## COORDINATING RESEARCH COUNCIL, INC.

3650 MANSELL ROAD · SUITE 140 · ALPHARETTA, GA 30022 

# CRC Report No. E-65-3

FUEL PERMEATION FROM AUTOMOTIVE SYSTEMS: E0, E6, E10, E20 AND E85

Final Report

December, 2006

# FUEL PERMEATION FROM AUTOMOTIVE SYSTEMS: E0, E6, E10, E20 and E85

Final Report CRC Project No. E-65-3

December, 2006



## Prepared by:

Harold M. Haskew, P.E. Thomas F. Liberty Harold Haskew & Associates, Inc. Milford, Michigan

Dennis McClement Automotive Testing Laboratories, Inc

. Mesa, Arizonai Table of Contents

A. Background and Introduction....................................................................1

B. Conclusions and Findings..........................................................................2

C. General Discussion I. Test Program Overview.......................................................................3 II. Project Scope – Fuel System Technology and Rig Construction ......5 III. The Project and the Procedures........................................................10 Fuels ..............................................................................................10 Procedures for Measuring Steady-State Permeation and Determining Stabilization ................................................................14 IV. Results Diurnal Performance – Technology.................................................16 Diurnal Performance – Fuels ...........................................................18 Data Summary..................................................................................21 Rig and Fuel Type Diurnal Result Comparisons .............................23 Steady-State Permeation Measurements..........................................24 Steady-State Permeation Results by Rig..........................................29 Speciation and Reactivity.................................................................31 Statistical Analysis...........................................................................41

D. The CRC E-65-3 Steering Committee Members ....................................49

E. Appendix: The Ethanol Hang-up.............................................................50ii List of Figures

Figure No. Description Page No.

1 Testing Chronology................................................................................... 4 2 Overall View – Rig 12 .............................................................................. 7 3 Rig 1 Fuel Tank......................................................................................... 7 4 Rig 2 Fuel Tank......................................................................................... 7 5 Rig 11 Fuel Tank and Canister.................................................................. 8 6 Rig 12 Fuel Tank....................................................................................... 9 7 Rig 12 Fuel Tank and Canister.................................................................. 9 8 Rig 14 Fuel Tank and Canister.................................................................. 9 9 Liquid Fuel Aromatics ............................................................................ 13 10 Constant-Temperature Test Cell ............................................................. 14 11 Steady-State Results – Rig 2 - Fuel E0 - Test #6309.............................. 14 12 Steady-State Results – Rig 12 – Fuel E6 – Test #6466........................... 15 13 Diurnal Permeation Comparison – E0 Fuel ............................................ 16 14 Diurnal Permeation Compar ison – Non-Ethanol Fuel............................ 17 15 Diurnal Emissions Comparison .............................................................. 17 16 Diurnal Emissions Comparison – Rig 1.................................................. 18 17 Diurnal Emissions Comparison – Rig 2.................................................. 18 18 Diurnal Emissions Comparison – Rig 11................................................ 19 19 Diurnal Emissions Comparison – Rig 12................................................ 20 20 Diurnal Emissions Comparison – Rig 14................................................ 20 21 Ethanol Impact – Stabilized Permeation - Rig 1..................................... 24 22 Ethanol Impact – Stabilized Permeation - Rig 2..................................... 25 23 Ethanol Impact – Stabilized Permeation - Rig 11................................... 26 24 Ethanol Impact – Stabilized Permeation - Rig 12................................... 27 25 Ethanol Impact – Stabilized Permeation - Rig 14................................... 28 26 Stabilized Permeation Levels – Rig 1 ..................................................... 29 27 Stabilized Permeation Levels – Rig 2 ..................................................... 29 28 Stabilized Permeation Levels – Rig 11 ................................................... 30 29 Stabilized Permeation Levels – Rig 12 ................................................... 30 30 Stabilized Permeation Levels – Rig 14 ................................................... 30 31 Diurnal & Steady-State Emissions & Reactivity vs Test Timing......42-43 32 Diurnal & Steady-State Emissions & Reactivity vs Aromatics.........44-45 33 Diurnal & Steady-State Emissions & Reactivity vs Ethanol .............46-47 34 Diurnal Emissions vs Ethanol Content – Rig 1....................................... 48 35 Ethanol Hang-up Rig 1 ........................................................................... 50 36 Ethanol Hang-up Rig 2 ........................................................................... 51 37 Ethanol Decay ......................................................................................... 53iii List of Tables

Table No. Description Page No.

1 Technology Groups and Corresponding Rig .....................................5 2 Vehicle Information for the Test Rigs ...............................................5 3 Test Fuel Inspections.................................................................. 10-11 4 Test Fuel Composition Comparison – Paraffins ..............................12 5 Test Fuel Composition Comparison – Olefins.................................12 6 Test Fuel Composition Comparison – Aromatics............................13 7 Detailed Permeation Emission Results ...................................... 21-23 8 Diurnal Emissions Test Results .......................................................23 9 Sample Speciation Results ......................................................... 32-36 10 Fuel E0 Diurnal Permeate Reactivity Results..................................38 11 Fuel E6 Diurnal Permeate Reactivity Results..................................39 12 Fuel E6Hi Diurnal Permeate Reactivity Results..............................39 13 Fuel E10 Diurnal Permeate Reactivity Results................................40 14 Fuel E20 Diurnal Permeate Reactivity Results................................40 15 Fuel E85 Diurnal Permeate Reactivity Results................................41 16 2001 Toyota Tacoma Stabilization – Fuel E0............................ 50-51 17 2000 Honda Odyssey Stabilization – Fuel E0 .................................521 

## Fuel Permeation from Automotive Systems E0, E6, E10, E20 and E85

A. Background and Introduction CRC Project E-65 investigated the effects of three different fuels on the permeation rates of the fuel systems from 10 different California vehicles, covering model years from 1978 to 2001. Results from this study were published in the report “Fuel Permeation from Automotive Systems” in September 2004, and are available on the websites of the Coordinating Research Council (CRC) and California Air Resources Board (CARB). Permeation is one of the three mech anisms identified as res ponsible for “evaporative emissions.” The other two are leaks (liquid a nd vapor) and fuel tank ve nting (canister losses).

The original study vehicles were sel ected to represent a cross-section of the California in-use fleet as it existed in calendar year 2001, where pr e-1983 model year (MY) vehicles were 10% of the registered fleet. The fuels tested in the original study included two oxygenated fuels: one with 11% MTBE and the other with 5.7% ethanol, and a non-oxygenate d fuel for comparison. All the fuels had properties typical of California summer gasoline. The two oxygenate d fuels contained 2.0 we ight percent oxygen, the minimum oxygen content required by then-existing re gulations for federal reformulated gasoline. Permeation increased in all vehicles wh en evaluated with the ethanol fuel.

Based on the previous work, four issues were identified for further st udy in CRC Project E-65-3:

1. Investigate the permeation characteristics of “n ear zero” evaporative emission control systems scheduled for California in MY 2004 and later. 2. Determine if changes in ethanol content affect permeation levels. 3. Establish the permeation effects of E85 (85 Volume% ethanol fuel) in a flexible fuel vehicle. 4. Determine if permeation rates are sensitive to changes in aromatics content of the fuel.

Harold Haskew & Associates, Inc. was selected as the prime contractor, with Automotive Testing Laboratories, Inc, in Mesa, AZ se rving as the testing la boratory. It was agreed to re-commission Rigs 1 and 2, the 2000 and 2001 MY systems from the E-65 pr oject, and build thre e new test rigs, one representing a MY 2004 California “N ear Zero” evap control vehicle, another representi ng the California “Zero Evap” control technology, and fi nally, a “Flexible-Fuel” vehicle, capable of operating on E85 or gasoline.

Six test fuels were blended for this project:
1. E0 – Non-oxygenated base fuel 2. E6 – 5.7 Volume% ethanol fuel (2 Weight% oxygen) 3. E6Hi – 5.7 Volume % ethanol fuel with increased aromatics content 4. E10 – 10 Volume% ethanol fuel 5. E20 – 20 Volume% ethanol fuel, and 6. E85 – 85 Volume% ethanol fuel

The testing for this project commenced in January of 2005, and continued thr ough early August 2006. An Interim Report was made available in August of 2006 with the results from the E0, E6, E6Hi, E10, and E85 fuel testing results. This final report adds the results from the tests with the E20, or 20 volume percentage, ethanol fuel, as well as a dditional test results on the E0 fuel.2 These data represent a limited number of samples; car e should be taken in exte nding these results to the fleet.



### B. Conclusions and Findings

Conclusions:
1. The low-level ethanol blends (E6, E6Hi, E10 and E20) increased permeation in all the vehicle systems and technologies tested, compared to the non-ethanol fuel (E0). Th ese increases were statistically significant.

2. The advanced technology LEV II and PZEV 1 systems (2004 MY) had much lower permeation emissions than the MY 2000-2001 enhanced evaporat ive systems. The zero evaporative emissions system (PZEV) had the smallest increase due to ethanol of all the vehicles tested.

3. The high-level ethanol blend (E85) tested in the flexible fuel vehicle system had lower permeation emissions than the non-ethanol (E0) fuel.

4. Diurnal permeation rates do not app ear to increase between E6 and E10, but do appear to increase between E6 and E20; however, this in crease is not statistically significant.

5. The highest diurnal permeation rate for three of the five rigs (1, 2, and 12) tested was measured when these rigs were tested on the E20 fuel. The highe st diurnal permeation rate for Rig 11 was recorded on the E6 fuel, while the highest diurnal permeati on rate for Rig 14 was measured on the E10 fuel.

6. Diurnal permeation emissions were lo wer on all four rigs tested with the higher-level aromatics fuel (E6Hi) versus the lower aromatics fuel (E6); howeve r, this decrease was not statistically significant.

7. Permeation rates with the E0 fuel at the start and the end of the test program were not significantly different on all five rigs, indica ting that there was no shift in the permeation performance during the
program.
8. The average specific reactivities of the permeates from the low-level ethanol bl ends were significantly lower than those measured with th e non-ethanol fuel (E0). There wa s no significant difference in the average specific reactiv ities within the low-level ethanol blends. Findings:

1. The average diurnal permeation ra te increased 347 mg/d ay (from 177 to 524 mg/day) when the E6 fuel was substituted for the base non-ethanol E0 fuel.

2. The average diurnal permeation rate increased 253 mg/day (from 177 to 430 mg/day) when the E6Hi fuel was substituted for the base non-ethanol E0 fuel.

3. The average diurnal permeation rate increased 3 07 mg/day (from 177 to 484 mg/day) when the E10 fuel was substituted for the base non-ethanol E0 fuel.

4. The average diurnal permeation rate increased 3 85 mg/day (from 177 to 562 mg/day) when the E20 fuel was substituted for the base non-ethanol E0 fuel.

1 Partial Zero Emission Vehicle – a vehicle with Super Ultra Low Exhaust Emission Levels (SULEV), and Zero Fuel Evaporative Emissions, certified to 150,000 mile and 15 year performance levels for the state of California3 5. On the “Flexible Fuel” Rig 14, the diurnal permeati on rate increased 205 mg /day (from 261 to 466 mg/day) from the base non-ethanol fuel (E0) rate when the E10 fuel was evaluated, increased 99 mg/day (from 261 to 360 mg/day) from the base fu el rate when the E20 fuel was evaluated, but decreased 133 mg/day (from 261 to 128 mg/day) from the base fuel rate when the E85 fuel was evaluated.

6. Relative to Rigs 1, 2 and 11, the “Zero Fuel Evaporative Emission” system (Rig 12) had a lower increase in permeation rate when the ethanol-cont aining fuels were evaluate d. A 14 mg/day (from 36 to 50) increase was measured with fuel E6, a 9 mg/day (from 36 to 45 mg/day) increase with fuel E6Hi, a 28 mg/day (from 36 to 64 mg/day) increase wi th fuel E10, and a 39 mg/day (from 36 to 75 mg/day) increase with fuel E20.

7. The average specific reactivity of the base E0 fuel permeate was 3.99, the highest of the five fuels evaluated.

8. Average specific reactivity of the E6 fuel permeate was 3.00.

9. Average specific reactivity of the E6Hi fuel permeate was 3.17.

10. Average specific reactivity of th e E10 fuel permeate was 2.94.

11. Average specific reactivity of th e E20 fuel permeate was 3.04.

12. Average specific reactivity of th e E85 fuel permeate was 2.73.

13. Rig 11 permeate had the lowest sp ecific reactivity of all the rigs on all the fuels tested.



### C. General Discussion

I. Test Program Overview

The objective of this test program was to measur e the permeation emissions of the newer (MY 2000 to 2005) California vehicles with gasolines containing etha nol at various volume percent concentrations: 0, 6 2 , 10, 20 and, on one system, 85. At the 6% ethanol leve l, two fuels were blended to meet different targets of total aromatics (designated as “E6” and “E6Hi”) in order to evaluate the effect of this latter parameter on permeation. Five vehicle fuel systems were included in this pr oject. Two California Enhanced Evap vehicles were carried over from the previous CRC E-65 project (the newest, Rigs 1 and 2). Three new rigs were constructed for this evaluation: a California LEV-II “n ear-zero” passenger car, a California PZEV Zero Evaporative Emission car, and a “Flexible-Fuel” vehi cle capable of operation on gasoline, 85% ethanol, or any mixture in between.

Stabilization - Once qualified as ready for test, each test ri g was filled (100% of rated capacity) with the appropriate test fuel and stored in a room (“soak room”) at 105° F and periodically tested in a SHED 3 until the results indicated that stabilization of the permea tion emissions was achieved. During this stabilization period, the fuel in each rig was circul ated twice a week. Every seventh week all of the fuel in each rig was drained and replaced with fresh fuel. Once a week, each rig was removed from the soak room and

2 The federal minimum requirement for “reformulated” fuel was 2.0 weight percent oxygen. That correlates to 5.7 volume percent ethanol. For purposes of this report, we will refer to the 5.7 Volume% specification in its rounded off value of 6, as in E6.
3 SHED – Sealed Housing fo r Evaporative Determination4 placed in a hot soak SHED at a temperature of 105° F for three to five hours to estimate the current permeation rate. The constant-temperature tests to determine stabiliz ation were performed in a 105°F hot-soak SHED for a three-hour test period, with the emi ssions measured during the last tw o hours (later tests on the lower permeation rigs were increased to a five hour peri od). All fixed-temperat ure (105°F) testing was performed in ATL’s SHED 14. Variable-temperature di urnal (65° to 105° to 65° F) testing was performed in ATL SHEDs 13 and 15. These three SHEDs are variable volume/variable temperature (VV/VT) equipment that can be operated in fixed or variable-t emperature modes, and are referred to as VT-SHEDs. All the SHED’s and equipment used for this program we re the same as were utilized for the original E-65
program.
Diurnal Evaluation - After the steady-state permeation rate of a rig was stabilized at 105°F, and approved by the CRC E-65-3 Steering Committee, it wa s evaluated for diurnal permeation performance using the California “Real-Time” 24-hour diurnal (65 to 105 to 65°F) emi ssion test procedures. The fuel was drained from the rig, and a 40% fresh fill of the appropriate test fuel added. The rig was then placed in a VT-SHED, and the California diurnal procedure was performed ov er a period of 24 hours. Samples of the ambient air in the VT-SHED were taken at the start of the diurnal and at the end of the 24-hour test period for later hydrocarbon speciation analysis. The fu el tanks and the canisters were vented to the outside of the SHED to eliminate the possibility of the tank venting emi ssions being counted as permeation. Emission rates were calculated using the 2001 California certification test procedure, with the appropriate corrections for the ethanol in the permeate. Testing Chronology - Figure 1 on the following page shows th e testing chronology to illustrate when the various rigs were being tested with the different fuels. Testing started on January 11, 2005, and the last diurnal test on Rig 2 was finished on August 10, 2006. The solid bar indicates the time interval for the steady-state and the diurnal evaluations. The interval between the solid bars indi cates the decision period where the Steering Committee was considering approval of the data and authorizing the move to the next test fuel.

Testing Chronology - Steady State and Diurnals
on Various Fuels

Date Rig 1 Rig 14

Rig 12

Rig 11

Rig 2

E0 E85

E10 E6Hi E6

Jan 2005 March Jan 2006 Nov Sept July May March July May E0b E20 E0c E0b

Figure 15 II. Project Scope – Fuel Syst em Technology and Rig Construction

Fuel System Technology

Two enhanced evap rigs were carri ed over from the original E-65 proj ect (Rigs 1 and 2) , and three new rigs were added. The technologies are described in Tables 1 and 2.

Table 1

Table 2 Vehicle Information for the Test Rigs

Rig No. MY Make Model Odo (miles) Evap Family Tank Size (Gal) Tank Material VIN 1 2001 Toyota Tacoma 15,460 1TYXE0095AE0 15.8 Metal 5TENL42N01Z718176 2 2000 Honda Odyssey 119,495 YHNXE0130AAE 20 Plastic 2HKRL1852YH518467 11 2004 Ford Taurus 29,973 4FMXR015GAK 18 Metal 1FAFP55S54G142635 12 2004 Chrysler Sebring 6434 4CRXR0130GZA 16 Metal 1C3EL46J74N363042
14 2005 Chevrolet Tahoe 4054 5GMXR0176820 26 Plastic 1GCEK13U85X7313EX

The California Enhanced Evaporative Emission Control regulations were the first to require “real-time” diurnal emission measurements (three 24-hour day di urnals) and were phased in during the 1995 – 1998 model year period. The pre-enhanced evap emission st andard was 2.0 g/test, but the test consisted of a one hour simulated diurnal day, with the fuel tank locally heat ed from 60° to 84°F. Only one hour’s worth of vehicle evaporative emissions was measured during th e diurnal, and that was with the vehicle at room temperature in a SHED, typically 72°F. The hot so ak was measured in a SHED following an 11 mile drive at room temperature. The enhanced evap pro cedure measured the emissions from the vehicle in a variable-temperature SHED (VT-SHED), and the SH ED ambient temperature wa s varied from 65° to 105°F, exposing the entire vehicle and the fuel syst em component to the ambi ent temperature. The one hour hot soak was performed as before but afte r the running loss test, a one hour drive at 105°F.

These regulations incorporated significant changes to the emissions certification test requirements, and produced corresponding changes in the vehicle ma terials and hardware us ed by the automobile manufacturers. The emission control system useful life and warranty period were extended to 10 years or 100,000 miles. Two-day and three-day diurnal tests were required, as was the measurement of “runningloss” emissions. The allowable limits for the highest one day of diurnal emissions for the three-day test, plus the one hour of hot soak following the drive are 2.0 g/test, or 2.5 g/test for ve hicles with fuel tanks rated at 30 or more gallons. Light-duty trucks are allowed slightly higher limits.

California’s Near Zero (LEV II) requirements dropped the allowable limits for passenger cars by 75% to 0.5 g/test for the three-day diurnal, and to 0.65 g/test for the two-day te st. Phase-in started with 40% of Technology Groups and Corresponding Rig

Enhanced Evaporative Emi ssions Rigs 1 & 2

California Near-Zero (LEV II) Rig 11
California PZEV (Zero Fuel Evaporative Emission) Rig 12
Flexible Fuel Vehicle (FFV) Rig 146 production in model year 2004, 80% in 2005, and 100% in 2006. Significant improvements in permeation performance and tank vapor control ( carbon canister design) were required.

California’s PZEV vehicles are developed and certified to ha ve “Zero” fuel evaporative emissions where zero is defined as less than 0.0 gr ams per test when measured on Cali fornia’s evaporative emission test procedures. This is agreed to be less than 54 milligra ms per test (highest of the 3 diurnal days + one hour high temperature hot soak). This sta ndard requires the highes t level of emission control in every aspect of the vehicle’s fuel and vapor control sy stem, both in performance and durability.

Flexible Fuel Vehicle is a vehicle capable of performing on ga soline or a high per centage of ethanol (85%), or any mixture of the two. The evapor ative emission standards are the enhanced emission standards with certain test procedur e modifications. Sensors (or in late r versions, software) are used to detect the mixture in the fuel system and make th e appropriate adjustments for the engine and emission control system. This is performed automatically, and no action is required by the vehicle operator. Flexible fuel vehicles are certified to meet the evaporative emission pe rformance limits on gasoline, or the worst combination of the ethanol/gasoline mixt ure (currently thought to be 10% ethanol).

Test Rig Construction

Fuel system test “rigs” are used in the automotiv e development process to isolate the fuel system’s contribution to the emissions. Since tires, adhesive s, paint and vinyl trim can also emit hydrocarbons, they need to be removed to provide a better chance of properly identifying the fuel-related emissions. Isolating the fuel system components on a “rig” is the appropriate choice.

Refueling vapor controls are commonly developed in the automotive industry using rigs, or “test bucks”, but they feature only the tank and canister system, with the carbon canister locate d close to th e tank. This project included the fuel and vapor lines, and their chassis-to-engine connection hoses at the front of the vehicle. All the fuel system co mponents (with the exception of the engine mounted injectors and hoses 4 ) that could contribute to permeation losses were kept in the original sp atial relationship. This meant that the rigs were almost as long as the vehicles. Fo r system integrity, all components were removed and remounted on the rigs without any fu el or vapor line disconnections.

In the original E-65 project, the ve hicle was sacrificed to remove th e fuel system components, and the remaining body parts and pieces sold as scrap. Our prev ious experience indicated that the fuel system on the newer vehicles (mid-90s and later) could be re moved from the vehicle w ithout catastrophic surgery.

The test rig frame was cons tructed of 1.5” square alum inum tube, with metal caster wheels at the four corners. A photo of Rig 12 appears in Figure 2 to show a typical conf iguration. There is a lot of empty space required to keep all of the fu el system components in their x, y, and z orientation as present in the vehicle.

4 It was decided in the original E-65 project to eliminate the engine-mounted fuel system components (including carburetors and injectors) to avoid the compromising contributions of leaks and vapor losses. The investigators wanted to identify the contribution of permeation, not leaks. The fuel supply lines and hoses, and the return components, if fitted, are present on t he rigs, with terminations where the engine connections are made. This practice was conti nued for the current project.7 Enhanced Evaporative Emissions Technology – Rigs 1 & 2

Rigs 1 and 2 were carry-over systems from the pr evious CRC fuel permeati on project reported in September of 2004, and photos of the fuel tank end of the rigs are shown here

Rig 1 was fabricated to evaluate the permeation perfor mance of the metal fuel tank system from a 2001 MY Toyota Tacoma pick-up truck, and is shown in Figure 3 above. The metal tank was coated with a black anti-rust paint w ith a short metal fill-pipe th at ran to the side of the truck body. The carbon canister and purge control solenoid for this pre-ORVR 5 system was located in the left front side of the engine compartment.

5 ORVR – On-board Refueling Vapor Recovery, an emission control configuration with components and function to capture the refueling vapors and store them for later combustion. The Toyota pick-up was not required by the California regulatory roll-out requirements to have such a system until MY 2003. Figure 3 - Rig 1 Fuel Tank Figure 2 - Overall View - Rig 12

Figure 4 - Rig 2 Fuel Tank8 Rig 2’s (2002 MY Honda Odyssey, a light-duty passenger va n) fuel system features a large (20 gallon capacity) plastic fuel tank of multi-layer blow-molded construction for a high degree of permeation control (Figure 4). The car bon canister for this pre-OR VR system is located in the vehicle’s under-body close to the position of the driver’s seat.

Both of these rigs were certified to the Californi a enhanced evaporative emi ssion standard of 2.0 grams per test for the three-day diurnal + hot soak, and 2.5 grams per test for the two-day diurnal + hot soak.

Rig 11 (Figure 5) was created from the fuel system components of a 2004 MY Ford Taurus sedan. The vehicle was purchased from a Califor nia dealer and driven to the laboratory in Mesa AZ, where after inspection and approval, the fuel sy stem was removed and mounted in the aluminum frame to become a “rig.” The fuel tank was of steel construction and had a rated capacity of 18 gallons. The fuel tank was located near the rear seat position on the vehicle, and the on-board refueling vapor recovery (ORVR) canister was positioned further aft, as shown in Figure 5.

Figure 5 - Rig 11 Fuel Tank and Canister9 Rig 12 (Figures 6 & 7) was fabricated using the fuel system components from a 2005 MY Chrysler Sebring sedan. It also featur ed a steel fuel tank and a carbon canister mounted adjacent to the tank. It was certified as an on-board refueling vapor recovery system (ORVR).

Rig 14 (Figure 8) featured the fuel system component s from a 2005 MY Chevrolet Tahoe SUV. It was certified to be a “Flexible-Fuel” system, which means it can operate on gasoline or E85, or any mixture of the two. The Tahoe has a 26 gallon multi-layer “plas tic” fuel tank, and a close- mounted carbon canister for tank vapor control. It is also an ORVR design system. Figure 6 - Rig 12 Fuel Tank

Figure 7 - Rig 12 Fuel Tank and Canister

Figure 8 - Rig 14 Fuel Tank and Canister10 III. The Project and Procedures

Fuels

Six test fuels were blended for th e CRC E-65-3 follow-up project. All of the low-level ethanol blends (i.e., E0-E20) were made from California blending co mponents and were targeted at California summer fuel characteristics with vapor pressures targeted at 7.0 psi. The gasoline used to blend the E85 fuel was a high vapor pressure conventional gasolin e, but butane still had to be ad ded to the blend to approach the target 7.0 psi vapor pressure. These fuels were:
Tag Description E0 Non-oxygenated base fuel E6 5.7 Volume% ethanol fuel (2 Weight% oxygen) E6Hi 5.7 Volume% ethanol fuel w ith increased aromatics content E10 10 Volume% ethanol fuel E20 20 Volume% ethanol fuel E85 85 Volume% ethanol fuel

The basic inspections of the six test fuels are shown in Table 3.

Table 3 Test Fuel Inspections Inspection Units E0 E6 E6Hi E10 E20 E85 API Gravity °API 61.4 58.8 52.3 58.3 55.4 48.6 Relative Density 60/60°F 0.7334 0.7434 0.7699 0.7455 0.7572 0.7855 DVPE psi 7.00 7.25 7.19 7.17 7.06 6.80 Oxygenates--D 4815 MTBE vol % 0.01 0.00 0.00 0.00 0.00 0.00 ETBE vol % 0.00 0.00 0.00 0.00 0.12 0.00 EtOH vol % 0.00 6.02 6.28 10.29 19.82 84.69 MeOH vol % 0.00 0.00 0.00 0.00 0.00 0.83 O2 wt % 0.00 2.23 2.25 3.81 7.23 29.73 FIAM Corrected--D 1319 Aromatics vol% 22.57 26.79 41.47 26.03 26.18 3.86 Olefins vol% 10.70 4. 91 3.32 4.77 4.85 1.57 Saturates vol% 66.73 62.24 50.45 58.83 49.23 9.82 Oxygenates vol% 0.00 6.02 6.28 10.31 19.94 85.21 Aromatics--D 5580 Benzene vol% 0.41 0.55 0.43 0.51 0.70 0.17 Toluene vol% 5.26 6.84 5.25 6.50 8.31 0.67 Ethylbenzene vol% 1.08 1.46 1.13 1.39 1.71 0.15

p/m-Xylene vol% 4.67 5.38 4.21 5.13 6.01 0.59 o-Xylene vol% 1.67 1.98 1.81 1.89 2.14 0.22 C9+ vol% 8.86 10.01 25.71 9.52 7.55 2.02 Total vol% 21.96 26.22 38.55 24.93 26.42 3.8211 Table 3 (Continued) Test Fuel Inspections Inspection Units E0 E6 E6Hi E10 E20 E85 D 86 Distillation IBP °F 101.1 108.9 98.0 107.7 112.1 116.8 5% Evaporated °F 123. 2 125.8 124.8 127.2 130.6 153.5 10% Evaporated °F 134. 5 130.7 132.1 132.1 135.8 164.0 20% Evaporated °F 148. 5 136.8 142.4 138.2 143.4 168.7 30% Evaporated °F 165. 0 144.8 159.0 144.7 149.7 170.4 40% Evaporated °F 186. 2 175.8 206.3 150.8 155.1 171.2 50% Evaporated °F 209. 5 202.0 241.9 182.6 159.6 171.5 60% Evaporated °F 231. 1 225.6 274.0 221.8 165.9 171.8 70% Evaporated °F 251. 2 249.3 302.8 246.0 234.6 172.0 80% Evaporated °F 273. 4 275.7 324.5 273.3 257.9 172.4 90% Evaporated °F 305. 6 309.9 345.3 309.4 291.1 173.1 95% Evaporated °F 330. 6 335.9 363.2 335.7 312.4 174.1 EP °F 389.9 380.4 411.4 378.3 352.0 297.4 Recovery vol % 97.7 97.6 97.2 98.0 97.3 97.1

Residue vol % 1.0 1.0 1.2 1.1 1.0 1.9 Loss vol % 1.3 1.4 1.5 0.8 1.7 1.0

Karl Fischer Water wt % - - - - - 0.42

Additional Inspections

Fuel Units E0 E6 E6Hi E10 E20 E85 Gum Unwashed mg/100ml 20 16 18 17 19 9

Washed mg/100ml 1 1 0 0 0 0

Peroxide Number ppm <1 <1 <1 1.0 <1 4.4

Induction Period Hr 24 24 24 24 24 24

Potential Gum Unwashed mg/100ml 22 22 24 20 19 7

Washed mg/100ml 0 0 0 0 0 2

Research ON 90.5 92.1 96.2 94.5 98.7 105.8

Motor ON 83.2 84.2 86.2 86.4 86.6 89.2

(R+M)/2 86.9 88. 2 91.2 90.5 92.7 97.512 Complete speciation analyses of the fuels were al so furnished, and the file s are available with the following names:

Tag File Name E0 E0-FR41677-LDR E6 E6-FR41678-LDR E6Hi E6High-FR41785-LDR E10 E10-FR41681-LDR E20 E20-FR43560-LD E85 E85-FR42011-LDR

Compositions of the E0 and low level ethanol ble nds are presented by hydrocarbon type and carbon number in Tables 4, 5 and 6 below.

Table 4 Test Fuel Composition Comparison - Paraffins Paraffins by Volume % Fuel C3- C4 C5 C6 C7 C8 C9 C10 C11 C12+ E0 0.419 18.789 10.322 6.783 14.017 4.341 1.618 0.502 0.068 E6 0.163 14.938 17.492 8.016 9.732 3.613 0.919 0.442 0.031 E6Hi 1.609 10.58 13.061 6. 091 7.394 2.808 1.343 0.424 0.126 E10 0.150 14.22 16.649 7.753 9.15 3.412 0.865 0.417 0.027 E20 0.876 9.202 12.752 8.295 9.066 1.585 0.446 0.049 0.007

Table 5 Test Fuel Composition Comparison - Olefins Olefins by Volume % Fuel C3- C4 C5 C6 C7 C8 C9 C10 C11 C12+ E0 0.029 0.101 2.025 5.126 0.579 0.514 0.013 E6 0.013 0.914 1.613 0.771 0.347 0.007 E6Hi 0.008 0.66 1.197 0.595 0.273 0.007 E10 0.011 0.876 1.509 0.727 0.324 0.007 E20 0.016 0.004 0.669 2.040 0.873 0.44813 Table 6 Test Fuel Composition Comparison – Aromatics
Aromatics by Volume % Fuel C3- C4 C5 C6 C7 C8 C9 C10 C11 C12+ E0 0.448 5.286 7.971 6.443 2.696 0.594 0.087 E6 0.6 6.875 9.249 7.055 2.928 0.568 0.048 E6Hi 0.454 5.25 7.603 16.538 9.101 1.724 0.216 E10 0.569 6.502 8. 715 6.650 2.753 0.523 0.045 E20 0.693 8.250 9. 878 5.978 1.505 0.146 0.042

Figure 9 illustrates the dist ribution of the aromatics content in the base non-ethanol fuel and the four lowethanol concentration fuels. The aromatics total a nd the distribution of the aromatics by carbon number are similar for fuels E0, E6, E10 and E20. The high aromatics fuel (E6Hi) has 39% aromatics compared to the 22-26% for the othe r three, and the concentr ation of the highe r carbon number molecules (C9-C11) is much higher. Figure 9 6 7 8 9 10 11 12 E0 E6 E10 E20 E6Hi 0 2 4 6 8 10 12 14 16 18

Volume Percent

Carbon Number Fuel Liquid Fuel Aromatics - Volume Percent

Total Aromatics = 22% 39%

25%

26% 26%14 Procedures for Measuring Steady-State Permeation and Determining Stabilization

Permeation is a molecular migration of the fuel th rough the elastomeric materials of the vehicle fuel system. The test plan anticipated that time would be required for stabilization to occur after a new fuel composition was introduced. This would be possibly six to twelve weeks at the 105°F stabilization temperature. The vehicle fuel tank was filled to 100% of its rated capacity for stabilization, and the contents circulated through the liquid and vapor system twice a week for a 20 minute period to keep the liquid and vapor in the hoses “fre sh.” The canister was purged by drawing ambient air through the canister bed for a period of 20 minutes, twice a week, using a vacuum pump.

The rigs were kept in a constant-temperature test cell at 105°F during the stabilization period. A photo of the cell occupi ed by various rigs is shown in Figure 10.

Once each week the rig was moved from the “soak room” to the SHED for the permeation determination. The steady-state test involved placing the rig in the pre-heated 105°F SHED, connecting the tank and can ister vent hoses to a bulk-head fitting in the SHED wall so that any tank or canister ventin g losses would not be measured as permeation, closing the door and allowing the SHED to come back to a to a stabilized temperature.

Either a three- or five- hour test was conducted to measure permeation. The three-hour test was used for the three higher permeation level rigs, 1, 2 and 14. The five-hour test was used for rigs 11 and 12 for tests starting in June 2005 on fuels E6 and later.

A sample plot of the steady-st ate test results is shown in Figure 11. The horizontal axis is time, in minutes, and the vertical axis is the mass (in milligrams) as measured in the SHED using the conventional SHED test procedure and equipment. The mass was calculated every 30 seconds and the results are plotted in Figure 11. The first hour of the test is shown in the red dots, and the last two hours in green. The trendline function in Microsoft EXCEL ® was used to calculate the rate of change in the SHED mass over the second and third hours (the green data). This slope became the estimate of the steady-state permeation rate in mg/hour. Steady State Results - Rig 2 Fuel E0 Test #6309

y = 0.719x + 214.835

200 250 300 350 400 450

0 60 120 180

Time in MinutesSHED Mass in milligrams mg/hr = 43.14 Figure 10 - Constant-Temperature Test Cell

Figure 1115 The five-hour test adopted for the E6 stabilization tests during June of 2005 was an attempt to improve the precision of the measurement on th ese really low permeation rigs (e.g ., 3 mg per hour). The five-hour test used the last four hours of the five-hour test for the perm eation measurement. An example of the five-hour test results is shown in Figure 12.

This plot illustrates the condi tions that are created when one tries to measure 3 mg/hour in a 2100 ft3 enclosure. The SHED concentration, as determined by the FID went from 7.105 ppm at 60 minutes to 7.551 ppm at the 300 minute mark, an increase of one half of a part per million (ppm) carbon in the enclosure over the four hour period. The mass in the SHED rose from 223 mg to 237 mg during the four hour period. That the SHED can measure these differences, and identify them with the precision and resolution s hown in Figure 12, would have been thought impossibl e just a few years ago. A smaller SHED volume (a mi ni-SHED) would increase the concentration change, and help with the precision, but these rigs were almost the same length as the vehicles they represente d – a significantly smaller SHED was not possible.

The plot format used here was also an excellent quality check on the data, and could point out leaks and test irregularities. The mass as measured by the FID had to be corrected for th e misidentification of the ethanol (if ethanol was present).

Stabilization was established when the four-week average of the permeation rate reversed in trend, i.e., when the average rate either incr eased or decreased over the previous trend’s rate. A recommendation was made by the program administrator in a weekly st atus report, and the Steering Committee approved (or disapproved) the recommendation. The time required for stabilization ranged from five weeks (Rig 14, Fuel E0) to 13 weeks for Rig 12, Fuel E6. Once decl ared stable, the rig was dr ained and prepped for the diurnal measurement.

IV. Results

This section of the report begins with the details of the diurnal and steady-st ate test results. Following that, the hydrocarbon speciation of the diurnal measurements is a ddressed and the average specific reactivities of the permeates are calculated for the vari ous technologies on the various fuels.

Diurnal 6 performance measurements are emphasized in this permeation study because the ultimate use of this information is to improve the ability of emissi ons inventory models to estimate the contribution of motor vehicles to air pollution. A porti on of this report is also devoted to the steady-state results, as it is hoped that the steady-state (constant temperature) re sults can one day be used to predict the diurnal emission performance.

6 “Diurnal”, occurring daily , or having a daily cycle Steady State Results - Rig 12 - Fuel E6 Test #6466

y = 0.0551x + 220.26

215 220 225 230 235 240

0 60 120 180 240 300

Time in MinutesSHED Mass in milligrams mg/hr =

3.31

Figure 1216 Diurnal Performance – Technology

The diurnal permeation performance of the different emission technol ogies tested in this study is summarized in Figure 13. These results were obtained when the rigs were tested with the base fuel, E0. On the left are the two vertical bars representing the diurnal permeation performance for the two enhanced evap Rigs 1 and 2.

The third bar from the left shows the 39 mg/day level of Rig 11, the LEV II, or California NearZero vehicle fuel system. The fourth bar is the 36 mg/day performance of the California “Zero Fuel Emission” vehicle. To qualify as a Zero Fuel Evaporative Emission system, this vehicle is certified to have less than 54 mg/day evaporative emissions, including the canister loss and a one hour hot soak. Finally, the last bar is the permeation performance of the “flexible fuel” Chevrolet Tahoe.

While the 458 mg/day permeation result on fuel E0 on Rig 2 seems high compared to the 91 mg/day from Rig 1, it is lower than previously meas ured with the plastic tank systems on the non-ethanol fuel in the E-65 project, one of which measured over 11,000 mg/day. The expanded plot shown in Figure 14 includes some of th e technologies from th e previous CRC E-65 report 7 “Fuel Permeation from Automotive Systems.” The blue bars on the left (Rigs 1-6) are the permeation results on the nonoxygenated fuel, “Fuel C” measured in the previous program. The red oval hi ghlights the performance level of Rigs 1 and 2 on Fuel C and the current program’s Fuel E0.

7 Coordinating Research Council ( CRC) web site, http://www.crcao.org Figure 13 Diurnal Permeation Comparison - E0 Fuel Various Technologies

91 458

39 36 261

0 50 100 150 200 250 300 350 400 450 500Diurnal Permeation - mg/day

LEV II FLEX PZEV Enhanced

Evap Rig 2 Rig 14 Rig 12 Rig 11 Rig 117 A plot showing the diurnal results for the five test ri gs on the fuels tested in this program is shown in Figure 15

.

Figure 15 Diurnal Emissions Comparison

0 200 400 600 800 1000 1200 1400 1600 1800

Ri g Numbe rDiurnal Emissions - mg/day Fuel E0

Fuel E6

Fuel E6Hi

Fuel E10

Fuel E85

Fuel E20

Rig 1 Rig 14 Rig 12 Rig 11 Rig 2 When replicate tests are run, the average is shown. Diurnal Permeation Comparison - Non-Ethanol Fuel Various Technolgies Tests

1225

341 253
91 596 458

39 36 261

0 500 1000 1500 2000 2500 3000 3500 4000Diurnal Permeation - mg/day 4055 12762

LEV II FLEX PZEV Enhanced

Evap Basic Evap - Plastic Tank ORVR Rig 1 Rig 14 Rig 12 Rig 11 Rig 6 Rig 5 Rig 4 Rig 3 Rig 2 E-65 Fuel "C"

E-65-3 Fuel E0

Figure 1418 Diurnal Performance - Fuels

Rig 1 - The diurnal emissions measured for Rig 1, the MY 2001 enhanced evap system, ranged from 91 mg/day on the base fuel (E0) to 508 mg/day on the E20 fuel. Figure 16 compares the results for the five fuels tested. Where multiple tests were run, such as those for the E0 and E6 fuels, the average results are presented. (Table 7 at the end of this section details the actual tests used.) The component on the top of each bar illustrates the ethanol fraction of the total emissions. For example, the E6 test total of 475 mg/day had 149 mg/day of ethanol. A very small amount of the E0 test (1 mg/day) was etha nol, even though there was no ethanol in the fuel, a pparently a “hang-up” from the rig’s previous experience on ethanol fuel. The issue of the “hang-up” and the concerns thereof is discussed in the appendix of this report.

The diurnal permeation emissions with the E6 fuel in creased by 384 mg/day compared to E0. The diurnal results with the E6Hi (high aromatics) fuel were 114 mg/day lower than the E6 fuel, with lower (91 mg/day compared to 149 mg/day) ethanol in the permeate. The permeation with the E10 fuel was almost identical compared to the E6 fuel (7 mg/day lower), but with higher ethanol in the results. The E20 permeation was the highest measured on this rig.

Rig 2 - Rig 2, another enhanced evap system (2000 MY), also had substantial increases in permeation when tested with the ethanol-containing fuels, as shown in Figure 17. The permeation increased from 458 mg/day with the base (E0) fuel to 1765 mg/day with the E20 fuel. The ethanol fraction was about 400 to 600 mg/day for the four ethanol blends evaluated. The permeation for the E10 fuel was 125 mg/day lower than for the E6 fuel. The higher aromatics fuel, E6Hi, showed a 199 mg/day lower permeation than the E6 fuel. The E20 permeation was also the highest measured on this rig. Diurnal Emissions Comparison - Rig 1

0 100 200 300 400 500 600Diurnal Emissions - mg/day

E0 E10 E6Hi E6 Pink Bar is Ethanol

91 475

361 468

1 149

91 184

E20 231 508

Figure 16

Diurnal Emissions Comparison - Rig 2

0 200 400 600 800 1000 1200 1400 1600 1800 2000Diurnal Emissions - mg/day

E0 E10 E6Hi E6 Pink Bar is Ethanol

458 1426

1227 1301

5 417

391 422

E20 623 1765

Figure 1719 Rig 11 - The results for Rig 11, shown in Figure 18, indicate that all the etha nol blends increased the permeation rate compared to the base (E0) fuel. The permeation rate for the E6 fuel was 105 mg/day higher than for the E0 fuel. The higher aromatics fuel, E6Hi, had 55 mg/day lower permeation than the E6 fuel. The E10 fuel had 21 mg/day lower permeation than the E6 fuel, and the E20 fuel was 42 mg/day lower than the E6 fuel.

This rig and Rig 14 were di fferent in their ethanol response than Rigs 1, 2 and 12, in that they had lower permeation on the E20 fuel than the E6 or E10 fuels. Rig 11 also had the lowest specific reactivity over all the fuels tested, as is described in a later section of this report on speciation and reactivity.

Rig 12 - When tested on the base (E0) non-ethanol fuel, this rig was measured at 36 mg/day. Rig 12was found to have less than 4 mg/day ethanol “hangup” when tested with the E0 fuel. The diurnal permeation increased when this rig was tested on any of the ethanol-contai ning fuels, as shown in Figure 19. The permeation for the E6 fuel was 14 mg/day greater than the E0 fuel. The permeation for the E6Hi fuel was 5 mg/day lower than the E6 fuel. This was the only rig that demonstrated a greater diurnal permeation for the E10 fuel vs. the E6 fuel, 14 mg/day higher. The highest permeation measured was on the E20 fuel, at 75 mg/day. Diurnal Emissions Comparison - Rig 11

0 20 40 60 80 100 120 140 160Diurnal Emissions - mg/day

E0 E10 E6Hi E6 Pink Bar is Ethanol

39 144

89 123

2 20

19 34

E20 102

38

Figure 18

Diurnal Emissions Comparison - Rig 12

0 10 20 30 40 50 60 70 80Diurnal Emissions - mg/day

E0 E10 E6Hi E6 Pink Bar is Ethanol

36 50

45 64

4 13

15 24 75

31

E20 Figure 1920 Rig 14 - A “FlexFuel” system evaluation was included in this project. Flexible fuel vehicles are designed and developed to perform on fuels containing just gasoline, or up to 85% ethanol fuel , and any combination in between.

Diurnal emissions were measured on four fuels, with the average results shown in Figure 20. The permeation emissions were nearly doubled (466 vs. 261 mg/day) with the E10 fuel, compared to the E0 fuel, but were approximat ely halved (128 vs. 261 mg/day) when the E85 fuel was tested. Like Rig 11, the permeation was lower on the E20 fuel compared to the E10 results. The ethanol was 139 mg/day when tested with the E10 fuel, similar in its fraction of the permeation total to the results from the other rigs evaluated. The ethanol of the E85 test results was 76 mg/day, almost 2/3 rd of the total permeation. It seems reasonable that if the fuel is almost all ethanol, the permeate ought to be mostly ethanol. Figure 20 Diurnal Emissions Comparison - Rig 14

0 100 200 300 400 500Diurnal Emissions - mg/day

E0 E10 E20 Pink Bar is Ethanol

261 466

128

9 139

76

E85 360

11121 Data Summary

A comprehensive table, Table 7, follows with the diur nal permeation results for ea ch vehicle and fuel, as well as the steady-state permeation resu lts, the ratio of the diurnal result to the steady-state result, and the specific reactivity of the permeate calculated for the individual diurnal tests.

Table 7 Detailed Permeation Emission Results
Rig #1 - 2001 Toyota Tacoma

Fuel 4-week Avg. mg/hour Diurnal Test ID mg/day Ratio Specific Reactivity g O 3 /g VOC E0 7.04 6389 83.9 11.9 4.31 E0b 8.57 6886 97.2 11.4 4.15 Avg. = 7.80 90.6 11.7 4.23

E6 25.6 6471 417.1 16.3 3.05 6479 533.3 20.8 3.08 Avg. = 475.2 18.6 3.07

E6Hi 29.2 6571 360.9 12.4 3.30

E10 35.2 6665 467.8 13.3 3.03

E20 43.4 6806 508.1 11.7 3.20

Rig #2 - 2000 Honda Odyssey

Fuel 4-week Avg. mg/hour Diurnal Test ID mg/day Ratio Specific Reactivity g O 3 /g VOC

E0 42.5 6390 463.3 10.9 4.26 E0b 33.7 6913 451.6 13.3 4.16 Avg. = 38.1 457.5 12.1 4.21

E6 97.7 6481 1426.0 14.6 3.54

E6Hi 88.9 6570 1227.0 13.8 3.66

E10 101.5 6673 1300.6 12.8 3.45

E20 148.8 6816 1765.1 11.9 3.3222 Table 7 (cont) Detailed Permeation Emission Results Rig #11 - 2004 Ford Taurus

Fuel 4-week Avg. mg/hour Diurnal Test ID mg/day Ratio Specific Reactivity g O 3 /g VOC E0 3.59 6370 48.0 13.4 2.91 E0b 2.53 6889 29.7 11.7 3.51 Avg. = 3.06 38.9 12.6 3.21

E6 11.2 6507 144.1 12.9 2.09

E6Hi 4.02 6598 88.7 20.3 2.58

E10 6.36 6675 149.3 24.1 2.23 6676 97.3 15.7 2.43 Avg. = 123.3 19.9 2.33

E20 5.42 6805 102.0 18.8 2.40

Rig #12 - 2004 Chrysler Sebring

Fuel 4-week Avg. mg/hour Diurnal Test ID mg/day Ratio Specific Reactivity g O 3 /g VOC E0 3.22 6372 38.7 12.0 5.48 6383 31.0 9.64 4.10 E0b 2.68 6874 38.3 14.3 3.73 Avg. = 2.95 36.0 12.0 4.44

E6 3.45 6492 49.6 14.4 3.30

E6Hi 3.86 6569 45.0 11.7 3.14

E10 4.65 6642 64.3 13.8 2.85

E20 5.38 6778 74.7 13.9 2.9223 Table 7 (cont) Detailed Permeation Emission Results

Rig #14 - 2005 Chevrolet Tahoe

Fuel 4-week Avg. mg/hour Diurnal Test ID mg/day Ratio Specific Reactivity g O 3 /g VOC E0 18.8 6360 250.5 13.3 3.80 6388 248.1 13.2 3.85 E0b 18.4 6645 282.7 15.4 3.89 E0c 20.5 6892 262.8 12.8 3.91 Avg. = 19.2 261.0 13.7 3.9

E10 29.8 6454 466.3 15.6 3.05

E85 16.3 6555 142.3 8.68 2.63 6566 112.8 6.88 2.82 Avg. = 127.6 7.78 2.73

E20 27.6 6779 359.5 13.0 3.36

Rig and Fuel Type Diur nal Result Comparisons

A table was made of the diurnal emission rates for the various rigs and fuels to look for trends or relationships. Table 8 below shows the diurnal results fo r all of the test fuels. Rig 1 showed a large increase in permeation when any of the ethanol-cont aining fuels was evaluated. Rig 2 was higher in basic permeation level, and showed proportiona tely less of an increase from th e ethanol fuels. Rig 11 had very low permeation emissions but still in creased when evaluated on the ethanol fuels. Rig 12, the “Zero Fuel Evaporative Emission” system, had a different result when tested on the ethanol-containing fuels in that the increase due to the ethanol was only 9 to 39 mg /day more than the base permeation rate, a much smaller increase than seen in the other rigs.

Table 8

Diurnal Emissions Test Results Total (Ethanol) – mg/day
Test Fuel Difference from E0, mg/day E0 E6 E6Hi E10 E20 E85 E6 E6Hi E10 E20 Rig 1 91 (1) 475 (149) 361 (91) 468 (184) 508 (231) 384 270 377 417 Rig 2 458 (5) 1426 (417) 1227 (391) 1301 (422) 1765 (623) 968 769 843 1307 Rig 11 39 (2) 144 (20) 89 (19) 123 (34) 102 (38) 105 50 84 63 Rig 12 36 (4) 50 (13) 45 (15) 64 (24) 75 (31) 14 9 28 39 Rig 14 261 (9) - - 466 (139) 360 (111) 128 (76) Average* 177 (4) 524 (150) 430 (129) 484 (161) 562 (207) 347 253 307 385 * Averages for E0, E10 and E20 are five-r ig; those for E6 and E6Hi are four-rig.24 Steady-State Permeation Measurements The plot format shown in Figures 21-25 was devel oped to compare the steady-state permeation rate results for each rig on the various fuels. The horizontal axis is a chronological sequence (not necessarily a linear time-scale) of the tests as they were accumulated. The red f illed-box data points represent the ethanol permeation rate. The labora tory established that 1 mg/hour was the detection limit of the analytical procedure used to establis h the ethanol content, and if the test level was less than 1.0 mg/hour it was reported as “b elow d etection l imit,” or BDL, and counted as zero in the calculation of the total. The black diamonds are the (non-ethanol) hydrocarbon, and the blue triangles are the to tal of the two, or the total permeation rate in mg/hour. A hor izontal blue line is dr awn at the average level of the last four data points.

Rig 1 started the stabilization on fuel E0 with an initial fill on January 11, 2005 and was tested on the following day to measure the permeation rate. Permeation measurements were made each week, not necessarily on the same day of th e week, although that was the norma l case. The actual test dates are contained in the data record file known as “rig sum.xls,” and are available on the CRC web-site.

A concern arose when ethanol was de tected in the steady-state permeation results on the E0 fuel, even though there was no ethanol in the test fuel. The first three tests on the E0 fuel reported no ethanol, but the Ethanol Impact - Stabilized Permeation Rig 1

0 10 20 30 40 50 60Permeation - mg/hr Total 4 Wk. Avg.
Non-Ethanol HC
Ethanol E0 E6Hi E6 E10 E20 E0b

Figure 2125 fourth test (#6306 on February 2, 2005) reported 4.8 mg/hour as the ethanol component. A discussion arose concerning the source and authenticity of the measurement. The following week’s measurement was 2.3, and then 4.8, 1.2 and 1.2 mg/hour in succeeding we eks. The test on March 9 returned to BDL for ethanol. A similar pattern arose, at the same time period, on Rig 2, as will be discussed later. Ethanol was not detected in Rigs 11, 12 or 14 during the initi al steady-state permeation E0 testing. A separate discussion concerning the “ethanol ha ng-up” is provided in the appendi x at the end of this report.

The steady-state permeation rate in creased when the 5.7 Volume% ethano l fuel (E6) was introduced, as shown in Figure 21. The four-week final average permeation rate was 7.04 mg/hour on Fuel E0 and increased to 25.6 mg/hour on the 5.7 Volume% ethanol fuel. The steady-state permeation rate increased slightly on the higher aromatics E6Hi fuel, with an average of 29.2 mg/hour, and was higher yet (35.2 mg/hour) on the 10 Volume% ethanol fuel. The E 20 steady-state average value was 43.4 mg/hour. The average of the original and the fi nal steady-state permeation rate measurements on the E0 fuel (7.04 and 8.57) was 7.8 mg/hour

Rig 2 also received its initial fill of the E0 test fuel on January 11, 2005, with its first test on the following day. (The practice was later changed to not test on th e day following the fuel change, but test after a week or more exposure.) It showed etha nol in the permeate on the fourth week, on February 4, of 8.8 mg/hour, and 7.9 mg/hour the following week, during the same time period as was seen on Rig 1. A check was made for any sort of a laboratory or soak room contamination problem, without finding any source of contamination or error. An expande d discussion on the ethanol “hang-up” appears in the appendix to this report.

Figure 22 Ethanol Impact - Stabilized Permeation Rig 2

0 20 40 60 80 100 120 140 160 180Permeation - mg/hr Total 4 Wk. Avg.
Non-Ethanol HC
Ethanol E0 E6Hi E6 E10 E20 E0b26 The following observations were made regarding the s econd test band in Figure 22. The first test on the E6 fuel was made after nine days of exposure. The second week’s test after 17 days shows that the total permeation trend had approached the eventual stabilized level. The ethanol conten t, shown in the red solid squares as the lower of the three tre nds in the plot, appeared to be in creasing slightly over the nine weeks of exposure. The permeation was declar ed to be stabilized after the 10 th week of stabilization, and the rig was then submitted for the diurnal test.

The permeation rate decreased slightly when the hi gher aromatics E6Hi fuel was introduced, and then increased with the introduction of the 10 Volume% ethanol fuel (E10). The 4-week average for the tests on the E10 fuel was 101.5 mg/hour, a nd 148.8 mg/hour on the E20 fuel. The average of the two steadystate averages on the E0 fuel (42.5 and 33.7) was 38.1 mg/hour

The permeation rate for Rig 11 was very low, ~ 3 mg/hour on the E0 fuel, as shown in Figure 23, which created measurement challenges. The measurement period was increased from three to five hours during the E6 fuel measurement period as was discussed earlier in this section.

The permeation performance of Rig 11 was erratic on th e E6 fuel. The erratic performance continued for the first two tests on the E6Hi fuel, when the permeation suddenly dropped from 24 mg/hour to ~4 mg/hour for no identified reason. Th is erratic condition may have also been present during the diurnal evaluation on the E6 fuel, but there is at present no basis to invalidate the data. Figure 23 Ethanol Impact - Stabilized Permeation Rig 11

0 5 10 15 20 25Permeation - mg/hr Total 4 Wk. Avg.
Non-Ethanol HC
Ethanol E0 E6Hi E6 E10 E20 E0b27 Rig 12 was expected to have low permeation as it wa s produced and certified to be a “zero fuel evaporative emission” vehicle. As anticipated, the steady-state permea tion results were very low (Note the vertical scale on Figure 24). The 4-week averag e permeation rate on the E0 fuel was 3.2 mg/hour for the original test sequence, with any ethanol cont ent below the detectable limit and 2.7 mg/hour on the final series, with about a 0.5 g/hour ethanol fraction. Th e E6 fuel increased the permeation rate slightly, mainly because the ethanol component triggered into the detectable limit of 1 mg/hour.

Unlike the other rigs, the high arom atics fuel, E6Hi, increased the permeation rate of Rig 12 over the value established for the lower aromatics E6 fuel. The 4-week average level was 3.4 mg/hour on the E6 fuel, and 3.9 mg/hour on the E6Hi fuel. The data suggests that although the non-ethanol measurement stayed about the same, there was an increase in the mass rate of the ethanol in the permeate with the higher aromatics fuel compared to the E6 fuel. The E10 steady-state average was 4.6 mg/hour, and the E20 value was 5.4 mg/hour

The final test sequence on the E0 fuel shows an etha nol content at the 0.5 mg/hour level, where the initial E0 tests were declared as below the detectable limit. This is attributed to the fact that the laboratory became more confident in declaring ethanol measurem ents below the level of 1 mg/hour as the program progressed.

The permeation results with the E20 fuel were the hi ghest measured of the f our test fuels, but the magnitude of the increase, when compared to th e base fuel (E0), was low, less than 3 mg/hour. Ethanol Impact - Stabilized Permeation Rig 12

0 1 2 3 4 5 6 7 8Permeation - mg/hr Total 4 Wk. Avg.
Non-Ethanol HC
Ethanol E0 E6Hi E6 E10 E20 E0b

Figure 2428 Rig 14 was tested on the E0, E10, E20 and E85 fuels. The committee authorized a final test on the E0 fuel after the E85 evaluation to see if it would return to the previously measured E0 level. The results of the steady-state evaluation are shown in Figure 25. The ethanol in the permeate jumped to the 8 mg/hour level on the second test with the E10 fuel. The E10 steady-state permeation (29.8 mg/hr) was 1.6 times the E0 steady-state rate of 18.8 mg/hr, more like the re sults from Rigs 11 and 12, than Rigs 1 and 2. The 4-week steady-state average on the E 20 test fuel was 27.6 mg/hour, close, but slightly less, than the E10 4-week average of 29.8 mg/hour.

Figure 25 Ethanol Impact - Stabilized Permeation Rig 14

0 5 10 15 20 25 30 35Permeation - mg/hr Total 4 Wk. Avg.
Non-Ethanol HC
Ethanol E0 E85 E10 E0b E20 E0c29 Steady-State Permeation Results by Rig

The steady-state tests were used to determine fuel system stability followi ng the introduction of a new fuel and to indicate that the rig was ready for the di urnal evaluation. A three or five hour steady-state test was performed in a SHED to dete rmine the 105°F hourly permeation ra te. The 4-week average steadystate permeation rates provide another measure of th e permeation performance of the various fuels on the different fuel systems, and are presented below.

Rig 1 - The bar chart in Figure 26 is used to illustrate the steady-state performance of the five test fuels on Rig 1. The hourly permeation rate is the lowest on the base fuel (E0) and increases to 43 mg/hour on fuel E20. The higher aromatic E6Hi fuel had slightly higher permeation than the E6 fuel on the steady-state measurement, a different finding than wa s indicated on the diurnal
test.

Rig 2 – Figure 27 shows the steady-state permeation estimate on the E6Hi fuel to be lower than the E6 fuel, more in line with the diurnal test results, while the E10 permeation is slightly higher than the E6 result, and the E20 permeation is substantially higher. Stabilized Permeation Levels - Rig 1

7.8 25.6 29.2 35.2 43.4

0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 50.0

E0 E6 E6Hi E10 E20

Test FuelStabilized Permeation - mg/hr

Stabilized Permeation L evels - Rig 2

38.2 97.7

88.9 101.5 148.8

0.0 20.0 40.0 60.0 80.0 100.0 120.0 140.0 160.0

E0 E6 E6Hi E10 E20

Test FuelStabilized Permeation - mg/hr Figure 26

Figure 2730 Rig 11 steady-state test resu lts, shown in Figure 28, are distorted by the hi ghly variable results experienced during the test s on the E6 fuel (see the earlier steady-state di scussion on Rig 11). The E20 permeation was lower than the results measured with the E10 fuel, a different result than was seen on Rigs 1, 2 and 12.

Rig 12 steady-state permeati on results, shown in Figure 29 are more like the relationship seen with Rigs 1 and 2.

Rig 14 steady-state results, shown in Figure 30, indicate lower emission on the E20 fuel than was measured on E10, similar to the behavior of Rig 11. The steady-state 105°F permeation result on the E85 fuel was lower (-2.8 mg/hour ) than the E0 base fuel, but not at half the value, as the diurnal results indicated. Stabilized Permeation Levels - Rig 12

3.0 3.4 3.9 4.6 5.4

0.0 1.0 2.0 3.0 4.0 5.0 6.0

E0 E6 E6Hi E10 E20

Test FuelStabilized Permeation - mg/hr

Stabilized Permeation Levels - Rig 14

19.2 29.8

27.6

16.4

0 5 10 15 20 25 30 35

E0 E10 E20 E85

Test FuelStabilized Permeation - mg/hr

Figure 30 Figure 28 Stabilized Permeation Levels - Rig 11

3.1 11.2

4.4 6.2

5.4

0.0 2.0 4.0 6.0 8.0 10.0 12.0

E0 E6 E6Hi E10 E20

Test FuelStabilized Permeation - mg/hr

Figure 2931 In summary, the steady-state results may offer a slight ly different picture of th e permeation behavior of the different fuels on the different rigs, relative to the diurnal results. The small sample size, and the limited testing conducted, suggest some caution in evaluating these observed differences.

Speciation and Reactivity

Diurnal Speciation Results – A sample of the ambient HC concen tration in the VT-SHED was collected in a TedlarTM bag at the start and the end of the 24-hour diurnal period and later analyzed for HC species using a VarianTM chromatograph. The results of this “speciation” allowed the ca lculation of the average reactivity of the permeate for each of the rigs and fuels. An example of the speciation result s and the reactivity calculations fo r Rig 1 – Fuel E0, Test 6389, is shown in Table 9. Table 9 is one file in a Micr osoft EXCEL® workbook titled “SHED Speciation and Reactivity Calculations for the Final Report.xls,” availa ble on the CRC web-site in the files for the E-65-3 report. This workbook contains all of the SHED speciations for the test fuels evaluated in this program.

Each file has been reordered into three vertical groups. The top group is those molecules with identified mass that have an assigned Carter M aximum I ncremental R eactivity (MIR) value. The second vertical group is those measured mass components that do not ha ve an assigned MIR value, and the last group is the molecules that had zero measured mass, but would ha ve been identified if they were present, using the “Auto-Oil” chromatographic test technique. The first and second ve rtical groups were sorted in descending order of mass in each group. The lengthy lis ting of the third group, of those molecules with no detected mass, is offered to indicate to the reader what would have been measur ed, if present, using the chromatographic techniques available at the laboratory.
This table, and the others in the workbook, are organized from left to right as follows. The first column is the elution order number, or the order that the molecu les would appear at the end of the chromatographic column. The second column is the specific molecu le’s name. The third column is the CAS number 8 for the molecule. The fourth column is the MIR value for the molecule, or the specific grams of ozone formed for each gram of HC iden tified under certain conditions. The fi fth column is the net mass of each species identified in the SH ED sample by the chromatograph. The si xth column is the percentage of the total mass identified as this species. The final column is the prediction of the mass of ozone that would be produced by that mass of that mo lecule using the Carter methodology.

8 The CAS number is the C hemical A bstract S ervice registry number assigned to each specific molecule. CAS registry numbers are copyright ed by the American Chemical Society. Redi stribution rights for CAS registry numbers are reserved by the American Chemical So ciety. “CAS registry” is a register ed trademark of the American Chemical Society. The CAS REGISTRY mostly co vers substances identified from the scientific literature from 1957 to the present with some classes (fluorine- and silicon-contai ning compounds) going back to the early 1900s. Each substance in REGISTRY is identified by a unique numeric identifier called a CAS Registry Number.32 Table 9
Rig: 01E0 Test#: 6389 Detailed Hydrocarbon Speciation Results 24-Hour

Elution No. Species Name CAS # MIR g O 3 /g HC Net mass (mg) % total

mass Predicted Ozone mg 81 Toluene 00108-88-3 3.97 14.321 17% 56.85 18 2-Methylbutane (Isopentane) 00078-78-4 1.67 10.787 13% 18.01 111.1 m-Xylene 00108-38-3 10.61 8.835 10% 93.74 21 n-Pentane 00109-66-0 1.53 3.666 4% 5.61 117 ortho-Xylene 00095-47-6 7.48 2.951 3% 22.08 111.2 p-Xylene 00106-42-3 4.24 2.591 3% 10.99 36.1 2-MePentane 00107-83-5 1.78 2.289 3% 4.08 135.1 1,2,4-TriMeBenz 0009 5-63-6 7.18 2.131 2% 15.30 109 Ethylbenzene 00100-41-4 2.79 2.066 2% 5.77 53 Benzene 00071-43-2 0.81 1.952 2% 1.58 34 2,3-Dimethylbutane 00079-29-8 1.13 1.514 2% 1.71 128 1-Methyl-3-Ethylbenzene 00620-14-4 9.37 1.501 2% 14.06 40 n-Hexane 00110-54-3 1.43 1.475 2% 2.11 63 2,2,4-TriMePentane (IsoOctane ) 00540-84-1 1.43 1.437 2% 2.05 26 2-Methyl-2-butene 00513-35-9 14.44 1.298 2% 18.75 Ethanol 00064-17-5 1.69 1.260 1% 2.13 49 Methylcyclopentane 00096-37-7 2.40 1.244 1% 2.99 56 Cyclohexane 00110-82-7 1.44 1.130 1% 1.63 79 2,3,4-Trimethylpentane 0056 5-75-3 1.22 0.986 1% 1.20 74 Methylcyclohexane 00108-87-2 1.97 0.955 1% 1.88 130 1,3,5-Trimethylbenzene 0010 8-67-8 11.22 0.953 1% 10.69 23 t-2-Pentene 00646-04-8 10.23 0.910 1% 9.31 38 3-Methylpentane 00096-14-0 2.06 0.905 1% 1.87 9 2-Methylpropane 00075-28-5 1.34 0.892 1% 1.20 12 n-Butane 00106-97-8 1.32 0.874 1% 1.15 86 3-Methylheptane 00589-81-1 1.33 0.832 1% 1.11 57 2-Methylhexane 00591-76-4 1.36 0.809 1% 1.10 42 t-2-Hexene 04050-45-7 8.35 0.754 1% 6.30 59.2 3-Methylhexane 00589-34-4 1.84 0.722 1% 1.33 129 1-Methyl-4-Ethylbenzene 00622-96-8 3.75 0.705 1% 2.64 127 n-Propylbenzene 00103-65-1 2.20 0.661 1% 1.45 136 n-Decane 00124-18-5 0.81 0.608 1% 0.49 90 2,2,5-Trimethylhexane 0352 2-94-9 1.31 0.541 1% 0.71 96 n-Octane 00111-65-9 1.09 0.532 1% 0.58 45.1 c-2-Hexene 07688-21-3 8.35 0.520 1% 4.34 83 2-Methylheptane 00592-27-8 1.18 0.500 1% 0.59 66 n-Heptane 00142-82-5 1.26 0.495 1% 0.62 77 2,4-Dimethylhexane 00589-43-5 1.79 0.476 1% 0.85 29 2,2-Dimethylbutane 00075-83-2 1.33 0.465 1% 0.62 50 2,4-Dimethylpentane 00108-08-7 1.63 0.447 1% 0.73 58 2,3-Dimethylpentane 00565-59-3 1.53 0.376 0% 0.5833 Table 9 (continued) Detailed Hydrocarbon Speciation Results 24-Hour

Elution No. Species Name CAS # MIR g O 3 /g HC Net mass (mg) % total

mass Predicted Ozone mg 133 1-Ethyl-2-Methylbenzene 00611-14-3 6.61 0.365 0% 2.41 25 c-2-Pentene 00627-20-3 10.23 0.361 0% 3.69 115 Styrene 00100-42-5 1.94 0.346 0% 0.67 14 t-2-Butene 00624-64-6 13.90 0.331 0% 4.60 84.2 4-MeHeptane 00589-53-7 1.46 0.321 0% 0.47 113 3-Methyloctane 02216-33-3 1.42 0.257 0% 0.36 140 1,2,3-Trimethylbenzene 00526-73-8 11.25 0.239 0% 2.69 39.1 2-Methyl-1-pentene 00763-29-1 5.15 0.235 0% 1.21 48 2,2-Dimethylpentane 00590-35-2 1.21 0.199 0% 0.24 16 c-2-Butene 00590-18-1 13.22 0.184 0% 2.44 20 2-Methyl-1-butene 00563-46-2 6.47 0.179 0% 1.16 1 Methane 00074-82-8 0.01 0.124 0% 0.00 76.1 2,5-DiMeHexane 00592-13-2 1.66 0.121 0% 0.20 30 Cyclopentene 00142-29-0 7.32 0.099 0% 0.72 19.1 1-Pentene 00109-67-1 7.73 0.096 0% 0.74 76.2 EtCyPentane 01640- 89-7 2.25 0.062 0% 0.14 39.2 1-Hexene 00592-41-6 6.12 0.033 0% 0.20 Mass w/MIR Values 81.9 95.7% 352.7 Specific Reactivity 4.31 43 3-Methyl-t-2-pentene 00616-12-6 1.196 1% 47 Unknown #16 0.686 1% 61 3-Methyl-c-2-pentene 00922-62-3 0.534 1% 82.2 c-1,3-Dimethylcyclopentane 02532-58-3 0.330 0% 88 2-Me-3-Et-pentane 00609-26-7 0.316 0% 36.2 c-1,3-Dimethylcyclohexane 00638-04-0 0.288 0% 62 4-Me-c-2-Pentene 00691-38-3 0.140 0% 45.2 t-1,2-Dimethylcycl opentane 00822-50-4 0.130 0% 123 3-MeCyclopentene 01120-62-3 0.069 0% Mass w/o MIR Values 3.69 4.3%

4 Ethane 00074-84-0 0.000 0% 2 Ethylene 00074-85-1 0.000 0% 3 Acetylene (Ethyne) 00074-86-2 0.000 0%34 Table 9 (continued) Detailed Hydrocarbon Speciation Results 24-Hour

Elution No. Species Name CAS # MIR g O 3 /g HC Net mass (mg) % total

mass Predicted Ozone mg 6 Propane 00074-98-6 0.000 0% 8 Propyne 00074-99-7 0.000 0% 22 2-Methyl-1,3-butadiene 00078-79-5 0.000 0% 168 Naphthalene 00091-20-3 0.000 0% 135.2 1,2,4,5-Tetramethy lbenzene 00095-93-2 0.000 0% 122 t-Butylbenzene 00098-06-6 0.000 0% 162 Isopropylbenzene (Cumene) 00098-82-8 0.000 0% 141 1,3-Diisopropylbenzene 00099-62-7 0.000 0% 166 4-Isopropyltoluene (p-Cymene) 00099-87-6 0.000 0% 70.1 1,4-Diisopropylbenzene 00100-18-5 0.000 0% 147 n-Butylbenzene 00104-51-8 0.000 0% 145 1,4-Diethylbenzene 00105-05-5 0.000 0% 10.2 1-Butene 00106-98-9 0.000 0% 11 1,3-Butadiene 00106-99-0 0.000 0% 15 1-Butyne 00107-00-6 0.000 0% 125.2 244Trimethyl1pentene 00107-39-1 0.000 0% 75 2,4,4-Trimethyl-2-P entene 00107-40-4 0.000 0% 59.1 Cyclohexene 00110-83-8 0.000 0% 91 1-Octene 00111-66-0 0.000 0% 120 n-Nonane 00111-84-2 0.000 0% 172 n-Dodecane 00112-40-3 0.000 0% 169 1-Dodecene 00112-41-4 0.000 0% 5 Propene 00115-07-1 0.000 0% 10.1 2-Methylpropene 00115-11-7 0.000 0% 118 1-Nonene 00124-11-8 0.000 0% 146 1,2-Diethylbenzene 00135-01-3 0.000 0% 138 sec-Butylbenzene 00135-98-8 0.000 0% 143 1,3-Diethylbenzene 00141-93-5 0.000 0% 32 Cyclopentane 00287-92-3 0.000 0% 7 AlBenz 00300-57-2 0.000 0% 163.1 Allene (Propadi ene) 00463-49-0 0.000 0% 13 2,2-Dimethylpropane 00463-82-1 0.000 0% 51 2,2,3-Trimethylbutane 00464-06-2 0.000 0% 163.2 1,2,3,4-TetMeB enzene 00488-23-3 0.000 0% 142 Indan 00496-11-7 0.000 0% 19.2 2-Butyne 00503-17-3 0.000 0% 158 1,2,3,5-Tetramethyl benzene 00527-53-7 0.000 0% 137 Amylbenz 00538-68-1 0.000 0% 80 Isobutylbenzene 00538-93-2 0.000 0% 28 Cyclopentadiene 00542-92-7 0.000 0% 24 3,3-Dimethyl-1-butene 00558-37-2 0.000 0% 78 2,3,3-Trimethylpentane 00560-21-4 0.000 0%35 Table 9 (continued) Detailed Hydrocarbon Speciation Results 24-Hour

Elution No. Species Name CAS # MIR g O 3 /g HC Net mass (mg) % total

mass Predicted Ozone mg 54 3,3-Dimethylpentane 00562-49-2 0.000 0% 92 3,3-Dimethylhexane 00563-16-6 0.000 0% 17 3-Methyl-1-butene 00563-45-1 0.000 0% 82.1 2,3-dimethylhexane 00584-94-1 0.000 0% 98.2 1,1-Dimethylcyclohexane 00590-66-9 0.000 0%

73 2,2-DiMeHexane 00590-73-8 0.000 0% 84.1 1-MeCyHexene 00591-49-1 0.000 0%

64 1-Heptene 00592-76-7 0.000 0% 37 c-1,4-DiMeCyHexane 00624-29-3 0.000 0% 44 2-Methyl-2-pentene 00625-27-4 0.000 0% 46 ETBE 00637-92-3 0.000 0% 69 4-Methyl-t-2-pentene 00674-76-0 0.000 0% 31.1 4-methyl-1-pentene 00691-37-2 0.000 0%

52 1-Methylcyclopentene 00693-89-0 0.000 0% 31.2 3-methyl-1-pentene 00760-20-3 0.000 0% 150 3-Ethyl-c-2-Pentene 00816-79-5 0.000 0% 153 1-Undecene 00821-95-4 0.000 0% 151 1,3-Dimethyl-4-Ethylbenzene 00874-41-9 0.000 0% 105 3,5-Dimethylheptane 00926-82-9 0.000 0% 148 1,2-Dimethyl-4-Ethylbenzene 00934-80-5 0.000 0% 100 2,3,5-Trimethylhexane 01069-53-0 0.000 0% 144 1-Methyl-2-Propylbenzene 01074-17-5 0.000 0% 149 1-Methyl-3-Propylbenzene 01074-43-7 0.000 0% 154 n-Undecane 01120-21-4 0.000 0% 33 MTBE 01634-04-4 0.000 0% 104 Ethylcyclohexane 01678-91-7 0.000 0% 125.3 PrCyHexane 01678-92-8 0.000 0%

119 1,4-Dimethyl-2-Ethylbenzene 01758-88-9 0.000 0% 103 c- & t-4-Nonene 02198-23-4 0.000 0% 98.1 c-1,2-Dimethylcyclohexane 02207-01-4 0.000 0%

89 t-1,3 02207-03-6 0.000 0% 67.1 t-1,4-Dimethylcyclo hexane 02207-04-7 0.000 0% 101 2,4-Dimethylheptane 02213-23-2 0.000 0% 112 4-Methyloctane 02216-34-4 0.000 0% 152 2-Methyl-2-Hexene 02738-19-4 0.000 0% 110.1 1,3-Dimethyl-2-Ethylbenzene 02870-04-4 0.000 0%

55 2,3-DiMeHeptane 03074-71-3 0.000 0% 110.2 2-MeOctane 03221-61-2 0.000 0% 68.1 3-Me-1-Hexene 03404-61-3 0.000 0% 139 3-Me-t-3-Hexene 03899-36-3 0.000 0% 125.1 2,4-DiMeOctane 04032-94-4 0.000 0%

121 1-Methyl-4-Isobutylbenzene 05161-04-6 0.000 0%36 Table 9 (continued) Detailed Hydrocarbon Speciation Results 24-Hour

Elution No. Species Name CAS # MIR g O 3 /g HC Net mass (mg) % total

mass Predicted Ozone mg 71 t-2-Nonene 06434-78-2 0.000 0% 97.2 c-2-Heptene 06443-92-1 0.000 0%

99 t-1,2-DiMeCyHexane 06876-23-9 0.000 0% 70.2 c-2-Octene 07642-04-8 0.000 0% 41.2 c-3-Hexene 07642-09-3 0.000 0% 67.2 c-3-Heptene 07642-10-6 0.000 0% 97.1 23-diMe-2-pentene 10574-37-5 0.000 0% 41.1 t-3-Hexene 13269-52-8 0.000 0%

27 t-2-Octene 13389-42-9 0.000 0% 68.2 t-2-Heptene 14686-13-6 0.000 0%

65 t-3-Heptene 14686-14-7 0.000 0% 94 t-4-Octene 14850-23-8 0.000 0% 87 2,2-Dimethyloctane 15869-87-1 0.000 0% 161 1c-2t-3-TriMeCyPentane 15890-40-1 0.000 0% 157 Methylindan 27133-93-3 0.000 0% 35 Unknown #1 0.000 0% 60 Unknown #2 0.000 0% 72 Unknown #3 0.000 0% 85 Unknown #4 0.000 0% 95 Unknown #5 0.000 0% 102 Unknown #7 0.000 0% 106 Unknown #8 0.000 0% 107 Unknown #9 0.000 0% 108 Unknown #10 0.000 0% 114 Unknown #11 0.000 0% 116 Unknown #12 0.000 0% 124 Unknown #13 0.000 0% 126 Unknown #14 0.000 0% 131 Unknown #15 0.000 0% 132 Unknown #17 0.000 0% 134 3-Methylnonane 0.000 0% 155 Unknown #18 0.000 0% 156 Unknown #19 0.000 0% 159 Unknown #20 0.000 0% 160 Unknown #21 0.000 0% 165 Unknown #23 0.000 0% 167 Unknown #24 0.000 0% 170 Unknown #25 0.000 0%

Total 85.6 100.0 %

83.9 SHED FID (mg) 102.0 % GC of SHED FID37 Specific Reactivity Calculations - The Carter Maximum Incrementa l Reactivity (MIR) scale for the various VOC molecules was adopted by the CARB. It estimates that for each gram of the various VOC molecules, X grams of ozone would be produced under ideal conditions for ozone formation. The reference (approved by the CARB Staff for this purpose) to the values and the documentation is “THE SAPRC-99 CHEMICAL MECHANISM AND UPDATED VOC REACTIVITY SCALES” which can be found at http://helium.ucr.edu/~carter/reactdat.htm
The link to the actual data is found down two thirds of the page, under the heading VOC Reactivity Data (Excel format) as of Fe bruary 5, 2003 (r02tab.xls). It contains CAS number, MIR value and species name for 543 different species.

The average specific reactivity of the permeate was calculated for each of the 25 diurnal tests conducted on the five rigs and five fuels. VOC reactivity varies with atmospheric conditions, in particular the VOC/NOx ratio. The MIR scale is based on low VOC/NOx ratios. The reactivity measur e reported in this study, average VOC specific reactivity, has units of potential grams of ozone per gram of VOC and is a function of the composition of the VOC permeate. Specific reactivity provides an estimate of the ozone-for ming potential per unit mass of the VOC permeate under c onditions favorable for ozone formation, but it is not meant to predict actual levels of ozone and should be inte rpreted on a relative basis. Furthe r, there are uncertainties in these reactivity estimates, e.g., the MIR scale represents a limited range of atmospheric conditions, does not include carryover of emissi ons from one day to the next, and does not include three-dimensional spatial variation in emissions.
The mass emissions times the MIR gives the theoretical potential ozone that wo uld be formed by that mass under ideal conditions. This ca lculation was performed on all the identified molecules that had MIR factors. Not all the molecules meas ured had MIR factors. The unident ified compounds were assumed to have the same reactivity as the average of the iden tified compounds with MIR fa ctors. The mass of the compounds for which no MIR factors existed was determined to be insignificant.
The specific reactivity for a speciated SHED diurnal sample was calculated by summing the mass of the individual species, and the predicte d potential ozone using the MIR fact or. The specific reactivity is the mass of ozone predicted divided by the mass of th e hydrocarbons measured, in our example, 352.7 mg/81.9 mg, or 4.31 g of potential O 3 /g VOC permeate emissions. The next part of this report discus ses the specific reactivities calculate d for the six fuels tested in this project. When the permeate specific reactivities of th e five rigs were compared across test fuels, it was observed that Rig 11 consistently produced the lowest result.38 Thirteen diurnal tests on the E0 fuel were speciated (Table10). The average specific reactivity of the permeate of all the E0 diurnals was 3.99 (grams of oz one per gram of HC mixt ure), with two “eyeball” outliers, (test 6370 – Rig 11 = 2.91), a nd (test 6372 – Rig 12 = 5.48). The other six tests ranged from 3.80 to 4.26. The third and fourth columns in Table 9 allo w a comparison of the SHED calculation of mass and the gas chromatograph’s value. In general, reas onable agreement was found between the two estimates. The fifth and sixth columns report th e identified mass (in mg and % of total) that had MIR factors for the individual species. Usually 90% or more had MIR values
Table 10 Fuel E0 Diurnal Permeate Reactivity Results

Total GC Mass w/MIR Values

Rig (test #) Test ID Reported SHED mg Mass - mg mg % Specific Reactivity Rig Wtd. Average 1 6389 83.9 85.6 81.9 95.7% 4.31 1b 6900 97.2 101.6 96.1 94.7% 4.15 2 6390 463.3 391.4 369.8 94.5% 4.26 2b 6913 451.6 435.6 412.6 94.7% 4.16 11 6370 48.0 36.6 32.5 88.8% 2.91 11b 6889 29.7 32.4 30.9 95.4% 3.51 12(1) 6372 38.7 29.3 26.0 88.8% 5.48 3.99 12(2) 6383 31.0 34.1 33.4 97.9% 4.10 12b 6874 38.3 41.0 39.8 97.3% 3.73 14(1) 6360 250.5 250.4 239.2 95.5% 3.80 14(2) 6388 248.1 241.3 236.9 98.2% 3.85 14b 6645 282.7 274.7 259.7 94.6% 3.89 14c 6892 262.8 265.8 247.9 93.3% 3.9139 The average specific reactivity of th e permeates for the five diurnal tests on the E6 fuel was 3.00 (Table 11), but this included one relatively low result (tes t 6507 – Rig 11 = 2.09). The average specific reactivity with that test omitted was 3.24. The 3.24 number comp ares well with the Fuel B permeate average of 3.27 from the original E-65 test program.

Table 11 Fuel E6 Diurnal Permeate Reactivity Results

Total GC Mass w/MIR Values

Rig (test #) Test ID Reported SHED mg Mass - mg mg % Specific Reactivity Rig Wtd. Average 1(1) 6471 417.1 264.1 264.1 100.0% 3.05 1(2) 6479 533.3 461.3 447.3 97.0% 3.08

2 6481 1426.0 1357.6 1326.8 97.7% 3.54 3.00 11 6507 144.1 127.7 127.7 100.0% 2.09 12 6492 49.6 36.8 36.0 97.8% 3.30

Four tests on the E6Hi fuel were speciated, with an average permeat e specific reactivity of 3.17 (Table 12). Rig 11 had the lowest reacti vity value for the four tests.

Table 12 Fuel E6Hi Diurnal Permeate Reactivity Results

Total GC Mass w/MIR Values

Rig (test #) Test ID Reported SHED mg Mass - mg mg % Specific Reactivity Rig Wtd. Average 1 6571 360.9 270.9 270.9 100.0% 3.30 2 6570 1227.0 1400.7 1290.1 92.1% 3.66 3.17 11 6598 88.7 82.0 82.0 100.0% 2.58 12 6569 45.0 39.2 38.7 98.6% 3.1440 The six diurnal tests on the E10 fuel had an average permeate specific reactivity of 2.94 (T able 13), with Rig 11 again yielding the lowest valu es. There is no current explanati on why the fuel system components used in Rig 11 might produce a lo wer, or less reactive permeate.

Table 13 Fuel E10 Diurnal Permeate Reactivity Results

Total

GC Mass w/MIR Values

Rig (test #) Test ID Reported SHED mg Mass - mg mg % Specific Reactivity Rig Wtd. Average 1 6665 467.8 443.2 438.2 98.9% 3.03 2 6673 1300.6 1289.2 1262.3 97.9% 3.45 11(1) 6675 149.3 163.2 160.8 98.6% 2.23 2.94 11(2) 6676 97.3 118.5 116.3 98.2% 2.43

12 6642 64.3 54.9 53.8 98.0% 2.85 14 6454 466.3 436.6 426.4 97.7% 3.05

The five diurnal tests on the E20 fuel had an average specific reactivity of 3.04 (Table 14), with a range of values from 2.40 to 3.36. Again, the lowest specific reactivity of the rigs evaluated was Rig 11.

Table 14 Fuel E20 Diurnal Permeate Reactivity Results

Total GC Mass w/MIR Values

Rig (test #) Test ID Reported SHED mg Mass - mg mg % Specific Reactivity Rig Wtd. Average 1 6806 508.1 568.4 558.3 98.2% 3.20 2 6816 1765.1 1687.5 1650.8 97.8% 3.32 11 6805 102.0 94.5 93.1 98.6% 2.40 12 6678 74.7 63.6 63.5 100.0% 2.92 3.04 14 6779 359.5 399.0 388.7 97.4% 3.3641 Two speciated diurnals were conduct ed on Rig 14 with the E85 fuel, a nd the results are shown in Table 15. The two permeate specific reactivities measured we re 2.63 and 2.82 with an arithmetic average value of 2.73. The specific reactivity of the E85 permeate is expected to be low compar ed to other fuels since the ethanol fraction of the diurnal permeate was approxi mately two-thirds of the total mass (59 to 65 mass %).

Table 15 Fuel E85 Diurnal Permeate Reactivity Results

Total GC Mass w/MIR Values

Rig (test #) ID Reported SHED mg Mass -mg mg % Specific Reactivity Rig Wtd. Average 14(1) 6555 142.3 137.6 137.4 99.9% 2.63 14(2) 6566 112.8 105.6 102.5 97.0% 2.82 2.73

Statistical Analysis

Statistical analyses were performed on the diurnal an d steady-state emissions resu lts, as well as on the specific reactivity results. Analysis of the residua ls from preliminary regres sions indicated that the variability in the diurnal data tende d to be proportional to the magnitude of the measurement; therefore, a natural log transformation was used on the diurnal data, which yielded a constant standard deviation over the range of the data. However, th e steady-state and reactivity data exhi bited constant sta ndard deviations without the log transformation, so no transf ormation was used for those variables.

For each of the three dependent variab les evaluated, tests were performed to determine the significance of three possible independent variables: 1) test timing; 2) fuel aromatics level; and 3) fuel ethanol content. Because E85 was only tested in one of the five vehicles (rigs), data for that fuel were not included in any of the analyses. All five vehicles (rigs) were incl uded in the analyses for te st timing and fuel ethanol content, but Rig 14 was not included in the analysis of the effect of fuel aromatics content because it was not tested on fuels E6 and E6Hi.

In recent years, CRC has employed mixed models that include both fixed a nd random effects in the analysis of emissions data. In these analyses, the random effects are the vehicle intercepts and vehicle-byfixed effect interactions. The advantage of these mi xed models is that the ra ndom effects are treated as being samples drawn from a normal population, and th e resulting statistical tests include the observed variation in the random sample of vehicles. As a re sult, the tests of significance are applicable to the population of vehicles from which the sample was draw n. On the other hand, sta tistical tests using fixedeffect models are applicable only to the specific vehicles tested.

While mixed models permit more powerful conclusions to be drawn, they also depend on having a large enough random vehicle sample to be able to draw c onclusions on fuel effects in the face of vehicle-tovehicle variation. In this study, the small sample si ze (five vehicles) was not j udged to be large enough to permit the use of mixed models, so fixe d effects models were used. As a result, the statistical significance determinations made in this report ap ply only to the specific vehicles tested.42 Test Timing

The E0 fuel was evaluated first and last on all the rigs . In addition, Rig 14 test ed E0 after E85 and before E20. Examination of these tests on E0 allows dete rmination of whether there was any change in rig performance over the course of the testing. These E0 results are shown graphically in Figure 31. The multiple initial E0 tests on Rigs 12 and 14 are the result of repeat diurnal tests and were thus very close together in time. The multiple final E0 results for Ri g 14 are due to the testing of E0 before and after E20 and are thus further apart in time, but not as far apart as they are from the initial E0 tests.

a. Diurnal

0 50 100 150 200 250 300 350 400 450 500

1 2 11 12 14 Overall RigDiurnal Measurement

Initial Test 1
Initial Test 2
Final Test 1
Final Test 243 b. Steady State

0 5 10 15 20 25 30 35 40 45

1 2 11 12 14 Overall RigSteady State Measurement

Initial Test 1
Initial Test 2
Final Test 1
Final Test 2

c. Specific Reactivity

0 1 2 3 4 5 6

1 2 11 12 14 Overall RigSpecific Reactivity

Initial Test 1
Initial Test 2
Final Test 1
Final Test 2

Figure 31

An ANOVA that treated the i ndividual fuels without regard to fuel characteristics was run for each of the dependent variables. The model incl uded fixed effects for fuel, rig and fu el by rig interaction. Within the44 ANOVA, a contrast was set up to test the hypothesis that there were no signi ficant differences between the E0 results at the beginning of the testing and the E0 results at the end of the testing (the extra E0 test on Rig 14 was treated as if it were made at the end of the test). No si gnificant effect of test timing was observed for any of the thre e dependent variables (p ≥ 0.32). Given that no significant effect was observed, all E0 measurements were treated the sa me, regardless of when they were obtained, in subsequent analyses.

Aromatics

Fuels E6 and E6Hi differed from one another primarily in their aromatics level. Comparison of these two fuels can thus determine the significance of any eff ect of aromatics content that was observed. These results are shown gra phically in Figure 32.

a. Diurnal

0 200 400 600 800 1000 1200 1400 1600

1 2 11 12 Overall RigDiurnal Measurement

E6 Test 1
E6 Test 2
E6Hi Test 1
E6Hi Test 245 b. Steady State

0 20 40 60 80 100 120

1 2 11 12 Overall RigSteady State Measurement

E6 Test 1
E6 Test 2
E6Hi Test 1
E6Hi Test 2

c. Specific Reactivity

0 0.5

1 1.5

2 2.5

3 3.5

4

1 2 11 12 Overall RigSpecific Reactivity

E6 Test 1
E6 Test 2
E6Hi Test 1
E6Hi Test 2

Figure 32

An ANOVA that treated the i ndividual fuels without regard to fuel characteristics was run for each of the dependent variables. The model incl uded fixed effects for fuel, rig and fu el by rig interaction. Within the46 ANOVA, a contrast was set up to test the hypothesis that there were no signi ficant differences between the E6 results and the E6Hi results. No significant e ffect of aromatics level was observed for any of the three dependent variables (p ≥ 0.11). Given that no significant effect was obs erved, aromatics level was not considered in subsequent analyses.

Ethanol Content

In contrast to the other evaluations, the design of this experiment allows the evaluation of ethanol content as a continuous variable. Figure 33 shows the results for the three depe ndent variables vs. ethanol content for each rig.

a. Diurnal Emissions vs. Ethanol Content

0 200 400 600 800 1000 1200 1400 1600 1800 2000

0 5 10 15 20 25 Ethanol Content, vol%Diurnal Emissions - mg/day

Rig 1 Rig 2 Rig 11 Rig 12 Rig 1447 b. Steady-State Emissions vs. Ethanol Content

0 20 40 60 80 100 120 140 160

0 5 10 15 20 25 Ethanol Content, vol%Steady-State Emissions - mg/hr

Rig 1 Rig 2 Rig 11 Rig 12 Rig 14

c. Specific Reactivity vs. Ethanol Content

0 1 2 3 4 5 6

0 5 10 15 20 25 Ethanol Content, vol%Specific Reactivity - g Ozone/g VOC

Rig 1 Rig 2 Rig 11 Rig 12 Rig 14

Figure 3348 The plots indicate a general nonlinear relationship between the dependent variables and ethanol content. Closer inspection of the data reveals that, while the overall rela tionship is nonlinear, the data at nonzero ethanol contents is actually fairly linear: the nonlineari ty exists between the E0 and ethanol-containing fuels. An example of this is shown in Figure 34 for Rig 1 diurnal emission results.

Diurnal Emissions vs. Ethanol Content

0 100 200 300 400 500 600

0 5 10 15 20 25 Ethanol Content, vol%Diurnal Emissions - g/hr

Figure 34

The dashed line is a linear fit vs. et hanol content for the five observati ons at nonzero ethanol contents. The reasonably good fit for these points contra sts with the E0 data. As a result of patterns lik e this in the data, a model was fit to the data that provides for a discontinuous function that includes a si ngle point (intercept) based on the E0 data and a linear fit based on the fuels with nonzero ethanol conten t. This allows two tests to be performed to determine the effect of ethanol: one test that evaluates the e ffect of the presence or absence of ethanol, and another that evaluates the effect of changes in ethanol content for ethanol-containing fuels.

The regression model is thus:

ε + + + + + = Ethanol Rig esent Rig Ethanol c esent b Rig a y * Pr * * Pr * *

Where: Rig = Test rig identifier Present = Presence or absence of ethanol Ethanol = Ethanol content, vol%

ε

= Error term

The presence or absence of ethanol was statistically significant (p ≤ 0.05) for all three independent variables. Both ln(diurnal) and steady-state emissions increased when ethanol was present, while Specific Reactivity decreased. Varying the ethanol cont ent was significant for the steady-state data (emissions increased as ethanol content increased), but was not significant (p ≥ 0.44) for the ln(diurnal) and reactivity data.49 D. The CRC E-65-3 Steering Committee Members

Richard Baker........................ Ford Motor Company Brent Bailey .......................... Coordinating Research Council Loren Beard........................... DaimlerChrysler Jane Beck .............................. Coordinating Research Council Norm Brinkman .................... General Motors Corporation Steve Cadle ........................... General Motors Corporation Dominic DiCicco .................. Ford Motor Company King Eng ............................... Shell Global Solutions (US), Inc. Frank Gerry ........................... BP Albie Hochhauser.................. Exxon Mobil Corporation Mike Ingham (Co-Chair) ...... Chevron Products Company Jeff Jetter ............................... Honda R&D Americas, Inc. Stuart Johnson ....................... Volkswagen of America, Inc. David Lax.............................. API Mani Natarajan...................... Marathon Petroleum Company LLC Robert Reynolds.................... Downstream Alternatives, Inc. (Representing the Renewable Fuels Association) Chris Tennant........................ Coordinating Research Council Jim Uihlein............................ BP Marie Valentine (Co-Chair) .. Toyota Technical Center Cynthia Williams .................. Ford Motor Company Ken Wright............................ ConocoPhillips

The authors want to thank the members of the CRC Staff and the Emissions Committee who sponsored and guided this project. In particul ar, we want to thank Jim Uihlein of BP for performing the statistical analyses of the project data. We also want to th ank Chevron for providing the test fuels used throughout the E-65 permeation studies and GM for donating the FFV us ed in this study. Spec ial thanks go also to Stuart Seale, the data and quality manager at ATL, and Melanie Swords, staff member at HH&A, for their contributions to the project and the report.50 E. Appendix

The Ethanol Hang-up

During our initial stabilization with the E0 fuel, Ri gs 1 and 2 unexpectedly exhi bited ethanol content in the permeate, which created considerable concern and discussion. It was surprising when Rigs 1 and 2 indicated an ethanol component in the permeate l ong after the use of any etha nol-containing fuel. This led to the hypothesis that ethanol can lie dormant in the vehicle’s fuel system, or be stored and reappear at a much later time.

Table 16 - 2001 Toyota Tacoma Stabilization – Fuel E0

Rig Fuel Week Date Test# NonEtOH mg/hour EtOH mg/hour NonEtOH + EtOH mg/hour Running Average mg/hour 01 E0 01/11/05 Drain and 100% fill Fuel E0

0 01/12/05 6286 12.3 BDL 12.3 1 01/19/05 6293 13.8 BDL 13.8 2 01/26/05 6301 14.0 BDL 14.0 3 02/02/05 6306 11.5 4.8 16.3 14.1 4 02/09/05 6313 12.3 2.3 14.6 14.7 5 02/16/05 6324 10.8 4.8 15.6 15.1 02/18/05 Drain and 100% fill Fuel E0 NonEtOH Running Ethanol Impact - Stabilized Permeation Rig 1 - E0 Fuel

0 2 4 6 8 10 12 14 16 18Permeation - mg/hr Total
Non-Ethanol HC
Ethanol

The first three tests on Rig 1 detected no ethanol in the permeate, but the fourth test on 2-02-05, resulted in an ethanol rate estimate of 4.8 mg/hour. Rig 2 had a similar result during the same time period, as indicated later. The tests after 3-9-05 did not indicate ethanol in the p ermeate sam p le.

Figure 3551 Rig Fuel Week Date Test# NonEtOH mg/hour EtOH Mg/hour + EtOH mg/hour Average mg/hour 6 02/23/05 6331 10.4 1.4 11.7 14.6 7 03/02/05 6341 9.9 1.2 11.0 13.2 8 03/09/05 6352 8.2 BDL 8.2 11.6 9 03/16/05 6364 6.8 BDL 6.8 9.4 10 03/23/05 6373 7.1 BDL 7.1 8.3 11 03/29/05 6381 6.1 BDL 6.1 7.0
The stabilization data for Rig 1 on fuel E0 are listed in Table 15 and shown in Figure 35, and a similar presentation for Rig 2 follows in Table 16 and Figure 36. These rigs had been tested in the previous program with an E6 fuel (Fuel B), but had finish ed the program on the non-ethanol “Fuel C”, and were stored for the down time (roughly six months) with the non-ethanol fuel in their ta nks. Rigs 11, 12 and 14 did not show any ethanol in their measurements during the same time pe riod. The measured levels were low, 5 mg/hour or less, but the sour ce of the ethanol was not identified.

Ethanol Impact - Stabilized Permeation Rig 2 - E0 Fuel

0 10 20 30 40 50 60Permeation - mg/hr

Total
Non-Ethanol HC
Ethanol Rig 2, like Rig 1, also had a sudden appearance of ethanol in the results in the time period of 2-4-05 to 3-16-05.

Figure 3652 Table 17 - 2000 Honda Odysse y Stabilization – Fuel E0

Rig Fuel Week Date Test# NonEtOH EtOH NonEtOH + EtOH Running Average 2 E0 01/11/05 Drain and 100% fill Fuel E0 0 01/12/05 6284 29.6 BDL 29.6 1 01/19/05 6294 47.6 BDL 47.6 1 01/20/05 6296 50.6 BDL 50.6 3 02/04/05 6309 39.8 8.8 48.6 44.1 4 02/09/05 6314 47.7 7.7 55.5 45.3 5 02/16/05 6326 47.8 7.9 55.7 51.9 02/18/05 Drain and 100% fill Fuel E0 6 02/22/05 6330 46.9 5.5 52.4 53.1 7 03/02/05 6343 37.6 1.5 39.1 50.7 8 03/09/05 6354 41.7 0.7 42.4 47.4 9 03/16/05 6365 44.2 1.0 45.2 44.8 10 03/24/05 6375 43.4 BDL 43.4 42.5 11 03/30/05 6385 38.9 BDL 38.9 42.5

That Rigs 1 and 2 had ethanol in their measured results at the same time, that later disappeared, can not be explained at this time.

Ethanol can persist as an element of the permeation emissions of a fuel system long after use of the ethanol fuel has been discontinued. The results fr om the previous E-65 test program indicated the presence of ethanol in the permeate at a measurable leve l for a period of up to 7 weeks after the fuel had been changed to the non-ethanol fuel (Fuel C). It is thought that this “hang-up” is due to the time it takes for the permeation components to make their way thr ough the various elastomers in the vehicle’s fuel system. Figure 37, representing the 10 rigs tested in the E-65 test program, is used to illustrate this effect. There appears to be a lingering presence of ethanol at levels of up to 5 mg/hour for a considerable period of time.53 The data used for this plot came from the original E-65 permeation test progr am, and represents the ethanol permeation measured after the switch from the 5.7% ethanol fu el evaluation (Fuel B) to the nonethanol fuel (Fuel C). The ten syst ems included in this analysis came from vehicle systems ranging from model year 1978 to 2001. A ll of the rigs exhibited “hang-up”, or carry-over of the ethanol component from the previous fuel, during the new stab ilization period with the non-ethanol fuel. Ethanol Decay Fuel "C"

0 10 20 30 40 50

0 10 20 30 40 50 Test Time From Original Fill - daysEthanol - mg

Figure 37