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The Effects of E20 on Elastomers Used in 

Automotive Fuel System Components 

 Bruce Jones, Gary Mead, Paul Steevens and Chris Connors 

 Minnesota Center for Automotive Research 

at Minnesota State University, Mankato

ABSTRACT 

The focus of this study was to compare the effects of 

E20 versus E10 and gasoline on elastomers found in 

automotive, marine, and small engine fuel system 

components and fuel dispensing equipment. The 

elastomer samples were prepared using SAE and ASTM 

standards and exposed to blends of Fuel C; Fuel C and 

10% aggressive ethanol; and Fuel C with 20% 

aggressive ethanol at an elevated temperature of 55 °C 

for 500 hours. Changes in the following properties were 

investigated before immersion, after immersion, and 

after dry-out: appearance, volume, weight, tensile 

strength, elongation, and hardness. 

INTRODUCTION 

Minnesota Governor Tim Pawlenty signed a bill on May 

10, 2005 that requires by volume 20% of the fuel sold in 

Minnesota to be ethanol. Currently, gasoline sold in 

Minnesota contains 10% ethanol (E10) by volume. 

Ethanol, C2H5OH, is an alcohol that can be derived from 

starches such as corn or materials containing sugars 

such as sugar cane. Ethanol can also be made from 

cellulosic materials such as grasses by converting them 

into sugars. However, this process is much more cost 

intensive and has not yet reached commercial 

production levels. Ethanol is considered a renewable 

fuel and is also classified as an alternative fuel since it 

can be used as a substitute for gasoline. 

The passage of the law is only the first step. The fuel 

may not be used on public roadways until a federal 

section 211f waiver is obtained from the United States 

Environmental Protection Agency (EPA). Extensive 

testing in five areas: vehicle driveability, vehicle 

emission control system effectiveness and durability, 

vehicle tailpipe and evaporative emissions, fuel system 

material compatibility, and public health must be 

conducted in order to obtain the waiver (C. Jewitt, 

personal communication, July 6, 2005). This will be a 

costly and timely process requiring many different 

studies. 

This paper represents one in a series of four papers that 

focus on the effects of 20% ethanol-blended fuel (E20) 

on fuel system components. This paper provides some 

of the background information on E20 and the various 

laws that affect its use as an on-road fuel. Next, it 

contains a brief review of literature on E20 with a 

particular focus on material compatibility issues. Finally, 

it investigates the issues of designing the material 

compatibility study in terms of standards, procedures, 

and equipment needed to carry out the testing. 

MINNESOTA ETHANOL LEGISLATION 

On May 10, 2005, Minnesota Governor Tim Pawlenty 

signed into law a bill requiring ethanol to constitute 20% 

of the gasoline sold in the State of Minnesota. The bill 

allows for two methods of achieving this. First, if by 

December 31, 2010 the volume of ethanol sold in the 

State through the combination of E10 and E85 reaches 

20% of the total gasoline sold in the State, then the goal 

will be met and there will not be any changes in the fuel 

sold. If the combination of the two fuels’ ethanol content 

does not reach at least 20% of the total fuel sold, then 

by August 30, 2013 the ethanol content of gasoline will 

be increased from 10% to 20% by volume (Eisenthal, 

2005). 

The second method, 20% ethanol in all gasoline, 

requires the EPA to approve a waiver for the use of E20. 

EPA waivers may be granted one of two ways. The EPA 

can review the application and supporting data and grant 

the waiver. Or, if the EPA fails to provide a decision on 

the waiver within 180 days, the waiver is automatically 

granted. This clause is of particular concern because 

the original fuel waiver for E10 was granted because the 

EPA failed to make a decision in 180 days. The 

Minnesota law explicitly states that the failure of the EPA 

to act shall not be deemed an approval. 

LITERATURE REVIEW 

The passage of the Minnesota E20 legislation raised 

many questions about the effects of E20 on non-flex fuel 

vehicles. All vehicles sold in the United States from the 

early 1980s to current are compatible with E10, but 

whether or not they are compatible with E20 is not 

known. Before E20 can be sold in Minnesota, a section 

211f waiver needs to be obtained from the United States 

Environmental Protection Agency (EPA). In order to 

obtain a waiver, extensive research and testing will need 

to be conducted in five areas: driveability, fuel system 

material compatibility, tailpipe and evaporative 

emissions, emission control system effectiveness and 

durability, and health effects. This research and testing 

will be conducted to ensure that the fuel does not cause 

any more problems than gasoline in the five categories. 
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The fuel systems on vehicles produced today are seeing 

an ever-increasing amount of ethanol-blended fuels and 

are expected to have a usable lifespan of 15 to 20 years. 

Currently, all fuel systems are compatible with E10, but 

as increased ethanol blends become more prevalent, 

the need to quantify the effects of higher blends on 

materials is necessary. Unfortunately, there is little 

information on the non-linear effects of increased 

ethanol blends on fuel system materials. This means 

that as the concentration of ethanol increases from 0 to 

100% there is no model that accurately predicts the 

effects on materials. In fact, neat ethanol and neat 

gasoline often have a smaller negative impact on 

materials than gasoline-ethanol blends. To compound 

this problem, mid-range blends of 15 to 50%, often have 

the largest negative impact on materials. 

The MSU material compatibility study started out like 

most research with a comprehensive review of the 

literature. To guide this review, a few questions were 

asked: (a) What literature exists on E20 and materials? 

(b) What materials are in a fuel system? (c) What 

standard test procedures are used to validate a material 

for compatibility with a fuel? (d) By what criteria is a 

material deemed compatible or incompatible with a fuel? 

With these questions in mind, a thorough review of the 

Society of Automotive Engineers’ (SAE) technical paper 

library was conducted along with an extensive internet 

search. Also, Original Equipment Manufacturers 

(OEMs), Tier I and II suppliers (supply parts to the 

OEMs), and material testing laboratories were contacted 

for information. 

During the search for information on E20, it became 

apparent that there was very little information publicly 

available. Most OEMs have tested with a fuel close to 

E20, such as E25 because of its extensive use in Brazil, 

but retain this information as proprietary. Several small 

material studies mentioned E20 or tested a blend close 

to E20 such as E25, but these studies offered only a 

small portion of the information that would be necessary 

for a waiver. In fact, only one major study on E20 was 

found, the Orbital Engine Company’s study for the 

Commonwealth Government of Australia conducted 

from October 2002 through March 2003 (Orbital, March 

2003, May 2003). 

The Orbital study was extremely comprehensive, 

covering both automobiles and small engines in areas of 

emissions, driveability, material compatibility, durability, 

and a well-to-wheel study. With regards to material 

compatibility, the Orbital study tested actual components 

from vehicles. The study found that E20 caused 

significant problems with many metal, plastic, and rubber 

components that gasoline did not. The Orbital study was 

carefully reviewed at MSU. The study identified 

significantly higher levels of discoloration and tarnishing 

on components exposed to the E20 than the gasoline 

reference fuels in the study. However, it should be 

noted that E10 was not included in this study and other 

research studies have noted similar discoloration and 

tarnishing associated with the use of E10. Also, it is 

believed that corrosive water was added to the E20 

blends at levels high enough to cause phase separation 

but was not added to the gasoline reference fuels. 

According to SAE recommended practice J1681 

Gasoline, alcohol and diesel fuel surrogates for 

materials testing, corrosive water is only added to 

gasoline or ASTM Fuel C, not ethanol (SAE, 2000). This 

test method could be a reason for the extreme negative 

results that the Orbital study reported. 

FORMULATING THE EXPERIMENTS 

With a lack of available literature on ethanol 

compatibility, it became apparent that actual material 

compatibility experiments would be necessary to answer 

some of the questions about the effects of E20. It was 

also determined that E10 should be included in any 

material compatibility tests as a reference to the 

changes caused by ethanol. Ethanol does cause 

different changes to materials than gasoline. But, if E20 

did not cause a larger negative impact on materials than 

E10, an accepted motor fuel, then E20 would be 

acceptable. The inclusion of E10 in the testing for the 

purpose of differentiating acceptable changes caused by 

ethanol is a significant component of the MSU material 

studies. 

PROCESS OVERVIEW 

Six standard practices from Society of Automotive 

Engineers (SAE) and the American Society for Testing 

and Materials (ASTM) were used to develop the specific 

testing procedures. The procedures developed were a 

combination of SAE J1748 Methods for determining 

physical properties of polymeric materials exposed to 

gasoline/oxygenate fuel mixtures, ASTM D471-06 

Standard test method for rubber property – effect of 

liquids, ASTM D412-06a Standard test methods for 

vulcanized rubber and thermoplastic elastomers – 

tension, ASTM D3183-02 Standard practice for rubber – 

preparation of pieces for test purposes from products, 

and ASTM D2240-04 Standard test method for rubber 

property - durometer hardness (SAE, 1998; ASTM, 

2006, 2006, 2002, 2004). The test fuels were blended 

as per SAE J1681, Gasoline alcohol and diesel fuel 

surrogates for materials testing (SAE, 2000). SAE 

J1748 modifies ASTM D471 to make it fuel-testing 

specific. After formulating the test procedures to reflect 

specific equipment and resources, they were forwarded 

for peer review and altered according to suggestions 

from several OEM fuel system engineers and Tier I and 

II suppliers. As per SAE J1748 and ASTM D471, 

specimens were completely immersed for 500 hours at 

55 ± 2 °C before testing. The following properties were 
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measured before immersion, after immersion, and after 

dry-out: volume, weight, appearance, tensile strength, 

ultimate elongation, and hardness (durometer M). 

The elastomers testing required two different shaped 

test specimens. The first was a 1 x 2 in. rectangle that 

was 0.080 in. thick. This specimen shape was used for 

the volume, weight, and appearance change testing. It 

will be referred to as the appearance specimen (see 

Figure 1). Five appearance specimens per fuel, per 

elastomer were used. The next specimen shape used 

was a Type C tensile dumbbell as specified by ASTM 

D412 (2006). These were used for tensile strength, 

ultimate elongation, and hardness testing. These 

specimens will be referred to as the tensile specimens. 

Ten tensile specimens per fuel, per elastomer were 

immersed. Five were used for wet testing and the other 

five were used for dry-out testing. Also, five specimens 

per elastomer that were not immersed were used as a 

reference. 

Figure 1. Appearance specimens with ID tags ready for 

immersion 

All testing and data collection took place in a room 

equipped with a ventilation system designed to handle 

hazardous fumes. The specimens were cut from 

molded test plaques in accordance with ASTM D3183 

(2002). The volume of each appearance specimen was 

measured using the fluid displacement method in 

accordance with ASTM D471 (2006). The weight of each 

was measured with an analytical balance to ± 0.0001 g. 

They were also photographed to show pre-immersion 

color and surface texture. The tensile specimens’ 

thickness and width were measured with a micrometer 

to ± 0.001 in. Hardness, durometer type M, was also 

measured on the clamping ends of the tensile 

specimens in accordance with ASTM D2240 (2004). 

After the initial measurements were made, the 

specimens were suspended via stainless steel wire and 

completely immersed in a glass container with one of the 

appropriate test fluids: C, C(E10)A, and C(E20)A. The 

containers were sealed and placed in an oven at 55 ± 

2 °C for 500 hours. The test fluid was replaced daily for 

the first three days and then weekly thereafter. Any 

changes in the test fluid color or loose materials in the 

bottom of the containers were noted. 

After 500 hours, the containers were removed from the 

oven and the specimens were placed in cool, clean fluid 

for 60 minutes to cool. The volume and weight of the 

appearance samples were measured in the same 

manner as the pre-immersion measurements. They 

were also photographed at this time to show the 

appearance changes due to immersion. The hardness 

was measured on the clamping end of the tensile 

specimens before they were pulled. One set of five 

immersion specimens per elastomer, per fuel was pulled 

to measure tensile strength and ultimate elongation. 

Also, one set of five specimens that had not been 

immersed was pulled as a reference. The pulls were 

made in accordance to ASTM D412 at a speed of 500 ± 

50 mm/min (2006). All measurements were made 

immediately after the samples were removed from the 

fuel to minimize fuel dry-out. 

The appearance specimens and remaining untested 

tensile specimens were placed in the oven to dry at 55 ± 

2 °C for 40 hours. After the 40-hour period, they were 

removed and measured again to obtain dry-out data. 

The specimens were measured in the same manner as 

the post-immersion measurements were taken. Refer to 

Appendix A for a detailed step-by-step procedure. 

MATERIALS 

Based on the review of numerous other material 

compatibility studies, only the raw materials that are 

used in the construction of fuel system components 

were tested, rather than actual components. Testing raw 

materials allows for much broader coverage than testing 

components. For instance, the results from a test on a 

particular elastomer could cover hoses, seals, and 

diaphragms of any manufacturer using that material. 

This was determined to be more practical than testing 

each of the components individually. Also, many 

industry-accepted standard tests require specimens of 

specific dimensions that would be difficult to obtain from 

actual components. 

The list of materials used in the fuel systems of 

automobiles from the 1970’s forward, marine engines, 

non-road engines, and fuel dispensing equipment is 

immense. It would be virtually impossible for one study 

to test every material and combination of materials used. 

The materials list for this study was created from various 

sources such as literature reviews, manuals, and 

recommendations from fuel system and engine 

manufacturers. After the list of elastomers was 

assembled, it was forwarded to a group of fuel system 

engineers from several OEMs and Tier I and II suppliers 

for peer review. The eight elastomers tested in this study 

are listed below. 
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• acrylic rubber (ACM) [Hytemp®] 

• epichlorohydrin homopolymer (CO) 

• epichlorohydnin ethylene oxide copolymer 

(ECO) 

• polychloroprene (CR) [Neoprene®] 

• nitrile rubber (NBR) [Buna N] with medium ACN 

content 

• nitrile rubber (NBR) [Buna N] with high ACN 

content 

• nitrile/PVC blend (OZO) [Paracril®] 

• fluoroelastomer (FKM) with dipolymers of 

VF2/HFP and 65% fluorine [Viton® A] 

These eight elastomers will be referred to by their two or 

three letter abbreviations for the remainder of this paper. 

Finally, several elastomers such as acrylic ethylene 

(AEM) [Vamac®], chlorinated polyethylene (CPE), 

chlorosulfonated polyethylene (CSM) [Hypalon®], 

hydrogenated nitrile rubber (HNBR), fluoroelastomer 

(FKM) with terpolymers of VF2/HFP/TFE and 68% 

fluorine [Viton® B], fluoroelastomer (FKM) with 

terpolymers of VF2/HFP/TFE and 70% fluorine [Viton® 

GFLT], and Santoprene® (PVDT) were not tested 

because they are commonly used in the fuel systems of 

flex-fuel vehicles and therefore have already been 

qualified for ethanol use. 

TEST FUEL 

The test fuel selection for this research was a major 

focus in the test plan development. In the review of the 

literature, several studies were identified in which it was 

difficult to determine the specific composition of the base 

gasoline or ethanol components. The test fuels used in 

this study were based on the test-fuel standard specified 

in SAE J1681, Gasoline alcohol and diesel fuel 

surrogates for materials testing. This paper was the 

result of a task force formed in the early 1990’s for 

testing materials with methanol. Since then, the 

standard has been altered to include many fuels. The 

task force adopted ASTM Fuel C to use as a reference 

for gasoline in material compatibility testing. ASTM Fuel 

C represents a worst-case-scenario gasoline due to its 

composition of 50% iso-octane and 50% toluene. The 

iso-octane represents the alkane group that makes up 

40 to 70% of gasoline (Harrigan, Banda, Bonazza, 

Graham, Slimp, 2000, p. 2). It is important that the 

alkane group is represented for two reasons. First, they 

make up a large percentage of gasoline and second, 

they can cause swelling in polymers (plastics and 

elastomers). The toluene represents the aromatic group 

that makes up 20 to 50% of gasoline (p. 2). Aromatics 

can cause swelling in polymers, but they also help 

suspend alcohols within the fuel mixture. 

Synthetic ethanol, not fuel-grade ethanol, should be 

used for materials testing because its known 

composition “will help to minimize some of the variables 

in the use of ethanol as a fuel test component” (Harrigan 

et al., p. 5). Many impurities can be found in fuel-grade 

ethanol including sulfuric acid, acetic acid, water, and 

sodium chloride. “The acid is formed either in the 

alcohol production process or due to oxidation of the 

alcohol during handling, transfer or storage” (p. 3). 

Water also is a by-product of production and can cause 

metal corrosion, especially when combined with sodium 

chloride. It is important that these are represented in the 

test fuel because they can cause material compatibility 

issues. As per SAE J1681, these impurities were added 

to the synthetic ethanol to form aggressive ethanol. 

Aggressive ethanol is a worst-case-scenario fuel that 

would still be acceptable under ASTM D4806, Standard 

specification for denatured fuel ethanol for blending with 

gasoline for use as automotive spark-ignition engine fuel

(ASTM, 2006). 

All fuels used in this study met SAE Standard J1681’s 

criteria. The three test fuels used included 

Surrogate gasoline [C] - ASTM Fuel C, 50/50 

toluene iso-octane mixture (500 ml toluene and 

500 ml iso-octane) 

E10 fuel [C(E10)A] - 90% Fuel C + 10% 

aggressive ethanol (450 ml toluene, 450 ml isooctane, 100 ml aggressive ethanol) 

E20 fuel [C(E20)A] - 80% Fuel C + 20% 

aggressive ethanol (400 ml toluene, 400 ml isooctane, 200 ml aggressive ethanol) 

Aggressive ethanol consists of synthetic ethanol 816.00 

g, de-ionized water 8.103 g, sodium chloride 0.004 g, 

sulfuric acid 0.021 g, and glacial acetic acid 0.061 g 

(SAE J1681 Appendix E.1.2). 

APPARATUS 

The specimens were placed in 16-oz glass jars with 

Teflon® lined lids. Two jars per elastomer, per fuel were 

used for a total of 48 jars. Stainless safety wire was 

used to suspend the specimens, via 1/8 in. hole in the 

end of each one, so that they were completely immersed 

but did not rest on the bottom of the jar (see Figure 2). 

An explosion-proof friction air oven was used to maintain 

the samples at 55 ± 2 °C. It uses the heat generated by 

circulating air to maintain the temperature instead of an 

element or a flame. This is very important when heating 

combustible liquids in the presence of oxygen due to the 

potential for an explosion if the vapors were to come into 

contact with an ignition source. 
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Figure 2. Specimens suspended from lid and glass jar 

DATA COLLECTION 

The weight, volume, and hardness of each specimen 

was recorded before being exposed to the test fluids, 

after exposure, and after dry-out. The tensile strength 

and elongation of the specimens was measured after the 

immersion period on non-immersed, immersed, and dryout specimens. The specimens were also photographed 

to show pre-immersion, post-immersion, and dry-out 

color and surface texture changes. The test fuel was 

also checked for color change and loose by-products. 

The volume of each appearance specimen was 

measured using the fluid displacement method in 

accordance with ASTM D471 (2006). To measure the 

volume, a quad beam balance was used with a 

resolution of 0.01 g (see Figure 3). The specimens were 

first weighed in air and then weighed in their appropriate 

test fuels. Next, the specific gravity of each test fuel was 

measured using a hydrometer with a resolution of 0.001. 

Then, using the formula below with the weights and the 

density, the volume of each specimen was calculated. 

V = (MA – MF) / d 

V = volume (cc) 

MA = mass in air (g) 

MF = mass in fuel (g) 

d = density (g/cc) 

Figure 3. Quad beam balance used for volume 

measurements 

For weight change, a Radwag WAX 220 analytical 

balance was used to measure the mass of the test 

samples. The balance has a linearity of ∀ 0.0002 g and 

a repeatability of 0.00015 g as outlined in the user’s 

manual. Based on the resolution and linearity of the 

scale, a weight change in a specimen that is under 

0.0008 g could be due to scale error and should not be 

considered a measurable change. The specimens were 

measured before being immersed. Next, they were 

weighed immediately after the immersion by blotting 

them dry with a lint-free cloth and placing them in a 

sealed weighing bottle. Finally, they were weight after 

the dry-out. 

A type M durometer was used to measure the hardness 

of the specimens for this study because it can be 

accurately used on thin specimens and its readings 

correlate to a type A durometer (see Figure 4). The 

durometer has a resolution of 1 hit point, and an 

accuracy of ± 4 hit points. The measurements were 

taken on the clamping ends of the tensile specimens 

before they were pulled. Six hits were made on each 

specimen in accordance with ASTM D2240 (2004). 

Measurements were taken on non-immersed, immersed, 

and dry-out samples. 
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Figure 4. Durometer 

The tensile specimens’ thicknesses and widths were 

measured with a micrometer to ± 0.001 in. Three 

measurements were made for thickness and width, one 

at the center and one at each end of the reduced 

section. The medians of the three thickness and width 

measurements were used to calculate the cross 

sectional area of the specimen (ASTM D412). Next, 

tensile and elongation measurements were made with 

an Instron Model 3369 tensile machine with an 11,250 

lbf load cell (see Figure 5). The specimens were pulled 

at a uniform rate of 500 ± 50 mm/min until they broke. 

Measurements were made on non-immersed, immersed, 

and dry-out specimens. All calculations on immersed 

and dry-out specimens, as per SAE J1748, were made 

using the original cross-sectional area measurements 

taken before immersion. 

Figure 5. Tensile and Elongation measurement 

equipment 

DATA ANALYSIS 

Six properties were used in this study to investigate the 

effects of E20 as compared to E10 and gasoline. The 

six properties include visual appearance, volume, 

weight, tensile strength, elongation, and hardness. The 

data from the E20 specimens were compared to that of 

the E10 and Fuel C specimens because the latter two 

represent approved fuels. With the variety of 

applications that the elastomers used in this study 

represent, it was very difficult to distinguish at what point 

a change would represent a potential problem. For that 

reason, much of the data analysis was of a comparative 

nature between the results of E20 and the results of E10 

and Fuel C. If E20 did not cause any more significant 

changes than E10 or Fuel C, then a material was 

deemed compatible. 

VISUAL EXAMINATION 

The first method of determining the effects of the 

different fuel blends was through a visual examination of 

each specimen. Pictures of the specimens were taken 

before immersion, after immersion, and after dry-out. 

The pictures were compared to note any changes in 

color, surface texture, glossiness, clouding, bubbling, 

tackiness, and cracking. Minor color and glossiness 

changes along with clouding were deemed acceptable. 

Changes in surface texture, cracking, bubbling, and 

tackiness were considered unacceptable because these 

could potentially lead to component failure. The test fuel 

was also checked after immersion for color change and 

loose by-products that could have been leached out of 

the specimens. Minor color changes in the test fluid 

were considered acceptable. It should be noted that 
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material leached out of elastomers can potentially cause 

problems in the fuel system and engine, but due to the 

budget of this study, the spent test fuel was not analyzed 

past color change for the presence of these. Loose byproducts were considered unacceptable because they 

represent a rapid degradation of the material along with 

the fact that they could potentially clog up other 

components. 

VOLUME CHANGE 

The volumes of the specimens were measured before 

immersion, after immersion, and after dry-out. The 

percent change in volume was calculated between preimmersion and post-immersion and between preimmersion and dry-out. The percent change in volume 

was used to determine if E20 caused a material to swell 

significantly differently than Fuel C or E10. Excessive 

swelling of a material can cause potential problems such 

as extruding, accelerated wear, and binding. Excessive 

shrinkage can also represent potential problems. Both 

excessive swelling and shrinking were considered 

unacceptable. 

WEIGHT CHANGE 

The weights of the specimens were measured before 

immersion, after immersion, and after dry-out. The preimmersion weight was compared to the post-immersion 

weight and the dry-out weight. From this data, the 

percent change in weight was calculated. The change in 

weight can indicate how much fuel was absorbed into 

the material for the pre-immersion and post-immersion 

comparison. While the change in weight when 

comparing pre-immersion to dry-out can indicate how 

much material was leached out of the specimens. The 

percent change in both states for E20, wet and dry, was 

compared to the percent change in both states for E10 

and Fuel C while looking for significantly different 

changes that would be unacceptable. 

HARDNESS CHANGE 

The hardness of each specimen was measured before 

immersion, after immersion, and after dry-out. Using 

these measurements, the percent change in hardness 

was calculated by comparing pre-immersion 

measurements to the post-immersion measurements 

and pre-immersion measurements to dry-out 

measurements. The percent change in hardness of the 

E20 specimens was compared to that of the E10 and 

Fuel C specimens to see if any significant differences 

existed. Excessive hardening or softening of an 

elastomer can lead to potential problems and is not 

acceptable. If an elastomer becomes too hard it might 

lose flexibility or crack. On the other hand, if an 

elastomer becomes too soft it might collapse under load. 

TENSILE STRENGTH AND ELONGATION 

All of the tensile specimens were evaluated after the 

500-hour immersion period ended. Three sets of 

specimens per elastomer, per fuel were pulled: nonimmersed, immersed, and dry-out. As with the other 

properties, the analyses was comparative between the 

E20 specimens and the E10 and Fuel C specimens 

while looking for significant differences. If E20 increased 

or reduced the tensile strength or elongation significantly 

more than E10 or Fuel C, it was considered 

unacceptable. Excessive reductions in tensile strength 

can lead to a component failure because the material 

will not be able to handle the intended loads. Also, 

significant increases in tensile strength, which typically 

result in a loss of elongation, can cause potential 

problems, too. 

RESULTS 

Visual appearance, mass, volume, tensile, elongation, 

and hardness change data was used to verify if a 

material was compatible with the fuels. For an elastomer 

to be considered compatible in E20, it must not undergo 

significantly different changes than it would in gasoline 

or E10. The tensile strength, ultimate elongation, and 

hardness can not be reduced to the point that a 

component made of these would fail. Also, volume and 

weight changes could not be such that a component 

failure would be caused. Finally, discoloration was 

deemed acceptable as long as it did not affect the 

component’s function. 

VISUAL CHANGE 

All of the specimens were visually inspected throughout 

the course of the study. None of the specimens 

exhibited any changes in color, texture, or glossiness. 

Also, there were no sings of cracking, bubbling, or 

tackiness. The only visual change apparent in some of 

the specimens was a size change, which is discussed 

below in the volume change section. 

In examining the spent fuel after each fuel change, no 

loose by-products were noticed in any of the containers. 

After the first day of immersion, five elastomers: CO, 

ECO, CR, NBR-M, and OZO discolored the fuel slightly, 

while NBR-H discolored the fuel to a greater extent (see 

Figure 6). Also, NBR-H was the only elastomer that 

exhibited a greater degree of fuel discoloration with both 

ethanol fuels than in Fuel C (see Figure 7). This 

discoloration difference between Fuel C and both 

ethanol fuels was not noticeable by the end of week 1 

(see Figure 8). By the end of the first week of immersion, 

only three elastomers, CO, ECO, and NBR-H, discolored 

the fuel very slightly. One elastomer, ACM, caused test 

Fuel C to become cloudy for the first week (see Figure 

9). No other cloudiness was noticed in any other test 
 2-22-2008 

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fuel. Overall, none of the fuel discolorations were 

deemed significant enough to raise any concerns. 

 Figure 6. Discoloration comparison of the fuel after day 1 

(front row E20; middle row E10; back row Fuel C) 

Figure 7. Fluid discoloration from NBR-H after day 1 

(Fuel C, left; E10, middle; E20, right) 

Figure 8. Fluid discoloration from NBR-H after week 1 

(Fuel C, left; E10, middle; E20, right) 

Figure 9. Cloudiness caused by ACM in Fuel C 

VOLUME CHANGE 

All of the elastomers swelled to some extent after being 

immersed in each of the test fuels. Refer to Appendix B 

for a graph comparing the pre-immersion and postimmersion volumes and Appendix D for the data. 

Elastomer ACM swelled the most in all three fuels (see 

Figure 10 for a visual comparison). With the exception of 

CR, all of the other elastomers swelled to a greater 

extent in the ethanol fuels than Fuel C. Only CR swelled 

more in Fuel C than in the ethanol blends. Several of the 

elastomers swelled a slight bit more with E20 than E10, 

but the difference was not large enough to be a concern. 

Only ECO swelled a noticeable extent larger in E20 than 

E10 or Fuel C but not a significantly large enough 

amount to raise concerns. 

Seven of the eight elastomers shrank down below their 

pre-immersion size after the dry-out period. Only FKM 

remained larger than its original size in all three fuels, 

possibly due to an insufficient dry-out period as indicated 

by the weight change data. Refer to Appendix C for a 

graph comparing the pre-immersion and dry-out 

volumes and Appendix D for the data. No significant 

differences were found among any of the elastomers in 

any of the fuels after the dry-out period. 
 2-22-2008 

9

Figure 10. Visual volume change of ACM in E10 (top 

left specimen shows original size) 

WEIGHT CHANGE 

After the immersion period, the weights of all of the 

specimens in all three fuels increased. Refer to 

Appendix E for a graph comparing the pre-immersion 

and post-immersion weights and Appendix G for the 

data. Seven of the eight elastomers’ weight increased 

more in the ethanol blends than in Fuel C. Only CR’s 

weight increased more in Fuel C than in the ethanol 

blends. Only one elastomer, ACM, exhibited a 

noticeable difference in E20 than in E10, but it was not 

to a level that would warrant concern. 

After the dry-out period, all but one elastomer, FKM, 

exhibited a weight loss in comparison to the preimmersion weights. In all three fuels, FKM weighed 

more after dry-out than it did before immersion. This 

was believed to be caused by an insufficient dry-out time 

for this particular elastomer. Refer to Appendix F for a 

graph comparing the pre-immersion and dry-out weights 

and Appendix G for the data. Overall, no significant 

differences existed between E20 and E10 or Fuel C after 

the dry-out. 

HARDNESS CHANGE 

In terms of hardness, all of the elastomers in all three 

fuels became softer after being immersed. Refer to 

Appendix H for a graph comparing the pre-immersion 

and post-immersion hardness and Appendix J for the 

data. One elastomer, ACM, became softer in Fuel C 

than in either of the ethanol fuels. Six of the elastomers: 

CO, ECO, NBR-M, NBR-H, OZO, and FKM became 

softer in the ethanol fuels than in Fuel C. None of the 

elastomers exhibited a significantly different change in 

hardness when immersed in E20 when compared to 

either E10 or Fuel C. 

After the dry-out period, seven of the elastomers 

became harder than they were before immersion in all 

three fuels. Only FKM remained softer than its preimmersion state in all three fuels. As mentioned earlier, 

this was believed to be caused by an insufficient dry-out 

period for this elastomer. Refer to Appendix I for a graph 

comparing the pre-immersion and dry-out hardness and 

Appendix J for the data. The data was very similar for 

each type of elastomer and no significant differences 

were found between E20 and E10 or Fuel C. 

TENSILE STRENGTH CHANGE 

The tensile strength was reduced, when compared to 

non-immersed data, on all eight elastomers after being 

immersed in any of the three fuels. Refer to Appendix K 

for a graph comparing the non-immersion and postimmersion tensile strengths and Appendix M for the 

data. In seven of the elastomers, the ethanol blends 

reduced the tensile strength more than Fuel C did. Only 

CR was affected more by fuel C than the ethanol blends. 

None of the elastomers exhibited a significantly different 

change in tensile strength after being immersed in E20 

than they did in either E10 or Fuel C. 

The tensile strengths of all of the elastomers in all of the 

fuels increased after dry-out in comparison to the 

immersion tensile strengths. When the tensile strengths 

of the dry-out specimens were compared to the nonimmersed specimens, some were slightly higher and 

some were slightly lower in all three fuels with the 

exception of ACM soaked in E20. Refer to Appendix L 

for a graph comparing the non-immersion and dry-out 

tensile strengths and Appendix M for the data. The 

ACM specimens soaked in E20 after dry-out, exhibited 

an 18.5% loss in tensile strength while the specimens 

soaked in E10 and Fuel C exhibited an increase of 7.1% 

and 1.6%, respectively. Although a difference exists, it 

does not represent a concern because ACM lost 

approximately 80% of its tensile strength while 

immersed in any of the three fuels. If a component 

made of ACM was going to fail, it would likely happen 

while immersed, not after dry-out. Other than the 

difference noted with ACM in E20, none of the other 

elastomers exhibited a significant difference in E20 as 

compared to E10 or Fuel C after dry-out. 
 2-22-2008 

10

ELONGATION CHANGE 

When the data was compared between non-immersed 

and immersed elastomer elongation, all of the 

elastomers exhibited a reduction in elongation in all 

three fuels. Refer to Appendix N for a graph comparing 

the non-immersion and immersion elongations and 

Appendix P for the data. Seven of the elastomers, with 

the exception of CR, were affected slightly more by the 

ethanol blends than Fuel C. Only one elastomer, ECO, 

was affected more by E20 than E10 or Fuel C, although 

the difference was only 6.6%, which did not raise any 

concerns. Other than ECO, none of the other 

elastomers exhibited a significant difference in 

elongation after being immersed in E20 than they did in 

E10 or Fuel C. 

All of the dry-out specimens in all three fuels elongated 

more than the immersion specimens, but less than the 

non-immersion specimens, with the exception of ACM. 

Refer to Appendix O for a graph comparing the nonimmersion and dry-out elongations and Appendix P for 

the data. The ACM dry-out Fuel C specimens elongated 

slightly more than the non-immersed ACM Fuel C 

specimens. These were the only specimens that 

elongated more than the non-immersed specimens. The 

ACM dry-out E20 specimens exhibited a 31.4% 

reduction in elongation, while the E10 specimens 

exhibited a 4.8% reduction and the Fuel C specimens 

exhibited a 5.0% increase in elongation. Although a 

difference exists, it does not represent a concern 

because ACM’s elongation was reduced by over 70% 

while immersed in any of the three fuels. If a component 

made of ACM was going to fail, it would likely happen 

while immersed, not after dry-out. Other than the 

difference noted with ACM in E20, none of the other 

elastomers exhibited a significant difference in E20 as 

compared to E10 or Fuel C after dry-out. 

CONCLUSIONS 

This study tested and compared the effects of E20 to 

that of E10 and Fuel C on eight different elastomers 

used in automotive, marine, and small engine fuel 

systems and fuel dispensing equipment. The following 

properties were measured before immersion, after 

immersion, and after dry-out: volume, weight, 

appearance, tensile strength, ultimate elongation, and 

hardness (durometer M). On many of the elastomers, 

both ethanol blends caused slightly different changes 

than did Fuel C. Only in a few cases did E20 cause a 

change greater than E10 or Fuel C. In each of these 

cases, the changes were not of a magnitude great 

enough to represent a concern. One elastomer, ACM, 

consistently had the greatest change in all three fuels for 

each of the properties examined with the exception of 

hardness through out the study. 

ACKNOWLEDGEMENTS 

This study would not have been possible without the 

support and recommendations from a number of 

individuals, organizations, and companies including 

Briggs & Stratton 

Delphi 

Ford Motor Company 

General Motors 

Intertek Automotive 

Jewitt and Associates 

Kohler 

Minnesota Corn Research and Promotion Council 

Minnesota Department of Agriculture 

Renewable Fuels Association 

S&S Cycle 

TI Automotive 

Toro 

Toyota 

Zen Fuel LLC / Michael Harrigan 

REFERENCES 

ASTM Recommended Practice, (2006). Standard 

specification for denatured fuel ethanol for blending with 

gasoline for use as automotive spark-ignition engine 

fuel. ASTM D4806. 

ASTM Recommended Practice, (2006). Standard test 

methods for rubber and thermoplastic elastomersTension. ASTM D412. 

ASTM Recommended Practice, (2006). Standard test 

methods for rubber property-Effect of liquid. ASTM 

D471. 

ASTM Recommended Practice, (2004). Standard 

specification for automotive spark-ignition engine fuel. 

ASTM D4814. 

ASTM Recommended Practice, (2004). Standard test 

methods for rubber properties-durometer hardness. 

ASTM D2240. 

ASTM Recommended Practice, (2002). Standard 

practice for rubber- Materials, equipment, and 

procedures for mixing standard compounds and 

preparing standard vulcanized sheets. ASTM D3812. 

Clean Air Act, 42 U.S.C. § 7547 (1977). 

Eisenthal, J. (2005, May). ′′E20 Bill finally reaches Gov. 

Pawlenty’s desk”. Minnesota Ag Connection. Retrieved 

October 22, 2005, from 

http://www.minnesotaagconnection.com/storystate.cfm?Id=405&yr=2005
 2-22-2008 

11

Environmental Protection Agency. (1995, August 22). 

Waiver Requests under section 211 (f) of the clean air 

act. Retrieved October 28, 2005, from 

http://www.epa.gov/docs/OMSWWW/regs/fuels/additive/

waiver.pdf

Environmental Protection Agency. (1991, January 24). 

Regulation of fuels and fuel additives; Definition of 

substantially similar. Retrieved October 28, 2005, from 

http://www.epa.gov/otaq/regs/fuels/additive/jan91.pdf

Orbital Engine Company. (2003, May). Market barriers 

to the uptake of biofuels study: A testing based 

assessment to determine impacts of a 10% and 20% 

ethanol gasoline fuel blend on non-automotive engines - 

2000hrs material compatibility testing. Report to 

Environment Australia. 

Orbital Engine Company. (2003, May). Market barriers 

to the uptake of biofuels study: A testing based 

assessment to determine impacts of a 20% ethanol 

gasoline fuel blend on the Australian passenger vehicle 

fleet - 2000hrs material compatibility testing. Report to 

Environment Australia. 

Orbital Engine Company. (2003, March). Market barriers 

to the uptake of biofuels study: A testing based 

assessment to determine impacts of a 20% ethanol 

gasoline fuel blend on the Australian passenger vehicle 

fleet. Report to Environment Australia. 

Oxygenated gasoline, Minnesota Stat. §§ 52-239.791 

(2004). 

Oxygenated gasoline, Minnesota Stat. §§ 52-239.791 

(2005). 

SAE Recommended Practice, (2000, January). 

Gasoline, alcohol and diesel fuel surrogates for 

materials testing. SAE J1681. 

SAE Recommended Practice, (1998, January). Methods 

for determining physical properties of polymeric 

materials exposed to gasoline/oxygenate fuel mixtures. 

SAE J1748. 

Society of Automotive Engineers. (2000). A rational 

approach to qualifying materials for use in fuel systems. 

Warrendale, PA: Harrigan, M., Banda, A., Bonazza, B., 

Graham, P., & Slimp, B. 

Sun Refining and Marketing Company. (1988, April). 

Waiver application for 15% MTBE (EPA Publication No. 

EN-88-02, III-A-1). Washington, DC: U.S. Environmental 

Protection Agency. 

United States Department of Energy: Energy Efficiency 

and Renewable Energy. (2005, September 9). 

Minnesota passes E20 law. Retrieved October 22, 2005, 

from 

http://www.eere.energy.gov/afdc/progs/ddown.cgi?/WHA

TS_NEW/480/1/0

TERMINOLOGY 

E10 - Fuel consisting of 90% gasoline and 10% ethanol 

E20 - Fuel consisting of 80% gasoline and 20% ethanol 

ASTM Test Fuel C - Test Fuel C is composed of 50% 

toluene and 50% iso-octane 

Aggressive ethanol - Synthetic ethanol 816.00 g, deionized water 8.103 g, sodium chloride 0.004 g, sulfuric 

acid 0.021 g, glacial acetic acid 0.061 g (SAE J1681 

appendix E.1.2)

C(E10)A - Fuel consisting of 90% ASTM test Fuel C and 

10% aggressive ethanol 

C(E20)A - Fuel consisting of 80% ASTM test Fuel C and 

20% aggressive ethanol 

CONTACT 

Department of Automotive Engineering Technology 

Minnesota State University, Mankato 

205 Trafton Science Center East 

Mankato, MN 56001 

Phone: 507-389-6383 
 2-22-2008 

12

APPENDIX A 

 MnCAR 

Minnesota Center for Automotive Research 

FROM Dr. Bruce Jones, Gary Mead, Paul Steevens and Chris Connors 

 Minnesota Center for Automotive Research 

 Minnesota State University, Mankato 

 Trafton Science Center 205E 

 Mankato, MN 56001 

 (507) 389-6383 

 (507) 389-5002 (fax) 

RE E20 Material Compatibility Testing Procedures - Elastomers 

Introduction 

This document outlines the testing procedures used by the Minnesota Center for Automotive Research (MnCAR) for 

measuring material compatibility of elastomers commonly found in automotive fuel systems. The purpose of this testing 

was to determine if E20 had a larger negative impact on fuel system elastomers than gasoline or E10. 

Standards Used 

Proposed testing will follow the procedures outlined in 

SAE J1748 Methods for determining physical properties of polymeric materials exposed to 

gasoline/oxygenate Fuel Mixtures (Jan 98) 

SAE J1681 Gasoline, alcohol, and diesel fuel surrogates for material testing (Jan 00) 

ASTM D471-06 Standard Test Method for Rubber Property – Effect of Liquids 

ASTM D412-06a Standard Test Methods for Vulcanized Rubber and Thermoplastic Elastomers - Tension 

ASTM D3183-02 Standard Practice for Rubber –Preparation of Pieces for Test Purposes from Products 

ASTM D2240-04 Standard Test Method for Rubber Property - Durometer Hardness 

ASTM D618 Standard Practice for Conditioning Plastics for Testing

ASTM D543 Standard Practices for Evaluating the Resistance of Plastics to Chemical 

 Reagents 
 2-22-2008 

13

Properties examined 

weight change 

volume change 

appearance 

 tensile 

percent change in elongation 

 hardness (Durometer M) 

These properties will be measured before soaking, after soaking, and after dry-out. 

Rubbers to Test 

ACM acrylic rubber (Hytemp®) 

CO epichlorohydnin homopolymer 

ECO epichlorohydnin ethylene oxide copolymer 

CR polychloroprene (Neoprene®) 

NBR-M nitrile/buna N medium ACN 

NBR-H nitrile/buna N high ACN 

OZO paracril (nitrile/PVC blend) 

FKM fluoroelastomer with dipolymers of VF2/HFP 65% fluorine (Viton A®) 

Test Fuels (SAE J1681) 

Three test fuels will be used consisting of 

C Surrogate gasoline- "base” ASTM Fuel C 50/50 toluene iso-octane mixture (500 ml toluene and 

500 ml iso-octane) 

C(E10)A E10 fuel- 90% fuel C + 10% aggressive ethanol (450 ml toluene, 450 ml iso-octane, 100 ml 

aggressive ethanol) 

C(E20)A E20 fuel- 80% fuel C + 20% aggressive ethanol (400 ml toluene, 400 ml iso-octane, 200 ml 

aggressive ethanol) 

 

Aggressive ethanol consists of synthetic ethanol 816.00 g, de-ionized water 8.103 g, sodium chloride 0.004 g, sulfuric 

acid 0.021 g, and glacial acetic acid 0.061 g (SAE J1681 Appendix E.1.2). 

Specimen Preparation and Condition 

1. Prepare five specimens of each material being tested for each fuel and for each property. 

Note: two extra sets of five tensile specimens of each material will be needed to determine non-immersion 

properties and dry-out changes since these specimens get destroyed during each phase of testing (SAE J1748 

5.1.2). 

2. Specimens for tensile tests will be molded following ASTM D3183 and cut to shape using Die C (ASTM D412 11.1). 

 

Specimen Sizes 

Specimens for Weight, Volume, and Appearance Change: Rectangle 25 x 50 x 2.0 mm ± 0.1 mm (1 x 2 x 0.08 in. 

± 0.004 in.) (ASTM D471 9.1). 

Specimens for Tensile Strength: Type C dumbbell tensile specimens 115 x 25 x 2 mm ± 0.25 mm (4.5 x 1 x 0.08 

in. ± 0.008 in.) that neck down to 6 mm + 0.00 mm – 0.05 mm (0.250 in. + 0.000 in. -0.002 in.) (ASTM D412 

11.1). 

3. ASTM D 618 Procedure A will be used for conditioning 

Condition specimens under 7mm (0.25 in.) thick for a minimum of 40 hours at 23 °C ± 2 °C at 50% ± 5% humidity. 

Allow adequate air circulation to all specimens by either hanging from metal clips or placing them on a wire 

screen with at least 25 mm (1 in.) of room between them and the bench (ASTM D618 8.1). 

Pre Immersion Measurements 

1. Prepare and condition specimens in the manner described above. 

2. Photograph all specimens to show original appearance. 
 2-22-2008 

14

3. After conditioning, weigh each appearance specimen on an analytical balance in grams to four decimal places (SAE 

J1748 4.1.3). 

4. Measure the dimensions of each specimen on the tensile specimens. Three measurements shall be made for 

thickness, one at the center, and one at the end of the reduced section. The median of the three shall be used. Specimen 

with a difference between the maximum and minimum thickness exceeding 0.08 mm (0.003 in.) shall be discarded. The 

width of the specimen shall be measured in the same three spots. Measure to the nearest ± 0.025 mm (± 0.001 in.) 

(ASTM D412 11.1.2) (ASTM D638 10.1.1). 

5. Measure the hardness, using the procedure described below, on of each tensile sample on the clamping ends in a 

manner that will not influence the tensile testing. 

NOTE: The tensile sample is also being used for hardness testing due to limited oven space. Testing the 

hardness at the clamping ends before tensile testing should not affect the tensile tests. 

6. Volume measurement (fluid displacement method) samples shall be measured in air to the nearest 0.01 g and then 

suspended in specific test fuel and re-weighed. 

Immersion 

1. Suspend the specimens in glass jars to avoid contact with the walls or bottom of the container using stainless steel 

wire and glass beads to separate each specimen. It may be necessary to attach small weights made from stainless steel 

to prevent floating (ASTM D471 10.1). 

2. For the weight/ volume/appearance change specimens, fill the glass containers with a minimum of 166 mL of the 

appropriate test fluid per five specimens or until the fluid level is 3 cm above the top of the specimens to compensate for 

swelling (SAE J1748 4.1.2), (ASTM D471 10.1, 11.1, 12.1). 

3. For tensile/hardness specimens, fill the glass containers with a minimum of 250 mL of the appropriate test fluid per five 

specimens, or until the fluid level is 3 cm above the top of the specimens to compensate for swelling (SAE J1748 4.1.2), 

(ASTM D471 15.2). 

4. Seal the container to avoid evaporative losses. 

5. Place the container in the oven and allow the test fuel to reach 55 °C ± 2 °C (131 °F) (SAE J1748 5.2). 

6. Replace the fuel daily for the first three days and weekly thereafter (SAE J1748 4.1.2). 

7. Continue exposure for 500 hours (SAE J1748 5.1.3). 

Change in Weight, Appearance, and Volume (ASTM D471) 

1. After soaking for the required length of time, remove the test specimens and allow them to cool to room temperature 

by placing them into a cool, clean portion of the test fluid for 30 to 60 minutes (ASTM D471 10.2). 

Measure Weight 

2. Blot dry with filter paper free of lint and foreign material and place in a tarred weighing bottle within 10 seconds to 

minimize evaporative weight loss. Weigh each specimen to the same level of precision as the pre-immersion weighing 

(SAE J1748 6.2, ASTM D471 10.2). 

Note Appearance 

3. Examine the appearance of each specimen noting any loss of gloss, developed texture, decomposition, discoloration, 

swelling, clouding, tackiness, rubberiness, crazing, bubbling, cracking, solubility, etc... Photograph any changes (ASTM 

D543 11.5). 

Measure Volume (fluid displacement method) 

4. Obtain the mass of each specimen by hanging it from a quad beam balance in a jar of specific test fuel. Weigh to the 

nearest 0.01 gram, and record the mass. Then blot dry the specimen and weigh in air at room temperature (ASTM D471 

11.1). 
 2-22-2008 

15

5. Leave samples in open air environment for 4 hours before placing the specimens in an oven at 55 °C ± 2 °C (131°F) 

and let dry for 40 hours. Allow the specimens to cool to room temperature before final measurements are made (ASTM 

D471 14.2). 

6. Measure the specimens in the same manner as pre-immersion. Calculate the mass of material extracted from the 

specimens and express it as a percent of the original mass (ASTM D471 14.2). 

Durometer Hardness (ASTM D2240—04) 

1. After soaking for the required length of time, remove the containers from the oven and place the specimens in clean 

room temperature fluid and allow them to be cooled for 30 to 60 minutes (ASTM D471 15.2). 

NOTE: Hardness measurements will be made on the clamping ends of the tensile specimens before the tensile 

tests in a manner that will not influence the tensile testing. 

 

2. Testing is to take place within 3 minutes, with the exception of the dry-out specimens, of removing the specimen from 

the room temperature fuel to minimize the effects of dry-out (SAE J1748 6.2.1). 

3. The dry-out tensile/hardness specimens will be suspended at room temperature for 4 hours to dry. Then placed in an 

oven and baked at 55 °C ± 2 °C (131°F) for at least 40 hours. Allow the samples to cool to room temperature before 

testing (ASTM D471 15.4.2). 

4. Durometer hardness shall be performed on a machine meeting all requirements of ASTM 2240-04. A type 3 operating 

stand with adjustable pneumatic dampening will be used with a type M durometers. The type M durometer has been 

chosen due to its ability to be used on thin test samples and correlation to type A durometers (ASTM D2240 9.1). 

5. Vertical distance from the presser foot to the contact surface of the test specimen shall be 25.4 ± 2.5 mm (1.00 ± 0.100 

in.). 

6. Make six determinations of hardness at different positions on the specimen at least 0.80 mm (0.03 in.) apart (ASTM 

D2240 9.18). 

7. Immediately proceed to step 4 of the tensile testing section. 

Tensile Strength (ASTM D412—06a) 

1. After soaking for the required length of time, remove the containers from the oven and place the specimens in clean 

room temperature fluid and allow them to be cooled for 30 to 60 minutes (ASTM D471 15.2). 

2. Testing is to take place within 3 minutes, with the exception of the dry-out specimens, of removing the specimen from 

the room temperature fuel to minimize the effects of dry-out (SAE J1748 6.2.1). 

 

3. The dry-out property tensile/hardness specimens will be suspended at room temperature for 4 hours to dry. Then 

placed in an oven and baked at 55 °C ± 2 °C (131°F) for 40 hours. Allow the samples to cool to room temperature before 

testing (ASTM D471 15.4.2). 

4. Tensile testing shall be performed on a machine meeting all requirements of section 6 of ASTM D412. 

5. Specimens shall be pulled at a uniform rate of 500 ± 50 mm/min (20 ± 2 in./min) until failure (ASTM D412 6.1). 

6. Record the force at the elongations specified for the test and at the time of rupture (ASTM D 412 12.1). 

7. Base all calculations on the original measurements taken before immersion (SAE J1748 6.1.2). 
16

APPENDIX B 

 Elastomer Volume Change of Wet Samples

02468

10

ACM-C ACM-E10 ACM-E20 CO-CCO-E10 CO-E20 ECO-C ECO-E10 ECO-E20 CR-CCR-E10 CR-E20 NBR-m-C NBR-m-E10 NBR-m-E20 NBR-h-C NBR-h-E10 NBR-h-E20 OZO-C OZO-E10 OZO-E20 FKM-C FKM-E10 FKM-E2

Volume in cc 
17

APPENDIX C 

Elastomers Volume of Dry Samples 

02468

10

ACM-C ACM-E10 ACM-E20CO-C CO-E10 CO-E20 ECO-C ECO-E10 ECO-E20CR-C CR-E10 CR-E20 NBR-m-C NBR-m-E10 NBR-m-E20 NBR-h-C NBR-h-E10 NBR-h-E20 OZO-C OZO-E10 OZO-E20 FKM-C FKM-E10 FKM-E20

Volume in cc 
18

APPENDIX D 

E20 Elastomer Study Volume Results

Fuel C E10 E20 Fuel C 

ACM Pre-Immersion 3.06 2.87 2.80 ACM Pre-Immersion 3

Post Immersion 7.42 9.26 9.45 Post Immersion 2% Change 142.5% 222.6% 237.5% % Change -11.8

Pre-Immersion Std Dev 0.25 0.13 0.24 Pre-Immersion Std Dev 0

Post Immersion Std Dev 0.54 0.37 0.74 Post Immersion Std Dev 0

Fuel C E10 E20 Fuel C 

CO Pre-Immersion 2.64 2.60 2.60 CO Pre-Immersion 2

Post Immersion 3.36 3.62 3.69 Post Immersion 2% Change 27.5% 39.2% 41.9% % Change -9.0

Pre-Immersion Std Dev 0.03 0.03 0.02 Pre-Immersion Std Dev 0

Post Immersion Std Dev 0.05 0.08 0.04 Post Immersion Std Dev 0

Fuel C E10 E20 Fuel C 

ECO Pre-Immersion 2.66 2.87 2.71 ECO Pre-Immersion 2

Post Immersion 3.58 4.16 4.43 Post Immersion 2% Change 34.6% 44.9% 63.5% % Change -13.2

Pre-Immersion Std Dev 0.03 0.15 0.07 Pre-Immersion Std Dev 0

Post Immersion Std Dev 0.10 0.18 0.04 Post Immersion Std Dev 0

Fuel C E10 E20 Fuel C 

CR Pre-Immersion 2.85 2.84 2.88 CR Pre-Immersion 2

Post Immersion 6.00 5.54 5.18 Post Immersion 2% Change 110.5% 95.1% 79.9% % Change -11.2

Pre-Immersion Std Dev 0.14 0.11 0.15 Pre-Immersion Std Dev 0

Post Immersion Std Dev 0.34 0.31 0.47 Post Immersion Std Dev 0

Volume in CC - Wet Volume in CC - DrVolume in CC - Wet Volume in CC - DrVolume in CC - Wet Volume in CC - Dr

Minnesota State University, Mankato

Volume in CC - Wet Volume in CC - Dr

Averages of 5 samples per fuel
19

APPENDIX D (CONTINUED) 

E20 Elastomer Study Volume Results

Fuel C E10 E20 Fuel 

NBR - medium Pre-Immersion 2.83 2.78 2.76 NBR - medium Pre-Immersion 2

Post Immersion 4.05 4.75 4.66 Post Immersion 2% Change 43.1% 70.9% 68.8% % Change -8.

Pre-Immersion Std Dev 0.06 0.05 0.04 Pre-Immersion Std Dev 0

Post Immersion Std Dev 0.19 0.17 0.17 Post Immersion Std Dev 0

Fuel C E10 E20 Fuel 

NBR - high Pre-Immersion 2.48 2.57 2.59 NBR - high Pre-Immersion 2

Post Immersion 2.65 3.23 3.32 Post Immersion 2% Change 6.9% 25.7% 28.2% % Change -14.9

Pre-Immersion Std Dev 0.05 0.03 0.04 Pre-Immersion Std Dev 0

Post Immersion Std Dev 0.05 0.09 0.04 Post Immersion Std Dev 0

Fuel C E10 E20 Fuel 

OZO Pre-Immersion 2.64 2.63 2.61 OZO Pre-Immersion 2

Post Immersion 2.98 3.48 3.63 Post Immersion 2% Change 12.9% 32.3% 39.1% % Change -18.6

Pre-Immersion Std Dev 0.04 0.04 0.02 Pre-Immersion Std Dev 0

Post Immersion Std Dev 0.12 0.05 0.09 Post Immersion Std Dev 0

Fuel C E10 E20 Fuel 

FKM Pre-Immersion 2.62 2.71 2.65 FKM Pre-Immersion 2

Post Immersion 3.43 3.60 3.74 Post Immersion 3% Change 30.9% 32.8% 41.1% % Change 18.7

Pre-Immersion Std Dev 0.09 0.04 0.08 Pre-Immersion Std Dev 0

Post Immersion Std Dev 0.15 0.11 0.14 Post Immersion Std Dev 0

Volume in CC - Wet Volume in CC - DrVolume in CC - Wet Volume in CC - DrVolume in CC - Wet Volume in CC - DrVolume in CC - Wet Volume in CC - Dr

Averages of 5 samples per fuel

Minnesota State University, Mankato
20

APPENDIX E 

Elastomer Mass Change of Wet Samples 

3456789

1011

ACM-C ACM-E10 ACM-E20CO-C CO-E10 CO-E20 ECO-C ECO-E10 ECO-E20CR-C CR-E10 CR-E20 NBR-m-C NBR-m-E10 NBR-m-E20 NBR-h-C NBR-h-E10 NBR-h-E20 OZO-C OZO-E10 OZO-E20 FKM-C FKM-E10 FKM

Mass in Grams
21

APPENDIX F 

Elastomer Mass Change of Dry Samples

3456789

1011

ACM-C ACM-E10 ACM-E20CO-C CO-E10 CO-E20 ECO-C ECO-E10 ECO-E20CR-C CR-E10 CR-E20 NBR-m-C NBR-m-E10 NBR-m-E20 NBR-h-C NBR-h-E10 NBR-h-E20 OZO-C OZO-E10 OZO-E20 FKM-C FKM-E10 FKM

Mass in Grams
22

APPENDIX G 

E20 Elastomer Study Mass Results

Fuel C E10 E20 Fuel C 

ACM Pre-Immersion 4.859 4.632 4.588 ACM Pre-Immersion 4.8

Post Immersion 8.506 9.657 10.101 Post Immersion 4.5% Change 75.1% 108.5% 120.2% % Change -6.3

Pre-Immersion Std Dev 0.21 0.19 0.24 Pre-Immersion Std Dev 0

Post Immersion Std Dev 0.43 0.22 0.46 Post Immersion Std Dev 0

Fuel C E10 E20 Fuel C 

CO Pre-Immersion 4.989 5.053 5.036 CO Pre-Immersion 4.9

Post Immersion 5.495 5.765 5.693 Post Immersion 4.8% Change 10.1% 14.1% 13.1% % Change -3.8

Pre-Immersion Std Dev 0.06 0.11 0.05 Pre-Immersion Std Dev 0

Post Immersion Std Dev 0.08 0.14 0.06 Post Immersion Std Dev 0

Fuel C E10 E20 Fuel C 

ECO Pre-Immersion 5.118 5.153 5.122 ECO Pre-Immersion 5.1

Post Immersion 5.616 6.058 6.072 Post Immersion 4.7% Change 9.7% 17.6% 18.6% % Change -7.4

Pre-Immersion Std Dev 0.06 0.13 0.07 Pre-Immersion Std Dev 0

Post Immersion Std Dev 0.06 0.15 0.08 Post Immersion Std Dev 0

Fuel C E10 E20 Fuel C 

CR Pre-Immersion 5.160 5.088 5.215 CR Pre-Immersion 5.1

Post Immersion 7.535 7.106 6.735 Post Immersion 4.6% Change 46.0% 39.7% 29.1% % Change -10.4

Pre-Immersion Std Dev 0.21 0.12 0.29 Pre-Immersion Std Dev 0

Post Immersion Std Dev 0.36 0.23 0.43 Post Immersion Std Dev 0

Averages of 5 samples per fuel

Mass in Grams - DMass in Grams - D

Mass in Grams - WetMass in Grams - WetMass in Grams - WetMass in Grams - Wet

Minnesota State University, Mankato

Mass in Grams - DMass in Grams - D
23

APPENDIX G (CONTINUED) 

E20 Elastomer Study Mass Results

Fuel C E10 E20 Fuel C 

NBR - medium Pre-Immersion 4.795 4.810 4.691 NBR - medium Pre-Immersion 4.7

Post Immersion 5.616 6.165 6.041 Post Immersion 4.4% Change 17.1% 28.2% 28.8% % Change -6.4

Pre-Immersion Std Dev 0.16 0.11 0.11 Pre-Immersion Std Dev 0

Post Immersion Std Dev 0.19 0.17 0.17 Post Immersion Std Dev 0

Fuel C E10 E20 Fuel C 

NBR - high Pre-Immersion 4.300 4.404 4.426 NBR - high Pre-Immersion 4.3

Post Immersion 4.457 4.833 4.880 Post Immersion 3.8% Change 3.7% 9.7% 10.3% % Change -9.7

Pre-Immersion Std Dev 0.09 0.06 0.04 Pre-Immersion Std Dev 0

Post Immersion Std Dev 0.09 0.07 0.04 Post Immersion Std Dev 0

Fuel C E10 E20 Fuel C 

OZO Pre-Immersion 4.554 4.587 4.583 OZO Pre-Immersion 4.5

Post Immersion 4.779 5.098 5.119 Post Immersion 4.0% Change 4.9% 11.1% 11.7% % Change -11.9

Pre-Immersion Std Dev 0.04 0.04 0.05 Pre-Immersion Std Dev 0

Post Immersion Std Dev 0.05 0.03 0.07 Post Immersion Std Dev 0

Fuel C E10 E20 Fuel C 

FKM Pre-Immersion 6.128 6.116 6.174 FKM Pre-Immersion 6.1

Post Immersion 6.765 6.859 6.915 Post Immersion 6.4% Change 10.4% 12.1% 12.0% % Change 5.6

Pre-Immersion Std Dev 0.11 0.07 0.15 Pre-Immersion Std Dev 0

Post Immersion Std Dev 0.13 0.08 0.18 Post Immersion Std Dev 0

Mass in Grams - WetMass in Grams - Wet

Averages of 5 samples per fuel

Mass in Grams - D

Mass in Grams - WetMass in Grams - Wet

Minnesota State University, Mankato

Mass in Grams - DMass in Grams - DMass in Grams - D
24

APPENDIX H 

Elastomer Hardness Wet Samples

30405060708090

ACM-C ACM-E10 ACM-E20CO-C CO-E10 CO-E20 ECO-C ECO-E10 ECO-E20CR-C CR-E10 CR-E20 NBR-m-C NBR-m-E10 NBR-m-E20 NBR-h-C NBR-h-E10 NBR-h-E20 OZO-C OZO-E10 OZO-E20 FKM-C FKM-E1

F

Type M durometer
25

APPENDIX I 

 Elastomer Hardness Dry Samples

30405060708090

ACM-C ACM-E10 ACM-E20CO-C CO-E10 CO-E20 ECO-C ECO-E10 ECO-E20CR-C CR-E10 CR-E20 NBR-m-C NBR-m-E10 NBR-m-E20 NBR-h-C NBR-h-E10 NBR-h-E20 OZO-C OZO-E10 OZO-E20 FKM-C FKM-E10 FK

Type M Durometer
26

APPENDIX J 

E20 Elastomer Study Type M Durometer Hardness Results

Fuel C E10 E20 Fuel C 

ACM Pre-Immersion 74 74 74 ACM Pre-Immersion 

Post Immersion 47 50 49 Post Immersion % Change -36.5% -32.4% -33.8% % Change 5.5

Pre-Immersion Std Dev 0.61 0.63 0.98 Pre-Immersion Std Dev 1

Post Immersion Std Dev 1.78 2.79 2.73 Post Immersion Std Dev 0

Fuel C E10 E20 Fuel C 

CO Pre-Immersion 76 75 74 CO Pre-Immersion 

Post Immersion 65 60 59 Post Immersion % Change -14.5% -20.0% -20.3% % Change 5.3

Pre-Immersion Std Dev 1.35 0.73 1.08 Pre-Immersion Std Dev 0

Post Immersion Std Dev 1.73 3.13 1.41 Post Immersion Std Dev 0

Fuel C E10 E20 Fuel C 

ECO Pre-Immersion 69 69 69 ECO Pre-Immersion 

Post Immersion 58 54 55 Post Immersion % Change -15.9% -21.7% -20.3% % Change 13.0

Pre-Immersion Std Dev 0.14 0.43 0.94 Pre-Immersion Std Dev 0Post Immersion Std Dev 0.36 0.82 1.29 Post Immersion Std Dev 0

Fuel C E10 E20 Fuel C 

CR Pre-Immersion 67 68 67 CR Pre-Immersion 

Post Immersion 45 46 46 Post Immersion % Change -32.8% -32.4% -31.3% % Change 16.4

Pre-Immersion Std Dev 0.45 0.22 0.19 Pre-Immersion Std Dev 0

Post Immersion Std Dev 1.21 0.31 0.81 Post Immersion Std Dev 0

Type M Durometer Hardness - Wet Type M Durometer HardnType M Durometer Hardness - Wet Type M Durometer HardnType M Durometer Hardness - Wet Type M Durometer Hardn

Minnesota State University, Mankato

Type M Durometer Hardness - Wet Type M Durometer Hardn

Averages of 6 points per sample, 5 samples per fuel
27

APPENDIX J (CONTINUED) 

E20 Elastomer Study Type M Durometer Hardness Results

Fuel C E10 E20 Fuel C 

NBR-medium Pre-Immersion 67 67 67 NBR-medium Pre-Immersion 

Post Immersion 48 40 41 Post Immersion % Change -28.4% -40.3% -38.8% % Change 11.9

Pre-Immersion Std Dev 0.29 0.30 0.44 Pre-Immersion Std Dev 0

Post Immersion Std Dev 0.74 1.02 0.72 Post Immersion Std Dev 0

Fuel C E10 E20 Fuel C 

NBR-high Pre-Immersion 67 68 67 NBR-high Pre-Immersion 

Post Immersion 61 57 56 Post Immersion % Change -9.0% -16.2% -16.4% % Change 17.9

Pre-Immersion Std Dev 0.52 0.42 0.40 Pre-Immersion Std Dev 0

Post Immersion Std Dev 0.89 0.55 0.38 Post Immersion Std Dev 0

Fuel C E10 E20 Fuel C 

OZO Pre-Immersion 76 76 77 OZO Pre-Immersion 

Post Immersion 62 57 57 Post Immersion % Change -18.4% -25.0% -26.0% % Change 18.4

Pre-Immersion Std Dev 0.52 0.07 0.32 Pre-Immersion Std Dev 0

Post Immersion Std Dev 1.17 0.57 0.70 Post Immersion Std Dev 0

Fuel C E10 E20 Fuel C 

FKM Pre-Immersion 72 72 72 FKM Pre-Immersion 

Post Immersion 61 58 58 Post Immersion % Change -15.3% -19.4% -19.4% % Change -9.7

Pre-Immersion Std Dev 0.32 0.32 0.14 Pre-Immersion Std Dev 0

Post Immersion Std Dev 0.30 0.40 0.22 Post Immersion Std Dev 0

Averages of 6 points per sample, 5 samples per fuel

Type M Durometer Hardn

Type M Durometer Hardness - WetType M Durometer Hardness - WetType M Durometer Hardness - WetType M Durometer Hardness - Wet

Type M Durometer HardnType M Durometer HardnType M Durometer Hardn

Minnesota State University, Mankato
28

APPENDIX K 

Elastomer Tensile Wet Results

0

500

10001500200025003000

ACM-N ACM-C ACM-E10 ACM-E20C0-NCO-C CO-E10 CO-E20 ECO-N ECO-C ECO-E10 ECO-E20CR-NCR-C CR-E10 CR-E20 NBR-m-N NBR-m-C NBR-m-E10 NBR-m-E20 NBR-h-N NBR-h-C NBR-h-E10 NBR-h-E20 OZO-N OZO-C OZO-E10 OZO-E20 FK

Max Tensile PSI
29

APPENDIX L 

Elastomer Tensile Dry Samples

0

500

10001500200025003000

ACM-N ACM-C ACM-E10 ACM-E20C0-NCO-C CO-E10 CO-E20 ECO-N ECO-C ECO-E10 ECO-E20CR-NCR-C CR-E10 CR-E20 NBR-m-N NBR-m-C NBR-m-E10 NBR-m-E20 NBR-h-N NBR-h-C NBR-h-E10 NBR-h-E20 OZO-N OZO-C OZO-E10 OZO-E20 FKM-N FKM

F

Max Tensile PSI
30

APPENDIX M 

E20 Elastomer Study Tensile Results

ACM No Soak Fuel C E10 E20 ACM No Soak Fuel C 

Tensile PSI 1729 371 346 326 Tensile PSI 1729 1757 Standard Deviation 82 152 136 100 Standard Deviation 82 57 % Change -79 -80 -81 % Change 2 

CO No Soak Fuel C E10 E20 CO No Soak Fuel C 

Tensile PSI 1376 839 680 744 Tensile PSI 1376 1314 Standard Deviation 36 75 25 104 Standard Deviation 36 86 % Change -73 -75 -76 % Change -5 

ECO No Soak Fuel C E10 E20 ECO No Soak Fuel C 

Tensile PSI 1298 990 768 800 Tensile PSI 1298 1333 Standard Deviation 77 47 23 63 Standard Deviation 77 44 

% Change -24 -41 -38 % Change 3 

CR No Soak Fuel C E10 E20 CR No Soak Fuel C 

Tensile PSI 1867 494 536 613 Tensile PSI 1867 1846 Standard Deviation 121 32 53 58 Standard Deviation 121 115 % Change -74 -71 -67 % Change -1 

Minnesota State University, Mankato

Averages of 5 samples per fuel

Tensile Results - Wet Tensile Results - DryTensile Results - Wet Tensile Results - DryTensile Results - Wet Tensile Results - DryTensile Results - Wet Tensile Results - Dry
31

APPENDIX M (CONTINUED) 

E20 Elastomer Study Tensile Results

NBR-medium No Soak Fuel C E10 E20 NBR-medium No Soak Fuel C 

Tensile PSI 2311 1181 788 826 Tensile PSI 2311 2207 Standard Deviation 288 68 75 106 Standard Deviation 288 160 % Change -49 -66 -64 % Change -5 

NBR-high No Soak Fuel C E10 E20 NBR-high No Soak Fuel C 

Tensile PSI 1799 713 587 627 Tensile PSI 1799 1746 Standard Deviation 162 83 96 74 Standard Deviation 162 138 % Change -60 -67 65 % Change -3 

OZO No Soak Fuel C E10 E20 OZO No Soak Fuel C 

Tensile PSI 1709 937 683 705 Tensile PSI 1709 1675 Standard Deviation 107 58 78 105 Standard Deviation 107 102 % Change -45 -60 -59 % Change -2 

FKM No Soak Fuel C E10 E20 FKM No Soak Fuel C 

Tensile PSI 1351 758 667 632 Tensile PSI 1351 1113 Standard Deviation 66 359 53 28 Standard Deviation 66 39 

% Change -44 -51 -53 % Change -18 

Minnesota State University, Mankato

Averages of 5 samples per fuel

Tensile Results - Wet Tensile Results - DryTensile Results - Wet Tensile Results - DryTensile Results - Wet Tensile Results - DryTensile Results - Wet Tensile Results - Dry
32

APPENDIX N 

Elastomer Elongation of Wet Samples

02468

101214161820

ACM-N ACM-C ACM-E10 ACM-E20C0-NCO-C CO-E10 CO-E20 ECO-N ECO-C ECO-E10 ECO-E20CR-NCR-C CR-E10 CR-E20 NBR-m-N NBR-m-C NBR-m-E10 NBR-m-E20 NBR-h-N NBR-h-C NBR-h-E10 NBR-h-E20 OZO-N OZO-C OZO-E10 OZO

Stretch in Inches
33

APPENDIX O 

Elastomer Elongation of Dry Samples

02468

101214161820

ACM-N ACM-C ACM-E10 ACM-E20C0-NCO-C CO-E10 CO-E20 ECO-N ECO-C ECO-E10 ECO-E20CR-NCR-C CR-E10 CR-E20 NBR-m-N NBR-m-C NBR-m-E10 NBR-m-E20 NBR-h-N NBR-h-C NBR-h-E10 NBR-h-E20 OZO-N OZO-C OZO-E10 OZO

Stretch in Inches
34

APPENDIX P 

E20 Elastomer Study Elongation Results

ACM No Soak Fuel C E10 E20 ACM No Soak Fuel C 

Extension at max load 9.176 2.536 2.451 2.283 Extension at max load 9.176 9.637 Standard Deviation 0.04 0.91 1.06 0.07 Standard Deviation 0.04 0.74 % Change in Elongation 0.72 0.73 0.75 % Change in Elongation 0.05 

CO No Soak Fuel C E10 E20 CO No Soak Fuel C 

Extension at max load 8.734 5.246 4.507 4.982 Extension at max load 8.734 7.750 Standard Deviation 1.43 0.98 0.18 0.53 Standard Deviation 1.43 0.88 % Change in Elongation -0.40 -0.48 -0.43 % Change in Elongation -0.11 

ECO No Soak Fuel C E10 E20 ECO No Soak Fuel C 

Extension at max load 12.448 11.247 8.309 7.486 Extension at max load 12.448 11.890 Standard Deviation 1.71 0.85 0.95 0.56 Standard Deviation 1.71 0.09 % Change in Elongation -0.10 -0.33 -0.40 % Change in Elongation -0.05 

CR No Soak Fuel C E10 E20 CR No Soak Fuel C 

Extension at max load 8.134 4.502 4.501 5.235 Extension at max load 8.134 7.472 Standard Deviation 0.48 0.25 0.32 0.50 Standard Deviation 0.48 0.34 

% Change in Elongation -0.45 -0.45 -0.36 % Change in Elongation -0.08 

Minnesota State University, Mankato

Averages of 5 samples per fuel

Elongation Results - Wet Elongation Results - DryElongation Results - Wet Elongation Results - DryElongation Results - Wet Elongation Results - DryElongation Results - Wet Elongation Results - Dry
35

APPENDIX P (CONTINUED) 

E20 Elastomer Study Elongation Results

NBR-medium No Soak Fuel C E10 E20 NBR-medium No Soak Fuel C 

Extension at max load 17.054 12.453 9.571 9.879 Extension at max load 17.054 15.901 Standard Deviation 1.34 0.07 0.86 1.08 Standard Deviation 1.39 0.05 

% Change in Elongation -0.27 -0.44 -0.42 % Change in Elongation -0.07 

NBR-high No Soak Fuel C E10 E20 NBR-high No Soak Fuel C 

Extension at max load 8.636 5.065 4.652 4.927 Extension at max load 8.636 7.344 Standard Deviation 0.50 0.37 0.56 0.51 Standard Deviation 0.50 0.36 

% Change in Elongation -0.41 -0.46 -0.43 % Change in Elongation -0.15 

OZO No Soak Fuel C E10 E20 OZO No Soak Fuel C 

Extension at max load 9.512 6.488 5.525 5.816 Extension at max load 9.512 6.547 Standard Deviation 0.75 0.31 0.29 0.61 Standard Deviation 0.75 0.25 

% Change in Elongation -0.32 -0.42 -0.39 % Change in Elongation -0.31 

FKM No Soak Fuel C E10 E20 FKM No Soak Fuel C 

Extension at max load 7.865 7.141 6.089 6.105 Extension at max load 7.865 7.362 Standard Deviation 0.16 0.67 0.46 0.36 Standard Deviation 0.16 0.57 

% Change in Elongation -0.09 -0.23 -0.22 % Change in Elongation -0.06 

Elongation Results - Wet Elongation Results - DryElongation Results - Wet Elongation Results - Dry

Minnesota State University, Mankato

Elongation Results - Wet Elongation Results - DryElongation Results - Wet Elongation Results - Dry

Averages of 5 samples per fuel