p.1 

OAR Box 1846 

Prepped by Ollie Stewart 

Document Number: 

86) IV-A-8 

Docket Number: 

A-90-07 

Printed 11/18/2008 7:30:17 AM Sheet 86 of 93 
P.2 

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Auto/Oil 

AIR QUALITY •BHB 

TECHNICAL BULLETIN 

No.1 

INITIAL MASS EXHAUST 

EMISSIONS RESULTS FROM 

REFORMULATED GASOLINES 

DECEMBER 1990 

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P.3 

AUTO/OIL AIR QUALITY IMPROVEMENT RESEARCH PROGRAM 

TECHNICAL BULLETIN No. t 

INITIAL MASS EXHAUST EMISSIONS RESULTS FROM REFORMULATED GASOUNES 

ABSTRACT 

Initial analyses of mass exhaust emission results from Phase I of the Auto/Oil Air 

Quality Improvement Research Program are presented. Fuels with varying compositions 

were tested in two fleets of vehicles: current (1989) and older (1983-1985) models. 

Subject to the cautions and qualifications described in the body of this bulletin, 

mass exhaust emissions of both current and older vehicle fleets were affected by 

changes in fuel composition. Responses to changes in olefin and MTBE content were 

similar for both fleets while responses to changes in aromatics and Tgj, levels were 

different, and in certain cases opposite in the two fleets. The largest percentage effect 

in the current fleet, the apparent impact of lower Tg-, on reducing exhaust HC emissions, 

was not found in the older fleet. More studies are needed to confirm this effect. 

INTRODUCTION 

The Auto/Oil Air Quality Improvement Research Program (AQIRP) is a cooperative 

research program initiated by three domestic auto companies and fourteen petroleum 

companies. Its objective is to conduct a research and testing program to develop data 

on the potential improvements in vehicle emissions and air quality - primarily ozone -

from reformulated gasoline, various other alternative fuels, and developments in 

automotive technology. The AQIRP will also develop data on the relative costeffectiveness of various fuel/vehicle combinations. 

Specifically, Phase I examines emissions from current and older vehicles using 

reformulated gasolines whose compositions vary between widely spaced values of 

aromatic content, olefin content, oxygenate content and type, sulfur content, RVP, and 

90 percent distillation temperature. Phase I will also examine emissions from Flexible 

and Variable Fuel vehicles using methanol/gasoline mixtures. Phase I is designed to 

help identify fuel characteristics that merit further study in future phases of the Program. 

Initial exhaust emissions results from the reformulated gasolines tested in Phase 

I are presented in this Technical Bulletin. It is envisioned that a number of Technical 

Bulletins will be issued during the course of the Program that will address additional 

results and tests on other reformulated gasolines, methanol/gasoline mixtures, and other 

fuels. Future bulletins will also contain results of air quality modeling studies. 

Attachment I shows the elements of Phase I of the Program and publications. A formal 

report will be issued upon completion of all Phase I testing. 

1 
P.4 

The AQIRP is in the forefront of research on air quality improvement and expects 

to make possible a substantial advancement in the understanding of the effects of fuels 

on vehicle emissions. The Program is wide ranging in its scope and will provide a vast 

library of complex data. Because much of the analysis of the Program data has yet 

to be completed and continuing research is expected to lead to additional findings, the 

results presented in this bulletin must be deemed qualified and should be interpreted 

with care for the reasons given below. 

Although the fuel blends tested were formulated from commercially available 

refinery streams, the composition of some blends is not necessarily representative of 

fuels that are or could be produced. The "industry average" gasoline may not be 

representative of fuels actually sold in all areas and may differ from national and 

regional fuels in its specific composition. Fuel factors other than the four described in 

this bulletin could have other significant effects on exhaust emissions. Because only 

two levels of each fuel variable were tested, only linear interpolation is possible, 

although non-linear relationships may exist for some variables. Results are reported for 

exhaust emissions only; evaporative emissions may be a substantial fraction of the total 

hydrocarbon emissions and they will be reported in future bulletins. No data have been 

obtained on the possible long-term effects of changing fuel properties. 

TEST DESIGN 

The effects of four gasoline composition parameters were tested in two fleets: 

one composed of twenty 1989 model year vehicles ("current fleet'), and one composed 

of fourteen 1983-1985 model year vehicles ("older fleet'). Factors that were applied in 

choosing current fleet models included high production volume and new/low emissions 

control technology. Current fleet vehicles had a minimum of 10,000 miles on the 

odometer. Models in the older fleet were chosen on the basis of high production 

volumes and the vehicles in the fleet had 40,000-80,000 miles on the odometer. 

Vehicles were in reasonable mechanical condition (driveable, safe to operate, and with 

all emissions hardware intact; repairs were made as necessary) and had emissions 

levels that were similar to those in EPA's in-use vehicle fleet data base. Details of the 

fleets are shown in Attachments II and III. 

Four fuel sets will be evaluated in Phase I as shown below: 

Fuel Set Variables 

A: Compositional Aromatics, MTBE, Olefins, Tg-, 

B: RVP/Oxygenates RVP, Ethanol, ETBE, MTBE 

C: Methanol Methanol/Gasoline Mixtures 

D: Sulfur Sulfur 

Partial results from Fuel Set A are reported in this Technical Bulletin. This fuel 

set consisted of sixteen fuels blended to represent a full factorial experiment involving 

four variables at each of two levels. In addition, a fuel representing industry average 

levels of aromatics, olefins, and Tg-, (without MTBE) was tested, as well as an emissions 
P.5 

certification test fuel as a reference. The target levels for each fuel variable are shown 

below. 

Factorial Design Industry 

Low HiGh Averaae 

Aromatics, vol % 20 45 32 

MTBE, vol % 0 15 0 

Olefins, vol % 5 20 12 

Tgo, °F 280 - 300 350 - 360 335 

Target levels of aromatics and olefins were chosen to approximate the 10th and 

90th percentile values for commercially available summertime fuels for each of the 

parameters. MTBE was set at 0 and 15 volume percent. The high MTBE value 

corresponds to 2.7 weight percent oxygen. Tg-, values were chosen to provide a wide 

enough range in which to identify any potential effects. All blends were formulated 

from currently available refinery streams but do not necessarily reflect fuel blends that 

are or could be produced in volume by existing refineries. 

Industry average fuel, which was also blended from existing refinery streams, 

may not be representative of fuels actually sold in all geographic areas and may differ 

from national as well as regional "average" fuels in its specific composition. There are 

numerous means of blending fuels having the gross compositional characteristics 

indicated above; no systematic effort was made to control for the speciated composition 

of the test fuels. The formulation and blending of specific program fuels is a result of 

the statistical design of the experiment, which was intended to test the effects of 

extreme values of the chosen parameters. Target and actual properties of the individual 

fuels are shown in Attachments IV and V. 

All fuels were tested at least twice in all vehicles. EExhaust emissions were 

measured for all tests according to federal certification test procedures. Vehicles 

underwent additional test preparation cycles when test fuels were changed to eliminate 

fuel carryover effects (fuel carryover effects can occur when switching from one fuel to 

another if the previous fuel is not fully eliminated from the vehicle). 

Many fuel/vehicle combinations were tested for evaporative and running loss 

emissions. In certain tests, detailed speciation measurements were made to identify 

approximately 150 individual compounds present in the emissions. These 

measurements will be used to relate fuel composition to emissions composition and 

air quality. 

RESULTS 

Results are presented in this bulletin for three responses: exhaust mass emissions 

of hydrocarbons (HC), carbon monoxide (CO), and oxides of nitrogen (NOx) from ail 

fuels tested in the current fleet and for ten fuels tested in the older fleet (about half of 

the fuels; analysis on older vehicles was not complete at the time of this bulletin). More 

detailed analyses of the exhaust emissions results, as well as the evaporative and 
P.6 

running loss emissions results, will be presented in future bulletins and in the final 

report. 

Other portions of Phase I consist of testing methanol fuels in Flexible and Variable 

Fuel Vehicles, and evaluating the effects of other gasoline parameters (vapor pressure, 

ethanol, ETBE, and sulfur) on emissions. These tests are currently being conducted 

and the emissions results, as well as results of air quality modeling, will be presented 

in future bulletins. 

Statistical Analvsis - Exhaust emission results are presented in two ways. First, 

the mass emissions were analyzed by regression analysis techniques using SAS 

(Statistical Analysis System) computer programs. This analysis provided estimates of 

the changes in emissions due to changing one or more of the fuel composition 

parameters. A full analysis is possible only after all fuels in the factorial experiment 

have been tested as has been done in the current fleet. For the older fleet, however, 

where the results of only half of the fuels were available for analysis, it was only 

possible to estimate the effect of changing one compositional parameter at a time. 

Because only two levels of each fuel factor were studied in this factorial design, 

quadratic curvature or non-linearity of the effects cannot be estimated although 

interaction effects can be estimated. 

The second analysis technique involved calculating the fleet averages for each 

fuel and the confidence interval associated with that average. Because multiple 

comparisons will be made among fuels, the Tukey Multiple Comparison Test was used 

and 95% confidence intervals were calculated for the averages. 

An analysis of the data from the current fleet indicated that NOx emissions 

increased an average of 4.7% between the first half and the second half of the testing 

program. This shift was significant at the 99% confidence limit and was taken into 

account in the regression analysis. The results shown in Tables 1 and 2 were 

corrected for this shift so that all fuels can be compared on an equivalent basis. This 

behavior was not observed for HC and CO emissions. 

Current Fleet - The regression analyses evaluated all main factor responses as 

well as all possible two, three, and four factor interactions among the variables. 

Main factor results for the current fleet are shown in Table 1 and Figure 1. 

• Main HC Responses - Individually, lowering aromatics, adding MTBE, and 

lowering Tg-, resulted in lowered HC emissions. Lowering olefins raised HC emissions. 

The largest single effect suggested by these data was associated with lowering Tx from 

360 °F to 280 °F which reduced exr.aust mass HC emissions by 22% on average for 

all fuels tested. This effect could also be the result of fuel compositional or physical 

parameters other than Tg-,. These results indicate the need for further examination in 

future phases of the Program. 

• Main CO Responses - CO emissions were lowered by reducing aromatics and 

by adding MTBE. Changing olefins and reducing Tg-, did not have a statistically 
P.7 

Emiwion 

Constituent 

HS 

..2 

NOx 

Table 1 

Main Effects Of Changes In Fuel Variables On Mass Exhaust Emissions 

Current Vehicle Fleet, (Percent Change) 

AROMATICS 

45%-* 20% 

-6.3 ±1.8 

•13.6 ±2.9 

Z1 ±2.0 

CHANGE IN FUEL VARIABLE 

MTBE OUEFINS 

0% •* 15% 20% -» 5% 

-5.1 ±1.8 6.1 ±2.0 

•11.2 ±3.1 1.5 ±3.4 

1.4 ±£ 0 4.0 ±1.9 

T

90 

360°F-»» 280°F 

-21.6 ±1.7 

0.8 ±3.9 

5.0 ±2.4 

Now: Values are shown with 95% confidence Intervals. Changes less than the confidence interval are not 

signifioanL 

Note: An 'affect* Is the difference In a response (HC. CO, NOx) computed using all experimental design data 

as particular variables (aromatics, MTBE, olefins, Tgg) change. 

significant impact on CO emissions. 

• Main NOx Responses - NOx emissions were lowered by reducing olefins, raised 

when Tgo was reduced, and only marginally increased when aromatics were lowered. 

Adding MTBE did not significantly affect NOx emissions. 

There appeared to be significant interactions among fuel variables for HC, CO, 

and NOx emissions as shown in Table 2 and Figure 1. 

• Interactions Affecting HC - At low values of Tgo, neither aromatic nor olefin 

content had an impact on HC mass emissions while at high levels of Tgo, both variables 

had an impact. Correspondingly, reducing Tgo always lowered HC emissions although 

the effect depends on the level of aromatics and olefins. 

• Interactions Affecting CO - Lowering aromatics when Tgo was high reduced CO 

more than when T^ was low. Reducing Tg-, when aromatics were low raised CO, while 

it reduced CO when aromatics were high. 

• Interactions Affecting NOx - Although the single factor (main) effects of 

aromatics and MTBE on NOx were slight or insignificant, there was a significant 

interaction between the two fuel variables. Adding MTBE raised NOx emissions when 

aromatics were low, and conversely, reducing aromatics raised NOx emissions only 

when MTBE was present. 

The full regression equations including the interaction terms are shown in 

Attachment VI. 

Fleet average emissions are plotted in Figures 2 through 5. Figure 2 organizes 

the fuels by average mass exhaust emission levels for HC, CO, and NOx. Confidence 

intervals (95%) are shown for each fuel as well as for industry average fuel to which the 

fuels are compared. Where there is no overlap of test fuel and industry average fuel 

confidence intervals, the difference is considered significant. 
P.8 

Table 2 

Interactive Effects Of Changes In Fuel Variables On Mass Exhaust Emissions 

Emission AROMATICS 

Constituent 45% •* 20% 

HC 

Low Tgo 1.7 ±2.5 

High fgo -13.2 ±2.5 

SS 

Low TgQ -8.6 ±4.1 

High tgo -18.0 ±4.1 

NOK 

W/O MTBE -1.5 ±2.8 

With MTBE 5.8 ±2.8 

Current Vehicle Fleet, (Percent Change) 

CHANGE IN FUEL VARIABLE 

MTBE OUEFMS 

0% -*• 15% 20% •* 5% 

Low TgQ 1.2 ±2.8 

High TgQ 11.0 ±2.8 

Aromatics 

Low 

High 

Low 

High 

Olefins 

Low 

Low 

High 

High 

Low Aromatics 

High Aromatics 

5.2 ±2.8 Low Aromatics 

•2.0 ±2.8 High Aromatics 

T

90 

360°F-»» 280°F 

-18.3 ±3.4 

-30.3 ±3.4 

-10.5 ±3.4 

-23.7 ±3.4 

5.7 ±5.5 

-5.1 ±5.5 

Note: Values are shown with 95% confidence intervals. Changes less than the confidence interval are not 

significant 

Note: An 'effect* is the difference In a response (HC, CO, NOx) computed using all experimental design data 

as particular variables (aromatics, MTBE, olefins, Tgo) change. 

Note: The table shows all statistically significant multiple interactions. 

Figure 3 also organizes the fuels by average mass exhaust emission levels for 

HC, CO, and NOx. In this case, however, average confidence interval bars (95%) are 

given which can be used to compare any two or more fuels for significant differences. 

Fuels separated by more than the length of a bar are significantly different. 

Figures 4 and 5 illustrate in three dimensions the relationship between average 

HC, CO, and NOx mass exhaust emission levels and fuel composition. Fuels with 

MTBE are plotted separately from fuels without MTBE and each fuel is plotted 

according to its actual aromatics, olefins, and Tgo values. Average HC, CO, and NOx 

levels are given for each fuel (refer to Figures 2 and 3 for the significance of the 

values). 

Emission results for individual fuels are consistent with the results of the 

regression analysis. 

6 
P.9 

An indication of the linearity of the responses and of the general applicability of 

the regression equations may be obtained by determining the ability of the regression 

equation to predict the emissions measured for fuels A (industry average fuel) and B 

(emissions certification fuel). Results of this exercise are shown in Table 3. 

Table 3 

Regression Equation Predictions For Fuels A and B 

Current Fleet 

Fuel A Fuel B 

Statistically significant values at the 95% confidence level. 

HC 

CO 

NOx 

Observed 

0.22 

Z79 

0.60 

Predicted 

0.23 

2.88 

0.58 

% Difference 

-72* 

-3.4 

-1-2.6 

Observed 

0.20 

2.62 

0.54 

Predicted 

0.22 

2.87 

0.58 

% Difference 

-11.2* 

-9.5* 

-8.7* 

The difference between actual and predicted HC values for fuels A and B may 

be attributable to compositional properties other than those studied in this program 

as well as non-linearity. Fuel B, which was used as a reference fuel, was blended to 

certification test fuel standards and was produced from entirely different feed stocks 

than other Program test fuels. 

Older Fleet - The main factor regression analysis results for the older fleet on 

half of the fuels are shown in Figure 6 and Table 4. The analysis includes fuels that 

were a half-replicate of the 16-fuel factorial design. 

Emission 

Constituent 

HQ 

SS 

NOK 

Main Effects Of 

AROMATICS 

45%-» 20% 

9.8 ±4.1 

-4.8 ±5.4 

-8.4 ±2.8 

Table 4 

Changes In Fuel Variables On Mass Exhaust Emissions 

Older Vehicle Fleet, (Percent Change) 

CHANGE IN FUEL VARIABLE 

MTBE OLEFINS 

0%-» 15% 20%-*> 5% 

-7.3 ±3.5 6.1 ±4.0 

-13.0 ±5.0 -0.8 ±5.7 

-0.6 ±3.0 -8.9 ±2.8 

T

90 

360°F-» 280V 

•1.6 ±3.7 

13.1 ±6.5 

3.4 ±3.1 

Note: Values are shown with 96% confidence intervals. Changes lees than the confidence interval are not 

significant 

Note: An 'effect* Is the difference in a response (HC, CO, NOx) computed using all experimental data as 

particular variables (aromatics, MTBE, olefins, Tgo) change. 

Because only half of the fuels have been analyzed in the older fleet, estimates 

of the interactions cannot be made to determine if the effects are additive. When the 
P.10 

analysis of all fuels is completed, interactions can be determined. It is possible that the 

values of the responses may change when the full analysis is performed. 

HC - Exhaust hydrocarbon emissions were reduced by adding MTBE and were 

increased by lowering aromatics and olefins. Lowering Tgo had no statistically significant 

effect on HC emissions. 

CO - CO emissions were lowered by adding MTBE and raised by lowering TgQ. 

The effects of reducing aromatics or olefins were not statistically significant. 

NOx - NOx emissions were lowered by reducing aromatics and olefins but were 

raised by reducing TgQ. Adding MTBE did not have a statistically significant effect on 

NOx. 

The regression equations for the main terms are shown in Attachment VII. 

Figures 7 through 10 show the fleet average results of the fuels tested in the 

older fleet. The figures are as described in the current fleet results except that fuels 

which have not yet been analyzed are shown without average emissions levels in 

Figures 9 and 10. 

Discussion of Results - Mass exhaust emissions of both current and older vehicle 

fleets were affected by changes in fuel composition. Responses to changes in olefin 

and MTBE content were similar for both fleets while responses to changes in aromatics 

and Tgo levels were different, and in certain cases opposite in the two fleets. The 

largest percentage effect in the current fleet, the impact of Tgo on exhaust HC 

emissions, was not found in the older fleet. 

The reasons for the impact of fuel composition parameters and especially the 

interactions between them are not yet fully understood. They may be related, in part, 

to the chemical composition of the specific refinery streams used to blend the test fuels. 

In this part of the program, only four compositional parameters were systematically 

investigated. As an example, all aromatics were assumed to behave in the same way, 

regardless of molecular weight or structure. Different refinery blends might result in 

fuels with different detailed compositions than those of the fuels tested in this program 

and hence different emissions performance. 

Beyond the analyses of the program design variables (aromatics, MTBE, olefins, 

Tgo), a preliminary examination of liquid fuel composition parameters has revealed that 

good statistical correlation exists between parameters such as light and heavy 

aromatics, light and heavy olefins, etc. and mass emissions for the current fleet. 

Characterizing fuel composition in terms of those parameters may be more useful in 

correlating mass emissions than the program design variables. Further analyses are 

planned to determine the most important compositional factors, to determine 

quantitatively how mass emissions respond to chemical composition, and to estimate 

the relative importance of chemical composition and physical properties such as 

distillation temperatures. 

8 
P.11 

Another area of inevitable uncertainty at this time as to the relationship of exhaust 

emissions to fuel composition is the fact that only two levels of each parameter were 

tested and there is no way to determine whether the response function over the regions 

investigated requires the inclusion of higher order (curvature) terms. The two level 

factorial designs employed in this study can detect interactions between factors, but not 

individual curvature effects. Future studies are planned. 

Based on the data available from this portion of the Program, a complete analysis 

of why the fleets responded differently to changes in the fuel composition may not be 

possible. There were a number of differences between the fleets such as vehicle 

mileage, catalytic converter age, methods of fuel metering (carburetion vs. fuel injection), 

and the employment of adaptive learning algorithms. These differences are 

characteristic of the different vehicle models which distinguish the two fleets and were 

not controlled systematically between the fleets. 

There are a number of other vehicle factors which may affect emissions and air 

quality and which were not tested in this part of the program. All test vehicles had 

emissions levels that were similar to those in EPA's in-use vehicle fleet data base. The 

program was not designed to study vehicles with high levels of emissions ("super 

emitters", tampered vehicles, etc.). In addition, all effects were instantaneous effects. 

There are no data on the long term effects of fuel composition changes on catalyst 

durability and emissions. These factors will be examined in Phase II of the Program. 

The implications of these results for air quality cannot be evaluated until the air 

quality modeling effort is completed. The modeling effort will take into account 

evaporative and running loss emissions as well as exhaust emissions. It will also make 

use of the speciation measurements carried out in many of the tests. Results of the 

air quality modeling will be reported in future Technical Bulletins. 

The estimated cost of producing some reformulated gasolines within the Phase 

I matrix will be determined by developing regional refinery linear programming models. 

Results will be reported at the end of Phase I following completion of the air modeling 

studies. 
p 1? 

FIGURE 1 

CHANGES IN MASS EXHAUST EMISSIONS 

CURRENT FLEET 

% Increase 

% Decrease 

% Increase 

% Decrease 

20 

10 

0 

•10 

•20 

•30 

•40 

+

1 

a 

EXHAUST HC 

D 

1 

* *« 

4"'° 

TDIA.0 

yAROMATICS MTBE OLEFINS T90 

45% — 20% 0 — 15% 20% — 5% 360 F — 280 F 

EXHAUST CO, NOx 

AROMATICS MTBE OLEFINS T90 

45%-* 20% 0—15% 20%— 5% 360 F—28 0 F 

A/a - High/Low Aromatics 

O/o - High/Low Olefins 

T/t - High/Low T90 

NOTES: 

1. Squares represent average effects for all fuels 

2. Effects for Aromatics, Olefins, T90 depend 

on levels of other parameters, as shown 

3. Bars represent 96% confidence intervals 
P.13 

FIGURE 2 

MASS EXHAUST EMISSIONS, CURRENT FLEET 

0.3 

0.28 

0.26 

0.24 

0.22 

0.2 

0.18 

0.16 

EXHAUST HC g/nH 

0 H N 

• 

c a P e » 

llll l 

• • l l l l l 

« 

C M P 0 ' 

T T I 4..\..L 

r 

L 

T 1 

in1 

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MIRMI 

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. T 

II 

1 

/cx 

1 1 —fc . 

3.6 

3.4 

3.2 

AaaAAaCAaaaaaAAA A 

M MMMMIncfllMrnfllMIWM M M fn 

OO00OOR0O0O00OO0 0 

ttttttTtTtTTTTTT T 

EXHAUST CO. a/mi 

3 • 

U 

2.6 

2.4 

2.2 

M J r 1 W 1 C ) 1 

il l 

I ' i 

i 

1 1 

i ' 

» ( 

i i 

: c 

i i 

j • 

. ' 

• < 

i 

i 

j 

i 

i < 

i 

i » 

i 

i 

i 

1 

t 

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\ 

IN0U6TRV 

mvuat 

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) 

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I 

>c.i 

aaaaaCaAaaAAAAAA A 

MMMMf n E fllMHIfllMMfflllinifll M 

oOOoOROoooOOoOOo o 

TTttTTttTttTttTT T 

0.7 

036 

0.6 

036 

EXHAUST NOi, a/ml 

1 

i 

I O R 1 J F C K I ( 

i 

l 

ri ' i ' i i > 

i 

i 

) 

i i 

I ' 

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r 

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H 

I 

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CaAAaaAAAAAaaaaA a 

B fn M M M fn M fn ftl M M fn M tn M fn M 

RoooooeoOOOOeOOO O 

TTTTTtttTtTttTTt t 

A/a * High/Low Aromatics 

M/m - High/Low MTBE 

O/o - High/Low Olefin 

T/t - High/Low T90 

CERT - Certification Test Fuel 

Note: Confidence intervals are for 

Comparisons of two fuels. 

Pairs which do not overlap 

are different. 
FIGURE 3 

MASS EXHAUST EMISSIONS, CURRENT FLEET 

EU£]_ 

A 

B 

C 

D 

E 

F 

G 

H 

1 

J 

K 

L 

M 

N 

O 

P 

Q 

R 

_£_=___ 

AVE 

CERT 

AMot 

amOT 

AMOT 

amot 

AmOt 

aMOt 

AmoT 

aMoT 

Amot 

AmOT 

aMOT 

aMot 

AMOt 

amOt 

amoT 

AMoT 

0.28 

() 

o R 

0.26(hL 

0.24 

0 Q.E 

0.22 

0.2 

0.18 

A 

M.F.D 

K 

C.G.P.B 

O.H.N 

3.3 

3.1 

2.9 ( ) 

2.7i 

2.5 

2.3 

O 

( ) 

( ) 

L.I.R 

K.G 

E 

A 

F.O 

P.C.Q 

B 

D 

H,N 

O J.M 

0.66 r 

O H 

0.62 ^ 

O P 

0.6 

0.58 

0.56 

() Q 

0.54(IJB 

0.52 

a 

Hi. 

O.E 

A 

C.K.L 

F 

J 

H C , g/mi CO , g/m i NOx , g/mi 

NOTE: Bars represent average 95% confidence intervals for comparison of pairs of fuels. 

Fuels separated by more than the length of a bar are significantly different. 

A / a - High/Low Aromatics 

M/m - High/Low MTBE 

O/o - High/Low Olefins 

T/t - High/Low T90 

AVE - Industry Average 

CERT - Emissions Certification Fuel 
P.15 

o ro o 

cn b ro to o> -4 

CD 

fi) 

0) 

CD 

i f 3 cn -5 

3 2.55" 

CD ••<• } g 

m J2. 

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3 

0) 

p ro p 

b> cn ro 
a. 

FIGURE 5 

Mass Exhaust Emissions, 

Current Fleet 

8 Fuels With MTBE 

(grams/mile) 

HC = 0.25 

CO = 2.92 J* ^ 

NOx = 0.61>""A, ,* ' , ,->« ^ 

Z^\ E ) 

0.27 ^ ^ 

3.16/—^ ^ 

0.57 U 

0.20 

2.68 S~\ 

0.24 

2.32 — 

0.58^X ^ 

(

 J 

0.19 V- ^ 

2.74 ^~S . 

0.61 ( o ) 

0.59 (^Cj^ 01 9 

45^J5^^^ 2.46 f 

^**v*^^ 0.62 ( h 

Aromatics—^^1 

20vol%^5vol% 

0.19 

2.45 J 

•^^0.65 ( 

•_ -

0.21 

^-^2.3 8 I M J 0.64 

360°F 

T90 H ) 

J^T^80°F 

^^20vol% 

Olefins 
FIGURE 6 

CHANGES IN MASS EXHAUST EMISSIONS - OLDER FLEET 

% Increase 

30 

20 

10 

% Decrease 

HC 

CO 

NOx 

- [ ] 

HC 

CO 

NOx 

T 

O 

III I 

l\ 

i 

HC HC 

CO 

NOx 

[ ] 

" [] 

( ) 

III I 

CO 

NOx 

Z\ 

O 

i i 

- 1 0 

20 

AROMATICS MTBE OLEFINS T90 

45% •-> 20% 0-*>15% 20% -•> 5% 360 F -•> 280 F 

NOTES: 1- Analysis of variance for half factorial 

2. Fuel variable effects on emissions are not additive 

3. Bars represent 95% confidence interval for individual 

effects 
P.18 

FIGURE 7 

MASS EXHAUST EMISSIONS, OLDER FLEET 

o.ss 

0.86 

0.4S • 

EXHAUST HC. fl/ml 

0.38 

c 

" 

1 

E a 

ii 

n 

i 

0 

•fH 1 ?! 

. 

> 

^s 

i 

". 

INDUSTRY 

vtntau 

j 

i 

F 

i A i Ci. 

A 

M 

0 

t 

A 

M 

0 

T 

m 

O 

t 

m 

0 

T 

M 

0 

t 

m 

o 

T 

M 

O 

t 

M 

0 

T 

m 

o 

t 

EXHAUST CO, g/mi 

EXHAUST NO». g/nl 

A/a - High/Low Aromatics Note: Confidence intervals are for 

M/m- High/Low MTBE comparisons of two fuels. 

O/o - High/Low Olefins Pairs which do not overlap 

T/t - High/Low T90 are different. 
FIGURE 8 

MASS EXHAUST EMISSIONS, OLDER FLEET 

fc-i-J-LI. 

A 

c 

D 

E 

F 

Q 

H 

1 

J 

N 

&£.. 

AVE 

AMot 

amOT 

AMOT 

amot 

AmOt 

aMOt 

AmoT 

aMoT 

aMot 

0.59 

o.syfF 

0.55 

0.53$ 

0.51 

0.49' 

0.47 

0.45(bE 

d)C 

0.43 

J • 

N.I.A 

UH.D 

OG 

6.5^G*» 

OF.A 

5.5 

O H 

N 

C.D 

4.5 

1.35 

<)G 

1.3 

1.25 

()E 

1.2 

1.15 

<)C 

()H 

()D 

Ol 

() A 

1.1(JN 

( ) J 

O F 

1.05

 L 

HC, g/mi CO, g/mi NOx, g/mi 

NOTE: Bars represent average 95% confidence limits for comparison of pairs of fuels. 

Fuels separated by more than the length of a bar are significantly different. 

A/a - High/Low Aromatics AVE - Industry Average 

M/m - High/Low MTBE 

O/o - High/Low Olefins 

T/t - High/Low T90 

CO 
FIGURE 9 

Mass Exhaust Emissions, 

Older Fleet 

9 Fuels Without MTBE 

(grams/mile) 

HC = 0.53 

CO = 6.49 

NOx = 1.131 I 

45 vol% 

Aromatics 

280°F 

0 vol% 

Olefins 

Tl 

ho 
FIGURE 10 

Mass Exhaust Emissions, 

Older Fleet 

8 Fuels With MTBE 

(grams/mile) 

HC = 0.45 

CO = 4.79 

NOx = 1.27/ 

'

E

 ) 

0.54 

4.69 

1.08 

45 vol% 

Aromatics 

280°F 

20 vol% 

Olefins 

20 vol%^5 vol% 

u 

ho 
ATTACHMENT I 

AIR QUALITY IMPROVEMENT RESEARCH PROGRAM 

PHASE I RESULTS PUBLICATIONS 

PROGRAM 

MATRIX 

CURRENT FLEET 

REFORMULATED 

GASOUNE 

OLDER FLEET 

REFORMULATED 

GASOUNE 

FLEXIBLE/ 

VARIABLE FUEL 

METHANOL 

EXHAM5T 

TECHNICAL 

BULLETIN 

#1 

TECHNICAL 

BULLETIN 

#1 

(PARTIAL) 

RESULTS CATEGORY 

EVAPORATIVE RUNNING LOSS AIR MODELING FUELS 

SAE 902098 

SAE 902098 

SULFUR 

RVP/ 

OXYGENATES 

ro 

ro 
Veh. 

OIA 

01B 

02A 

02B 

03A 

03B 

04A 

04B 

05A 

05B 

06A 

06B 

07A 

07B 

08A 

08B 

09A 

09B 

10A 

10B 

Key: 

Mfr. 

Chrysler 

Chrysler 

Chrysler 

Chrysler 

Ford 

Ford 

Ford 

Ford 

Ford 

Ford 

Toyota 

Toyota 

Honda 

Honda 

GM 

GM 

GM 

GM 

GM 

GM 

M<*W 

ATTACHMENT II 

Current Model Fleet Vehicles 

Displ. 

Year Liters 

Sundance 1989 

Sundance 1989 

Shadow 

Shadow 

Mustang 

Mustang 

Taurus 

Taurus 

Aerostar 

Aerostar 

Camry 

Camry 

Accord 

Accord 

Suburban 

Suburban 

1989 

1989 

1989 

1989 

1989 

1989 

1989 

1989 

1989 

1989 

1989 

1989 

1989 

1989 

Grand Am 1989 

Grand Am 1989 

Delta 88 1989 

Bonneville 1989 

TC - Turbocharged 

TBI - Throttle Body Injection 

PFI - Port Fuel Injection 

SFI - Sequential Fuel Injection 

Carb. - Carburetor 

2.5 

2.5 

2.5 TC 

2.5 TC 

5.0 

5.0 

3.0 

3.0 

3.0 

3.0 

2.0 

2.0 

2.0 

2.0 

5.7 

5.7 

2.3 

2.3 

3.8 

3.8 

10,000 to 29,000 Miles 

Fuel 

Svstem 

TBI 

TBI 

PFI 

PFI 

SFI 

SFI 

PFI 

PFI 

PFI 

PFI 

PFI 

PFI 

Carb. 

Carb. 

TBI 

TBI 

PFI 

PFI 

SFI 

SFI 

Air 

EGR Iniection 

Yes 

Yes 

No 

No 

Yes 

Yes 

No 

No 

No 

No 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

No 

No 

Yes 

Yes 

Air - Secondary Air Injection 

Pair - Pulsed Air Injection 

No 

No 

No 

No 

Air 

Air 

No 

No 

No 

No 

No 

No 

Pair 

Pair 

Air 

Air 

No 

No 

No 

No 

Catalvst 

TWC 

TWC 

TWC 

TWC 

2TWC&20C 

2TWC&20C 

TWC 

TWC 

2TWC 

2TWC 

TWC 

TWC 

TWC 

TWC 

TWC 

TWC 

TWC 

TWC 

TWC 

TWC 

TWC - Three Way Catalyst 

OC - Oxidation Catalyst 

Location 

CC 

CC 

UB 

UB 

CC&UB 

CC&UB 

CC 

CC 

UB 

UB 

CC 

CC 

UB 

UB 

UB 

UB 

UB 

UB 

UB 

UB 

ccUB -Close 

Enoine Familv 

KCR2.5V5FBD6 

KCR2.5V5FBD6 

KCR2.5V5FAC3 

KCR2.5V5FAC3 

KFM5.0V5HBF4 

KFM5.0V5HBF4 

KFM3.0V5FEG0 

KFM3.0V5FEG0 

KFM3.0T5FYK2 

KFM3.0T5FYK2 

KTY2.0V5FFFX 

KTY2.0V5FFFX 

KHN2.0V2F4F6 

KHN2.0V2F4F6 

K3G5.7T5TYA3 

K3G5.7T5TYA3 

K2G2.3V8XEW0 

K2G2.3V8XEW0 

K2G3.8V8XEB1 

K2G3.8V8XEB1 

Coupled 

Under Body 
Veh. Mfr. 

20A Chrysler 

20B Chrysler 

21A Ford 

21B Ford 

22A Ford 

22B Ford 

23A Honda 

23B Honda 

24A GM 

24B GM 

25A GM 

25B GM 

26A GM 

26B GM 

Displ. 

Model Year Liters 

Reliant 1985 

Reliant 1985 

Tempo 1985 

Tempo 1985 

F-150 1983 

F-150 1983 

Accord 1985 

Accord 1985 

Grand Prix 1984 

Cutlass 1984 

Impala 1985 

Caprice 1985 

Suburban 1984 

Suburban 1984 

Note: * Open loop control system. 

Key: 

TBI - Throttle Body Injection 

Carb. - Carburetor 

2.2 

2.2 

2.3 

2.3 

4.9 

4.9 

1.8 

1.8 

3.8 

3.8 

5.0 

5.0 

5.7 

5.7 

ATTACHMENT III 

Older Model Fleet Vehicles 

42,000 to 79,000 Miles 

Fuel 

Svstem 

Carb. 

Carb. 

TBI 

TBI 

Carb.* 

Carb.* 

Carb. 

Carb. 

Carb. 

Carb. 

Carb. 

Carb. 

Carb* 

Carb.* 

Air 

EGR Iniection 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Air - Secondary Air Injection 

Pair-I Pulsed Air Injection 

Air 

Air 

Air 

Air 

Air 

Air 

Pair 

Pair 

Air 

Air 

Air 

Air 

Air 

Air 

Qataryst 

TWC 

TWC 

TWC/OC 

TWC/OC 

OC 

OC 

TWC 

TWC 

TWC/OC 

TWC/OC 

TWC/OC 

TWC/OC 

OC 

OC 

TWC - Three Way Catalyst 

OC - Oxidation Catalyst 

Location 

CC 

CC 

UB 

UB 

UB 

UB 

UB 

UB 

UB 

UB 

UB 

UB 

UB 

UB 

CC - Close 

UB - Under 

Enaine Family 

FCR2.2V2HDH5 

FCR2.2V2HDH5 

FFM2.3V5HCF4 

FFM2.3V5HCF4 

DFM4.9T1ADF9 

DFM4.9T1ADF9 

FHN1.8V3FXF5 

FHN1.8V3FXF5 

E4G3.8V2NEY0 

E4G3.8V2NEY0 

F1G5.7V4NEA4 

F1G5.7V4NEA4 

E1G5.7T4HHCX 

E1G5.7T4HHCX 

Coupled 

Body 

• 

,. 

% 

* 

_, 

• 
QQPE 

A 

B 

C 

D 

E 

F 

G 

H 

1 

J 

K 

L 

M 

N 

O 

P 

Q 

R 

J__L 

AVG 

CERT 

AMot 

amOT 

AMOT 

amot 

AmOt 

aMOt 

AmoT 

aMoT 

Amot 

AmOT 

aMOT 

aMot 

AMOt 

amOt 

amoT 

AMoT 

ATTACHMENT IV 

COMPOSITIONAL MATRIX 

FUEL PROPERTIES 

AROMATICS 

% 

32 

35 MAX 

45 

20 

45 

20 

45 

20 

45 

20 

45 

45 

20 

20 

45 

20 

20 

45 

» - TARGET 

MTBE 

% 

0 

0 

15 

0 

15 

0 

0 

15 

0 

15 

0 

0 

15 

15 

15 

0 

0 

15 

OLEFINS 

% 

12 

10 MAX 

5 

20 

20 

5 

20 

20 

5 

5 

5 

20 

20 

5 

20 

20 

5 

5 

^90 

°F 

335 

330/325 

280 

360 

360 

280 

280 

280 

360 

360 

280 

360 

360 

280 

280 

280 

360 

360 

. ALL FUELS ARE 8.7 PSI RVP AND CONTAIN NO ETHANOL OR ETHANOL COMPOUNDS 

• A/a - HIGH/LOW AROMATICS 

• M/m - HIGH/LOW MTBE 

• O/o - HIGH/LOW OLEFINS 

• T/t - HIGH/LOW Tgj, 

Tl 

. ho 

cn 
CQDfE 

A 

B 

C 

D 

E 

F 

G 

H 

1 

J 

K 

L 

M 

N 

O 

P 

Q 

R 

. A/a-

. M/m-

. O/o -

• T/t-

_IQAVG 

CERT 

AMot 

amOT 

AMOT 

amot 

AmOt 

aMOt 

AmoT 

aMoT 

Amot 

AmOT 

aMOT 

aMot 

AMOt 

amOt 

amoT 

AMoT 

ATTACHMENT V 

COMPOSITIONAL MATRIX 

FUEL PROPERTIES -

AROMATICS 

% 

32.0 

29.9 

43.8 

20.7 

43.7 

20.0 

44.3 

20.2 

42.9 

21.4 

45.7 

47.8 

18.0 

21.4 

46.7 

20.3 

21.5 

46.0 

HIGH/LOW AROMATICS 

HIGH/LOW MTBE 

HIGH/LOW OLEFINS 

HIGH/LOW T^ 

SEE SAE 902098 FOR MORE DETAILS 

MTBE 

% 

0 

0 

15.4 

0 

14.8 

0 

0 

14.6 

0 

14.9 

0 

0 

14.5 

13.9 

14.6 

0 

0 

15.2 

ACTUAL 

OLEFINS 

% 

9.2 

4.6 

3.3 

22.3 

17.2 

3.2 

17.4 

20.2 

4.1 

4.0 

4.9 

17.7 

21.8 

5.7 

19.3 

18.3 

4.8 

4.0 

T

90 

°F 

330 

309 

288 

357 

357 

279 

286 

286 

353 

356 

294 

357 

356 

292 

283 

284 

357 

354 

RVP 

PSI 

8.7 

8.7 

8.7 

8.5 

8.7 

8.8 

8.8 

8.5 

8.9 

8.6 

8.8 

8.5 

8.7 

8.8 

8.6 

8.5 

8.6 

8.4 

* 

• 

t 
Attachment VI 

P.27 

Current Fleet 

Table of Regression Coefficients 

R

2 

Std. Error 

Variable 

Mean(1) 

A 

M 

0 

T 

AM 

AO 

AT 

MO 

MT 

OT 

AMO 

AMT 

AOT 

MOT 

Block 

ao 

« i 

-h. 

% 

3 4 

3

12 

3

13 

314 

%3 

324 

^34 

3

123 

3

124 

3

134 

3234 

3i2a_ 

HC 

0.9827 

0.0829 

-1.5114042 

0.0025823* 

-0.0034959* 

-0.0039509* 

0.0030304* 

0.0001036 

-0.0000117 

0.0000795* 

0.0001009 

0.0000179 

-0.0000764* 

-0.0000111 

-0.0000027 

-0.0000010 

0.0000010 

-0.0087728 

CQ 

0.9723 

0.1471 

1.0082863 

0.0058362* 

-0.0079158* 

-0.0009679 

-0.0001049 

0.0000749 

•0.0000829 

'#0.0000542* 

'" 0.0000012 

-0.0000067 

-0.0000588 

-0.0000132 

0.0000019 

-0.0000022 

0.0000015 

0.0050379 

NOx 

0.9883 

0.0865 

-0.5066676 

-0.0008132 

0.0009509 

0.0041530* 

-0.0006042* 

-0.0001905* 

-0.0000191 

-0.0000109 

-0.0001298 

0.0000044 

0.0000187 

0.0000023 

0.0000030 

-0.0000016 

0.0000021 

-0.0014858 

* = Significant at the 95% confidence level. 

(HC, CO, NOx) EXP [a, + a, * (A) + a- * (M) + a, * (O) + a4 • (T) + a,a * (AM) 

+ a,, * (AO) + a,4 * (AT) + a,, * (MO) + a* • (MT) + a* * (OT) 

+ a, a * (AMO) + a,* * (AMT) + a,* * (AOT) + a-^ • (MOT)] 

where, A • (% Aromatics - 328) 

M = (% MTBE - 7.37) 

O =» (% Olefins- 11.8) 

T - (T, - 321) 

(32.8, 7.37, 11.8, 321) mean values of Aromatics, MTBE, Olefins, and T^ respectively, for 

the 16 factorial* fuels (fuels C • R) 

Block > • 0.5 for Block 

+ 0.5 for Block 

Example of interaction terms: 

AM « A * M = (% Aromatics - 328) * (% MTBE • 7.37) 
Attachment VII 

Older Fleet 

Table Qf Regression Qn*mr\an^ 

Preliminary, Based on Block I Fuels Only 

HQ_ 

R

2 

Std. Error 

Variable 

Mean(l) 

* A 

M 

__f\ 0 

T 

i 

3o 

ai 

32 

33 

34 

0.9759 

0.0972 

-0.696352 

-0.003742* 

-0.005089* 

-0.003975* 

0.000202 

-GO. 

0.9532 

0.1471 

1.722784 

0.001956 

-0.009269* 

0.000539 

-0.001537* 

* _ 

NOx 

0.9840 

0.0790 

0.164667 

0.003526* 

-0.000383 

0.006212* 

-0.000416* 

= Significant at the 95% confidence level. 

(HC, CO, NOx) - EXP [a- + a, * (A) + a, * (M) + a, * (0) + a, • (T)] 

A M, 0, T are defined as for Current Vehicle Fleet Equations. 

This equation is simpler than reported herein for the current vehicle fleet because only half of the 16 

fuels are included and only the main effects A, M. O, and T can be determined. 
"n-?jp '(ATittc'cA'A/- X '"MJ 

. • t'.;. .''„••_!'.' .-..• );%7.-.<.- • "-.*

:

 '•": >^ i->3 

P.29 

«*.-

X.r;-i