Lubricant Effects on Combustion, Emissions, and Efficiency · Lubricant Effects on Combustion, Emissions, and Efficiency Presenter: Brian West Melanie DeBusk, Shean Huff, Sam Lewis,

Lubricant Effects on Combustion, Emissions, and Efficiency

Presenter: Brian WestMelanie DeBusk, Shean Huff, Sam Lewis,Faustine Li, Eric Nafziger, Alex Pawlowski, Scott Sluder, Derek Splitter, John Storey, James Szybist, John Thomas, Robert Wagner (PI)

Oak Ridge National Laboratory

This presentation does not contain any proprietary, confidential, or otherwise restricted information.

2016 DOE Annual Merit ReviewProject ID # FT036June 8, 2016

Technology Managers: Kevin Stork and Michael WeismillerFuels and Lubricants Technology

Vehicle Technologies Office

2 FT036 2016 AMR

Project Overview

• Effort is ongoing; re-focused annually to address DOE and industry needs

• FY13: Lubricants activity separated from “fuels and lubes”– Lubricant Additive Catalyst Effects, Lube

Effects on GDI PM, Low-Speed Pre-Ignition, Vehicle-level Fuel Economy

• FY17: 4-lab team response to Labcall

Timeline

Budget

Barriers

Partners• Industry Collaborators

– GM, Driven Racing Oil, Ford, Umicore• National Laboratories

– ANL, NREL, PNNL• Academic

– Univ. of Tennessee

• Inadequate data on long-term impact of fuel and lubricants on engines and emissions control systems. – MYPP 2.4 E

• FY15: $750k

• FY16: $750k

• Covers 3 sub-projects

3 FT036 2016 AMR

Objectives and Relevance Objectives

• Explore/understand cause(s) of Low-Speed Pre-ignition (LSPI)

• Elucidate lubricant property impacts on emissions and emissions control systems

• Identify concerns associated with new lubricants

• Develop vehicle-based protocol to evaluate lubricants that can improve fuel economy

Relevance:

• Downspeeding and boosting are limited by LSPI

• Important to ensure new/novel lubricant or lubricant additives do not contribute to increased PM emissionsor impact emissions control durability in a negative way

• Small fuel economy gain across legacy fleet can have significant impact on national fuel consumption

4 FT036 2016 AMR

Fuel and lubricant effects on PM formation in DISI enginesExploring LSPI in engines

Approach

Compatibility of advanced lubes with emissions control devices (FT014)

Vehicle-based fuel economy evaluation of advanced lubes

(CH2)5CH3P

(CH2)5CH3

(CH2)13CH3

H3C(H2C)5 -OP

O OCH2CH(C2H5)CH2CH2CH2CH3

OCH2CH(C2H5)CH2CH2CH2CH3

9 nm

40 nm 18 nm

HCs

PM

Filter

Empore

HCs

PM

Filter

Empore

Bring together targeted, engine, vehicle, and flow-reactor studies with in-depth characterization of combustion, PM, HCs, emissions control devices, and fuel economy to better understand fuel and lubricant effects and interactions

IL-18:

Catalyst

-20 0 20 40 60 80 1000

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Crank Angle (°CA aTDCf)

Cyl

inde

r Pre

ssur

e (b

ar)

Average LSPI (cycle #116)

Spark timing

0.0

2.5

5.0

7.5

10.0

12.5

Spar

k Pr

imar

y C

oil S

igna

l (vo

lt)

Spark timing

5 FT036 2016 AMR

Milestones met or on track (=completed)

• Low-Speed Pre-Ignition

Successfully sampled/analyzed from Top Ring Zone in utility engine (FY15)

Completed setup of single-cylinder GDI engine (FY16)

– Report experimental results (FY16)

• Lubricant and Fuel impacts on GDI particulate emissions

Characterized PM morphology and lubricant contribution (FY14 and FY15)

– Commission GDI Engine Start Cart and collect cold start PM data (FY16)

• Complete vehicle experiments to measure fuel economy differences betweenlubricants on multiple vehicles

Cadillac SRX, DOHC V6 (same engine as Sequence VID test – FY14)

Chevrolet Silverado pushrod V8 (FY15-16)

FY15 – commercially available Lube

FY16 – PNNL Lube (FT035)

– Repeat on 4-cylinder engine (FY16)

6 FT036 2016 AMR

Summary of Technical Accomplishments• Low-Speed Pre-Ignition Study

– Successfully sampled and analyzed liquid in top ring zone (TRZ) of running utility engine• Speciation of sample shows boiling point dependence – mostly larger aromatics• Increased load or decreased temperature increases TRZ liquid

– Established dedicated single-cylinder GDI engine• Ford 1.6L EcoBoost (DRIVVEN controller)• Partner providing custom lubes for parametric variation of lubricants

• Effects of Lubricants/Fuels on Emissions– Quantified effects of lubricant additives on catalysts (FT014)– Examined lube and fuel impacts on GDI particulate emissions

• Confirmed higher PM emissions for Start/Stop operation (Malibu GDI e-Assist)• No evidence of lubricant on PM collected on filters• Ethanol blend lowers, isobutanol increases PM mass and soot fraction

– Established engine Start Cart to support future experiments

• Vehicle Fuel Economy– Developed and demonstrated vehicle-based test protocol to screen

lubricants for improved fuel economy• Completed four campaigns (2 campaigns x 2 vehicles)

7 FT036 2016 AMR

• Low-Speed Pre-Ignition Study– Successfully sampled and analyzed liquid in top ring zone (TRZ) of running

utility engine• Speciation of sample shows boiling point dependence – mostly larger aromatics• Increased load or decreased temperature increases TRZ liquid







Summary of Technical Accomplishments

8 FT036 2016 AMR

Downspeeding and Downsizing Trend is Increasing Conditions Conducive to LSPI

• OEMs increasingly relying on downsped, downsized, turbocharged engines for Fuel Economy improvement

• Data mined from Ward’s shows increase in rated power and BMEP for boosted engines since 2000

– Increased use of >6 speed transmissions, CVTs lead to higher BMEP in real-world operation

– Note: rated power and torque shown, not average over cycle

LSPI Relevance

1000 2000 3000 4000 5000 6000 70008

10

12

14

16

18

20

power

power

torque

torque

BM

EP

(ba

r)

Engine Speed (RPM)

turbocharged

naturally aspirated

20002004200820122014

BMEP vs Engine SpeedModel Years 2000 - 2014

1 Pawlowski, Alexander, and Derek Splitter. SI Engine Trends: A Historical Analysis with Future Projections. No. 2015-01-0972. SAE Technical Paper, 2015.

9 FT036 2016 AMR

Understanding the interactions of fuel and oil in LSPI are critical for realizing fuel economy potential of SI engines

Hypothesis: LSPI occurs from ignition source of liquid ejection from ringland area

Proof-of-concept Experiment

• In-situ top-ring zone (TRZ) sampling and speciation– Air cooled utility-engine generator used•Direct liquid sampling from TRZ of running engine•GC/MS of sampled liquid employed

Setup of Modern Research Engine Experiment

• Dedicated LSPI single-cylinder engine– Ford 1.6-L EcoBoost, converted to SCE

LSPI Approach

10 FT036 2016 AMR

Completed sampling and analysis of liquid from Top Ring Zone (TRZ) on running utility engine

• Inexpensive development tool, proof of concept

• Air-cooled, carbureted generator NOT representative of modern GDI engines

• Samples from TRZ collected during operation under multiple conditions

• Gas chromatography/mass-spectrometry (GC/MS) applied to raw fuel, raw lube, TRZ samples

• Results show significant fuel (23%) in TRZ liquid after 1 hour operation

• Results complementary to literature; Samples show change in TRZ fuel fraction with change in operating conditions

– Fuel fraction of TRZ liquid highest for low coolant temperature and increased load

– Literature: High load and low coolant temp leads to LSPI

LSPI Technical Accomplishment

5 10 15 20 25 30 35 40 450.0

2.0x106

4.0x106

6.0x106

8.0x106

1.0x107

1.2x107

1.4x107

GC response to raw S.S. uncondensed 1 hr. TRZ sample

Abun

danc

e (a

.u.)

Retention Time (min)

Lube.Fuel

11 FT036 2016 AMR

Fuel retention in TRZ is condition and species dependent

0

1x105

2x105

3x105

4x105

5x105

Abu

ndan

ce (a

.u.)

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1x105

2x105

3x105

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5x105

Abu

ndan

ce (a

.u.)

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1x105

2x105

3x105

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5x105

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ndan

ce (a

.u.)

0

1x105

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Abu

ndan

ce (a

.u.)

8 10 12 14 16 18 20 220

1x105

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ndan

ce (a

.u.)

retention time (min)

0

1x105

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ce (a

.u.)

8 10 12 14 16 18 20 220

1x105

2x105

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5x105

Abu

ndan

ce (a

.u.)

retention time (min)8 10 12 14 16 18 20 22

retention time (min)

warmup @ 1/3 load

warmup @ idle

1 hr. S.S. @ idle sump @ 2.5 hr.


• Raw fuel sample shown in black on all plots

• Results illustrate TRZ fuel is load and temperature dependent.

– Lighter components in less abundance on warm engine, very little fuel in sump

• Naphthalene present in all samples

12 FT036 2016 AMR

Single-cylinder Ford Ecoboost Set Up For Hi-Fidelity Measurements With Improved Control

• Ford 1.6L EcoBoost converted to single-cylinder

– Simulated Turbocharging– Independent control of intake

temperature and pressure, lube and coolant temperature, exhaust backpressure, etc.

• Engine experiments conducted on automated cycle

– Alternate high/low load– Record ~15,000 consecutive

combustion cycles per high load cycle• Engine failure “accomplishment”

– Hot spot runaway occurred at 26 bar IMEP, 2000 RPM

• New engine operational– Experiments underway– Exploring means to sample from TRZ


-20 0 20 40 60 80 1000

25

50

75

100

125

150

175

200

Crank Angle (°CA aTDCf)

Cyl

inde

r Pre

ssur

e (b

ar)

Average LSPI (cycle #116)

Spark timing

0.0

2.5

5.0

7.5

10.0

12.5

Spar

k Pr

imar

y C

oil S

igna

l (vo

lt)

Spark timing

13 FT036 2016 AMR

0

400

800

1200

1600

2000

2400

2800

FR20

Mob

il 1

CPO

-61

CPO

-81

CPO

-80

CPO

-112

CPO

-83

CPO

-63

CPO

-64

CPO

-65

CPO

-85

CPO

-84

CPO

-113

CPO

-114

CPO

-115

Conc

entr

atio

n (p

pm)

Calcium Magnesium Zinc Molybdenum Tungsten Sodium

Established Partnerships for LSPI Experiments

• Partnering with Driven Racing Oil – Providing custom lubes

• Parametric variation of lubricant properties in common basestock

– All lubes 5W-20, Group III (except Mobil 1)

– Vary additive package in parametric manner

• Leverage Co-Optima effort with fuel effects

• Partnering with NREL to measure ignition delay – Same lubes, fresh

and aged, evaluated in IQT

Production

Lubes

Vary Ca Vary Zn (P)

anti-wear

Vary

anti-oxi.

Vary

Mg vs. Ca

Vary

Mg vs. Ca vs. Na

LSPI Accomplishment, Collaboration

14 FT036 2016 AMR










15 FT036 2016 AMR

Effect of Start-Stop Operation on GDI Vehicle PM Emissions Will fuel saving technology of start-stop impact GDI PM emissions? How do lube and fuel impact PM?• Previously observed highest GDI PM

during cold start of FTP• Obtained and evaluated 2014 Malibu

e-Assist vehicle • Fuel chemistry may impact both fuel

and lube contribution to PM• Focus on Start-Stop effect on PM

mass, soot and number– Tier 3 mass standard = 3 mg/mi– PM soot ≈ black carbon, a potent

“greenhouse gas”– Particle number is currently regulated

in Europe • Malibu PN ~10-100 times Euro 6 limit

0

1

2

3

4

5

Start-Stop No Start-Stop

PM m

ass e

mis

sion

s (m

g/m

ile) E0E20IBu12

Tier 3 PM limit is 3 mg/mile

GDI PM - Technical Accomplishment

16 FT036 2016 AMR

Negligible Lubricant HCs Detected on PM sample filters• Thermal desorption/pyrolysis GC/MS method developed at

ORNL to chemically characterize PM– HC fraction desorbed and analyzed by GC/MS– Heavier compounds such as lubricant HCs have longer retention time

• Three consecutive cold cycles on cold start filter, 27consecutive cycles on hot start filter

• Soot emissions by photoacoustic sensor indicate majority ofGDI PM is soot carbon

0.0E+00

1.0E+06

2.0E+06

3.0E+06

5 10 15 20 25 30 35 40 45

Amou

nt (a

rbitr

ary

units

)

Time (min)

Hot startCold start

Lube HCs appear here if presentHCs

PM

Filter

HCs

PM

Filter

2 mm

40 nm9 nm


17 FT036 2016 AMR

Established Mobile Start Cart Apparatus for Measuring Lubricant Effects on Emissions and Fuel Consumption• Research tool to study cold start and

hot re-start emissions and fuel consumption

• 2013 2.0-L Ford Focus ST engine– Modern turbocharged GDI

– Dyno-ready ECU provided by Ford

• Mobile cart - Set up in Vehicle Laboratory for full-flow dilution emissions sampling

• Instrumented for cylinder pressure, crank angle, fuel flow, etc.

• Scheduled for investigating lubricant and fuel effects on GDI cold start particulate matter (PM)

High accuracy fuel flow meter

High speed DAQ and control

Cold-start and idle fuel consumption


18 FT036 2016 AMR










19 FT036 2016 AMR

“Energy Conserving” Lubricants are qualified on ASTM D7589 Sequence Test• Lubricants compared to “ASTM Base Lube” (BL)

– 20W-30 oil, provided to all Sequence test labs– GM V6 engine

• BSFC with test lubricant (TL) compared to BSFC with BL at six modal conditions after 16 and 100 hours of aging

– Modal tests at relatively light load (backup slide)– Constant temperatures (115, 65, 35°C)– Weighted modes produce “Fuel Economy

Improvement” (FEI) rating– Typical test result: “2.0% FEI” = FEI1 + FEI2

• No correlation to mpg, single engine result

Objective• Develop vehicle-based test protocol to bridge

Sequence Test results to “real-world” mpg• Investigate lubricant impact on FEI in broader

scope (e.g., 4, 6, 8 cylinder)

Fuel Economy Relevance and Approach

20 FT036 2016 AMR

Fuel Economy Improvements from <1% to >3% Measured in Vehicle Experiments Compared to ASTM BL (backup slide)

• Protocol includes City (FTP), Highway Fuel Economy Test (HFET), and Steady State Fuel Economy test (SSFE)

– All Test Lubes anchored to ASTM Base Lube from Sequence VID/VIE (ASTM D7589)

• Completed 4 campaigns (2 veh x 2 campaigns)– Statistically significant FE improvement measured– Up next, vehicle with 4 cylinder engine

Cadillac SRX has same DOHC V6 engine used in Sequence VID test

Results show ability of careful vehicle FTP tests to distinguish fuel economy improvement of <1% to over 3%. Range bars show max and min of multiple tests.

(similar results for HFET and SSFE)

Experiment repeated in vehicle with pushrod V8 engine on 2 lubes

(Mobil1 and PNNL prototype)

Technical Accomplishment

14.0

15.0

16.0

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20.0

Bag 1 Bag 2 Bag 3 Weighted

FTP

Fuel

Eco

nom

y (m

pg)

Avg ASTM Base Lube (15 runs)Mobil 1 (5 runs)

Chevrolet Silverado

21 FT036 2016 AMR

2015 Review (FT007 – Fuel and Lubricant Effects on Emissions Control)

Emissions efforts reviewed last year as FT007. Score (3.3/4.0)Reviewer Comments Favorable/Supportive:• Good approach• Multiple independent subprojects, broadens

impact• Milestones met in timely fashion• Determining start-stop has no major impact on

PM is addressing emissions barriers• Interesting data on oxidative character of GDI PM• Excellent collaboration• Understanding fuel/lubricant interaction is

complex, requires lots of effort• Supports DOE goals• Engine and flow-reactor studies with in-depth

characterization of PM, HCs, and emissions control devices…successful

22 FT036 2016 AMR

Collaborators and Partners• Low Speed Pre-Ignition:

– Driven Racing Oils – custom lubricants– NREL – IQT applied to fresh and used oils– Informal support from major OEM

• Fuel and lubricant formulation impacts on GDI particulate emissions:– Umicore: gasoline particulate filter washcoating– Ford – engine controller for start cart– PNNL: PM collection and characterization campaigns

• Lube Effects on Vehicle Fuel Economy– PNNL – Prototype Lube evaluated– ASTM Test Monitoring Center – provide ASTM lubes

• 2017 Labcall partners– ANL, PNNL, NREL

• Compatibility of emerging fuels and lubricants with emissions control devices (FT014):

– NREL, Ford, Cummins, MECA – GM, Lubrizol, Shell: Ionic liquid development and evaluation

23 FT036 2016 AMR

Future Directions• Low-Speed Pre-Ignition – Lube/fuel chemistry

• LSPI mechanics – wall impingement effects

• Effects of Lubricants on Fuel Economy

• Lubricant and fuel formulation impacts on GDI particulate emissions

Understanding Lubricant/Fuel Interactions critical to ameliorating LSPI

Quantify LSPI tendency with matrix of custom-blended lubes

Does fuel impingement exacerbate LSPI? Explore and quantify impingement effects with injector indexing

Will small FE improvements be less detectable in downsped / downsized applications?

Evaluate additional engine types.Explore means to predict vehicle mpg change from Sequence test

No direct contribution of lubricant to PM noted, but how do fuel switching or lubricant switching affect PM?

Examine PM from cold and hot starts with range of lubricants and fuels

Remaining Challenges

24 FT036 2016 AMR

Summary• Relevance: Studies provide understanding of impacts of lubricants on LSPI,

PM emissions, and fuel economy.

• Approach: Targeted engine, vehicle, and flow-reactor studies with in-depth characterization of PM, HCs, and fuel economy to better understand lubricant effects and interactions.

• Collaborations: Wide-ranging collaboration with industry, academia, and other national labs designed to maximize impact and lead to marketable solutions

• Technical Accomplishments:– Developed and employed engine-based test stands to explore LSPI, emissions, and

fuel economy impacts of lubricants• Speciation of top-ring zone liquid confirms boiling point dependence and effect of engine conditions

• Established vehicle-based method to measure mpg improvement from lubricants

• Quantification of fuel and lubricant impacts on GDI PM

• Future Work: well-designed plans in place to address remaining barriers; guidance from industry incorporated into future directions

25 FT036 2016 AMR

TECHNICAL BACKUP SLIDES

26 FT036 2016 AMR

Measuring Lubricant Effect on Vehicle Fuel Economy Currently Focused on 3 Cycles

• Federal Test Procedure (FTP), also known as City Cycle

– Includes “cold” start at 75°F

– Used in emissions and fuel economy certification

• HFET – Highway Fuel Economy Test– Also for FE certification, warm engine

• Steady State Fuel Economy Test– Custom cycle, 5 min at each of 9 speeds

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Time (s)

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d (m

ph)

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Time (s)

Spee

d (m

ph)

"Bag 1""Phase 1"

"Cold Transient"505s

"Bag 2""Phase 2"

"Cold Stabilized"867s

10 minute soak"Bag 3"

"Phase 3""Hot Transient"

505 s

LA- 41372s, 7.45 mi

FTP11 mi

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Spee

d (m

ph)

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Steady State Fuel Economy Test

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mup

Cool down

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HFETHighway Fuel Economy Test

SSFE

Technical Backup Slide – Vehicle Fuel Economy

27 FT036 2016 AMR

500

1000

1500

2000

2500

3000

0.0 10.0 20.0 30.0 40.0 50.0 60.0

Fuel

MEP

(kPa

)

Road Load Power (hp)

FTP Bag 1

SSFE-BL1

SSFE-BL2

SSFE-TL

SSFE-BLA

Seq Test BL

Bridging vehicle Fuel Economy tests to Sequence tests:Fuel Mean Effective Pressure (Fuel MEP) normalizes to engine size and illustrates overlap of various tests.

• Six modes of Sequence test at fairly light loads

• Plot shows Fuel MEP vs hp for Seq Test, cold bag of FTP, SSFE

Technical Backup Slide – Vehicle Fuel Economy

0

500

1000

1500

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20 40 60 80 100 120

Fuel

MEP

(kPa

)

Oil Temperature (C)

FTP Bag 1FTP Bag 2HFETSSFESeq Test

• Sequence test conducted at fixed oil temperatures

• Wide variation in oil temperature in transient vehicle operation

• FTP bag 1&2, HFET, SSFE, SeqTest Shown

mass rate fuel * LHV*2Displacement*RPMFuel MEP =

28 FT036 2016 AMR

Results: GDI vehicle PM depends on fuel and mode

Hot Start, Lowest values: No Start-Stop Start-StopPM Mass (Filter) iBu12 E0Soot Mass (AVL-MSS) iBu12 E20Particle # (EEPS) iBu12 E0

• ORNL measured particle number emissions for FTP over order of magnitude higher than European reg• (~1013 /mile vs. ~1012/mile)

How about lubricant contribution? • Not conclusive, no lubricant found in PM organic fraction by GC-MS• Future Start-Cart studies will isolate start-up, lube impact on PM

Why is this research important?• Lower lubricant viscosity can lead to more volatility in combustion chamber• Start-up has highest PM emissions for GDI• Start-stop will impact particulate filter operation if GPF needed in 2025

Takeaway: Operation and fuel both have to be considered for PM control strategies

• Lowest Cold Start PM mass, soot and number measured with E20• Hot start PM affected differently:

Technical Backup Slide - PM

29 FT036 2016 AMR

Start-stop mode + fuel influence soot, PN production for hot drive cycle

0

2

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E0 E20 IB12

Soot

(mg/

mi)

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Stop Start

0

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Part

icle

Num

ber (

x10^

14 /

mi) No Start Stop

Start Stop

Cold cycle

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mi)

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Part

icle

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ber (

x10^

14/m

i)No Start StopStart Stop

• Soot measured with photoacoustic sensor (AVL), 10X higher for cold cycle• Particle number measured with differential mobility analyzer (EEPS), 5x higher for cold cycle• E20 has a larger effect over cold cycles; IB12 has larger effect for hot cycle


30 FT036 2016 AMR

ANOVA (Analysis Of Variance) for GDI PM Data shows interactions between fuel and start-stop mode

Soot F p Fuel (E0, E20, IB12) 5.19 0.0072Mode (SS, no SS) 19.18 0Fuel * Mode 14.54 0

Particle Number F pFuel (E0, E20, IB12) 1.31 0.273Mode (SS, no SS) 1.78 0.1837Fuel * Mode 56.86 0

• E0= 87 AKI gasoline; • E20 =20% ethanol in the E0; • IB12 = 12% isobutanol in the E0

• SS= start-stop enabled

• No SS = start-stop disabled

• Null hypothesis: there is no difference between fuels or start-stop modes for PM generation

– p< 0.05 means null hypothesis is rejected

– p< 0.05 is statistically significant

• For soot PM production, Fuel, Mode, and their interaction produced a significant difference in soot emissions

• For particle number, Fuel and Mode did not produce a significant effect, but their interaction does affect PN


Documents

Lubricant Effects on Combustion, Emissions, and Efficiency · Lubricant Effects on Combustion, Emissions, and Efficiency Presenter: Brian West Melanie DeBusk, Shean Huff, Sam Lewis,