Page 1/2 World Headquarters One American Road Dearborn, MI 48126-2701 USA

November 19, 2013

Michael Olechiw Paul Machiele Director, Light-Duty Vehicles and Small Engines Cen ter Director, Fuels Center
Assessment and Standards Division Assessment and St andards Division U.S. EPA Office of Transportation and Air Quality U .S. EPA Office of Transportation and Air Quality
2000 Traverwood Drive 2000 Traverwood Drive Ann Arbor, MI 48105 Ann Arbor, MI 48105

Attention: Docket No. EPA-HQ-OAR-2011-0135

Subject: Fuel Quality Changes Needed to Meet Tier 3 Emissio n Standards and Future Greenhouse Gas

Requirements

Dear Mr. Michael Olechiw and Mr. Paul Machiele:

This letter and the attached documents constitute s upplemental comments of Ford Motor Company (“Ford’) on the Environmental Protection Agency’s (“EPA’s”) propose d “Tier 3” regulations. Please add these comments to Docket No. EPA-HQ-OAR-2011-0135 so that they are included as part of the administrative record for this rule making.

These comments further address the need to decrease market fuel sulfur concentrations to a maximum of 10 ppm.
The attachments to this letter include data and inf ormation demonstrating the adverse effects of fuel sulfur on exhaust emission aftertreatment devices planned for use to meet future proposed Tier 3 emission regula tions. The
attachments are as follows:

1. Sulfur Effects on Gasoline Exhaust Emissions (previously presented to EPA in May 2011)
2. Tier 3 Sulfur Test Program (data recently generated in 2013)

Summary of Ford’s Position

In setting emission standards for motor vehicles, F ord believes it is essential for regulators to addr ess fuels and vehicles as a system. The ability to deploy emissi ons control technologies on a vehicle, in order to meet specified emission standards, often depends on the quality of the fuel to be used in the vehicle. It is critica l that EPA use a systems approach in setting the proposed Tier 3 exh aust and evaporative emission regulations, as well as future fuel economy and greenhouse gas standards.

EPA is a global leader in vehicle emissions reducti ons. However, improvements in fuel quality in the U.S. have not kept pace with advances in other developed countrie s, which have demonstrated the capability to provid e gasoline with 10 ppm sulfur to the retail marketplace.

Ford believes that, based on the data presented her e and elsewhere, reductions in sulfur content in ga soline to a maximum of 10 ppm are needed for the following reas ons:

 Aftertreatment systems are expected to experience r educed efficiency, resulting in increased tailpipe emissions, when exposed to fuel containing higher sulfur content  New advanced lean-burn technology will be inhibited if fuel sulfur content is not controlled to 10 ppmMr. Michael Olechiw

Mr. Paul Machiele November 19, 2013

Page 2/2 Summary of Attachments

Attachment 1 is a presentation titled, “Sulfur Effe cts on Gasoline Exhaust Emissions.” The presentati on includes data addressing the following topics:

• Fuel sulfur content in the U.S. and worldwide

• The harmful effects of fuel sulfur on catalyst effi ciency

• The contribution of fuel sulfur to particulate emis sions

• The adverse impacts of fuel sulfur on lean NOx stor age efficiency

Attachment 2 is a summary of a recent test program comparing the exhaust emissions of a vehicle operat ing on 30 ppm sulfur gasoline with the exhaust emissions of t he same vehicle operating on 10 ppm gasoline. The test results show that NMHC + NOx emissions were 45% higher on t he vehicle using the high-sulfur fuel, and the emis sions increase is statistically significant at a 95% conf idence level. The test is further evidence that fu el containing 30 ppm sulfur is not compatible with current and futur e proposed emission standards, or with the technolo gy necessary to meet such standards.

Conclusion

These supplemental comments add important data to t he record that should be considered by EPA as it se ts limits on the sulfur content of gasoline. We believe that a 10 ppm sulfur limit is both appropriate and essenti al based on the data in these comments, as well as other data and i nformation presented by the Alliance of Automobile Manufacturers and many of our competitors in the au to industry.

We note that, in addition to sulfur reductions, the re are other fuel quality improvements needed to en able automobile manufacturers to achieve future standards imposed o n motor vehicles. For example, reduced summer gaso line vapor pressure is needed to assist in achieving Tier 3 ev aporative emission regulations, and an increase in the minimum gasoline octane rating is needed to enable manufact urers to achieve future fuel economy requirements a nd reductions in greenhouse gases. We urge EPA to tak e action on all fuel quality improvements necessary to support upcoming vehicle standards.

If there are specific questions regarding these rec ommendations or any clarifications or comments prov ided within the documents, please feel free to contact me at 31 3-594-2916 for further discussions. Thank you for including this
material in the Tier 3 docket.

Sincerely,

Dominic M. DiCicco Manager, Environmental Policy and Fuel Quality Sustainability and Vehicle Environmental Matters

cc via email: Mr. Joseph McDonald, Senior Engineer, U.S. EPA/OTAQ/ASD Mr. Antonio Fernandez, Senior Engineer, U.S. EPA/O TAQ/ASD**ATTACHMENT 1**Sulfur Effects on Gasoline ExhaustEmissionswith Advanced Catalyst FormulationsFord / EPA Technical DiscussionPresented:May 10, 2011Submitted to: EPA Tier 3 Docket No. EPA-HQ-OAR-2011-0135SLIDE 2 / 24Submitted to: EPA Tier 3 Docket No. EPA-HQ-OAR-2011-0135OutlineI. Gasoline Sulfura. Market FuelII. Three-way Catalystsa. LEV I & pre-Tier 2b. Laboratory Tier 2c. Vehicle PZEV TestingIII. Particulate MatterIV. Lean NOx Trapsa. Mechanismb. Storage Efficiency* NOTE: The data in this presentation are a compilation of existing information and summaries.SLIDE 3 / 24Submitted to: EPA Tier 3 Docket No. EPA-HQ-OAR-2011-0135Market Fuel – Sulfur – U.S. Summer 2010Present EPA max. 80ppmFord Proposed max. of 10 ppm capPresent EPAaverage 30ppmARB CAP30ppmARB CAPto be 20ppmSource: Alliance of Automobile Manufacturer Fuel SurveySLIDE 4 / 24Submitted to: EPA Tier 3 Docket No. EPA-HQ-OAR-2011-0135Market Fuel – Sulfur – WorldwideU.S. EuropeCanadaJapan10 ppmSource: Alliance of Automobile Manufacturer Fuel SurveySGS Worldwide Fuel SurveySLIDE 5 / 24Submitted to: EPA Tier 3 Docket No. EPA-HQ-OAR-2011-0135Three-Way Catalysts (TWC)SLIDE 6 / 24Submitted to: EPA Tier 3 Docket No. EPA-HQ-OAR-2011-0135HCCO/NOxFuel Sulfur

% Catalyst EfficiencySulfur decreases conversion efficiency ofpre-Tier 2 technologyEffects of Fuel Sulfur – LEV I Catalyst TechnologySLIDE 7 / 24Submitted to: EPA Tier 3 Docket No. EPA-HQ-OAR-2011-0135Fuel Sulfur, ppm

%CO/NOx Catalyst EfficiencySulfur effects on varyingcatalyst formulations (differentprecious metal types)Effects of Fuel Sulfur – Tolerance of Catalyst FormulationsSLIDE 8 / 24Submitted to: EPA Tier 3 Docket No. EPA-HQ-OAR-2011-0135Laboratory Catalyst EvaluationObjective:Evaluation of catalyst formulations and determinationof sulfur effectsConducted:At the Ford Research and Innovation Center inDearborn, MIProcess:Samples evaluated in a setting designed to replicate thetypical inlet catalyst exhaust environment encountered duringvehicle operation (exhaust constituents, temperature, Air/Fuel,Space Velocity, etc...)*Effects of Fuel Sulfur – Tier 2 Catalyst TechnologySLIDE 9 / 24Submitted to: EPA Tier 3 Docket No. EPA-HQ-OAR-2011-0135LeanRichHCCONOx

% Catalyst EfficiencyLambdaTIER 2 / LEV II TechnologyCatalyst Efficiency Evaluation – Air/Fuel SweepHC, 30 ppm SNOx, 30 ppm SHC, 0 ppm SCO, 30 ppm SNOx, 0 ppm SCO, 0 ppm SSLIDE 10 / 24Submitted to: EPA Tier 3 Docket No. EPA-HQ-OAR-2011-0135LeanRich0 ppm vs. 30 ppm SulfurHCNOx

% Catalyst EfficiencyLambda1. Catalyst Efficiency for allcriteria emissions decline(HC, CO, NOx)TIER 2 / LEV II TechnologyCatalyst Efficiency Evaluation – Air/Fuel Sweepcont...HC, 30 ppm SNOx, 30 ppm SHC, 0 ppm SCO, 30 ppm SNOx, 0 ppm SCO, 0 ppm SCOSLIDE 11 / 24Submitted to: EPA Tier 3 Docket No. EPA-HQ-OAR-2011-0135LeanRichCO-NOx Crossover0 ppm vs. 30 ppm SulfurHCCONOx

% Catalyst EfficiencyLambda1. Catalyst Efficiency for allcriteria emissions decline(HC, CO, NOx)2. CO/NOx CrossoverdeclinesTIER 2 / LEV II TechnologyCatalyst Efficiency Evaluation – Air/Fuel Sweepcont...HC, 30 ppm SNOx, 30 ppm SHC, 0 ppm SCO, 30 ppm SNOx, 0 ppm SCO, 0 ppm SSLIDE 12 / 24Submitted to: EPA Tier 3 Docket No. EPA-HQ-OAR-2011-0135LeanRichCO-NOx Crossover0 ppm vs. 30 ppm SulfurHCCONOx

% Catalyst EfficiencyLambda1. Catalyst Efficiency for allcriteria emissions decline(HC, CO, NOx)2. CO/NOx Crossoverdeclines3. Window of operationbecomes more narrowSulfur affectscatalyst Air/FuelSweepperformanceTIER 2 / LEV II TechnologyCatalyst Efficiency Evaluation – Air/Fuel Sweepcont...HC, 30 ppm SNOx, 30 ppm SHC, 0 ppm SCO, 30 ppm SNOx, 0 ppm SCO, 0 ppm SSLIDE 13 / 24Submitted to: EPA Tier 3 Docket No. EPA-HQ-OAR-2011-0135Samples provided below are technologies in production and/or planned for usein Tier 2 vehicles.Data show that 30 ppm Sulfur reducesCatalyst Efficiency in Tier 2 catalyst technologiesCatalyst CO/NOx InEfficiency Data – Air/Fuel SweepExample of Sample #3:100% Conversion Efficiency = 0% Inefficiency; thus, 98.7% conv. Eff. = 1.3% InefficiencyIf the vehicle engine-out catalyst feedgas emission levelis 2.0 g/mile...98.7% conv. Eff. (1.3% inefficiency) results in 0.026 g/mile emissions97.1% conv. Eff. (2.9% inefficiency) results in 0.058 g/mile emissionsFinally, calculating the increase in emissions due to sulfur results in [(0.058 – 0.026)/0.026] * 100 =123%increase

400cpsi 900cpsiSLIDE 14 / 24Submitted to: EPA Tier 3 Docket No. EPA-HQ-OAR-2011-0135Including the 250ppm Sulfurdata appears to indicate adifferent function below 30ppmCO/NOx Crossover Linear Interpolation ExtrapolationCatalyst CO/NOx InEfficiency Data – Air/Fuel Sweepcont...SLIDE 15 / 24Submitted to: EPA Tier 3 Docket No. EPA-HQ-OAR-2011-013518%17%48%78%44%26%Using Trendline 1:% values shown onchart relate to thechange in emissions.InEfficiency region below 30 ppm Sulfur~44 % Reduction in Emissions when Sulfur isreduced from 30 ppm to 5 ppm SulfurCatalyst CO/NOx InEfficiency Data – Air/Fuel Sweepcont...SLIDE 16 / 24Submitted to: EPA Tier 3 Docket No. EPA-HQ-OAR-2011-01352009MY 2.4L Malibu PZEV; 33 ppm sulfur vs 3 ppm sulfurExhaust aftertreatment system uses one close-coupled & one under floor converterCatalyst NOx mg/mile Data–from SAE 2011-01-030043% ReductionNo NOx creep & lower NOx emissions w/3 ppm SPrep Protocol #1Prep Protocol #1Prep Protocol #2SLIDE 17 / 24Submitted to: EPA Tier 3 Docket No. EPA-HQ-OAR-2011-0135Particulate MatterSLIDE 18 / 24Submitted to: EPA Tier 3 Docket No. EPA-HQ-OAR-2011-0135•Sulfur in fuel results in sulfurin the exhaust stream•Sulfur in the exhaust can oxidizeinto sulfates•Sulfates contribute to thefraction of particulate matter inthe environmentParticulate matter mass originating from sulfates resulting fromgasoline containing higher levels of sulfur need consideration.“Particulate Matter”SootCondensedHydrocarbonsMetal /Inorganic AshSulfateSulfur in fuel contributes to ParticulateMatter (PM) massMarket Fuel Quality – PM due to SulfurSLIDE 19 / 24Submitted to: EPA Tier 3 Docket No. EPA-HQ-OAR-2011-0135Lean NOx TrapsSLIDE 20 / 24Submitted to: EPA Tier 3 Docket No. EPA-HQ-OAR-2011-0135Conventional TWC and NOx ReductionThe conventional TWC is ineffective for NOxreduction under lean conditions

%NOx Conversion Efficiency4010 20 30

stochiometric operation020406080100 Lean PFIStratified lean

Homogeneous lean

Stochiometric operationA/F RatioSLIDE 21 / 24Submitted to: EPA Tier 3 Docket No. EPA-HQ-OAR-2011-0135The Lean NOx trap suffers due to sulfur poisoningSulfur attaches to the sitesused by NOx, interferingwith the Lean NOxtrapping functionality.Lean NOx Trap – Sulfur Poisoning MechanismSLIDE 22 / 24Submitted to: EPA Tier 3 Docket No. EPA-HQ-OAR-2011-013501020304050607080901000 10 20 30 40 50 60 70 80 90Hours

Avg NOx Storage Efficiency (%) @ 1 Minute~ 200 ppm fuel sulfur level~ 40 ppm fuel sulfur level~ 100 ppm fuel sulfur levelLean NOx Trap – Sulfur Poisoning@ 60 mph80 hrs is 4800 miles> 95% Efficiencyrequired for Tier 2 Bin 2SLIDE 23 / 24Submitted to: EPA Tier 3 Docket No. EPA-HQ-OAR-2011-0135• According to market fuel surveys, leading countries have introduced10 ppm maximum sulfur for gasoline• Sulfur in gasoline has been shown to poison catalysts resulting inreduced catalytic conversion efficiency• Sulfur is expected to continue to affect all precious metal catalystformulations (Pd-only, Pd-Rh, Tri-metal, Pt-Rh) –i.e. No CatalystSolution• Laboratory and independent vehicle testing show >40% reduction inNOx emissions when decreasing sulfur from 30 ppm to5 ppm• Sulfur in gasoline can transition into sulfates which contribute to thefraction of PM in the environment• Very low levels of sulfur are needed to avoid sulfur poisoning ofLean NOx Traps resulting in NOx storage efficiencies belowrequired targeted levelsConclusionSulfur at 10 ppm maximum (or lower) is bothrecommended & supported by the dataSLIDE 24 / 24Submitted to: EPA Tier 3 Docket No. EPA-HQ-OAR-2011-0135THANK YOU!

# ATTACHMENT 2Ford Tier 3 Sulfur Test Program November 19, 2013
Docket No. EPA-HQ-OAR-2011-0135

1/10 

## Tier 3 Sulfur Test Program
Ford Motor Company Summary Report

Provided to the U.S. Environmental Protection Agenc y

BACKGROUND:

Sulfur, which occurs naturally in crude oil, is kno wn for its notorious ability to poison catalysts, a ffect
heated oxygen sensors and dramatically reduce the f unctionality of advanced exhaust emissions systems. Laboratory research has shown sulfur to d ecrease catalyst criteria emissions conversion efficiency and impact the rich to lean Air/Fuel tra nsition. Sulfur presence in gasoline is also known for its
propensity to corrode metallic components found in the engine and fuels system as well as being linked
to fuel injector deposits. On the other hand, redu ctions in sulfur levels in gasoline result in immed iate improvements in emission levels. Markets with high ly advanced requirements for emissions control and
durability are particularly concerned with maintain ing market fuels at ultra-low sulfur levels of 10 p pm or less as exhaust catalysts must maintain extremel y high efficiencies throughout the expected useful life of the vehicle, 150,000 miles in the proposed Tier 3 standards. As communicated previously and
more recently during the April 2013 Tier 3 NPRM pub lic hearings in addition to the Alliance of
Automobile Manufacturers comments and via separate Ford comments submitted on July 1, 2013, Ford continues to strongly support a reduction of sulfur levels to a 10 ppm (or less) maximum for market
fuels. This sulfur reduction is a key enabler to m eet the strict standards imposed by the proposed Ti er 3 program/One National Program and is necessary to ma intain the integrity of the engine and exhaust
emission aftertreatment systems throughout the vehi cle’s mandated full useful life (FUL).

OBJECTIVE:

A testing program was designed to assess the exhaus t emission difference for a vehicle operating with
10 ppm sulfur gasoline compared to the same vehicle operating with the same gasoline formulation
containing 30 ppm sulfur.

VEHICLE AND CATALYTIC EXHAUST AFTERTREATMENT SYSTEM :

The vehicle selected was a Ford Explorer 2.0L GTDI calibrated to meet BIN50 or ULEV50 tailpipe

emissions. The vehicle included an exhaust emissio n aftertreatment system that is representative of
technologies under study to meet Tier 3 emissions s tandards (close-coupled, catalyst volume of 110 in 3

, 150 g/ft 3 loading of precious metal). A diagram of the exha ust system is shown in Figure 1. Additionally,
the catalysts, UEGO & CMS were dynamometer aged to simulate 150,000 miles (using Ford’s proprietary
ADP process for the proposed Tier 3 FUL requirement ).Ford Tier 3 Sulfur Test Program November 19, 2013
Docket No. EPA-HQ-OAR-2011-0135

2/10 Figure 1: Catalyst configuration for 2.0L GTDI Exp lorer used in testing program.

FUEL:

The gasoline formulation used for this testing prog ram (Appendix A) is aligned with the specifications approved for LEV 3 (having 10 vol% ethanol, 8-11 pp m sulfur, 87-88.4 AKI). The LEV 3 certification fu el
was chosen since the Tier 3 certification fuel is y et to be finalized. Given that the Tier 3 program is
structured to harmonize with LEV 3, the Ford team a greed that the LEV 3 certification fuel would be th e
most suitable fuel.

In order to minimize the variability in as many fue l parameters as possible and to eliminate any poten tial
secondary effects on the emissions measurements, th e higher sulfur gasoline blend was produced from
the same batch of LEV III certification fuel by ble nding a sulfur additive into a portion of the LEV I II fuel. The sulfur additive (Tert-butyl sulfide or Di-tert- butyl-disulfide) was selected to be the same additi ve used by EPA in their Tier 2 sulfur testing program and used in the SGS sulfur study that API included as part of their Tier 3 comments.

TEST PROGRAM:

The flow chart in Figure 2 depicts the testing prog ram:Ford Tier 3 Sulfur Test Program November 19, 2013
Docket No. EPA-HQ-OAR-2011-0135

3/10 Figure 2: Testing program flow chart, typical cert ification procedures and

practices were followed to conduct emission testing

.

Catalyst temperatures were recorded during a sampli ng of both city and highway driving on local area
roads, see Figure 3.

Figure 3: Sampling of local driving catalyst tempe ratures.Ford Tier 3 Sulfur Test Program November 19, 2013
Docket No. EPA-HQ-OAR-2011-0135

4/10 DATA ANALYSIS:

The following summarizes the data collected for thi s sulfur study.

Figure 4: NMHC+NOx FTP Tailpipe Emissions Summary for 2.0L GTDI Explorer.

The data presented in Figure 4, shows that NMHC+NOx emissions increased by 16 mg/mile for the 26.5
ppm sulfur fuel compared to the emissions measured when using the 10 ppm sulfur gasoline. Statistical
analyses using the T-test on the emissions data set s resulted in a P-value of 0.0216, which indicates that

the difference between the two sulfur levels tested is statistically significant. Figure 5 shows the sec-byFigure 5: Cumulative FTP mass for NMHC+NOx Tailpip e Emissions for 2.0L GTDI Explorer.insec-by-sec plotdata used in sec-by-sec plot

• 2.0L GTDI Explorer

• 150K FUL Catalyst (Dyno)

• ETW = 4750 lbs

• Calif. LEV III – E10/91RON

• BIN50/ULEV50

• Calibration

• AftertreatmentFord Tier 3 Sulfur Test Program November 19, 2013
Docket No. EPA-HQ-OAR-2011-0135

5/10 -sec cumulative measured mass for NMHC+NOx tailpipe emissions collected from the 2.0L GTDI Explorer
across the FTP drive cycle. Shown are the lowest 1 0 ppm sulfur and highest 26.5 ppm sulfur NMHC+NOx emissions data, identified in Figure 4, to provide a perspective on the cumulative emissions range.

The following shows the calculation for estimated t otal sulfur exposure experienced by the catalyst during the high-sulfur testing portion of this stud y.

Although the total amount of sulfur exposure to the catalyst during this sulfur study appears to be
relatively small, it is enough to contaminate the c atalytic exhaust emission aftertreament system to
result in an increase in tailpipe emissions for NMH C+NOx by 45 %.

DISCUSSION:

Recently, the American Petroleum Institute (API) sp onsored a new study of sulfur reversibility conduct ed by SGS Environmental Testing Corp. (SGS Study) and subsequently submitted the results as part of joint
API and AFPM comments regarding the Tier 3 NPRM. This SGS study examined the sulfur reversibility in

a set of six late model vehicles in the under-6000 pound vehicle class. Five of the vehicles were cer tified to California SULEV II/PZEV, and one was certified to Federal Tier 2 Bin 5 standards. The SGS Study
included new catalysts that were then aged using 18 -43 ppm sulfur fuel for the equivalent of 120,000-
150,000 miles. After the aged catalysts were insta lled in each respective test vehicle, the study conducted catalyst purging for each vehicle using t he EPEFE protocol, involving 10 wide open throttle (WOT) cycles, to establish baseline vehicle exhaust emissions. The vehicles were then operated and
tested using the following order of 10, 80 and 10 p pm sulfur fuels. The base fuel used to test emissi ons after the catalyst purge contained 10 ppm sulfur wh ile the high sulfur test gasoline contained 80 ppm
sulfur. The study’s results indicated that the inc rease in exhaust emissions due to 80 ppm sulfur fue l was fully reversible after 70 miles of driving (ope rating with 10 ppm sulfur fuel) and preparation ( purge )
cycles linked to LA4 and US06 emission drive cycles

.

In summary, the following conclusions were drawn fr om the SGS study:

• Gaseous exhaust emissions were higher for the vehic les conditioned and tested using 80 ppm
sulfur fuel, relative to baseline tests run using 1 0 ppm sulfur fuel.

• Mean emissions increased for vehicles run on the 80 ppm sulfur (relative to 10ppm sulfur) fuel
as follows, with greater than 95% confidence:

o Fleet average NMOG increased by 20% (0.002 g/mile c hange)

o Fleet average NOx increased by 58% (0.006 g/mile ch ange)

o Fleet average CO increased by 31% (0.078 g/mile cha nge)Ford Tier 3 Sulfur Test Program November 19, 2013
Docket No. EPA-HQ-OAR-2011-0135

6/10 Keep in mind that even if the sulfur effects were d emonstrated to be reversible in the SGS Study, it i s the
average sulfur level on the catalyst that degrades efficiency and degrades criteria emission conversio n performance, and, more importantly, that the act of purging (reversing the sulfur contamination)
negatively impacts fuel economy.

Figure 6 overlays the 2.0L Explorer data collected from the present test program with the data means
collected from the SGS Study.

Figure 6: API/SGS Sulfur Testing Program on 2009-2 012 PZEV Vehicles

w/ 2.0L GTDI Explorer Comparison.

When comparing the 2.0L GTDI Explorer data to the r esults from the SGS study, the following was

observed:

• 2.0L GTDI Explorer experienced an increase in NOx t ailpipe emissions from a loss in

catalyst efficiency (~0.5% less efficient). Most l ikely, the 2.0L GTDI Explorer NOx feedgas was greater than that of the API/SGS Study vehicles – this could be related to the engine
displacement to vehicle mass ratio

• 2.0L GTDI Explorer exhibited higher air mass flow ( and encountered boosting during the second hill of the FTP) compared to the 2.0L Focus PZEV

o 2.0L GTDI Explorer represents an engine displacemen t to vehicle mass ratio that
aligns with what is expected to achieve CO 2 compliance in the near future

• 2.0L GTDI Explorer with 26.5ppm sulfur content in g asoline resulted in considerably higher emission degradation than the 80 ppm sulfur used in the SGS Study for a
comparable engineFord Tier 3 Sulfur Test Program November 19, 2013
Docket No. EPA-HQ-OAR-2011-0135

7/10 CONCLUSIONS:

This sulfur study again confirms the deleterious ef fects of sulfur in our market fuel supply. Specifi cally,
upon inspection of the emissions data from this For d Tier 3 Sulfur Test Program, the following

conclusions can be drawn:

• The test vehicle exhaust emission aftertreatment sy stem was exposed to approximately 1.1
grams of sulfur during the mileage accumulation per iod (~ 15 gallons over 400 miles)

• For a BIN50 certified vehicle under the proposed Ti er 3 regulations, the sulfur contamination

was:

1. Sufficient to cause the NMHC+NOx to increase by 45% and

2. Enough to result in a failed In-Use Verification Pr otocol (IUVP) test

• A T-test was completed on the emissions data set (c omparing 10 ppm sulfur and 26.5 ppm sulfur) with the conclusion that the two population s are significantly different (P = 0.0261) @ 95% confidence level

• This study shows that ~30 ppm sulfur still contamin ates today’s vehicles and is not compatible
with future vehicles required to meet the low emiss ions regulations related to the proposed Tier

3 rules

Overall, these results corroborate the conclusions drawn from a May 2011 Technical Discussion and Presentation by Ford Motor Company entitled “Sulfur Effects on Gasoline Exhaust Emissions with
Advanced Catalyst Formulations” where the following conclusions were previously stated:

• According to market fuel surveys, leading countries have introduced 10 ppm maximum sulfur for
gasoline

• Sulfur in gasoline has been shown to poison catalys ts resulting in reduced catalytic conversion
efficiency

• Sulfur is expected to continue to affect all precio us metal catalyst formulations (Pd-only, Pd-Rh, Tri-metal, Pt-Rh) – i.e. No Catalyst Solution

• Laboratory and independent vehicle testing show >40 % reduction in NOx emissions when decreasing sulfur from 30 ppm to 5 ppm
Additionally,

• Sulfur in gasoline can transition into sulfates whi ch contribute to the fraction of PM

• Very low levels of sulfur are needed to avoid sulfu r poisoning of Lean NOx Traps

In summary, the new data collected in this Ford Stu dy, in tandem with the data provided by the SGS
Study as well as previous work and literature, comp letely support the message that:

Ford continues to strongly support a reduction of s ulfur levels to a 10 ppm (or less) maximum
for market fuels to meet the strict standards propo sed by the Tier 3 program and finalized in the
One National Program, in addition to maintaining th e integrity of the engine and exhaust
emission aftertreatment systems throughout the vehi cle’s full useful life.Ford Tier 3 Sulfur Test Program November 19, 2013
Docket No. EPA-HQ-OAR-2011-0135

8/10 

# APPENDIX AFord Tier 3 Sulfur Test Program November 19, 2013
Docket No. EPA-HQ-OAR-2011-0135

9/10 

# REFERENCES

1. Alliance of Automobile Manufacturers, “Supplemental Comments of the Alliance of Automobile Manufacturers on Market Gasoline Sulfur,” EPA Docke t EPA-HQ-OAR-2011-0135, October 31,

2013.

2. Ball, D.B., Clark, D., Moser, D., “Effects of Fuel Sulfur on FTP NOx Emissions from a PZEV 4 Cylinder Application,” SAE 2011-01-01-0300, 2011.

3. American Petroleum Institute and American Fuel & Pe trochemical Manufacturers Attachment No. 11 to the EPA Docket EPA-HQ-OAR-2011-0135, SGS Environmental Testing Corp., “Reversibility of Gasoline Sulfur Effects on Exhaus t Emissions From Late Model Vehicles,” June

2013.

4. U.S. EPA 2005 Review of the National Ambient Air Qu ality Standards for Particulate Matter: Policy Assessment of Scientific and Technical Infor mation, US EPA OAQPS Staff Paper, EPA452/R-05-005a, December 2005.

5. Truex, T.J., “Interaction of Sulfur with Automotive Catalysts and the Impact on Vehicle Emissions-A Review,” SAE 1999-01-1543.

6. Farrauto, R.J., Mooney, J.J., “Effects of Sulfur on Performance of Aftertreatment Devices,” SAE 920557, 1992.

7. Hoyos, L.J., Praliaud, H., Primet, M., “Catalytic C ombustion of Methane over Palladium Supported on Alumina and Silica in Presence of Hydr ogen Sulfide,” App. Cat. A: General, 98, p. 125, 1993.

8. Beck, D.D., Krueger, M.H., Monroe, D.R., “The Impac t of Sulfur on Three-Way Catalyst: Storage and Removal”, SAE Paper No. 910844, 1991.

9. Benson, J., Burns, V., Gorse, R., Hochhauser, A., e t. al., “Effects of Gasoline Sulfur Level on Mass Exhaust Emissions – Auto/Oil Air Quality Improvemen t Research Program,” SAE 912323, 1991.

10. 78 FR 29816, May 21, 2013.

11. U.S. EPA Summary and Analysis of the 2005 Highway a nd Nonroad Diesel Fuel Pre-Compliance Reports, EPA 420-R-06-12, June 2006.

12. U.S. DOE. 2000. U.S. Petroleum Refining: Assuring t he Adequacy and Affordability of Cleaner Fuels, June 2000.

13. MathPro Inc. 2003. Evolution of Process Technology for FCC Naphtha Desulfurization: 1997- 2003; An Example of Technical Progress Induced by E nvironmental Regulation, March 2003.

14. Draft EPA, “The Effects of Gasoline Sulfur Level on Emissions from Tier 2 Vehicles in the In-Use Fleet,” EPA-420-D-13-003, U.S. EPA, April 2013.

15. Blumberg, K.O., Walsh, M.P., Pera, C., “Low-Sulfur Gasoline and Diesel: The Key to Lower Vehicle Emissions,” May 2003.

16. Owen, K., Coley, T. “Automotive Fuels Reference Bo ok,” 2 nd Edition, 1995.

17. Manufacturers of Emissions Controls Association (ME CA), “The Impact of Gasoline Fuel Sulfur on Catalytic Emission Control Systems,” June 2013.

18. Schleyer, C., Eng, K., Gorse, R., Gunst, R., et. al ., “Reversibility of Sulfur Effects on Emissions of
California Low Emission Vehicles.”

19. Ford Technical Discussion, Sulfur Effects on Gasoli ne Exhaust Emissions with Advanced Catalyst Formulations, May 2011.

20. Worldwide Fuel Charter 5 th Edition, September 2013, Source: www.autoalliance.org

21. “Clean Air Facts: Cleaner Fuels for Cleaner Motor V ehicles,” Source: www.meca.orgFord Tier 3 Sulfur Test Program November 19, 2013
Docket No. EPA-HQ-OAR-2011-0135

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# REFERENCES cont.

22. Review of Prior Studies of Fuel Effects on Vehicle Emissions,” CRC E-84, August 2008, Available

at: www.crcao.org. 23. American Automobile Manufacturers Association/Assoc iation of International Automobile Manufacturers “AAMA/AIAM Study on the Effects of Fu el Sulfur on Low Emission Vehicle Criteria Pollutants,” December 1997.

24. Schleyer, C., Gorse, r., Gunst, R., Barnes, G. et. al., “Effect of Fuel Sulfur on Emissions in California Low Emission Vehicles,” SAE 982726, 1998

. 25. D. M. DiCicco et. al. “The Effect of Fuel Sulfur on the HC, CO and NOx Conversion Efficiencies of Pd/Rh, Pt/Rh, Pd-Only and Tri-metal Catalysts,” 210 th American Chemical Society National Meeting, August 1995.

26. American Automobile Manufacturers Association/Assoc iation of International Automobile Manufacturers “AAMA/AIAM Study on the Effects of Fu el Sulfur on Low Emission Vehicle Criteria Pollutants,” December 1997.

27. Coordinating Research Council (CRC), “CRC Sulfur/LE V Program,” December 1997.

28. Takei, Y., Kinugasa, Y., Okada, M., Tanaka, T, Futi moto, Y., “Fuel Property Requirement for Advanced Technology Engines,” SAE 2000-01-2019.

29. Anthony, J., Kubsh, J., “The Potential for Achievin g Low Hydrocarbon and NOx Exhaust Emissions from Large Light-Duty Gasoline Vehicles,” SAE 2007- 01-1261.

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