8

95% 32.5 32.8 32.6 31.1 32.1 30.9 29.7 29.0 28.5

100% 50.0 50.0 48.7 46.9 49.1 45.8 46.6 47.6 49.1

Volume

(gal): 14,914,411,907 15,059,853,293 15,079,861,417 15,829,263,333 15,724,574,173 16,433,999,720 16,679,773,135 17,190,635,125 18,044,832,058
186

RFG Aromatics by Gasoline Volume (continued)

(Cumulative Distributions for Latest Year Data)

Figure 3

Figure 4
187

RFG Aromatics by Grade

Figure 5

Figure 6
188

RFG Aromatics By Grade (continued):

RFG Average Aromatics Content (v%) and Volume (gal) by Year, Grade, and Season-From Reporting Data

Reporting Year

Grade Season Data 1997 1998 1999 2000 2001 2002 2003 2004 2005

PRM s Average 27.0 27.4 26.5 22.5 23.2 22.4 22.6 22.4 22.8

Volume 3,449,496,834 3,651,258,096 3,537,723,033 2,788,564,977 2,773,110,841 2,931,886,907 2,736,973,386 2,385,535,898 2,144,095,101

w Average 23.3 25.0 24.4 23.5 24.6 23.3 23.1 22.7 23.3

Volume 3,889,379,685 4,139,316,745 3,839,207,618 3,420,180,881 3,305,514,921 3,387,457,520 3,103,333,727 2,945,338,123 2,583,694,635

REG s Average 20.6 20.9 20.5 18.4 19.3 19.8 19.4 19.7 20.6

Volume 8,931,922,101 9,007,552,063 9,320,974,363 10,122,448,765 10,392,283,260 10,879,031,865 10,824,904,975 11,783,350,501 11,881,795,879

w Average 17.8 17.9 17.9 17.7 17.7 18.4 18.6 18.4 19.0

Volume 10,816,109,633 10,663,420,477 10,900,737,704 12,246,078,983 12,361,561,882 13,031,122,001 13,486,978,064 14,160,927,780 15,422,172,055

Users of these grade-specific property estimates calculated from RFG and Anti-Dumping data should be aware that grade-specific estimates based

on reporting data may differ from actual retail property values by grade. Although aggregate estimates from the reporting system may also differ from

actual retail property values, there are several additional reasons why these grade-specific estimates may differ. Mid-grade gasoline is often blended from

regular and premium gasoline at some point downstream of the refinery. Thus, some of the gasoline volume reported and included in these tables as

regular or premium would be marketed as mid-grade. Additionally, EPA's grade-specific average analysis excludes some gasoline and blendstock that was

included in aggregate average estimates. EPA has presented averages for batches labeled as regular and premium gasoline only; excluding batches

labeled as mid-grade (since these batches may not be a representative sample of gasoline marketed as mid-grade), mix of grades, or without a grade

label. EPA also excluded CG blendstock batches from grade-specific analyses even if they had a grade designation.

The table shows the total volume, in gallons, for the batches used to calculate each grade average. In part, because of factors discussed above

these volumes are not expected to represent the actual volumes by grade of retail gasoline.
189

RFG Aromatics-Geographic

Figure 7 Figure 8
190

Conventional Gasoline

CG Aromatics by Gasoline Volume

Figure 9

Summer CG Aromatics Content (Vol %) by Volume (from Batch Reports excluding Blendstocks)

Reporting Year

Volume

%tile

1997 1998 1999 2000 2001 2002 2003 2004 2005

minimum 0.0 0.0 0.9 0.0 0.0 0.0 1.0 0.0 0.0

5% 16.30 16.60 17.10 18.90 19.00 18.10 18.50 18.10 17.60

10% 19.00 19.30 19.40 20.60 20.80 20.40 20.30 20.20 20.00

15% 20.60 20.80 20.80 21.90 22.10 21.70 21.70 21.70 21.70

20% 21.90 22.10 22.00 23.00 23.00 22.70 22.70 22.80 22.90

25% 22.90 23.10 23.10 24.00 23.90 23.60 23.60 23.80 23.80

30% 23.80 24.10 24.00 24.90 24.60 24.40 24.40 24.60 24.70

35% 24.70 24.90 24.90 25.80 25.40 25.30 25.10 25.40 25.40

40% 25.50 25.50 25.80 26.50 26.10 26.10 25.90 26.20 26.10

45% 26.20 26.30 26.40 27.40 26.80 26.90 26.80 26.90 26.70

50% 26.90 26.90 27.10 28.10 27.60 27.80 27.50 27.70 27.40

55% 27.70 27.60 27.90 28.80 28.40 28.70 28.30 28.40 28.10

60% 28.50 28.30 28.80 29.50 29.20 29.40 29.00 29.10 28.80

65% 29.20 29.10 29.50 30.10 30.00 30.20 29.80 30.00 29.60

70% 30.10 29.90 30.40 30.80 30.80 30.90 30.70 30.90 30.50

75% 31.00 30.90 31.40 31.60 31.70 31.60 31.60 31.90 31.40

80% 32.40 32.10 32.20 32.70 32.60 32.50 32.60 32.80 32.40

85% 34.00 33.60 33.50 34.10 34.10 33.80 33.70 34.00 33.50

90% 36.10 35.90 35.60 36.20 36.30 35.60 35.60 35.80 35.30

95% 39.40 39.70 39.10 39.80 40.80 39.50 39.40 39.30 38.60

100% 60.20 59.50 60.50 60.00 59.80 59.30 58.30 60.50 59.90

Volume(gal): 39,380,364,542 39,078,941,326 37,192,967,557 36,387,851,238 38,542,042,404 40,818,795,156 43,243,575,045 43,509,104,037 42,196,228,805
191

CG Aromatics by Gasoline Volume (continued):

Figure 10

Winter CG Aromatics Content (Vol %) by Volume (from Batch Reports excluding Blendstocks)

Reporting Year

Volume %tile 1997 1998 1999 2000 2001 2002 2003 2004 2005

minimum 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

5% 15.5 14.5 15.2 15.2 16.2 16.0 15.8 15.2 15.2

10% 17.3 16.8 17.1 17.2 18.0 18.0 17.9 17.2 17.8

15% 18.5 18.3 18.6 18.6 19.2 19.2 19.2 18.6 19.1

20% 19.5 19.5 19.7 19.6 20.2 20.1 20.2 19.8 20.1

25% 20.3 20.4 20.6 20.6 21.1 20.9 21.0 20.8 20.9

30% 21.1 21.3 21.4 21.5 21.9 21.7 21.8 21.5 21.6

35% 21.9 22.1 22.1 22.3 22.7 22.2 22.4 22.1 22.3

40% 22.5 22.9 23.0 23.1 23.5 22.9 23.1 22.7 23.0

45% 23.4 23.6 23.7 23.8 24.2 23.6 23.8 23.4 23.6

50% 24.3 24.3 24.5 24.4 24.8 24.3 24.4 24.0 24.2

55% 25.1 24.9 25.2 25.1 25.5 24.9 25.0 24.9 24.8

60% 26.0 25.7 26.0 25.7 26.2 25.7 25.7 25.7 25.6

65% 26.8 26.6 26.8 26.5 26.9 26.4 26.3 26.4 26.3

70% 27.8 27.4 27.7 27.2 27.7 27.2 27.2 27.2 27.1

75% 28.7 28.4 28.6 28.2 28.5 28.1 28.0 28.1 27.9

80% 30.0 29.5 29.7 29.2 29.7 29.2 29.2 29.1 28.8

85% 31.6 31.1 31.2 30.6 31.1 30.7 30.5 30.4 30.1

90% 33.5 33.4 33.2 32.8 33.4 32.7 32.6 32.4 32.3

95% 36.9 36.7 36.7 36.5 37.0 37.3 36.3 35.7 35.8

100% 60.3 60.5 58.0 60.4 58.9 58.8 59.0 58.5 59.2

Volume (gal): 44,627,982,120 46,293,631,981 47,701,715,605 48,024,395,442 48,797,132,426 49,655,135,030 47,469,723,098 47,654,786,710 48,705,329,856
192

CG Aromatics by Gasoline Volume

(Cumulative Distributions for Latest Year Data)

Figure 11

Figure 12
193

CG Aromatics by Grade

CG Average Aromatics Content (Vol %) and Volume (gal) by Year, Grade, and Season – from Reporting Data

Reporting Year

Grade Season Data 1997 1998 1999 2000 2001 2002 2003 2004 2005

PRM s Average 31.8 32.6 31.6 33.1 34.7 32.4 32.2 31.2 31.3

Volume 6,910,973,553 6,635,803,305 6,252,416,423 4,957,386,104 4,996,778,324 5,181,939,065 5,149,486,549 4,635,507,910 4,138,979,931

w Average 28.2 29.7 29.6 29.1 30.3 29.8 29.5 28.3 29.5

Volume 8,310,678,815 8,233,384,513 7,690,219,372 6,648,441,003 6,548,540,176 6,571,003,043 5,517,761,736 5,077,869,493 4,510,104,837

REG s Average 26.3 26.4 26.6 27.6 27.4 27.4 27.4 27.5 27.3

Volume 28,062,618,693 28,410,709,416 26,656,367,421 27,358,607,481 28,964,604,238 30,995,449,082 33,053,399,345 34,601,650,558 33,851,903,439

w Average 24.3 23.8 24.1 24.0 24.6 24.3 24.4 24.1 24.3

Volume 32,175,385,639 32,177,203,389 33,356,627,836 35,199,495,331 35,935,271,164 36,931,713,041 35,949,009,293 37,504,589,388 39,123,690,864

Users of these grade-specific property estimates calculated from RFG and Anti-Dumping data should be aware that grade-specific estimates based

on reporting data may differ from actual retail property values by grade. Although aggregate estimates from the reporting system may also differ from

actual retail property values, there are several additional reasons why these grade-specific estimates may differ. Mid-grade gasoline is often blended from

regular and premium gasoline at some point downstream of the refinery. Thus, some of the gasoline volume reported and included in these tables as

regular or premium would be marketed as mid-grade. Additionally, EPA's grade-specific average analysis excludes some gasoline and blendstock that was

included in aggregate average estimates. EPA has presented averages for batches labeled as regular and premium gasoline only; excluding batches

labeled as mid-grade (since these batches may not be a representative sample of gasoline marketed as mid-grade), mix of grades, or without a grade

label. EPA also excluded CG blendstock batches from grade-specific analyses even if they had a grade designation.

The table shows the total volume, in gallons, for the batches used to calculate each grade average. In part, because of factors discussed above

these volumes are not expected to represent the actual volumes by grade of retail gasoline.
194

Appendix to Olefins Chapter

RFG Olefins Content by Gasoline Volume

Figure 1

Summer RFG Olefins Content (Vol %) by Volume (from Batch Reports)

Reporting Year

Volume %tile 1997 1998 1999 2000 2001 2002 2003 2004 2005

minimum 0.0 0.3 0.3 0.3 0.3 0.0 0.3 0.0 0.0

5% 2.7 2.4 2.8 1.3 2.0 1.8 1.5 2.0 1.8

10% 4.4 3.9 4.4 2.4 3.9 3.5 3.2 4.1 4.1

15% 5.6 4.8 5.3 4.4 6.4 5.4 5.4 6.0 5.9

20% 6.5 5.8 6.2 5.8 8.1 6.8 6.8 7.1 7.1

25% 7.1 6.7 7.2 7.0 9.3 8.0 7.8 8.2 8.4

30% 7.9 7.4 8.1 8.1 10.0 8.9 8.9 9.1 9.4

35% 8.6 8.3 8.9 9.0 10.6 9.5 9.5 9.9 10.1

40% 9.5 9.2 9.5 9.9 11.2 10.0 10.1 10.5 10.8

45% 10.3 9.9 10.1 10.5 11.6 10.5 10.6 11.1 11.6

50% 11.1 10.7 10.8 11.0 12.0 11.0 11.2 11.8 12.3

55% 11.9 11.5 11.4 11.6 12.6 11.6 11.8 12.3 13.0

60% 12.7 12.1 12.1 12.2 13.2 12.1 12.5 12.9 13.7

65% 13.7 12.9 13.0 12.8 13.7 12.6 13.1 13.4 14.4

70% 14.8 13.7 13.9 13.6 14.4 13.2 13.8 14.1 15.1

75% 16.1 14.6 14.9 14.5 15.1 13.9 14.4 14.7 15.7

80% 17.5 15.4 16.1 15.1 15.7 14.6 15.1 15.3 16.5

85% 19.0 16.5 17.5 15.9 16.5 15.5 15.9 16.0 17.2

90% 20.9 18.1 19.2 16.6 17.5 16.3 16.8 16.9 18.1

95% 23.8 20.0 21.3 17.9 18.9 17.7 18.4 18.5 19.4

100% 39.7 28.0 28.6 24.8 24.7 25.0 24.9 24.7 24.4

Volume (gal): 12,424,923,379 12,832,964,637 12,996,111,169 12,983,168,478 13,222,633,468 13,847,178,590 13,584,860,845 14,232,658,149 14,083,382,582
195

RFG Olefins Content by Gasoline Volume (continued):

Figure 2

Winter RFG Olefins Content (Vol %) by Volume (from Batch Reports)

Reporting Year

Volume %tile 1997 1998 1999 2000 2001 2002 2003 2004 2005

5% 2.00 2.90 3.10 3.00 2.90 1.90 1.50 1.30 1.40

10% 3.60 3.90 4.30 4.20 4.40 3.60 3.30 3.60 3.40

15% 4.70 4.70 5.10 5.20 5.70 4.90 4.50 4.80 4.70

20% 5.60 5.60 6.10 6.20 6.90 6.00 5.80 5.90 5.90

25% 6.40 6.40 6.80 7.10 8.00 6.90 6.80 6.80 6.90

30% 7.00 7.10 7.60 8.00 8.90 7.80 7.70 7.50 7.80

35% 7.70 7.90 8.40 8.90 9.70 8.60 8.60 8.30 8.60

40% 8.50 8.60 9.30 9.70 10.50 9.50 9.40 9.20 9.40

45% 9.40 9.20 9.90 10.60 11.30 10.20 10.10 10.10 10.00

50% 10.30 9.90 10.70 11.30 12.00 10.90 10.80 10.80 10.60

55% 11.20 10.60 11.40 12.10 12.70 11.60 11.50 11.60 11.30

60% 12.00 11.50 12.10 13.10 13.40 12.30 12.20 12.30 12.00

65% 13.10 12.40 12.90 13.90 14.20 13.20 13.00 13.10 12.70

70% 14.00 13.30 13.90 14.90 15.10 13.90 13.90 14.00 13.60

75% 15.20 14.40 14.80 16.00 16.10 14.70 14.70 14.80 14.50

80% 16.50 15.80 16.10 17.20 17.30 15.60 15.80 15.80 15.50

85% 18.30 17.40 17.40 18.50 18.90 16.70 17.10 17.10 17.10

90% 20.30 18.90 19.50 19.90 20.80 18.30 18.90 18.80 19.10

95% 23.40 21.00 21.70 21.70 22.80 21.00 21.00 21.20 21.30

100% 44.10 25.00 25.40 25.00 26.90 25.00 27.00 24.80 25.00

Volume (gal): 14,918,897,927 15,059,853,293 15,081,898,669 15,829,263,333 15,724,574,173 16,433,999,720 16,679,773,135 17,194,948,147 18,044,832,058
196

RFG Olefins Content by Gasoline Volume (continued):

(Cumulative Distributions for Latest Year Data)

Figure 3

Figure 4
197

RFG Olefins by Grade

Figure 5

Figure 6
198

RFG Olefins by Grade

RFG Average Olefins Content (v%) and Volume (gal) by Year, Grade, and Season-From Reporting Data

Reporting Year

Grade Season Data 1997 1998 1999 2000 2001 2002 2003 2004 2005

PRM s Average 8.4 7.8 8.1 8.1 9.2 7.8 7.6 8.3 8.6

Volume 3,449,496,834 3,651,258,096 3,537,723,033 2,788,564,977 2,773,110,841 2,931,886,907 2,736,973,386 2,385,535,898 2,144,095,101

w Average 8.7 8.2 8.4 9.0 9.5 8.1 8.0 8.6 8.8

Volume 3,891,638,151 4,139,316,745 3,839,207,618 3,420,180,881 3,305,514,921 3,387,457,520 3,103,333,727 2,945,338,123 2,583,694,635

REG s Average 13.4 12.2 12.6 11.3 12.5 11.6 11.8 12.0 12.5

Volume 8,933,744,061 9,007,552,063 9,320,974,363 10,122,448,765 10,392,283,260 10,878,238,821 10,824,904,975 11,783,350,501 11,881,795,879

w Average 12.3 11.8 12.4 12.6 13.1 12.0 11.7 11.6 11.4

Volume 10,818,337,187 10,663,420,477 10,902,774,956 12,246,078,983 12,361,561,882 13,031,122,001 13,486,978,064 14,160,927,780 15,422,172,055

Users of these grade-specific property estimates calculated from RFG and Anti-Dumping data should be aware that grade-specific estimates based

on reporting data may differ from actual retail property values by grade. Although aggregate estimates from the reporting system may also differ from

actual retail property values, there are several additional reasons why these grade-specific estimates may differ. Mid-grade gasoline is often blended from

regular and premium gasoline at some point downstream of the refinery. Thus, some of the gasoline volume reported, and included in these tables, as

regular or premium would be marketed as mid-grade. Additionally, EPA's grade-specific average analysis excludes some gasoline and blendstock that was

included in aggregate average estimates. EPA has presented averages for batches labeled as regular and premium gasoline only; excluding batches

labeled as mid-grade (since these batches may not be a representative sample of gasoline marketed as mid-grade), mix of grades, or without a grade

label. EPA also excluded CG blendstock batches from grade-specific analyses even if they had a grade designation.

The table shows the total volume, in gallons, for the batches used to calculate each grade average. In part, because of factors discussed above

these volumes are not expected to represent the actual volumes by grade of retail gasoline.
199

RFG Olefins-Geographic

Figure 7 Figure 8
200

Conventional Gasoline

CG Olefins Content by Gasoline Volume

Figure 9

Summer CG Olefins Content (Vol %) by Volume (from Batch Reports excluding Blendstocks)

Reporting Year

Volume %tile 1997 1998 1999 2000 2001 2002 2003 2004 2005

minimum 0.0 0.0 0.0 0.2 0.0 0.0 0.1 0.1 0.0

5% 1.4 1.8 1.9 2.3 2.8 2.2 2.1 2.0 2.5

10% 3.1 3.6 3.7 4.3 4.5 3.9 3.9 3.8 4.4

15% 5.0 5.2 5.1 5.5 5.9 5.4 5.1 5.0 5.7

20% 6.7 6.4 6.3 6.6 6.8 6.6 6.4 6.0 6.7

25% 7.6 7.0 7.1 7.4 7.7 7.5 7.2 6.8 7.6

30% 8.5 7.9 7.9 8.3 8.7 8.4 8.0 7.6 8.4

35% 9.4 8.7 8.9 9.1 9.5 9.2 8.9 8.4 9.2

40% 10.3 9.5 9.7 9.7 10.5 10.1 9.8 9.1 10.0

45% 11.0 10.3 10.6 10.5 11.3 11.0 10.6 9.8 10.7

50% 11.8 11.0 11.4 11.2 12.2 11.7 11.4 10.6 11.4

55% 12.6 11.7 12.2 12.1 13.0 12.4 12.2 11.4 12.0

60% 13.4 12.5 13.0 12.9 13.8 13.3 12.9 12.1 12.7

65% 14.2 13.3 13.9 13.8 14.6 14.1 13.8 12.9 13.6

70% 15.1 14.3 14.7 14.7 15.4 14.9 14.7 13.7 14.4

75% 16.0 15.4 15.7 15.5 16.2 15.8 15.6 14.8 15.4

80% 17.4 16.4 16.7 16.4 17.2 16.9 16.6 15.8 16.5

85% 18.6 17.7 18.1 17.5 18.4 18.2 17.8 17.2 17.9

90% 20.6 19.3 19.9 19.0 20.0 19.7 19.4 18.7 19.5

95% 24.1 21.8 22.6 21.3 23.1 22.2 22.5 21.1 22.3

100% 32.9 32.8 32.9 33.0 33.0 32.9 33.0 32.8 33.0

Volume (gal): 39,012,171,998 39,086,529,466 37,192,967,557 36,389,951,364 38,541,577,884 40,819,234,602 43,243,575,045 43,497,571,635 42,178,688,849
201

CG Olefins Content by Gasoline Volume (continued):

Figure 10

Winter CG Olefins Content (Vol %) by Volume (from Batch Reports excluding Blendstocks)

Reporting Year

Volume %tile 1997 1998 1999 2000 2001 2002 2003 2004 2005

minimum 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

5% 1.4 1.2 1.7 1.5 1.8 1.9 1.6 1.7 1.7

10% 3.1 2.8 3.4 3.7 3.9 3.5 3.3 3.7 4.1

15% 4.8 4.5 4.7 5.1 5.3 4.8 4.7 4.8 5.3

20% 6.2 5.7 5.9 6.3 6.5 6.1 5.8 5.6 6.3

25% 7.2 6.7 6.9 7.4 7.6 7.1 6.8 6.5 7.2

30% 8.2 7.5 7.7 8.2 8.6 8.2 7.6 7.4 7.9

35% 9.1 8.3 8.6 8.9 9.5 9.0 8.4 8.2 8.7

40% 9.9 9.1 9.3 9.6 10.3 9.8 9.1 8.9 9.4

45% 10.8 9.8 10.0 10.4 11.1 10.6 9.9 9.5 10.0

50% 11.7 10.6 10.7 11.3 11.9 11.3 10.7 10.3 10.8

55% 12.7 11.5 11.5 12.2 12.8 12.0 11.4 11.1 11.4

60% 13.5 12.3 12.4 13.0 13.6 12.7 12.2 11.9 12.2

65% 14.4 13.1 13.3 13.8 14.5 13.5 13.2 12.8 12.9

70% 15.3 14.0 14.2 14.8 15.4 14.3 14.1 13.8 13.7

75% 16.2 14.9 15.3 15.8 16.5 15.3 15.0 14.9 14.7

80% 17.2 16.1 16.3 16.9 17.5 16.4 16.2 16.2 15.9

85% 18.6 17.4 17.7 18.3 18.7 17.8 17.7 17.8 17.3

90% 20.4 19.0 19.4 20.0 20.7 19.8 19.6 19.5 19.4

95% 23.8 21.8 22.1 23.0 23.8 22.7 22.8 22.9 23.2

100% 33.0 33.0 33.0 33.0 33.0 33.0 33.0 33.0 33.0

Volume (gal): 44,301,841,176 46,293,525,301 47,701,715,605 48,024,395,442 48,786,984,011 49,644,581,942 47,465,390,042 47,636,716,042 48,690,992,232
202

CG Olefins by Grade

CG Average Olefins Content (v%) and Volume (gal) by Year, Grade, and Season-from Reporting Data

Reporting Year

Grade Season Data 1997 1998 1999 2000 2001 2002 2003 2004 2005

PRM s Average 6.65 5.91 6.33 6.41 6.74 5.80 6.65 6.33 6.86

Volume 6,846,643,119 6,635,688,729 6,252,416,423 4,957,386,104 4,996,778,324 5,181,939,065 5,149,486,549 4,623,975,508 4,123,526,493

w Average 6.97 6.00 6.22 6.99 7.13 6.63 5.86 6.20 6.42

Volume 8,265,699,839 8,233,277,833 7,690,219,372 6,648,441,003 6,551,541,289 6,569,323,421 5,517,761,736 5,069,256,175 4,498,707,927

REG s Average 14.03 13.13 13.35 13.10 13.83 13.38 12.95 12.11 12.80

Volume 27,758,756,583 28,418,412,132 26,656,367,421 27,360,707,607 28,964,139,718 30,995,888,528 33,053,399,345 34,601,650,558 33,849,816,921

w Average 13.85 12.81 12.80 13.39 13.89 12.98 12.65 12.38 12.44

Volume 31,894,223,671 32,177,203,389 33,356,627,836 35,199,495,331 35,928,338,728 36,922,839,575 35,944,676,237 37,495,132,038 39,120,750,150

Users of these grade-specific property estimates calculated from RFG and Anti-Dumping data should be aware that grade-specific estimates based

on reporting data may differ from actual retail property values by grade. Although aggregate estimates from the reporting system may also differ from

actual retail property values, there are several additional reasons why these grade-specific estimates may differ. Mid-grade gasoline is often blended from

regular and premium gasoline at some point downstream of the refinery. Thus, some of the gasoline volume reported, and included in these tables, as

regular or premium would be marketed as mid-grade. Additionally, EPA's grade-specific average analysis excludes some gasoline and blendstock that was

included in aggregate average estimates. EPA has presented averages for batches labeled as regular and premium gasoline only; excluding batches

labeled as mid-grade (since these batches may not be a representative sample of gasoline marketed as mid-grade), mix of grades, or without a grade

label. EPA also excluded CG blendstock batches from grade-specific analyses even if they had a grade designation.

The table shows the total volume, in gallons, for the batches used to calculate each grade average. In part, because of factors discussed above

these volumes are not expected to represent the actual volumes by grade of retail gasoline.
203

Appendix to Distillation Parameters Chapter

RFG E200 by Gasoline Volume

Figure 1

Summer RFG E200 (%) by Volume (from Batch Reports)

Reporting Year

Volume %tile 1998 1999 2000 2001 2002 2003 2004 2005

minimum 30.6 29.9 31.3 32.4 29.0 30.1 31.4 30.4

5% 39.1 39.6 40.5 39.9 39.4 39.5 40.0 40.7

10% 41.2 41.9 41.9 41.4 40.9 41.0 41.8 42.1

15% 42.8 43.2 42.7 42.5 41.7 42.1 42.8 43.4

20% 44.0 44.5 43.4 43.4 42.5 43.1 43.7 44.2

25% 45.1 45.4 44.1 44.1 43.1 44.0 44.6 44.9

30% 46.0 46.4 44.7 44.7 44.0 44.8 45.2 45.6

35% 47.1 47.5 45.4 45.3 45.0 45.6 45.8 46.4

40% 47.9 48.3 46.0 46.1 46.0 46.3 46.4 47.2

45% 48.7 48.9 46.6 46.7 46.6 47.0 47.0 47.8

50% 49.3 49.5 47.3 47.4 47.3 47.7 47.6 48.5

55% 49.9 50.1 47.9 48.0 47.9 48.4 48.2 49.2

60% 50.7 50.8 48.5 48.6 48.6 49.2 48.8 50.0

65% 51.2 51.3 49.1 49.2 49.3 49.8 49.4 50.8

70% 51.8 51.9 49.8 49.8 50.0 50.6 50.1 51.7

75% 52.4 52.8 50.7 50.5 50.8 51.3 50.9 52.4

80% 53.2 53.6 51.7 51.2 51.9 52.1 51.8 53.2

85% 54.3 54.7 52.8 52.1 53.2 53.2 52.9 54.3

90% 55.3 56.1 54.1 53.2 54.7 54.8 54.2 55.7

95% 56.8 57.7 55.6 55.3 56.4 56.7 56.0 57.4

100% 64.9 73.7 65.9 63.3 63.1 63.5 63.0 67.9

Volume (gal): 12,832,964,637 12,996,111,169 12,983,168,478 13,222,633,468 13,847,971,634 13,584,860,845 14,232,658,149 14,083,382,582
204

RFG E200 by Gasoline Volume (continued):

Figure 2

Winter RFG E200 (%) by Volume (from Batch Reports)

Reporting Year

Volume %tile 1998 1999 2000 2001 2002 2003 2004 2005

minimum 30.3 31.5 32.1 30.9 31.4 30.4 30.5 31.3

5% 44.9 45.2 46.2 45.6 45.3 45.9 47.1 47.0

10% 47.6 48.0 48.7 47.9 48.5 48.6 49.2 49.3

15% 49.6 49.9 50.4 49.6 50.3 50.4 50.8 50.8

20% 51.2 51.3 51.5 51.1 51.7 51.6 51.9 52.0

25% 52.6 52.6 52.7 52.3 52.8 52.6 53.0 52.9

30% 53.7 53.7 53.7 53.4 53.8 53.6 53.8 53.8

35% 54.6 54.5 54.5 54.2 54.6 54.5 54.5 54.7

40% 55.4 55.3 55.3 55.0 55.3 55.3 55.3 55.5

45% 56.1 56.1 56.0 55.8 56.1 56.0 55.9 56.3

50% 56.8 56.7 56.8 56.5 56.7 56.7 56.4 57.0

55% 57.3 57.4 57.5 57.0 57.3 57.3 57.0 57.6

60% 57.9 58.0 58.0 57.6 57.9 57.9 57.7 58.3

65% 58.5 58.5 58.7 58.2 58.5 58.5 58.4 58.7

70% 59.1 59.1 59.3 58.9 59.1 59.1 59.0 59.2

75% 59.8 59.7 60.0 59.6 59.9 59.7 59.6 59.8

80% 60.4 60.4 60.7 60.3 60.6 60.3 60.4 60.4

85% 61.3 61.2 61.5 61.2 61.2 61.0 61.1 61.1

90% 62.4 62.3 62.7 62.4 62.0 62.0 62.2 62.0

95% 64.4 64.2 64.9 64.1 63.8 63.6 63.9 63.2

100% 70.0 73.6 70.0 71.8 69.5 70.0 69.9 69.1

Volume (gal): 15,059,853,293 15,081,898,669 15,829,263,333 15,724,574,173 16,433,999,720 16,679,773,135 17,190,635,125 18,044,832,058
205

RFG E200 by Gasoline Volume (continued):

(Cumulative Distributions for Latest Year Data)

Figure 3

Figure 4
206

RFG E200 by Grade

Figure 5

Figure 6
207

RFG E200 by Grade (continued):

RFG Average E200 (%) and Volume (gal) by Year, Grade, and Season-From Reporting Data

Reporting Year

Grade Season Data 1998 1999 2000 2001 2002 2003 2004 2005

PRM s Average 43.95 44.24 43.75 43.20 42.44 42.97 43.09 43.08

Volume 3,649,195,434 3,537,723,033 2,788,564,977 2,773,110,841 2,931,886,907 2,736,973,386 2,385,535,898 2,144,095,101

w Average 50.76 50.73 51.14 50.47 50.58 50.64 51.29 50.91

Volume 4,139,316,745 3,839,207,618 3,418,369,505 3,301,129,239 3,387,457,520 3,103,333,727 2,943,555,811 2,583,694,635

REG s Average 50.73 51.09 48.76 48.60 48.88 49.13 48.86 49.90

Volume 9,007,552,063 9,320,974,363 10,122,448,765 10,389,949,614 10,879,031,865 10,824,904,975 11,783,350,501 11,881,795,879

w Average 57.95 57.83 57.72 57.31 57.22 57.27 57.21 57.18

Volume 10,638,539,349 10,902,774,956 12,246,078,983 12,307,517,794 13,031,122,001 13,486,978,064 14,160,927,780 15,422,172,055

Users of these grade-specific property estimates calculated from RFG and Anti-Dumping data should be aware that grade-specific

estimates based on reporting data may differ from actual retail property values by grade. Although aggregate estimates from the reporting

system may also differ from actual retail property values, there are several additional reasons why these grade-specific estimates may differ. Midgrade gasoline is often blended from regular and premium gasoline at some point downstream of the refinery. Thus, some of the gasoline volume

reported and included in these tables as regular or premium would be marketed as mid-grade. Additionally, EPA's grade-specific average analysis

excludes some gasoline and blendstock that was included in aggregate average estimates. EPA has presented averages for batches labeled as

regular and premium gasoline only; excluding batches labeled as mid-grade (since these batches may not be a representative sample of gasoline

marketed as mid-grade), mix of grades, or without a grade label. EPA also excluded CG blendstock batches from grade-specific analyses even if

they had a grade designation.

The table shows the total volume, in gallons, for the batches used to calculate each grade average. In part, because of factors discussed

above these volumes are not expected to represent the actual volumes by grade of retail gasoline.
208

RFG E200-Geographic

Figure 7 Figure 8
209

RFG E300 by Gasoline Volume

Figure 9

Summer RFG E300 (%) by Volume (from Batch Reports)

Reporting Year

Volume %tile 1998 1999 2000 2001 2002 2003 2004 2005

minimum 63.9 70.2 74.5 74.7 72.4 74.8 74.4 73.8

5% 76.1 76.5 79.2 79.3 79.1 79.3 78.2 79.1

10% 77.7 78.1 80.1 80.1 80.2 80.1 79.2 79.9

15% 78.6 79.0 80.8 80.7 80.8 80.7 79.8 80.5

20% 79.3 79.7 81.3 81.2 81.3 81.3 80.4 81.1

25% 79.8 80.2 81.8 81.8 81.8 81.8 80.9 81.6

30% 80.3 80.7 82.3 82.3 82.3 82.1 81.2 82.0

35% 80.8 81.2 82.8 82.8 82.7 82.5 81.6 82.4

40% 81.3 81.7 83.3 83.3 83.1 83.0 82.0 82.7

45% 81.8 82.2 83.8 83.8 83.6 83.5 82.4 83.1

50% 82.3 82.6 84.3 84.2 84.1 84.0 82.8 83.5

55% 82.7 83.1 84.9 84.7 84.6 84.5 83.3 83.9

60% 83.2 83.5 85.3 85.1 85.1 85.0 83.9 84.4

65% 83.8 84.0 85.8 85.5 85.5 85.6 84.5 85.0

70% 84.4 84.6 86.4 86.0 86.0 86.1 85.1 85.6

75% 85.0 85.1 87.0 86.4 86.5 86.7 85.8 86.3

80% 85.9 85.9 87.8 86.9 86.9 87.2 86.4 87.0

85% 86.7 86.7 88.6 87.6 87.7 88.0 87.3 87.9

90% 87.9 87.7 89.7 88.5 88.7 88.9 88.2 88.9

95% 89.6 89.2 91.1 89.8 90.3 90.1 89.7 90.1

100% 100.0 100.0 99.0 99.9 99.7 100.0 100.0 100.0

Volume (gal): 12,832,964,637 12,996,111,169 12,983,168,478 13,222,633,468 13,847,971,634 13,584,860,845 14,232,658,149 14,083,382,582
210

RFG E300 by Gasoline Volume (continued):

Figure 10

Winter RFG E300 (%) by Volume (from Batch Reports)

Reporting Year

Volume %tile 1998 1999 2000 2001 2002 2003 2004 2005

minimum 64.4 70.5 71.0 67.5 71.0 64.1 69.6 70.3

5% 77.6 77.6 79.1 78.7 78.7 78.6 78.1 79.0

10% 79.5 79.2 80.8 80.0 80.3 80.0 79.8 80.5

15% 80.8 80.4 81.9 81.2 81.4 81.0 80.8 81.5

20% 81.7 81.2 82.8 82.0 82.2 81.7 81.5 82.2

25% 82.4 82.0 83.5 82.7 82.9 82.4 82.2 82.9

30% 82.9 82.6 84.0 83.5 83.5 82.9 82.8 83.4

35% 83.3 83.1 84.5 84.0 84.0 83.5 83.3 83.8

40% 83.8 83.6 84.9 84.6 84.5 84.0 83.8 84.3

45% 84.3 84.0 85.4 85.1 85.0 84.5 84.3 84.7

50% 84.9 84.4 85.9 85.7 85.4 84.9 84.8 85.2

55% 85.4 84.9 86.5 86.2 85.8 85.4 85.3 85.7

60% 85.9 85.5 87.0 86.8 86.4 85.9 85.7 86.2

65% 86.5 86.0 87.5 87.5 87.0 86.6 86.2 86.7

70% 87.1 86.6 88.1 88.1 87.6 87.2 86.8 87.2

75% 87.7 87.3 88.8 88.8 88.3 87.9 87.4 87.9

80% 88.2 88.0 89.4 89.5 89.0 88.5 88.3 88.4

85% 88.9 88.8 90.2 90.3 90.1 89.3 89.1 89.2

90% 89.9 89.9 91.2 91.2 91.1 90.3 90.2 90.0

95% 91.3 91.4 92.6 92.7 92.5 91.8 91.8 91.2

100% 99.5 100.0 99.1 99.4 100.0 100.0 100.0 100.0

Volume (gal): 15,059,853,293 15,081,898,669 15,829,263,333 15,724,574,173 16,433,999,720 16,679,773,135 17,190,635,125 18,044,832,058
211

RFG E300 by Gasoline Volume (continued):

(Cumulative Distributions for Latest Year Data)

Figure 11

Figure 12
212

RFG E300 by Grade

Figure 13

Figure 14
213

RFG E300 by Grade (continued):

RFG Average E300 (%) and Volume (gal) by Year, Grade, and Season-From Reporting Data

Reporting Year

Grade Season Data 1998 1999 2000 2001 2002 2003 2004 2005

PRM s Average 83.70 84.14 86.85 86.27 85.86 86.42 85.62 86.05

Volume 3,649,195,434 3,537,723,033 2,788,564,977 2,773,110,841 2,931,886,907 2,736,973,386 2,385,535,898 2,144,095,101

w Average 85.23 85.72 86.96 86.22 86.99 86.15 86.31 86.68

Volume 4,139,316,745 3,839,207,618 3,420,180,881 3,301,129,239 3,387,457,520 3,103,333,727 2,943,555,811 2,583,694,635

REG s Average 82.16 82.38 84.09 83.85 83.98 83.87 82.97 83.72

Volume 9,007,552,063 9,320,974,363 10,122,448,765 10,389,949,614 10,879,031,865 10,824,904,975 11,783,350,501 11,881,795,879

w Average 84.79 84.24 85.85 85.65 85.11 84.91 84.67 85.12

Volume 10,638,539,349 10,902,774,956 12,246,078,983 12,307,517,794 13,031,122,001 13,486,978,064 14,160,927,780 15,422,172,055

Users of these grade-specific property estimates calculated from RFG and Anti-Dumping data should be aware that grade-specific estimates

based on reporting data may differ from actual retail property values by grade. Although aggregate estimates from the reporting system may also

differ from actual retail property values, there are several additional reasons why these grade-specific estimates may differ. Mid-grade gasoline is

often blended from regular and premium gasoline at some point downstream of the refinery. Thus, some of the gasoline volume reported and

included in these tables as regular or premium would be marketed as mid-grade. Additionally, EPA's grade-specific average analysis excludes

some gasoline and blendstock that was included in aggregate average estimates. EPA has presented averages for batches labeled as regular and

premium gasoline only; excluding batches labeled as mid-grade (since these batches may not be a representative sample of gasoline marketed as

mid-grade), mix of grades, or without a grade label. EPA also excluded CG blendstock batches from grade-specific analyses even if they had a

grade designation.

The table shows the total volume, in gallons, for the batches used to calculate each grade average. In part, because of factors discussed

above these volumes are not expected to represent the actual volumes by grade of retail gasoline.
214

RFG E300 Geographic

Figure 17 Figure 18
215

RFG T50 Geographic

Figure 19 Figure 20
216

RFG T90 Geographic

Figure 21 Figure 22
217

Conventional Gasoline

CG E200 by Gasoline Volume

Figure 23

Summer CG E200 (%) by Volume (from Batch Reports excluding Blendstocks)

Reporting Year

Volume %tile 1998 1999 2000 2001 2002 2003 2004 2005

minimum 27.0 27.0 27.0 27.0 27.0 27.0 27.0 27.0

5% 32.1 32.6 34.5 34.8 34.8 34.7 35.0 35.4

10% 35.4 36.0 37.3 37.7 37.6 37.4 37.7 38.1

15% 37.8 38.5 38.9 39.3 39.1 39.0 39.2 39.6

20% 39.6 40.0 40.0 40.4 40.3 40.3 40.3 40.7

25% 40.9 41.3 41.1 41.3 41.2 41.3 41.3 41.7

30% 41.9 42.2 42.2 42.1 42.1 42.2 42.1 42.5

35% 42.9 43.1 43.1 42.9 42.8 43.0 42.8 43.3

40% 43.5 43.9 43.8 43.7 43.5 43.8 43.5 44.0

45% 44.3 44.6 44.6 44.4 44.2 44.5 44.2 44.7

50% 45.0 45.3 45.3 45.2 44.9 45.2 44.8 45.4

55% 45.8 46.0 45.9 45.9 45.6 45.9 45.5 46.1

60% 46.4 46.6 46.7 46.5 46.2 46.5 46.3 46.9

65% 47.2 47.3 47.4 47.2 47.0 47.2 46.9 47.6

70% 47.9 48.2 48.1 47.9 47.9 47.9 47.8 48.4

75% 48.9 49.0 49.0 48.9 48.8 48.7 48.8 49.2

80% 50.0 50.0 49.8 49.9 49.7 49.6 49.8 50.2

85% 51.3 51.4 50.9 50.9 50.5 50.9 50.9 51.5

90% 52.9 52.7 52.1 52.4 51.6 52.3 52.5 53.1

95% 54.9 54.9 54.1 54.3 53.5 54.6 54.4 55.1

100% 68.9 76.0 64.6 69.8 76.4 76.8 73.5 67.0

Volume (gal): 39,086,644,042 37,192,967,557 36,389,951,364 38,542,457,289 40,819,234,602 43,243,575,045 43,509,104,037 42,196,228,805
218

CG E200 by Gasoline Volume (continued):

Figure 24

Winter CG E200 (%) by Volume (from Batch Reports Excluding Blendstocks)

Reporting Year

Volume %tile 1998 1999 2000 2001 2002 2003 2004 2005

minimum 27.0 27.0 27.0 27.0 27.0 27.0 27.0 27.0

5% 35.90 35.90 37.50 37.60 37.80 38.20 38.90 38.70

10% 39.10 39.40 40.90 40.50 41.30 41.50 42.10 41.90

15% 41.70 42.10 43.10 42.70 43.00 43.60 43.90 43.90

20% 44.00 44.20 44.70 44.20 44.50 45.00 45.40 45.40

25% 45.60 45.60 45.80 45.40 45.60 46.20 46.60 46.60

30% 46.90 46.80 47.00 46.50 46.60 47.10 47.50 47.50

35% 47.90 47.90 48.00 47.50 47.60 48.10 48.40 48.40

40% 48.90 48.80 48.90 48.40 48.50 48.80 49.20 49.10

45% 49.70 49.60 49.70 49.20 49.30 49.70 49.90 49.90

50% 50.50 50.40 50.40 50.00 50.10 50.40 50.70 50.60

55% 51.20 51.30 51.20 50.80 50.90 51.10 51.40 51.40

60% 51.90 51.90 51.90 51.60 51.60 51.80 52.00 52.10

65% 52.60 52.60 52.70 52.30 52.30 52.40 52.70 52.90

70% 53.50 53.40 53.50 53.10 53.20 53.20 53.50 53.60

75% 54.50 54.20 54.30 54.00 54.00 54.00 54.40 54.40

80% 55.60 55.30 55.20 54.80 55.00 55.10 55.30 55.40

85% 56.70 56.50 56.40 55.90 56.00 56.00 56.30 56.30

90% 58.10 57.90 57.80 57.20 57.40 57.30 57.50 57.40

95% 60.40 60.20 59.70 58.80 59.00 59.30 59.30 59.20

100% 75.50 75.50 76.30 76.90 75.90 75.40 76.80 73.60

Volume (gal): 46,293,637,987 47,701,715,605 48,030,024,114 48,810,395,817 49,655,135,030 47,469,723,098 47,654,973,148 48,705,329,856
219

CG E200 by Gasoline Volume (continued):

(Cumulative Distributions for Latest Year Data)

Figure 25

Figure 26
220

CG E200 (by Grade)

CG Average E200 (%) and Volume (gal) by Year, Grade and Season –From Reporting Data

Reporting Year

Grade Season Data 1998 1999 2000 2001 2002 2003 2004 2005

PRM s Average 36.7 37.9 37.8 38.1 37.4 37.8 37.8 37.2

Volume 6,635,803,305 6,252,416,423 4,957,386,104 4,996,778,324 5,181,939,065 5,149,486,549 4,635,507,910 4,138,979,931

w Average 40.5 40.7 41.2 41.2 41.1 41.4 42.1 41.1

Volume 8,233,390,519 7,690,219,372 6,648,441,003 6,555,892,276 6,571,003,043 5,517,761,736 5,077,869,493 4,510,104,837

REG s Average 46.3 46.6 46.0 46.1 45.9 46.1 45.8 46.3

Volume 28,418,412,132 26,656,367,421 27,360,707,607 28,965,019,123 30,995,888,528 33,053,399,345 34,601,650,558 33,851,903,439

w Average 51.9 51.6 51.4 50.7 51.0 51.0 51.1 50.9

Volume 32,177,203,389 33,356,627,836 35,199,495,331 35,941,182,455 36,931,713,041 35,949,009,293 37,504,775,826 39,123,690,864

Users of these grade-specific property estimates calculated from RFG and Anti-Dumping data should be aware that grade-specific estimates

based on reporting data may differ from actual retail property values by grade. Although aggregate estimates from the reporting system may also

differ from actual retail property values, there are several additional reasons why these grade-specific estimates may differ. Mid-grade gasoline is

often blended from regular and premium gasoline at some point downstream of the refinery. Thus, some of the gasoline volume reported and

included in these tables as regular or premium would be marketed as mid-grade. Additionally, EPA's grade-specific average analysis excludes

some gasoline and blendstock that was included in aggregate average estimates. EPA has presented averages for batches labeled as regular and

premium gasoline only; excluding batches labeled as mid-grade (since these batches may not be a representative sample of gasoline marketed as

mid-grade), mix of grades, or without a grade label. EPA also excluded CG blendstock batches from grade-specific analyses even if they had a

grade designation.

The table shows the total volume, in gallons, for the batches used to calculate each grade average. In part, because of factors discussed

above these volumes are not expected to represent the actual volumes by grade of retail gasoline.
221

CG E300 by Gasoline Volume

Figure 27

Summer CG E300 (%) by Volume (from Batch Reports Excluding Blendstocks)

Reporting Year

Volume %tile 1998 1999 2000 2001 2002 2003 2004 2005

minimum 63.2 63.0 63.1 63.0 63.1 64.4 64.5 63.6

5% 73.8 74.3 73.1 74.0 73.4 73.7 73.0 74.0

10% 75.4 75.9 74.9 75.8 75.0 75.3 74.8 75.7

15% 76.5 77.1 76.1 77.0 76.2 76.3 76.1 77.0

20% 77.4 77.9 77.0 77.9 77.1 77.1 77.0 78.1

25% 78.1 78.5 77.7 78.5 77.8 77.8 77.7 78.9

30% 78.6 78.9 78.4 79.0 78.3 78.4 78.4 79.5

35% 79.2 79.4 78.9 79.5 78.8 78.9 79.0 80.0

40% 79.7 79.9 79.4 79.9 79.3 79.5 79.6 80.5

45% 80.2 80.4 79.8 80.4 79.8 80.0 80.1 81.0

50% 80.7 80.9 80.3 80.9 80.2 80.4 80.7 81.5

55% 81.1 81.4 80.8 81.2 80.8 80.8 81.2 82.0

60% 81.6 81.8 81.3 81.7 81.3 81.4 81.7 82.5

65% 82.1 82.3 81.9 82.3 81.8 82.1 82.1 83.1

70% 82.8 82.8 82.4 82.9 82.3 82.7 82.6 83.6

75% 83.4 83.4 83.0 83.5 83.0 83.3 83.1 84.2

80% 84.0 84.0 83.7 84.2 83.8 84.0 83.8 84.9

85% 84.9 84.8 84.6 84.9 84.8 84.9 84.7 85.6

90% 85.9 85.9 85.7 85.9 85.9 86.1 85.8 86.8

95% 87.6 87.6 87.5 87.9 88.1 88.2 87.4 88.3

100% 100.0 98.6 98.2 100.0 99.4 98.3 98.2 100.0

Volume (gal): 39,086,644,042 37,192,967,557 36,389,951,364 38,542,457,289 40,819,234,602 43,243,575,045 43,509,104,037 42,196,228,805
222

CG E300 by Gasoline Volume (continued):

Figure 28

Winter CG E300(%) by Volume (from Batch Reports Excluding Blendstocks)

Reporting Year

Volume %tile 1998 1999 2000 2001 2002 2003 2004 2005

minimum 63.4 63.4 63.4 63.4 63.4 63.4 63.4 63.4

5% 75.3 74.8 75.9 75.8 75.9 75.7 75.5 76.8

10% 77.0 77.0 77.8 77.6 77.6 77.3 77.2 78.5

15% 78.3 78.4 79.2 78.9 78.6 78.3 78.6 79.7

20% 79.2 79.3 80.0 79.7 79.4 79.2 79.6 80.5

25% 80.0 80.1 80.7 80.4 80.1 79.9 80.4 81.2

30% 80.7 80.7 81.3 81.0 80.8 80.5 81.1 81.8

35% 81.4 81.3 81.8 81.5 81.4 81.1 81.7 82.4

40% 82.0 81.8 82.4 82.0 81.9 81.7 82.2 82.9

45% 82.6 82.3 82.8 82.5 82.4 82.1 82.8 83.3

50% 83.1 82.9 83.3 83.0 82.9 82.7 83.2 83.8

55% 83.7 83.3 83.8 83.5 83.5 83.2 83.7 84.2

60% 84.2 83.9 84.4 83.9 84.0 83.7 84.2 84.7

65% 84.8 84.4 84.9 84.5 84.5 84.1 84.7 85.2

70% 85.4 85.0 85.5 85.1 85.1 84.7 85.3 85.7

75% 86.0 85.6 86.2 85.7 85.6 85.3 85.9 86.3

80% 86.8 86.4 86.9 86.4 86.4 86.0 86.6 87.1

85% 87.7 87.4 87.9 87.4 87.2 87.0 87.6 88.1

90% 88.7 88.6 89.0 88.7 88.5 88.2 88.8 89.2

95% 90.3 90.6 90.9 90.9 90.4 90.2 90.4 90.9

100% 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0

Volume (gal): 46,293,637,987 47,701,715,605 48,030,024,114 48,810,395,817 49,655,135,030 47,469,723,098 47,654,973,148 48,705,329,856
223

CG E300 by Gasoline Volume (continued):

(Cumulative Distributions for Latest Year Data)

Figure 29

Figure 30
224

CG E300 by Grade

CG Average E300 (%) and Volume (gal) by Year, Grade and Season-From Reporting Data

Reporting Year

Grade Season Data 1998 1999 2000 2001 2002 2003 2004 2005

PRM s Average 81.9 82.4 81.6 83.2 82.1 82.8 82.4 83.2

Volume 6,635,803,305 6,252,416,423 4,957,386,104 4,996,778,324 5,181,939,065 5,149,486,549 4,635,507,910 4,138,979,931

w Average 83.6 83.6 84.2 83.7 84.0 83.7 83.5 85.2

Volume 8,233,390,519 7,690,219,372 6,648,441,003 6,555,892,276 6,571,003,043 5,517,761,736 5,077,869,493 4,510,104,837

REG s Average 80.5 80.7 80.0 80.5 80.1 80.2 80.2 81.2

Volume 28,418,412,132 26,656,367,421 27,360,707,607 28,965,019,123 30,995,888,528 33,053,399,345 34,601,650,558 33,851,903,439

w Average 82.9 82.8 83.2 82.9 82.8 82.5 82.9 83.6

Volume 32,177,203,389 33,356,627,836 35,199,495,331 35,941,182,455 36,931,713,041 35,949,009,293 37,504,775,826 39,123,690,864

Users of these grade-specific property estimates calculated from RFG and Anti-Dumping data should be aware that grade-specific estimates

based on reporting data may differ from actual retail property values by grade. Although aggregate estimates from the reporting system may also

differ from actual retail property values, there are several additional reasons why these grade-specific estimates may differ. Mid-grade gasoline is

often blended from regular and premium gasoline at some point downstream of the refinery. Thus, some of the gasoline volume reported and

included in these tables as regular or premium would be marketed as mid-grade. Additionally, EPA's grade-specific average analysis excludes some

gasoline and blendstock that was included in aggregate average estimates. EPA has presented averages for batches labeled as regular and

premium gasoline only; excluding batches labeled as mid-grade (since these batches may not be a representative sample of gasoline marketed as

mid-grade), mix of grades, or without a grade label. EPA also excluded CG blendstock batches from grade-specific analyses even if they had a

grade designation.

The table shows the total volume, in gallons, for the batches used to calculate each grade average. In part, because of factors discussed

above these volumes are not expected to represent the actual volumes by grade of retail gasoline.
225

Appendix to Emissions and Emissions Performance Chapter

RFG VOC Performance by Gasoline Volume

Figure 1

Summer RFG VOC Reduction (%) by Volume (from Batch Reports)

Reporting Year

Volume

%tile

1998 1999 2000 2001 2002 2003 2004 2005

minimum -5.7 -2.7 21.9 21.4 20.2 21.7 21.5 22.2

5% 11.0 11.1 25.4 25.0 25.0 25.0 25.1 25.0

10% 12.5 12.6 26.1 25.8 25.7 25.8 25.7 25.7

15% 13.6 13.6 26.6 26.4 26.2 26.2 26.2 26.2

20% 14.4 14.4 27.0 26.8 26.6 26.6 26.6 26.5

25% 15.1 15.1 27.2 27.2 26.9 27.0 27.0 27.0

30% 15.7 16.0 27.5 27.5 27.2 27.3 27.3 27.3

35% 16.4 16.8 27.8 27.8 27.5 27.5 27.5 27.6

40% 17.1 17.5 28.0 28.0 27.7 27.8 27.8 27.8

45% 17.7 18.4 28.2 28.3 28.0 28.1 28.0 28.0

50% 18.5 19.3 28.5 28.5 28.2 28.3 28.2 28.2

55% 19.4 20.4 28.7 28.8 28.5 28.5 28.5 28.5

60% 20.4 21.4 29.0 29.0 28.7 28.8 28.7 28.7

65% 21.5 22.5 29.3 29.2 28.9 29.0 29.0 29.0

70% 22.8 23.4 29.5 29.5 29.1 29.3 29.2 29.2

75% 24.1 24.6 29.8 29.7 29.4 29.5 29.5 29.5

80% 25.0 25.6 30.1 30.0 29.7 29.8 29.8 29.8

85% 26.0 26.5 30.5 30.4 30.1 30.1 30.1 30.1

90% 27.0 27.4 30.9 30.8 30.5 30.5 30.6 30.5

95% 28.1 28.6 31.6 31.4 31.1 31.2 31.3 31.1

100% 35.2 33.3 33.9 33.6 33.6 34.8 34.4 33.6

Volume

(gal): 12,551,351,739 12,605,647,535 12,924,625,994 13,215,304,396 13,838,063,327 13,583,809,485 14,230,001,733 14,070,501,006
226

RFG VOC Performance by Gasoline Volume (continued):

(Cumulative Distribution for Latest Year Data)

Figure 2

RFG VOC Performance by Gasoline Volume (continued):

(Batches separated by VOC control region designation)

Region 1 Summer RFG VOC Reduction (%) by Volume (from Batch Reports)

Reporting Year

Volume %tile 2000 2001 2002 2003 2004 2005

minimum 24.3 24.0 24.6 23.6 25.0 25.1

5% 27.0 26.9 27.0 26.9 26.9 27.2

10% 27.5 27.5 27.3 27.4 27.3 27.6

15% 27.9 27.8 27.6 27.8 27.6 27.9

20% 28.1 28.1 27.9 28.1 27.9 28.1

25% 28.4 28.4 28.2 28.4 28.1 28.4

30% 28.7 28.6 28.5 28.6 28.3 28.6

35% 29.0 28.8 28.6 28.8 28.6 28.8

40% 29.1 29.0 28.8 29.0 28.8 29.0

45% 29.3 29.1 29.0 29.2 29.0 29.2

50% 29.5 29.3 29.2 29.4 29.2 29.3

55% 29.7 29.5 29.4 29.5 29.4 29.5

60% 29.9 29.7 29.6 29.7 29.6 29.6

65% 30.1 29.9 29.8 29.9 29.8 29.8

70% 30.3 30.2 30.0 30.1 30.0 30.1

75% 30.6 30.4 30.2 30.3 30.3 30.2

80% 30.8 30.7 30.5 30.5 30.5 30.5

85% 31.1 31.0 30.7 30.8 30.8 30.7

90% 31.5 31.3 31.1 31.1 31.3 31.0

95% 32.1 31.8 31.6 31.6 31.9 31.6

100% 33.9 33.6 33.6 34.8 34.4 33.6

Volume (gal): 5,710,929,463 5,909,480,958 6,017,416,713 6,095,268,147 6,329,701,695 5,983,085,189
227

Region 2 “Unadjusted Standard” Summer RFG VOC Reduction (%) by Volume (from Batch Reports)

Reporting Year

Volume %tile 2000 2001 2002 2003 2004 2005

minimum 21.9 22.2 23.4 23.4 23.4 23.3

5% 24.8 25.2 25.3 25.5 25.3 25.0

10% 25.6 25.9 25.9 26.0 25.8 25.8

15% 26.0 26.3 26.2 26.3 26.2 26.2

20% 26.4 26.7 26.5 26.5 26.4 26.4

25% 26.6 27.0 26.7 26.8 26.7 26.8

30% 26.9 27.3 26.9 27.0 27.0 27.0

35% 27.1 27.5 27.2 27.2 27.3 27.2

40% 27.3 27.7 27.3 27.4 27.4 27.4

45% 27.5 27.9 27.5 27.6 27.6 27.6

50% 27.7 28.1 27.7 27.8 27.8 27.7

55% 27.9 28.3 27.9 27.9 28.0 27.8

60% 28.1 28.6 28.1 28.1 28.2 28.1

65% 28.3 28.7 28.3 28.3 28.4 28.2

70% 28.5 29.0 28.5 28.5 28.6 28.5

75% 28.7 29.3 28.8 28.7 28.8 28.7

80% 29.0 29.5 29.0 29.0 29.0 29.0

85% 29.4 29.8 29.3 29.2 29.3 29.3

90% 29.9 30.1 29.6 29.6 29.7 29.7

95% 30.7 30.6 30.1 30.0 30.2 30.2

100% 33.9 32.8 32.6 33.6 33.1 32.6

Volume(gal): 7,213,696,531 5,680,076,425 6,070,322,689 5,978,921,094 6,160,483,137 6,247,759,799

Region 2-“Adjusted VOC” Summer RFG VOC Reduction (%) by Volume (from Batch Reports)

Reporting Year

Volume %tile 2000 2001 2002 2003 2004 2005

minimum N/A 21.4 20.2 21.7 21.5 22.2

5% N/A 23.1 23.0 23.5 24.2 23.8

10% N/A 23.9 23.7 24.1 24.4 24.3

15% N/A 24.2 24.0 24.4 24.6 24.7

20% N/A 24.6 24.4 24.6 24.7 24.9

25% N/A 24.9 24.8 24.8 24.9 25.1

30% N/A 25.1 25.0 25.0 25.1 25.2

35% N/A 25.4 25.1 25.1 25.3 25.5

40% N/A 25.6 25.4 25.3 25.4 25.6

45% N/A 25.8 25.6 25.4 25.5 25.7

50% N/A 26.0 25.7 25.6 25.6 25.9

55% N/A 26.3 25.9 25.7 25.8 26.0

60% N/A 26.5 26.1 25.9 26.0 26.2

65% N/A 26.7 26.4 26.1 26.2 26.3

70% N/A 26.8 26.6 26.2 26.4 26.5

75% N/A 27.0 26.8 26.5 26.8 26.6

80% N/A 27.3 27.1 26.7 26.9 26.9

85% N/A 27.6 27.5 27.0 27.4 27.7

90% N/A 27.9 27.9 27.2 27.9 28.4

95% N/A 28.4 28.6 27.7 28.7 29.3

100% N/A 31.1 29.8 30.7 32.2 30.9

Volume (gal): 1,625,747,013 1,639,100,323 1,509,620,244 1,739,816,901 1,839,656,018
228

RFG VOC Performance by Grade

Figure 3

RFG VOC Emissions Performance (% reduction) by Year and Grade-From Reporting Data

Reporting Year

Grade Season Data 2000 2001 2002 2003 2004 2005

PRM s Average 28.0 28.0 27.7 27.7 27.9 27.9

Volume 2,775,514,551 2,772,816,841 2,930,007,747 2,735,922,026 2,385,535,898 2,141,224,947

REG s Average 28.8 28.6 28.4 28.5 28.4 28.3

Volume 10,076,956,707 10,377,246,679 10,871,002,718 10,822,132,177 11,770,292,617 11,862,678,003

Users of these grade-specific property estimates calculated from RFG and Anti-Dumping data should be

aware that grade-specific estimates based on reporting data may differ from actual retail property values by

grade. Although aggregate estimates from the reporting system may also differ from actual retail property

values, there are several additional reasons why these grade-specific estimates may differ. Mid-grade gasoline is

often blended from regular and premium gasoline at some point downstream of the refinery. Thus, some of the

gasoline volume reported and included in these tables as regular or premium would be marketed as mid-grade.

Additionally, EPA's grade-specific average analysis excludes some gasoline and blendstock that was included in

aggregate average estimates. EPA has presented averages for batches labeled as regular and premium gasoline

only; excluding batches labeled as mid-grade (since these batches may not be a representative sample of

gasoline marketed as mid-grade), mix of grades, or without a grade label. EPA also excluded CG blendstock

batches from grade-specific analyses even if they had a grade designation.

The table shows the total volume, in gallons, for the batches used to calculate each grade average. In

part, because of factors discussed above these volumes are not expected to represent the actual volumes by

grade of retail gasoline.
229

RFG VOC Performance (Geographic)

Figure 4

Figure 5
230

RFG Toxics Performance by Gasoline Volume

Figure 6

Summer RFG Toxics Reduction (%) by Volume (from Batch Reports)

Reporting Year

Volume

%tile

1998 1999 2000 2001 2002 2003 2004 2005

minimum 1.3 0.3 20.1 16.8 6.0 19.0 16.9 16.2

5% 18.2 17.7 27.4 24.9 26.2 26.1 26.7 26.2

10% 20.9 20.5 28.9 27.4 28.4 28.0 28.3 27.7

15% 22.8 22.1 30.1 28.8 29.5 29.2 29.5 28.7

20% 24.3 23.6 30.9 29.9 30.5 30.1 30.3 29.4

25% 25.6 24.8 31.6 30.7 31.0 30.7 30.9 30.1

30% 26.6 25.8 32.1 31.4 31.6 31.3 31.6 30.7

35% 27.4 26.7 32.6 32.0 32.1 32.0 32.0 31.1

40% 28.2 27.7 33.2 32.5 32.7 32.6 32.5 31.5

45% 29.0 28.7 33.6 33.0 33.1 33.2 33.1 32.0

50% 29.6 29.4 34.1 33.4 33.6 33.8 33.5 32.5

55% 30.4 30.3 34.6 33.9 34.0 34.4 34.1 32.9

60% 31.2 31.1 35.0 34.4 34.4 34.9 34.6 33.4

65% 31.8 31.8 35.4 34.8 34.8 35.4 35.1 33.9

70% 32.6 32.6 35.8 35.2 35.3 36.0 35.7 34.5

75% 33.1 33.4 36.4 35.7 35.9 36.6 36.2 35.1

80% 33.9 34.2 37.0 36.1 36.6 37.1 36.7 35.8

85% 34.7 34.9 37.6 36.8 37.2 37.8 37.3 36.6

90% 35.8 36.0 38.4 37.5 38.2 38.7 38.1 37.4

95% 37.6 37.7 39.6 38.8 39.6 40.0 39.4 38.8

100% 45.6 45.7 45.0 44.2 43.8 44.9 45.5 45.1

Volume

(gal): 12,551,351,739 12,605,647,535 12,924,625,994 13,215,304,396 13,838,063,327 13,583,809,485 14,230,001,733 14,070,501,006
231

RFG Toxics Performance by Gasoline Volume (continued):

Figure 7

Winter RFG Toxics Reduction (%) Volume (from Batch Reports)

Reporting Year

Volume

%tile

1998 1999 2000 2001 2002 2003 2004 2005

minimum -6.9 -8.7 2.8 -2.3 0.6 -3.2 -5.0 -1.0

5% 14.5 13.5 15.4 15.4 16.4 16.4 19.0 19.2

10% 17.0 15.9 17.6 17.7 18.5 18.9 20.5 20.7

15% 18.3 17.6 19.1 19.4 20.0 20.4 21.7 21.9

20% 19.6 19.1 20.3 20.8 21.1 21.4 22.7 22.9

25% 20.8 20.6 21.4 22.0 22.2 22.3 23.6 23.7

30% 21.9 21.9 22.4 23.0 22.9 23.0 24.4 24.4

35% 22.9 22.8 23.1 23.8 23.7 23.8 25.1 25.1

40% 23.9 23.7 24.0 24.5 24.4 24.5 25.8 25.7

45% 24.8 24.5 24.9 25.3 25.1 25.2 26.5 26.3

50% 25.6 25.3 25.7 25.9 25.9 25.9 27.1 26.9

55% 26.2 26.0 26.5 26.5 26.6 26.5 27.7 27.5

60% 26.8 26.9 27.2 27.0 27.2 27.2 28.2 28.0

65% 27.5 27.6 27.9 27.7 27.8 27.8 28.8 28.6

70% 28.3 28.3 28.6 28.3 28.5 28.5 29.4 29.1

75% 29.0 29.1 29.3 28.9 29.1 29.1 30.0 29.8

80% 29.9 29.9 30.1 29.5 29.7 29.9 30.7 30.5

85% 30.8 30.7 31.0 30.4 30.4 30.6 31.4 31.2

90% 32.1 31.8 32.0 31.4 31.3 31.6 32.3 32.4

95% 34.1 33.6 33.5 33.0 32.7 33.2 33.7 33.5

100% 41.1 39.6 39.3 39.9 38.7 38.5 39.9 39.0

Volume

(gal): 14,617,590,035 14,589,007,345 15,829,263,333 15,703,151,227 16,429,670,147 16,679,773,135 17,190,635,125 18,044,155,549
232

RFG Toxics Performance by Gasoline Volume (continued):

(Cumulative Distributions for Latest Year Data)

Figure 8

Figure 9
233

RFG Toxics Performance by Grade

Figure 10

Figure 11
234

RFG Toxics Performance by Grade (continued):

RFG Toxics Emissions Performance (% reduction) and Volume (gal) by Year, Grade, and Season-From Reporting Data

Reporting Year

Grade Season Data 2000 2001 2002 2003 2004 2005

PRM s Average 34.4 33.8 34.5 34.5 34.1 33.4

Volume 2,775,514,551 2,772,816,841 2,930,007,747 2,735,922,026 2,385,535,898 2,141,224,947

w Average 24.7 24.0 25.3 25.9 26.5 26.0

Volume 3,418,369,505 3,288,964,179 3,387,457,520 3,103,333,727 2,943,555,811 2,581,178,988

REG s Average 33.9 32.8 33.2 33.4 33.4 32.5

Volume 10,076,956,707 10,377,246,679 10,871,002,718 10,822,132,177 11,770,292,617 11,862,678,003

w Average 25.5 25.6 25.5 25.5 26.9 26.9

Volume 12,246,078,983 12,289,025,746 12,966,338,451 13,486,978,064 14,158,974,318 15,422,172,055

Users of these grade-specific property estimates calculated from RFG and Anti-Dumping data should be

aware that grade-specific estimates based on reporting data may differ from actual retail property values by

grade. Although aggregate estimates from the reporting system may also differ from actual retail property

values, there are several additional reasons why these grade-specific estimates may differ. Mid-grade gasoline is

often blended from regular and premium gasoline at some point downstream of the refinery. Thus, some of the

gasoline volume reported and included in these tables as regular or premium would be marketed as mid-grade.

Additionally, EPA's grade-specific average analysis excludes some gasoline and blendstock that was included in

aggregate average estimates. EPA has presented averages for batches labeled as regular and premium gasoline

only; excluding batches labeled as mid-grade (since these batches may not be a representative sample of

gasoline marketed as mid-grade), mix of grades, or without a grade label. EPA also excluded CG blendstock

batches from grade-specific analyses even if they had a grade designation.

The table shows the total volume, in gallons, for the batches used to calculate each grade average. In

part, because of factors discussed above these volumes are not expected to represent the actual volumes by

grade of retail gasoline.
235

RFG Toxics Performance (Geographic)

Figure 12

Figure 13
236

RFG Toxics Performance Geographic (continued):

Figure 14 Figure 15
237

RFG NOx Performance by Gasoline Volume

Figure 16

Summer RFG NOx Reduction (%) by Volume (from Batch Reports)

Reporting Year

Volume %tile 1998 1999 2000 2001 2002 2003 2004 2005

minimum -15.2 -16.1 -5.5 -11.1 -5.9 -8.1 -6.2 -4.4

5% -2.8 -3.5 3.1 2.4 2.7 3.4 4.1 3.1

10% -1.1 -1.8 4.3 3.9 4.6 4.8 5.5 4.7

15% 0.1 -0.5 5.1 5.0 5.5 5.7 6.3 5.8

20% 0.8 0.3 5.8 5.6 6.1 6.3 7.1 6.6

25% 1.5 1.0 6.5 6.1 6.6 6.9 7.7 7.3

30% 2.2 1.6 7.0 6.6 7.0 7.3 8.3 7.9

35% 2.9 2.3 7.6 7.0 7.5 7.7 8.9 8.4

40% 3.5 3.0 8.0 7.4 7.9 8.2 9.3 9.0

45% 4.1 3.8 8.4 7.8 8.2 8.6 9.8 9.5

50% 4.8 4.4 8.9 8.2 8.7 9.1 10.3 10.0

55% 5.4 5.2 9.4 8.6 9.1 9.5 10.8 10.7

60% 6.1 6.0 9.9 8.9 9.6 10.0 11.4 11.3

65% 6.8 6.8 10.5 9.3 10.1 10.5 12.0 11.9

70% 7.5 7.6 11.1 9.7 10.7 11.2 12.5 12.5

75% 8.3 8.3 11.7 10.3 11.3 11.8 13.2 13.1

80% 9.3 9.0 12.3 11.0 12.1 12.6 13.8 13.8

85% 10.2 10.0 13.1 11.9 12.8 13.4 14.5 14.4

90% 11.4 11.1 14.0 13.1 14.0 14.4 15.4 15.3

95% 13.1 12.4 15.5 14.6 15.7 16.0 16.6 16.6

100% 20.4 19.2 19.6 19.2 21.5 21.0 21.1 21.0

Volume (gal): 12,551,351,739 12,605,647,535 12,924,625,994 13,215,304,396 13,838,063,327 13,583,809,485 14,230,001,733 14,070,501,006
238

RFG NOx Performance by Gasoline Volume (continued):

Figure 17

Winter RFG NOx Reduction (%) by Volume (from Batch Reports)

Reporting Year

Volume %tile 1998 1999 2000 2001 2002 2003 2004 2005

minimum -12.2 -14.6 -13.2 -13.4 -10.4 -16.0 -8.6 -11.0

5% -1.5 -3.2 -2.2 -2.1 -1.4 -0.8 0.1 1.3

10% 0.2 -1.0 -0.3 -0.3 0.2 0.6 2.6 3.6

15% 1.2 0.1 1.0 0.6 1.2 1.7 4.4 5.5

20% 1.8 1.0 1.8 1.5 2.1 2.7 5.7 7.0

25% 2.4 1.8 2.4 2.1 3.0 3.5 6.9 8.2

30% 3.1 2.4 2.9 2.8 3.7 4.3 7.7 9.1

35% 3.7 3.2 3.5 3.4 4.4 5.2 8.4 9.8

40% 4.4 3.9 4.0 4.0 5.1 6.0 9.1 10.3

45% 5.1 4.6 4.7 4.8 5.7 6.8 9.7 10.8

50% 5.8 5.4 5.3 5.7 6.6 7.5 10.3 11.3

55% 6.6 6.2 6.1 6.6 7.3 8.3 10.9 11.7

60% 7.3 6.9 7.0 7.5 8.2 9.0 11.5 12.2

65% 8.1 7.7 7.8 8.3 8.9 9.7 11.9 12.5

70% 9.0 8.4 8.8 9.2 9.6 10.3 12.4 12.9

75% 9.9 9.3 9.6 10.0 10.5 11.1 13.0 13.4

80% 10.7 10.1 10.6 10.8 11.3 11.8 13.6 13.8

85% 11.6 11.1 11.6 11.7 12.2 12.7 14.2 14.3

90% 12.6 12.1 12.7 12.7 13.2 13.8 15.1 15.0

95% 14.0 13.4 14.0 14.4 14.8 15.2 16.8 16.5

100% 19.8 20.2 20.0 20.6 19.3 20.4 21.5 21.1

Volume (gal): 14,617,590,035 14,589,007,345 15,829,263,333 15,703,151,227 16,429,670,147 16,679,773,135 17,190,635,125 18,044,155,549
239

RFG NOx Performance by Gasoline Volume (continued):

(Cumulative Distributions for Latest Year Data)

Figure 18

Figure 19
240

RFG NOx Performance by Grade

Figure 20

Figure 21
241

RFG NOx Performance by Grade (continued):

RFG NOx Emission Performance (% reduction) by Year, Grade, and Season-From Reporting Data

Reporting Year

Grade Season Data 2000 2001 2002 2003 2004 2005

PRM s Average 11.8 11.0 12.0 12.5 12.8 13.0

Volume 2,775,514,551 2,772,816,841 2,930,007,747 2,735,922,026 2,385,535,898 2,141,224,947

w Average 8.9 9.2 10.4 11.0 12.4 12.6

Volume 3,418,369,505 3,288,964,179 3,387,457,520 3,103,333,727 2,943,555,811 2,581,178,988

REG s Average 8.4 7.7 8.2 8.7 9.9 9.6

Volume 10,076,956,707 10,377,246,679 10,871,002,718 10,822,132,177 11,770,292,617 11,862,678,003

w Average 5.1 5.3 5.8 6.6 9.1 10.1

Volume 12,246,078,983 12,289,025,746 12,966,338,451 13,486,978,064 14,158,974,318 15,422,172,055

Users of these grade-specific property estimates calculated from RFG and Anti-Dumping data should be

aware that grade-specific estimates based on reporting data may differ from actual retail property values by

grade. Although aggregate estimates from the reporting system may also differ from actual retail property

values, there are several additional reasons why these grade-specific estimates may differ. Mid-grade gasoline is

often blended from regular and premium gasoline at some point downstream of the refinery. Thus, some of the

gasoline volume reported and included in these tables as regular or premium would be marketed as mid-grade.

Additionally, EPA's grade-specific average analysis excludes some gasoline and blendstock that was included in

aggregate average estimates. EPA has presented averages for batches labeled as regular and premium gasoline

only; excluding batches labeled as mid-grade (since these batches may not be a representative sample of

gasoline marketed as mid-grade), mix of grades, or without a grade label. EPA also excluded CG blendstock

batches from grade-specific analyses even if they had a grade designation.

The table shows the total volume, in gallons, for the batches used to calculate each grade average. In

part, because of factors discussed above these volumes are not expected to represent the actual volumes by

grade of retail gasoline.
242

RFG NOx Performance (Geographic)

Figure 22

Figure 23
243

RFG NOx Performance-Geographic (continued):

Figure 24 Figure 25
244

Conventional Gasoline

CG Exhaust Toxics Emissions by Gasoline Volume

Figure 26

Summer CG Exhaust Toxics Emissions (mg/mi) by Volume (Calculated from Batch Data)

Reporting Year

Volume %tile 1998 1999 2000 2001 2002 2003 2004 2005

minimum 49.9 48.6 49.6 47.0 47.0 47.0 46.4 48.4

5% 58.9 57.9 59.3 59.1 59.0 58.6 57.9 58.2

10% 60.9 60.7 61.5 61.5 61.2 60.7 59.8 59.8

15% 62.8 62.4 62.9 63.3 62.8 62.3 61.1 61.0

20% 64.2 63.9 64.3 64.6 64.0 63.5 62.0 61.9

25% 65.5 65.1 65.5 65.8 65.0 64.7 62.8 62.7

30% 66.5 66.4 66.5 66.9 66.0 65.8 63.5 63.5

35% 67.5 67.5 67.6 67.9 67.0 66.9 64.3 64.3

40% 68.5 68.8 68.8 69.1 68.1 68.1 65.0 65.0

45% 69.5 70.1 70.1 70.4 69.2 69.6 65.8 65.8

50% 70.6 71.3 71.5 71.7 70.3 71.1 66.6 66.7

55% 71.7 72.7 73.0 72.9 71.7 72.6 67.6 67.8

60% 72.9 74.0 74.5 74.4 73.1 74.4 68.6 69.0

65% 74.0 75.4 76.1 76.0 74.7 76.0 69.7 70.2

70% 75.4 76.7 77.8 77.8 76.4 77.6 71.1 71.5

75% 77.2 78.2 79.5 79.7 78.5 79.3 72.8 73.0

80% 79.5 80.1 81.4 81.9 80.6 81.1 74.7 75.0

85% 82.1 82.7 83.7 84.2 82.9 83.3 76.8 77.4

90% 86.1 86.7 87.2 87.5 86.3 87.0 79.7 80.9

95% 93.2 95.1 93.7 93.1 92.2 93.7 85.0 86.8

100% 155.2 252.3 255.2 258.0 245.8 159.3 154.0 175.8

Volume (gal): 38,992,885,793 37,127,053,812 36,355,722,872 38,541,026,687 40,811,369,914 43,215,951,157 43,495,028,871 42,171,355,985
245

CG Exhaust Toxics by Gasoline Volume (continued):

Figure 27

Winter CG Exhaust Toxics Emissions (mg/mi) by Volume (Calculated from Batch Data)

Reporting Year

Volume %tile 1998 1999 2000 2001 2002 2003 2004 2005

minimum 76.4 73.8 76.2 75.5 75.4 74.4 72.9 73.9

5% 89.7 90.9 89.8 91.2 90.4 90.3 88.6 88.5

10% 93.1 94.0 93.3 94.2 93.5 93.1 91.0 91.3

15% 95.6 96.4 95.8 96.5 95.8 94.9 92.7 92.8

20% 97.6 98.4 97.6 99.0 97.8 96.4 93.9 94.0

25% 99.4 100.1 99.4 100.8 99.4 98.1 94.9 95.1

30% 101.0 101.8 101.2 102.4 101.0 99.5 96.0 96.3

35% 102.7 103.2 102.6 104.0 102.6 101.2 97.2 97.4

40% 104.3 105.0 104.1 105.6 104.3 102.9 98.4 98.5

45% 105.7 106.7 105.6 107.2 105.9 104.7 99.7 99.7

50% 107.5 108.5 107.2 108.9 107.5 106.6 101.0 100.8

55% 109.3 110.3 108.7 110.5 109.2 108.4 102.7 102.4

60% 110.9 111.9 110.5 112.1 111.1 110.4 104.4 104.1

65% 112.8 113.7 112.5 114.0 113.1 112.5 106.3 105.8

70% 114.8 115.9 114.7 116.5 115.4 114.7 108.3 108.0

75% 117.1 118.0 117.6 119.4 117.8 117.2 110.2 110.1

80% 119.6 120.8 121.0 122.6 121.1 120.4 113.1 112.7

85% 123.5 124.7 125.4 127.0 124.7 124.0 116.1 116.5

90% 128.7 129.9 131.1 134.7 130.9 129.3 120.9 121.9

95% 140.1 139.9 140.4 146.7 141.9 139.4 129.5 132.0

100% 408.8 395.2 419.4 414.9 239.8 399.7 276.7 260.6

Volume (gal): 46,167,047,173 47,555,086,633 47,925,321,684 48,770,268,393 49,640,309,828 47,426,711,234 47,615,735,564 48,664,360,993
246

CG Exhaust Toxics by Gasoline Volume (continued):

(Cumulative Distributions for Latest Year Data)

Figure 28

Figure 29
247

CG NOx Emissions by Gasoline Volume

Figure 30

Summer CG NOX Emissions (mg/mi) by Volume (Calculated from Batch Data)

Reporting Year

Volume %tile 1998 1999 2000 2001 2002 2003 2004 2005

minimum 1069.8 1053.6 1071.4 1072.8 1064.4 1072.6 1058.0 1052.1

5% 1163.8 1159.2 1168.0 1163.5 1160.5 1157.1 1154.1 1154.9

10% 1182.3 1178.2 1191.5 1184.0 1179.9 1172.4 1163.6 1166.4

15% 1201.4 1199.5 1206.9 1202.0 1196.7 1186.8 1171.7 1175.7

20% 1224.7 1220.2 1225.9 1221.2 1214.9 1201.1 1180.3 1182.4

25% 1244.0 1243.2 1248.0 1242.2 1232.3 1221.7 1187.6 1187.9

30% 1262.8 1265.4 1271.2 1263.5 1254.1 1247.7 1194.8 1195.8

35% 1280.4 1288.0 1291.9 1283.4 1275.1 1273.0 1204.5 1204.0

40% 1298.3 1306.5 1308.9 1302.4 1295.1 1295.3 1217.6 1213.6

45% 1311.3 1320.6 1320.9 1319.5 1313.5 1314.9 1231.3 1223.9

50% 1323.5 1335.2 1334.2 1334.6 1329.1 1330.1 1245.8 1234.0

55% 1335.4 1351.7 1345.5 1348.1 1344.3 1343.6 1259.9 1246.2

60% 1349.3 1364.7 1358.5 1362.3 1357.2 1357.4 1270.4 1259.1

65% 1365.6 1377.0 1371.6 1379.6 1373.1 1373.1 1283.3 1272.6

70% 1382.0 1391.7 1389.3 1394.0 1392.6 1388.9 1293.4 1287.2

75% 1399.4 1406.6 1405.9 1411.5 1411.0 1408.5 1304.5 1301.4

80% 1418.1 1425.2 1427.8 1432.2 1430.6 1428.3 1316.0 1314.8

85% 1440.3 1446.8 1449.5 1453.7 1450.5 1450.6 1330.3 1331.0

90% 1463.3 1470.9 1472.6 1477.3 1472.9 1477.0 1349.6 1353.4

95% 1494.0 1508.3 1507.4 1511.2 1503.3 1515.9 1384.7 1395.6

100% 1790.5 1799.1 1765.5 1813.7 1769.8 1782.6 1629.2 1662.1

Volume (gal): 38,992,885,793 37,127,053,812 36,355,722,872 38,541,026,687 40,811,369,914 43,215,951,157 43,495,028,871 42,171,355,985
248

CG NOx Emissions by Gasoline Volume (continued):

Figure 31

Winter CG NOX Emissions (mg/mi) by Volume (Calculated from Batch Data)

Reporting Year

Volume %tile 1998 1999 2000 2001 2002 2003 2004 2003

minimum 1207.9 1214.1 1210.4 1202.6 1217.4 1201.5 1204.1 1205.4

5% 1318.6 1321.9 1317.5 1320.1 1314.0 1313.1 1304.8 1305.4

10% 1335.1 1339.9 1337.8 1339.0 1334.7 1328.0 1320.6 1319.9

15% 1352.9 1361.7 1358.7 1358.6 1355.1 1341.8 1329.4 1327.8

20% 1372.9 1382.2 1378.0 1379.8 1374.4 1356.9 1337.7 1335.1

25% 1393.0 1403.5 1400.9 1403.7 1397.8 1376.0 1346.9 1342.3

30% 1413.8 1426.1 1420.7 1428.5 1421.3 1397.4 1356.5 1349.5

35% 1434.3 1446.9 1444.2 1451.4 1444.7 1421.6 1369.8 1357.2

40% 1454.4 1464.0 1464.0 1471.9 1462.3 1441.0 1383.6 1365.7

45% 1473.4 1481.8 1480.9 1487.8 1479.3 1456.8 1397.0 1376.0

50% 1489.4 1497.5 1496.4 1507.4 1496.1 1472.9 1411.4 1386.2

55% 1506.0 1514.0 1512.5 1524.4 1511.9 1489.8 1425.5 1398.4

60% 1524.0 1531.8 1530.2 1542.5 1527.7 1507.8 1440.1 1412.1

65% 1540.8 1549.8 1551.1 1561.3 1544.0 1524.4 1454.4 1428.7

70% 1558.3 1568.4 1567.4 1579.7 1564.7 1544.3 1466.2 1444.8

75% 1576.2 1588.4 1586.2 1599.5 1589.0 1567.0 1480.8 1463.6

80% 1596.7 1611.5 1607.7 1619.6 1613.9 1592.8 1495.0 1481.2

85% 1618.6 1633.6 1632.4 1644.1 1637.3 1624.1 1516.3 1503.7

90% 1645.9 1660.2 1661.5 1672.2 1666.4 1659.0 1543.6 1531.9

95% 1686.6 1696.9 1709.0 1719.0 1710.6 1708.8 1599.2 1584.2

100% 2033.8 2048.4 2019.9 2010.7 2005.6 2017.4 1886.7 1897.0

Volume (gal): 46,167,047,173 47,555,086,633 47,925,321,684 48,770,268,393 49,640,309,828 47,426,711,234 47,615,735,564 48,664,360,993
249

CG NOx Emissions by Gasoline Volume (continued):

(Cumulative Distributions for Latest Year Data)

Figure 32

Figure 33
250

Regression Analysis

This report has largely focused on how gasoline has changed in response to EPA=s regulatory

requirements. In order to supplement more subjective evidence that gasoline composition has or has not

changed concurrent with regulatory changes, EPA has made limited use of regression analysis.

RFG composition was expected to change when the Phase II standards were implemented. Many

of the descriptive analyses presented in this report show property changes between 1999 and 2000.

However it is not always clear that these changes are distinguishable from year-to-year fluctuations and

any overall linear time trend that may be present. EPA fit each set of average estimates to the model:

Y=b0+b1*YEAR+b2*Phs2

where Y is EPA's estimate of the property average. YEAR is the reporting or survey year and Phs2 is a

categorical variable set to 0 for 1998 and 1999 and 1 for 2000 through 2004. (Although EPA's data for

some properties included years prior to 1998, and the report examines trends through 2005, these

regression analyses were limited to years 1998 through 2004.) 42A statistically significant Phs2 term

would provide objective evidence that a sustained shift in a property value occurred concurrent with the

transition from Phase I to Phase II RFG standards. Table 1 shows an estimate of the Phs2 coefficient and

its p-value for each data set. The value of the Phs2 coefficient is an estimate of the magnitude of the

parameter shift and a p-value of 0.050 or less indicates a Phs2 coefficient that can be considered

statistically significant.

42 These regression analyses were done before the 2005 averages were calculated. They were not updated

since the primary intent of this analysis was to provide a more objective basis for evaluating changes between 1999

and 2000.
251

P-Value and Coefficient for Phs2 Term RFG

Season Parameter Term Data 1998-2004 Surveys 1998-2004 RFG Reporting

Benzene Phs2 P-value 0.006 0.019

Coefficients -0.112 -0.092

Aromatics Phs2 P-value 0.002 0.008

Coefficients -6.109 -2.904

RVP Phs2 P-value 0.000 0.000

Coefficients -0.913 -0.859

E200 Phs2 P-value 0.003 0.003

Coefficients -2.124 -1.710

E300 Phs2 P-value 0.004 0.006

Coefficients 2.451 2.311

T50 Phs2 P-value 0.003

Coefficients 4.892

T90 Phs2 P-value 0.004

Coefficients -9.039

Sulfur Phs2 P-value 0.030 0.024

Coefficients -51.320 -53.790

Oxygen Phs2 P-value 0.340 0.700

Coefficients -0.125 -0.050

Olefins Phs2 P-value 0.028 0.652

Coefficients -1.436 -0.320

NOx reduction Phs2 P-value 0.002 0.012

Coefficients 4.717 3.267

Toxics reduction Phs2 P-value 0.000 0.001

Coefficients 6.617 4.811

VOC reduction Phs2 P-value 0.000 0.000

Summer

Coefficients 9.674 9.168

Benzene Phs2 P-value 0.072 0.288

Coefficients -0.037 0.008

Aromatics Phs2 P-value 0.001 0.132

Coefficients -3.295 -0.611

E200 Phs2 P-value 0.245 0.872

Coefficients -0.275 0.044

E300 Phs2 P-value 0.002 0.000

Coefficients 1.928 1.726

T50 Phs2 P-value 0.099

Coefficients 2.826

T90 Phs2 P-value 0.003

Coefficients -9.838

Sulfur Phs2 P-value 0.365 0.367

Coefficients 29.467 29.143

Oxygen Phs2 P-value 0.206 0.191

Coefficients -0.242 -0.192

Olefins Phs2 P-value 0.512 0.104

Coefficients 0.315 1.290

NOx reduction Phs2 P-value 0.812 0.228

Coefficients 0.330 -1.515

Toxics reduction Phs2 P-value 0.026 0.867

Winter

Coefficients 2.087 -0.101

Table 1
252

For Summer RFG, both survey (retail) and reporting (production)-based data analyses indicated

that statistically significant shifts occurred in all Complex Model input properties except oxygen and

olefins. Neither analysis indicated a statistically significant shift in oxygen content and only the

survey-based analysis indicated a shift in olefins content. The survey analysis indicated statistically

significant shift in T50 and T90. (These parameters are not reported for all production data, so these

trends were analyzed for surveys only.) Both analyses found that emissions performance for VOCs, NOx

and toxics changed significantly concurrent with the transition.

For Winter RFG, the survey data analysis detected statistically significant shifts in aromatics,

E300, T90 and toxics performance. Reporting data analysis detected a shift in E300 only.

In general, these regression results are consistent with subjective interpretation of the data and

consideration of the underlying cause-effect relationships. This analysis, in some cases, may have failed

to detect shifts that occurred between 1999 and 2000 because important variables or terms were omitted

from the regression model. For example, the Winter NOx emission performance graph based on survey

data gives a distinct impression of a shift (see the RFG Trends and Emissions Chapters). However the

regression analysis did not conclude significance quite possibly because an even larger change occurred

between 2003 and 2004. This latter change occurred as a result of Tier 2 sulfur reductions, and there is

no term in the regression model to account for anything but a linear change over time.

Table 2 shows an estimate of the YEAR coefficient and its p-value for each data set. A

statistically significant (P ≤0.050) YEAR coefficient indicates that an upward (positive coefficient) or

downward (negative) linear trend was detected between 1998 and 2004 after correcting for any upward

or downward Phase I to Phase II shift.
253

P-Value and Coefficient for Year Term RFG

Season Parameter Term Data 1998-2004

Surveys

1998-2004 RFG

Reporting

Benzene YEAR P-value 0.051 0.894

Coefficients 0.013 0.001

Aromatics YEAR P-value 0.232 0.421

Coefficients 0.257 0.121

RVP YEAR P-value 0.047 0.008

Coefficients 0.023 0.020

E200 YEAR P-value 0.280 0.162

Coefficients 0.091 0.100

E300 YEAR P-value 0.022 0.085

Coefficients -0.340 -0.223

T50 YEAR P-value 0.480

Coefficients -0.128

T90 YEAR P-value 0.013

Coefficients 1.433

Sulfur YEAR P-value 0.043 0.038

Coefficients -10.287 -10.430

Oxygen YEAR P-value 0.044 0.068

Coefficients 0.076 0.068

Olefins YEAR P-value 0.015 0.593

Coefficients 0.389 0.086

NOx reduction YEAR P-value 0.434 0.116

Coefficients 0.126 0.337

Toxics reduction YEAR P-value 0.017 0.731

Coefficients -0.306 -0.040

VOC reduction YEAR P-value 0.559 0.379

Summer

Coefficients -0.060 -0.065

Benzene YEAR P-value 0.027 0.074

Coefficients 0.012 -0.003

Aromatics YEAR P-value 0.015 0.686

Coefficients 0.301 0.032

E200 YEAR P-value 0.286 0.989

Coefficients 0.056 -0.001

E300 YEAR P-value 0.007 0.000

Coefficients -0.318 -0.288

T50 YEAR P-value 0.038

Coefficients -0.910

T90 YEAR P-value 0.009

Coefficients 1.611

Sulfur YEAR P-value 0.036 0.035

Coefficients -20.333 -20.325

Oxygen YEAR P-value 0.152 0.151

Coefficients 0.064 0.049

Olefins YEAR P-value 0.230 0.157

Coefficients 0.140 -0.242

NOx reduction YEAR P-value 0.192 0.027

Coefficients 0.460 0.816

Toxics reduction YEAR P-value 0.472 0.071

Winter

Coefficients -0.109 0.311

Table 2
254

For Summer RFG, the analysis detected a statistically significant upward linear trend in RVP and a

downward linear trend in sulfur in both data sets. The analysis found statistically significant downward

E300 and sulfur trends in both Winter RFG data sets. For several other properties only one of the two

data sets indicated a statistically significant trend. Again, this analysis may have failed to detect

systematic increases or decreases between 1998 and 2004 because the regression model chosen does

not adequately describe the trend. For instance, although only the reporting data indicated statistical

significance, there is little doubt (because of required sulfur reductions) that the NOx performance of both

retail and production Winter RFG improved between 1998 and 2004.

Since substantial changes in some RFG properties occurred with Phase II, it is possible that the

transition to Phase II RFG standards also affected CG composition. (EPA's Anti-Dumping regulations were

designed to limit RFG's adverse impact on CG's emission-related qualities.) EPA applied the same

regression model to its reporting data-based CG average estimates in order to detect possible property

value shifts between 1999 and 2000.

Table 3 shows estimates of the Phs2 coefficients and p-values. For Summer CG, aromatics and

RVP indicated statistically significant values. The shift in aromatics was positive, opposite in direction to

the statistically significant negative change in RFG aromatics. While this may indicate that some

aromatics were shifted from RFG to CG production to achieve RFG aromatics reductions, this is uncertain

(see the Aromatics Chapter.) The RVP shifts for CG and RFG were in the same direction. For Winter

CG, only olefins showed a statistically significant value, and the RFG regression analysis did not indicate a

change in Winter olefin content.

Season Parameter Term Data 1998-2004 CG Anti-Dumping

Aromatics Phs2 P-value 0.004

Coefficient 0.960

Benzene Phs2 P-value 0.955

Coefficient 0.002

E200 Phs2 P-value 0.853

Coefficient 0.043

E300 Phs2 P-value 0.447

Coefficient -0.274

Olefins Phs2 P-value 0.234

Coefficient 0.903

RVP Phs2 P-value 0.027

Coefficient -0.063

Sulfur Phs2 P-value 0.309

Summer

Coefficient 89.591

Aromatics Phs2 P-value 0.433

Coefficient 0.299

Benzene Phs2 P-value 0.572

Coefficient 0.020

E200 Phs2 P-value 0.556

Coefficient -0.233

E300 Phs2 P-value 0.388

Coefficient 0.301

Olefins Phs2 P-value 0.038

Coefficient 1.281

RVP Phs2 P-value 0.120

Coefficient -0.208

Sulfur Phs2 P-value 0.308

Winter

Coefficient 75.818

Table 3
255

Table 4 shows estimates of the YEAR coefficients and p-values. None of these are statistically

significant. As previously stated, this regression analysis may not have detected systematic changes

between 1998 and 2004 because the model does not adequately describe the trend. For example, there

is no question that Summer and Winter CG sulfur decreased between 1998 and 2004, but the decreases

were very non-linear.

Season Parameter Term Data 1998-2004 CG Anti-Dumping

Aromatics Year P-value 0.059

Coefficient -0.099

Benzene Year P-value 0.874

Coefficient -0.001

E200 Year P-value 0.344

Coefficient 0.053

E300 Year P-value 0.959

Coefficient 0.004

Olefins Year P-value 0.283

Coefficient -0.180

RVP Year P-value 0.086

Coefficient 0.009

Sulfur Year P-value 0.102

Summer

Coefficient -36.705

Aromatics Year P-value 0.396

Coefficient -0.074

Benzene Year P-value 0.750

Coefficient -0.003

E200 Year P-value 0.170

Coefficient 0.137

E300 Year P-value 0.431

Coefficient -0.062

Olefins Year P-value 0.073

Coefficient -0.229

RVP Year P-value 0.128

Coefficient 0.046

Sulfur Year P-value 0.079

Winter

Coefficient -34.410

Table 4
256

PADD Level Analysis of Reporting Data

United States gasoline production and supply data are often aggregated into geographic regions

referred to as Petroleum Administration for Defense Districts (PADDs). The US is divided into five PADDs

(PADD I-East Coast, PADD II-Midwest, PADD III-Gulf Coast, PADD IV-Rocky Mountain, PADD V-West

Coast).

In the various individual parameter appendices, EPA presented estimates of RFG property averages in

each year and season, aggregated at the PADD level. These estimates were based on the retail data

collected in RFG Surveys. EPA did not have comparable geographic data for CG, and did not include any

"geographic" CG trend analysis in those appendices. This appendix includes a limited PADD-specific

analysis of RFG and CG batch reporting data. It does not examine trends, but separately summarizes

2004 and 2005 reporting data. 43 These PADD averages also appear in the individual parameter chapters.

Batch records do not explicitly identify a PADD, but each batch record contains a "facility"

identifier, so that a refiner's batch data can be related to a refinery, and the refinery related to a PADD,

based on its location. This PADD-specific analysis excluded those batches where the "facility" was an

importer. Importer batches were included in the aggregate trend analyses presented in the body of the

report.

In order to provide the additional geographic information contained in this PADD-level analysis,

while still maintaining a sufficient degree of aggregation to prevent gasoline properties or volumes from

being strongly associated with individual companies or facilities, EPA has reported gasoline property

averages for PADDs I, II and III only. (The parties that submit these data to EPA have claimed that the

data are confidential business information (CBI), and these data may be protected by CBI regulations.)

Users of these PADD-specific averages should be aware that while these estimates are likely to

provide better information about the properties and emissions qualities of gasoline sold or used within a

PADD than national averages, the properties of gasoline produced in a PADD are likely to differ somewhat

from the properties of gasoline consumed in a PADD. Significant PADD to PADD movement of gasoline

(e.g. via the Colonial Pipeline which transports gasoline from PADD III to PADD I) as well as importation

of finished gasoline account for this difference. PADD-specific retail property averages estimated from

RFG Survey data are included in the parameter chapters.

43 Resources did not permit PADD-specific analysis of each year’s batch data. EPA felt that analysis of more

recent data may be of greater use to a wider audience than analysis of older data.

Tables 1 and 4 show the volumes, in gallons, for the batches allocated to the various PADDs in

each of the two years. The gasoline volume in the column labeled "Other" includes total volume from

batches associated with PADD IV or V refineries and refineries in US territories. The column labeled

"Grand total" is the sum of the volumes in the PADD I through III and "Other" columns. The column

labeled "Aggregate Total" represents the volume of the batches considered in the aggregate analyses

reported in the body of this report and in the individual parameter appendices. The "Aggregate Totals"

are higher because the aggregate analyses included importer as well as refiner batches. The volume

totals in Tables 1 and 4 are totals prior to any data screening done in conjunction with computation of the

averages presented in this report. (The PADD-average tables in the parameter chapters give the postscreening volumes for each parameter average calculation). PADD I, II and III volume totals are

expected to be approximately the total gasoline production in each of those PADDs, excluding any

gasoline volume that is exported.
257

EPA reporting data "Grand Totals" by PADD in Table 1 compare reasonably well to estimates of

finished gasoline production volume minus exports based on data published in the Energy Information

Administration's "Petroleum Supply Annual 2004” (EIA,2005). 44 Using the EIA data, EPA calculated

that these volumes were, for PADDs I, II and III, respectively, 18,926,166,000 gallons, 31,976,994,000

gallons and 54,012,336,000 gallons. The purpose of these volume comparisons was not to question

EIA's volume data, but to provide some independent verification of the completeness of EPA's data, and

to detect any gross inconsistencies, possibly indicating a problem with EPA's data or analysis. Although

there were some differences (see footnote), EPA does not believe that they are "gross inconsistencies",

and has not investigated them. EPA did not do a similar comparison of 2005 volumes. The volumes in the

"Grand total" column do not represent total PADD I through V gasoline production because they exclude

PADD V "California" gasoline, and include some volume from refineries outside of the 50 states.

2004 Gasoline Production Volumes (gallons) by PADD-Calculated from Refiner Batch Reports

PADD

Gas

type

Season I II III Other Grand total Aggregate total

CG Summer 3,752,272,894 11,456,437,187 21,722,608,623 6,400,078,025 43,331,396,729 44,009,126,002

Winter 3,484,116,076 13,323,944,095 23,628,091,025 6,809,448,022 47,245,599,218 48,333,969,089

CG

Total

7,236,388,970 24,780,381,282 45,350,699,648 13,209,526,047 90,576,995,947 92,343,095,091

RFG Summer 4,792,114,891 1,740,499,436 5,890,920,167 624,073,296 13,047,607,790 14,243,059,617

Winter 6,489,530,475 2,438,403,544 6,059,647,031 461,826,582 15,449,407,632 17,194,370,899

RFG Total 11,281,645,366 4,178,902,980 11,950,567,198 1,085,899,878 28,497,015,422 31,437,430,516

Grand Total 18,518,034,336 28,959,284,262 57,301,266,846 14,295,425,925 119,074,011,369 123,780,525,607

Table 1

Tables 2, 3, 5, and 6 show the volume-weighted parameter averages calculated for PADDs I, II,

and III RFG and CG. In both cases, the data were screened as for the aggregate average computations;

i.e. for estimation of most seasonal average parameter values, data were screened on a parameterspecific basis primarily to exclude missing data. Additionally, for Complex Model emission average

calculations, batches with "outlier" property values and CG blendstock batches were excluded. Although

EPA's aggregate CG emissions rate averages were based on EPA's recalculated Complex Model emissions

values for each batch, these PADD-level analyses used reported emission values. Further information

relating to data screening, as well as information relating to each parameter can be found in the body of

this report. The negative value for the volume-weighted average TAME content that appears in the CG

average table warrants further explanation. This arises because certain batches, for compliance

calculations, are reported with negative volumes. When a refiner uses previously certified gasoline (PCG)

as a blending component to make other gasoline the PCG batch properties are reported with a negative

volume in order to avoid double-counting this gasoline in calculations. When a batch of certified gasoline

is exported, it is also reported with a negative volume. Consequently, although a negative property

average may be physically impossible, it could occur in volume-weighted average calculations

44EPA used supply and disposition data for Finished Motor Gasoline for PADD I (Table 4 page 34), PADD II

(Table 6, page 36) and PADD III (Table 8, page 38) summing field production and refinery production and

subtracting exports. Volumes were reported in thousand barrels. These tables also subdivided Finished Gasoline into

"Reformulated", "Oxygenated" and "Other" categories. EPA compared the EIA "Reformulated" volumes with its RFG

volumes and the sum of the "Oxygenated" and "Other" volumes with its CG volumes. EIA's PADD II "Reformulated"

volume was about 32% higher than EPA's and its PADD III "Reformulated" volume about 13% lower. The remaining

differences ranged from about 0.4% to under 7 percent. The sum of the compared gasoline category volumes over

the three PADDs as well as the sum of gasoline volume over these PADDs each differed by less than 1 percent.
258

2004 RFG Parameter Averages by PADD-Volume Weighted Averages Calculated from Batch Reports

Gasoline Properties Complex Model

Performance

PADD Aromatics

(v%)

Benzene

(v%)

Olefins

(v%)

Oxygen

(wt%)

E200

(%)

E300

(%)

RVP

(psi)

Sulfur

(ppm)

Ethanol

(v%)

MTBE

(v%)

ETBE

(v%)

TAME

(v%)

T_butanol

(v%)

NOx

(%)

Toxics

(%)

VOC

(%)

I 21.2 0.55 12.97 2.59 47.3 83.6 6.83 91 3.01 8.02 0.00 0.14 0.01 8.8 32.8 28.0

II 18.9 0.84 5.29 3.48 46.6 84.7 6.98 78 9.39 0.00 0.00 0.00 0.00 13.3 29.9 26.6

Summer

III 18.7 0.54 11.24 2.36 48.7 82.5 6.88 73 1.75 8.74 0.00 0.55 0.05 11.3 35.6 29.1

I 20.4 0.65 12.92 2.45 55.4 85.1 118 3.00 7.11 0.00 0.05 0.01 7.6 25.0

II 17.3 0.79 4.86 3.26 58.4 85.7 93 8.61 0.00 0.00 0.00 0.00 12.9 25.2

Winter

III 17.9 0.54 11.40 2.09 55.8 83.7 101 0.98 8.52 0.00 0.68 0.04 10.3 29.0

Table 2

2004 Conventional Gasoline Parameter Averages by PADD-Volume Weighted Averages Calculated from Batch Reports

Gasoline Properties Complex Model Emission

Rates (mg/mi)

PADD Aromatics

(v%)

Benzene

(v%)

Olefin

s (v%)

Oxygen

(wt%)

E200

(%)

E300

(%)

RVP

(psi)

Sulfur

(ppm)

Ethanol

(v%)

MTBE

(v%)

ETBE

(v%)

TAME

(v%)

T_butanol

(v%)

Exhaust

toxics

NOx

I 28.4 0.96 12.8 0.44 45.5 82.7 8.40 125 0.82 0.70 0.09 -0.17 0.00 67.7 1275.8

II 28.7 1.38 8.8 0.34 46.6 81.4 8.46 140 0.97 0.00 0.00 0.00 0.00 71.2 1249.9

Summer

III 27.3 0.98 12.2 0.17 44.6 79.4 8.19 108 0.06 0.76 0.00 0.04 0.00 67.1 1254.5

I 24.0 0.93 15.7 0.37 51.5 84.4 12.66 138 0.83 0.35 0.01 0.03 0.00 103.7 1477.5

II 25.1 1.32 8.6 0.40 52.6 84.1 13.31 135 1.16 0.00 0.00 0.00 0.00 107.6 1413.5

Winter

III 24.1 0.89 12.2 0.14 49.7 81.8 11.77 115 0.05 0.65 0.00 0.02 0.00 101.1 1424.9

Table 3
259

2005 Gasoline Production Volumes (gallons) by PADD-Calculated from Refiner Batch Reports

PADD

Gas type Season I II III Other Grand total Aggregate total

CG Summer 3,547,001,722 10,568,941,899 20,889,546,279 6,061,232,118 41,066,722,018 42,849,893,176

Winter 4,064,064,814 13,589,333,929 22,444,880,341 6,725,201,537 46,823,480,621 49,467,392,607

CG Total 7,611,066,536 24,158,275,828 43,334,426,620 12,786,433,655 87,890,202,639 92,317,285,783

RFG Summer 4,431,080,230 1,844,913,833 5,690,766,967 546,882,756 12,513,643,786 14,092,489,036

Winter 7,081,940,665 2,718,751,541 5,766,524,033 388,731,882 15,955,948,121 18,046,671,196

RFG Total 11,513,020,895 4,563,665,374 11,457,291,000 935,614,638 28,469,591,907 32,139,160,232

Grand Total 19,124,087,431 28,721,941,202 54,791,717,620 13,722,048,293 116,359,794,546 124,456,446,015

Table 4

2005 RFG Parameter Averages by PADD-Volume Weighted Averages Calculated from Refiner Batch Reports

Gasoline Properties Complex Model Performance

PADD Aromatics

(v%)

Benzene

(v%)

Olefins

(v%)

Oxygen

(wt%)

E200

(%)

E300

(%)

RVP

(psi)

Sulfur

(ppm)

Ethanol

(v%)

MTBE

(v%)

ETBE

(v%)

TAME

(v%)

T_butanol

(v%)

NOx

(%)

Toxics

(%)

VOC

(%)

I 21.9 0.62 13.3 2.50 47.6 84.1 6.88 73 3.14 7.13 0.01 0.28 0.01 9.0 31.9 27.9

II 19.1 0.86 4.7 3.50 46.3 84.3 6.95 64 9.46 0.00 0.00 0.00 0.00 13.8 29.9 26.5

Summer

III 19.2 0.60 12.5 2.25 49.9 83.2 6.93 78 1.31 8.96 0.01 0.59 0.04 10.0 34.7 29.2

I 20.7 0.69 13.0 2.41 55.6 85.7 90 3.02 6.82 0.04 0.09 0.01 8.6 25.1

II 18.4 0.81 5.3 3.24 56.5 84.7 78 8.63 0.00 0.00 0.00 0.00 13.2 24.5

Winter

III 18.0 0.57 11.0 2.05 56.7 84.5 83 0.91 8.53 0.02 0.53 0.03 11.3 29.4

Table 5

2005 Conventional Gasoline Parameter Averages by PADD-Volume Weighted Averages Calculated from Batch Reports

Gasoline Properties Complex Model Emission Rates

(mg/mi)

PADD Aromatics

(v%)

Benzene

(v%)

Olefins

(v%)

Oxygen

(wt%)

E200

(%)

E300

(%)

RVP

(psi)

Sulfur

(ppm)

Ethanol

(v%)

MTBE

(v%)

ETBE

(v%)

TAME

(v%)

T_butanol

(v%)

Exhaust

toxics

NOx

I 28.9 1.12 12.7 0.34 45.1 82.8 8.31 108 0.74 0.39 0.00 0.07 0.00 69.5 1264.9

II 28.6 1.41 9.6 0.34 47.5 81.9 8.46 121 0.97 0.00 0.00 0.00 0.00 71.2 1244.9

Summer

III 27.0 1.07 12.8 0.13 44.8 80.5 8.22 98 0.05 0.60 0.01 0.02 0.00 68.0 1253.9

I 24.6 1.18 14.8 0.30 51.0 84.4 12.31 110 0.68 0.30 0.00 0.05 0.00 107.7 1453.4

II 24.5 1.25 9.4 0.33 52.7 84.6 13.25 117 0.92 0.00 0.00 0.00 0.00 105.6 1405.3

Winter

III 24.5 1.01 12.1 0.11 49.3 82.6 11.73 86 0.07 0.41 0.01 0.02 0.00 102.6 1405.2

Table 6