Page Contents:


3.1. EPA studies

3.1.1. Reformulated gasoline

3.1.2. US ethanol mandates

3.2. Ethanol in existing vehicles

3.2.1. Value of E15

3.2.2. Main conclusions of the Ricardo Study

3.2.3.Effects of E15-E40 blends Minnesota study -optimal blends

3.2.4. Larger E20 Minnesota study Fuel economy comparison from different labs

3.2.5. How is better mileage possible?

3.2.6. Low Speed Torque

3.2.7. Ethanol optimal performance blends

3.2.8. Can 'gasoline' only vehicles use optimal blends?

3.2.9. Using optimal blends in E85 vehicles

3.2.10. Using E85 vehicles to find optimal blends

3.2.11. Blender Pumps Grants for Blender Pumps

Charley hopes that you don't think he's flat on his back because he drank to much!

Link back to Alternative Transportation Fuels

Link to Methanol Fuels

3. Value of Ethanol in Current and Near-Future US Vehicles


We briefly list the key benefits of using ethanol, then expand on these, showing how they benefit your driving, your environment and the world's greenhouse gas problems.

I. Higher octane

II. Higher Flame Speed

III. Higher heats of evaporation

IV. Ethanol is an oxygenated fuel that contains 35% oxygen which reduces nitrogen oxides emissions from combustion.

V. A renewable source of energy extracted from plants.

VI. The fuel is eco-friendly and saves the environment from the hazards of other fossil fuels.

VII. The discharge of benzene and butadiene that cause cancer is also decreased by 50%.

VIII. All petrol engines can utilize the mixtures of ethanol and need no alterations. These blends also decrease the emission of hydrocarbons that deplete the ozone layer.

3.1. US EPA ethanol fuel studies

The EPA has been studying the effects of ethanol (and methanol) at all levels, from research into their maximum benefit, to estimating the mileage differences they resulting in. In this chapter we focus on how ethanol affects existing vehicles. In Chapter 4 we will discuss how much better engine performance will be when used in engines that take its benefits into consideration, rather than let those qualities go out the tailpipe.

The benefits of ethanol relative to race fuel and/or methanol are multifold, but let's start with the one many of you already have guessed - power and performance. A typical (R+M)/2 octane rating of E85 is around 100. The naturally high octane allows for greater compression and expansion ratios - the power and efficiency benefits to the racer of higher octane are well known and widely published.

Second, ethanol has a higher heat of vaporization relative to gasoline-a significantly higher value. A typical heat of vaporization for gasoline may be on the order of 59 kilojoules per kilogram of fuel. For ethanol, it's approximately 130 kilojoules per kilogram, which is more than twice that value for gasoline.

Why is this important? Before a fuel combusts, it must exist as vapor mixed with air, using oxygen in the atmosphere as the source of its oxidant. Therefore, as liquid fuel is introduced into the manifold either by carburetion or fuel injection, it must first change from the liquid to vapor phase and sufficiently mix with the air before it will combust.

The energy required to vaporize the fuel comes mostly from the air, but a portion actually comes from engine intake surfaces as the fuel vapor contacts it. However, it is most ideal to use as much of the air for vaporization to maximize volumetric efficiency. If a fuel has a higher heat of vaporization, the intake air temperature will be reduced, resulting in better volumetric efficiencies as the inlet charge has a higher density (more oxygen gets into the cylinder). From this, one would expect significant gains in torque performance with ethanol relative to gasoline, and this will be shown to indeed be the case.

In published research work conducted by General Motors, full-load data of a four-cylinder, naturally aspirated spark-ignition direct-injection flex-fuel engine running on E85 demonstrated a near 15 percent increase in specific output relative to production gasoline counterparts, while showing an improvement in part load operation of 3-6 percent. These gains were associated with reduced heat rejection, increased volumetric efficiency, and increased dilution (EGR) tolerance.

Beyond the power benefits that ethanol can provide there are two other big factors that make ethanol an attractive fuel. First, it's renewable; and second, it's clean-burning. In addition, since ethanol is less volatile than gasoline, there's a reduced chance of explosion in spills and accidents. And although ethanol is more corrosive than gasoline to certain materials, it is less toxic to the user.

The production of ethanol today is energy positive; that is, we obtain nearly 2 times the energy in the fuel produced as is needed to make it.

But perhaps as important as all of the above is that ethanol displaces aromatic compounds that are added to gasoline. They are the most expensive part of the fuel we call 'gasoline' and the most hazardous. The volatile organic compounds (VOC’s), particulate matter (PM), PAH & SOA’s can find their roots in the Benzene, Toluene and Xylene aromatics added to gasoline. A result is that E10 is 20 to 30 cents a gallon cheaper. But the oil companies will never tell you that E10 is, since they don’t want to disrupt the petro chemical market.

Ethanol runs an engine more efficiently as well since most FFV’s will lose only 15 to 20 percent mileage with consistent E85 fueling compared to gasoline, even thought with 85% ethanol in the fuel mix there is 28 percent less energy in the tank.

But things could easily get better. Current engines are engineered to operate on low-octane fuels. Typical unleaded fuel measures at about 87 octane while, by comparison, a fuel comprised of 98 percent ethanol, has octane levels ranging from the upper 90s to low 100s. Because gasoline has dominated the transportation fuels sector since automakers began mass producing vehicles, engines have been optimized for low-octane fuels. In order to experience the true benefits of ethanol, engines need to be optimized for increased fuel compression. This would result in improved mileage and greater efficiency, experts say, and would benefit E85 as well as midlevel blends. “If we could get the manufacturers to put additional software in the computers to be able to run on, let’s say E30 as well as E10, they could change the timing in the computer program and get the same mileage as you get on gasoline,” Bob Kozak, cofounder of the nonprofit biofuels educational group Advanced Biofuels USA says.


3.1.1. Reformulated Gasoline Contains 10% Ethanol

RBOB (Reformulated Gasoline Blendstock for Oxygen Blending) gasoline is a reformulated regular wholesale non-oxygenated blendstock that is ready for the addition of 10% denatured fuel ethanol (92% purity) at the truck rack. It is traded at the New York Harbor barge market. RBOB gasoline futures are traded at the NYMEX under ticker symbol RB. Contract size is 42,000 gallons (1,000 barrels) quoted in US Dollars and Cents per gallon. Delivery dates are all calendar months. Contract settlement is by physical delivery. Thus, the measured amount of ethanol in low test gasoline is 9.2%.

Since the 1970s this amount of ethanol has been in the fuel we call 'gasoline'. It was part of the overall replacement of lead that included the aromatics Benzene, Toluene, and Xlyene. The lead was deadly to our brains. Of major importance to our readers, is the fact that the auto industry and the oil companies DID NOT remove the lead added to gasoline for 5 decades, even though they new the lead was dumbing all of us down - to say the least. The only reason they got the lead out was that the EPA required catalytic converters on all vehicles to reduce the general level of emissions, and the lead added to gasoline killed the catalytic converters.


3.1.2. US Ethanol Mandates

To meet the 2007 Renewable Fuels Standard (RFS) Federal Mandate, we must use more ethanol than, it appears, the number of Flex Fueled vehicles being made will require. Thus the EPA is raising the amount of ethanol it will allow more of it to be sold in gasoline. First the picture in a nutshell looks like:

If we maintain the 10% ethanol limit, we will be on the black line. The requirement is the dark gray bars. Going to 15% ethanol we move to the red line. By 2022 we are supposed to be able to use approximately 25% in our vehicles (36 billion gallons is the mandate).




Since the Renewable Fuel Standard has taken effect, gasoline usage has decreased as ethanol usage has increased.


3.2 Value of using ethanol in existing vehicles

Recently the EPA has approved an increase of ethanol to 15% in reformulated gasoline, for vehicles model year 2001 and newer. This is about 130,000,000 in the US (out of 250,000,000). Years earlier the world's research community had reached the conclusion that no damage would be done to vehicles. However, there is a vocal outcry from the oil industry. Furthermore, they have gathered their allies, and of all organizations, the AAA, to warn that older vehicles will suffer. We will look into this soon.


3.2.1 What is story of using E15? Will you pay more to get less, or will you benefit?

From Farm Oct. 2012: "Robert White of the Renewable Fuels Association says time will tell how fast E15 gains market share, but that it is worth noting that at the stations where it is sold, it is the highest-octane gasoline sold — comparable to premium — and it is sold at the cheapest price."

A DOE web page states the fuel economy drops for mid-level ethanol blends. The average measured fuel economy drop (decrease in miles per gallon) was stated to be 3.7% with E10, 5.3% with E15, and 7.7% with E20 when compared with gasoline. Using 85% ethanol, E85, and an Oak Ridge National Laboratory report found flexible fuel vehicles using E85 experienced a 27% drop in fuel economy when compared with conventional gasoline. These are of course the official government estimates. see "Effects of Intermediate Blends on Legacy and Small Non-Road Engines", National Renewable Energy Laboratory and Oak ridge National Laboratory, February 2009. Discussing this we find that the EPA numbers look identical to the decrease in mileage one would calculate by just assuming it is exactly the same as the decrease in energy per unit volume found in the ethanol blends. But, as you can see below this is not what happens in the real world.

Vander Griend head of ICM Inc.’s research and development of ethanol engines (ICM is the leading the research effort in Detroit, which is focused on testing the actual fuel) and others say ethanol testing conducted by the U.S. EPA and U.S. DOE does not accurately display ethanol’s benefits because the agencies often use indolene, a form of standardized gasoline, as the blend fuel rather than the conventional gasoline available to consumers. “It is virtually impossible to identify fuel ethanol testing protocols in which ethanol is simply added to gasoline; in government study after government study the base gasoline makeup is changed when tests are performed with ethanol,” Vander Griend recently stated. “It is time for the domestic ethanol industry to better understand the value of ethanol, learn how it is tested, and then offer solutions that deliver the most benefits. Ethanol offers much more value than it is traditionally given credit for, as far as improving efficiency and reducing emissions. However, current policy and regulatory challenges have hidden a significant part of what ethanol has to offer.”

Because the presence of ethanol makes the engine behave differently, these theoretical estimates, and EPA tests don't hold across the board, or hold in general! Clearly, see below, some vehicles get better mileage using intermediate blends.

An important study by Ricardo Engine Consultants, entitled Technical Assessment of the Feasibility of Introducing E15 Blended Fuel in the US Vehicle Fleet, 1994 to 2000 Model Years, September 2010, concluded that with reasonable certainty "The analysis concluded that the adoption and use of E15 would not adversely affect fuel system components in properly engineered vehicles, nor would it cause them to perform in a sub-optimal manner, when compared to the use of E10." Ricardo is a long standing very well respected independent consulting firm, and would not put their name against such a conclusion if they expected customer's to have trouble. In spite of Ricardo's work and the Oak Ridge National Laboratory studies, and the University of Minnesota studies (see below), the EPA defaulted on the safe side and only permitted vehicles for MY 2001 and later to get the waiver. As the map shows, at the moment a large number of states have legislation that is blocking even this modest increase in ethanol (see map below). We hope that science, not politics will inform this next small move forward.


3.2.2. Main Conclusions from the Ricardo Study of 1994-2000 vehicles

Ricardo is one of the primary auto designers/consultants. Their report thus has very high weight. Here are their conclusions:

The primary effect of increasing the ethanol content in gasoline is the enleanment of the air-fuel ratio and the key issue is the ability of the vehicle’s engine management system (EMS) to compensate for it – Increasing the ethanol content from E10 to E15 will not affect the air-fuel control in vehicles that have a switching oxygen sensor.

Studies by the Coordinating Research Council (CRC, Report No. E-87-1) have shown that vehicles with open loop adapted fuel trims have more consistent catalyst temperatures when using fuel blends between E0 and E20, which reduces the potential of catalyst degradation due to temperature. 

Tailpipe Emissions - Assuming that the EMS can maintain a stoichiometric air fuel ratio in the engine, the catalytic converter should be able to process the engine-out emissions into non-polluting species, with no change in this capability between E10 and E15. 

Evaporative Emissions - Since vapor pressure of E15 is lower than E10, evaporative emissions related to vapor pressure would not increase and may, in some instances, decrease depending on the exact formulation of the gasoline source. Insufficient data exists to predict the effect of E15 on permeation based evaporative emissions – in some cases they may be lower than on E10.

Overall, “The analysis concluded that the adoption and use of E15 would not adversely affect fuel system components in properly engineered vehicles, nor would it cause them to perform in a sub-optimal manner, when compared to the use of E10.”


3.2.3. Studies of the Effects of 15%, 20%, 30% and Higher Ethanol Addition to Gasoline in Both Flex-Fueled and Non-Flex Fueled Vehicles

We are told that we can't use blends other than the E10 that is now considered by everyone as 'regular gas' and E85 made for Flex Fueled vehicles. Well this is a great disservice to us and to our country. As we shall see below, using higher blends on ordinary vehicles may give you better value, and using blends lower than E85 in Flex Fueled vehicles may also give you better value.

As things stand now, you can certainly legally put lower ethanol blends in your Flex Fueled vehicle (but you are not told by your auto manufacturer what the blend that your car will run best at). So you must experiment - (read below first). How would you experiment if there are no blender pumps in your area? Well, for example with 1/2 a tank of gasoline, fill the rest with E85, and check whether your mileage has changed for the better or for worse. When you find it better, like some Flex Fuel Yukon drivers do, try filling a 1/3 of your tank with E85 and the rest with gasoline, and compare results (this may take a few tank fills of each blend if you don't drive a consistent pattern). In this way you cover a wide swath of blend results, but you get an idea of where you would like to be. At this point you will start wondering why you are not given this info by your auto company. The Minnesota Study and the Phenomenon of an Optimum Blend of Ethanol in Gasoline

In a fascinating study done by the University of North Dakota and the Minnesota State University in 2007 by Shockey and Aulich, it was found that different vehicles had a 'sweet point' in terms of mileage changes using various amounts of ethanol in their gasoline. Amazingly, they tested both Flex Fueled cars and just gasoline cars. Below we show the 'sweet spots' for both a 2007 Flex Fueled Chevy Impala, and a 2007 gasoline Chevy Impala.

Figure 12, below, and the table beneath it show the dramatic occurrence of a 'sweet spot' where the mileage significantly INCREASED when 20% ethanol was mixed in the with gasoline. The red line is the expected decrease in mileage due to the use of ethanol (ethanol, on an equal volume basis, has only 67% of the energy gasoline has). However, the actual mileage was very different. We will explore some of the reasons late (see 3.2.5. "How is it possible..." below). But it clearly argues that the use of E20 in a Flex Fueled Impala is an option to get the best bang for the buck (remember ethanol is cheaper than gasoline), depending on the cost of gasoline. It is giving 15% better fuel economy. However, there is another possible choice for best 'bang for the buck', and that is E50. At E50 the mileage is essentially the same, so the lower cost of ethanol will weigh more against the cost of the 50% gasoline. If driver had the option, then they could determine what was the most economical fuel blend for their vehicle, but clearly certain ethanol blends are going be money winners.

When the same tests were done on a non-flex fuel Chevy Impala, there was also a sweet spot, this time at 40% ethanol. As the table shows, at E40, there was only a slight decrease (24.51 to 23.30) in gas mileage from using E10, again less than the theoretical decrease. In this case note that using 40% ethanol also defied the theoretical decrease, this time by significantly more, even though the mileage went down to 22.65. Now this sets up an interesting situation. If Blender Pumps existed, one would have to calculate whether the cheaper price of E40 over Tier 2 gasoline made it a better deal than the situation found using E20, and again whether either of these was a better deal financially than using straight Tier 2 gasoline. Certainly, using E20 is a better deal than using E10, as the mileage does not decrease, but in theory the fuel is cheaper. In reality, Brazilians have this flexibility and do these calculations often to save money. Americans, of course, do not have this opportunity, despite the high costs of gasoline we have to pay.

The Impala lost 5% using 20% ethanol in the gasoline, but should have lost 6.5%. Using E40 it lost 7.6% using 20% ethanol, but should have lost 13%. As discussed below many non-flex fueled vehicles have been tested, and roughly half have shown mpg gains at 20% ethanol. A 2005 Impala showed a 1% gain (vs. the 5% loss above).

But you may ask: what is the difference in the two Impala's that could cause such a large difference in fuel economy performance? Certainly the seals and static safety measures and reinforced values, i.e., mechanical things that have to do with wear do not effect the mileage. The only difference that this could be attributed to is that the computer on the flex fueled car allowed more charge to go in and could advance the spark timing to give the impression of higher compression ratio and therefore more efficient running. The fuel injector on an E85 vehicle may also be larger, see Flex Fueled Vehicles subsection in Ethanol.

The results for other non-Flex Fuel vehicles show even better results. Two other non-flex fueled vehicles that were tested are shown below. The 2007 Ford Fusion and the 2007 Toyota Camry both allowed drivers to use E30 with no loss of fuel economy, but, of course, with the savings in cost and emissions, and the reduction in oil use.

Three things are clear from the above study:

1) Very subtle differences in the way the onboard computer handles the increased amount of ethanol, will determine whether you get a gain or loss of mileage at all of the blends tested. Thus, if automakers 'tuned' their computer programs to using ethanol, many more vehicles could take advantage of its properties.

2) Based again on these studies, it may make sense for Flex Fuel vehicle to use a lower fraction of ethanol in their vehicles than E85. U.S. practice has clearly shown that customers shy away from using E85 in these vehicles because they either calculate or use DOE numbers that show the slightly reduced price of E85 does not compensate for the theoretical reduction in mileage. And at E85, as you can see above, the actual mileage does get reduced almost by this theoretical amount. However, if they used lower blends, of say E20, or E40 or E50 they would be getting a better deal!!! They would be paying less and getting the same or better mileage using these blends in their Flex Fueled vehicles -- if of course, they had this Impala, or a vehicle whose computer behaved similarly.

3) Based on the Minnesota studies (see more below) it certainly appears that stock 'gasoline only' vehicles can use up to E20. (We pointed out above that all 'gasoline only' vehicles from at least 1994 can use E15.)


3.2.4. A larger Minnesota Study using E20 on non-flex fueled ('gasoline only') vehicles

In November 2008 the University of Minnesota issued a Demonstration and Drive ability Project Report to Determine the Feasibility of Using E20 as a Motor Fuel. The report is entitled "Demonstration and Driveability Project to Determine the Feasibility of Using E20 as a Motor Fuel" by Kittelson, Tan, Zarling, Evans and Jewitt.

Eighty vehicles, consisting of 40 matched pairs, were selected from the University of Minnesota Twin Cities Fleet Services car pool in order to determine whether E20 can be used effectively in current vehicle technology. These were ordinary 'gasoline only' models. The selection of vehicles included a wide cross section of model year 2000 through 2006 Chrysler, Ford, General Motors, and Toyota vehicles; all vehicles were fuel-injected and included hybrid models. The vehicles are part of the University’s system of vehicles that include service vans and are used as standard transportation in both city and highway use. Fuel for this study was commercially available non-oxygenated gasoline and gasoline up blended to 20% volume with commercially available fuel grade ethanol.

One vehicle in each pair was fueled with non-oxygenated gasoline while the other vehicle in the pair was fueled with 20 percent ethanol blended gasoline. The vehicles were driven over the course of a year to expose the vehicles and the fuels to weather conditions typical of each of the four seasons. Drivers of the vehicles were trained to complete incidents logs to track issues associated with the performance of the vehicles. Blind refueling cards were supplied for each individual vehicle in order to prevent bias toward either fuel. Experts in vehicle derivability performance were brought to Minnesota once each season to provide and assess additional fuel performance data.

It showed, that after 13 months of tests with two of each of 40 vehicles that the following vehicles actually had mileage increases on E20.

Table 1 shows the makes and models tested.

  % change  
2005 Chevy Malibu 2%  
2005 Chevy Impala 1%  
2005 Chevy Astro #1 15%  
2000 Chevy Astro #2 19%  
2000 Chevy Astro #3 6%  
2003 Ford Focus #1 6%  
2003 Ford Focus #2 24%  
2000 Chevy Express 2500 19%  
2001 Ford E250 #1 11%  
2001 Ford E250 #2 11%  
2006 Chevy Express 3500 2%  
2000 Ford F450 28%  
2003 Ford E150 2%  
2005 Ford Escape Hybrid 3%  
2005 Chevy Malibu 2%  
2005 Ford Escape Hybrid 3%  
2000 Workhorse UCBC 22%  
2000 Workhorse UCBC 10%  
2005 Ford Crown Victoria 4%  
19 vehicles average 10% AVERAGE Mileage Increase

Remember, a 6.5% loss in fuel economy is suggested by the amount of energy missing from E20. This list includes a number of very popular vehicles. Their average mileage increased by 10% over using gasoline in them.

Now this chart only shows the 19 vehicles that had a mileage gain. What about the other ones? First it is import to point out that many of the other vehicles in the tests that had lower mileage would not be considered consumer vehicles or even light duty vehicles, thus we are not concerned with their performance. But, even more important, looking at the results above for the 4 cars presented in the Shockey and Aulich study, we see that at E20, 3 of them did get worse mileage at E20, but 2 of these got better mileage at E30! E30 was not tested in this study, so we can't know how all of the vehicles in this test would have performed at E30.

The 20 percent ethanol blended fuel proved effective at both powering the vehicles successfully and was also non distinguishable in performance by either the University drivers or the professionally trained drivers.

This study begs the question: why shouldn't car companies enable us to use 20% ethanol, or higher blends, so we can save money? Earlier South Dakota study of 3 cars and E-10, E20 and E30

In this study of a 2005 Chevy Impala, a 2005 Toyota Camry and a 2005 Ford Taurus - all gasoline only vehicles. This study

The results are shown in the graph below. The fuel represented by the blue bar is not available to the pubic.

As we now know, different vehicles react diferently to mixtures of ethanol and gasoline. This reinforces the above studies, and points out that each vehicle must be optimized independently.

Looked at independently, and from today's situation where all gas pumps distribute E10, not E0, the comparision of usage of E20 and E30 must be made to E10 mileage. The 2005 Chevy impala should be run on E30 where it gets (27.89-27.43)/27.43 = 1.68% better gas mileage; the 2005 Ford Taurus should be run on E20 where it gets (24.64-23.85)/23.85 = 3.31% higher mileage; and the Toyota Camry should be run on E10 (where it actually gets the same mileage as on pure gasoline).

Another way to evaluate the economy of using ethanol blends the cost per mile of these 3 cars were compared, and as we see below, even the Camry, with no apparent mileage advantage shows significant cost advantage when using ethanol blends as high as E30.

Top Fuel economy comparison of two different test series

But first, since there is great interest in fuel economy, lets look at their results. The report summarizes: "changes in fuel economy were consistent based on fuel type and the change in energy density of the ethanol blends—approximately a 3.5% decrease in energy for every 10% of ethanol in the fuel." But by inspecting their data tables we see a situation reminiscent of the North Dakota and Minnesota tests, but interestingly different.

It appears that they have only one overlapping vehicle, the 2007 Toyota Camry (not Flex Fuel). So lets look at it. The Shockey et al results are immediately below and the Knoll et al 2009 results are below Shockey's.   


As we can see the Shockey results show the Camry looses mileage for E10 and E20, but remarkably recovers at E30. However, the Knoll results (look at the FE/100 -- FE=Fuel Economy) show that the Camry does not lose mileage between E10 and E20, the difference is within the error of the tests, and has its greatest loss between E0 and E10 - there is no data for E30. Why is this so? They are both 2007, both 2.4 Liter engines. Was it the test cycles or the mileage, both which were different? In any case the Knoll Camry did not follow Knoll's average trend. It did not decrease in mileage between E10 and E20. Neither did the test they did with a 2003 Camry. We are looking further into this very sparse evidence.

There is also overlap between Minnesota experiments by Kittelson et al 2008 with a Ford Crown Victoria, and Knoll et al. 2009 with a Ford Crown Victoria. Kittelson testing a 2005 Crown Victoria for over 13 months found a 4% increase in gas mileage using E20. Knoll found surprising little decrease in mileage in the 1999 Crown they tested (within the errors of the tests, see right), certainly again not following the rule of thumb of 7% decrease. Again the discrepancy may have many roots, but there is one, and it needs to be better understood.



3.2.5. How is it possible that better mileage can be obtained?

Drivers of flex-fuel vehicles (FFVs), which are approved for midlevel blends, also often report that they experience fewer miles lost when using E30 as compared to E85. Sometimes they say E30 gives them as many miles per gallon as regular unleaded, and it often costs a few cents per gallon less than unleaded. The evidence suggests that E30 may be the optimal blend for vehicles, and it presents an interesting case for improved testing of midlevel blends to determine just how high the ethanol-to-gasoline ratio can be in the nation’s vehicles.

An important supporter of the higher blends is Ron Beazley of Ricardo Engine Consulting, the famous engine company. He said "the EBDI vehicle test program will evaluate performance using various ethanol fuel blends." “We think there’s a blend compromise somewhere between E35 and E50 that gives good performance with good fuel economy, and will prove the cost-competitiveness of this technology.”

How is it possible to get better mileage on a fuel with less energy? Remember, the more ethanol that is added to the gasoline, the less energy each gallon of the fuel has in it. However, the 4 factors that will give your engine the most power are:

1. OCTANE - The rating of fuels’ ability to resist detonation and/or pre-ignition. Octane is rated in Research Octane Numbers (RON), Motor Octane Numbers (MON), and Pump Octane Numbers (R+M/2). Pump Octane Numbers are what you see on the yellow decal at the gas stations and represents an average of RON and MON. VP uses MON because this test method is more prevalent in racing. Most other companies use RON because it is higher, easier to come by, and sounds better in marketing messages. Don't be fooled by high RON numbers or an average -- MON is the most important for a racing application. However, the ability of the fuel to resist pre-ignition is more that just a function of octane.

2. BURNING SPEED - The speed at which fuel releases its energy. In a high-speed internal combustion engine, there is very little time (real time - not crank rotation) for the fuel to release its energy. Peak cylinder pressure should occur around 20° ATDC. If the fuel is still burning after this, it is not contributing to peak cylinder pressure, which is what the rear wheels see.

3. ENERGY VALUE - An expression of the potential in the fuel. The energy value is measured in BTU's per pound, not per gallon. The difference is important. The air fuel ratio is in weight, not volume. Remember, this is the potential energy value of the fuel. This difference will show up at any compression ratio or engine speed.

4. COOLING EFFECT: The cooling effect on fuel is related to the heat of vaporization. The higher the heat of vaporization, the better its effect on cooling the intake mixture. This is of some benefit in a low rpm engine, but can be a big gain in high rpm engines.

Thus, the answer is in how it enters the combustion chamber and how well it burns. When alcohol enters the cylinder of your engine, it cools the region as it expands into the chamber. This allows a greater charge of air to enter, enabling more complete combustion. Furthermore, the ethanol component of the fuel burns cooler and faster than gasoline. Thus, less fuel energy is lost via heat transfer, and more of the fuel is burnt during the time available, which is shorter because timing of the spark can be delayed to effectively increase the compression ration, thus creating more energy to push the piston; rather than having the unburnt fuel go out the tailpipe. We examine this further on the page "the potential of ethanol in IC engines" here.

The large variation in mileage increases shown is attributable to a number of reasons. Clearly, the way the vehicle was driven will have an impact. But, beyond that, and according to the professor directing the experiments, the flexibility and restraints of the onboard computer program have a role to play. It is suggested that the more adaptable the onboard software, the more likely it will enable the qualities of the ethanol to be utilized. One of the most important flexibilities is the ability of the oxygen sensor and computer software to sense the ethanol, and advance the timing of the engine to account for the much higher octane ethanol has, thus increasing the compression ratio, and therefore the power output.


3.2.6. What about low speed torque?

Computations by Gravalos et al. show that over the range of engine speeds the ethanol blends E10, E20, E30 will give better brake torque than gasoline.

Experiments by Boretti (2010) also show that E100 gives better than 50 Nm of torque than gasoline.

Experiments by Ricardo Engines Company on a dynamometer show that SI engines can achieve higher low speed torque with less cylinder pressure.

3.2.7. Need for an ethanol blend mileage 'performance' map for each vehicle

Clearly, from the above figures and tables we can see that if we have such 'performance' data for the vehicles we bought, we could make informed choices that could save us money, and induce us to used less oil.

Perhaps we should ask our dealers about it. Especially if we own Flex Fueled vehicles, and don't use E85 because of the reduced mileage at 85% ethanol in these vehicles. By doing so we can seed the information in dealer's minds.

Another possibility is that third party independent auto 'enhancer's can do the tests and report on the results.

Another possibility is that vehicle owners themselves, who own E85 vehicles could do the tests on their own vehicles, and report them, perhaps a Website could be set up, or we could publish them here.

There are more options. As we will show in the next chapter, engines can get MUCH better performance when using ethanol, but the auto companies must design around ethanol's strong properties, not around gasoline as the basic fuel.


3.2.8. Can a 'Gasoline Only' Vehicle use these higher blends?

This is a very important question. We will not have the final answer here, but there is mounting evidence that many 'gasoline only' vehicles can use modest amounts of ethanol without any noticeable issues.

For years, in coffee shops and grain elevators across the upper Midwest, independent thinkers have voiced their opinions on the benefits of midlevel ethanol blends. Tales of fueling the old Buick, or otherwise unapproved vehicle, with E20 or E30 without experiencing any of the dire consequences threatened by auto manufacturers are not hard to come by, although getting anyone to report the results of their own private fuel test on the record are not so easy. The nonconformists are often corn farmers eager to use as much ethanol as they can and curious to see what will happen if they bump up the blends. They blend it themselves by partly filling the tank with E85 and finishing it off with E10. Or, when available, they use a blender pump. These types of do-it-yourself experiments are certainly not recommended by the ethanol industry nor by the automakers, who say unapproved fuel use will violate warranty agreements. But the fact is, people do it anyway.

One independent authority is Marc Rauch, the Executive Editor of The Auto Channel and the ( Rauch states on Jan 3, 2013 in response to the AAA saying E15 will damage older cars, that "E15 will not damage the engines of vehicles older than 2012. It has been extensively tested. It can be safely used in all modern gasoline-powered vehicles manufactured since the early 1990's, whether they are "flex-fuel" vehicles or not. Incidentally, when the EPA conducted their tests on E15 and gave their "clean bill of health," they also tested E20 and had the same positive conclusions."

He continues "I have been test driving vehicles for 25 years and have regularly used various blend levels of gasoline and ethanol with no negative reactions. Furthermore, I own and drive a non-flex fuel 2002 Ford Taurus that I run on high blend levels of gasoline and ethanol. My vehicle suffers from no problems that are not normally associated with all gasoline-powered vehicles."

He finally asserts "The misinformation that Lauren Fix quoted is just part of the routine lies circulated by the American Petroleum Institute and other anti-ethanol entities to discredit any viable alternative fuel solution. I would be happy to provide you with, or direct you to correct information."

The Ricardo study, referenced above, has published the following table of fuel system materials - locations and compatibility.

Although it only indicates the compatibility up to E15, it also indicates that the component changes that may be need to be made for higher blends are well defined. Presumably they could be upgraded by your dealer or even your corner garage.

Next we talk about some of the very large number of independent experiments on standard "gasoline only cars" that have been run on E85 (85% ethanol). We start with the following video show a remarkable experiment. Uploaded on Aug 12, 2007 This is a video of a 2000 Chevy Tahoe which was run almost exclusively on E85 Ethanol for over 100,000 miles. The amazing thing is that this is NOT a Flex Fuel vehicle-it was not Flex Fuel ready from the factory. They probably used an E85 conversion kit, but do not mention this in the video. The Tahoe's engine was taken apart and inspected. The results prove that E85 will not harm a standard engine, fuel pump, fuel lines and other components of the fuel system. The results showed that the engine was in excellent condition.


Lets continue with a report from the University of Minnesota. Bonnema et al. 1999 tested 15 vehicles....more to come. How the Engine Computer Decides how much fuel to use

First here is how your engine decides how to use the fuel you put into it. We quote from Shockey, Aulich, Jones, Mead and Steevens 2007 who did the North Dakota and Minnesota tests:

"Virtually all vehicles manufactured since the early 1980s utilize a computer to monitor and adjust specific engine parameters that affect fuel economy and tailpipe emissions. These systems attempt to adjust the amount of fuel delivered and ignition timing to the optimal level for performance, drivability, and emissions.

The air/fuel ratio (AFR) on all cars utilizing computer controls is primarily controlled through the interaction of the fuel injector, oxygen sensor in the exhaust system, and engine computer. While the vehicle is cruising or driving under light to moderate load, the engine control unit (ECU) tries to target a stoichiometric AFR. A stoichiometric AFR means that there is a perfect mixture of air and fuel so that when combustion takes place, the only products are CO2 and water. The AFR is controlled through the amount of time the fuel injector is turned on by the ECU; the longer it is on, the more fuel is added to achieve a stoichiometric AFR. The injector “on-time” is controlled by the ECU based on many sensor inputs. However, the primary sensor used is the oxygen sensor.

The oxygen sensor is placed in the exhaust stream of the vehicle between the engine and the catalytic converter. It sends a signal to the ECU that is a function of the amount of oxygen in the exhaust. If there is not enough fuel in the air–fuel mixture entering the engine, the oxygen content of the exhaust is high, indicating a “lean” AFR. A signal is sent to the ECU requesting more fuel. If the oxygen content of the exhaust is low, the air–fuel mixture is considered “rich.” A signal is sent to the ECU requesting less fuel. The signals sent to the ECU allow fuel adjustment to occur approximately once a second. This is referred to as “closed-loop operation.”

However, there are times when the engine requires a mixture that is not stoichiometric. These conditions include, but are not limited to, a cold start and/or a wide-open throttle situation, which requires a richer mixture than a light cruising or idle condition, which requires a leaner mixture to obtain improved fuel economy. Also, the oxygen sensor does not generate a signal until it has reached operating temperature, which can take several minutes of engine operation to attain. During these times, the oxygen sensor signal cannot be used by the ECU for engine control.

The ECU must, therefore, estimate how much time to hold the injectors open during those conditions. The ECU has an internal “target fuel map,” based on gasoline, that has been generated by the automobile manufacturer. The ECU uses the target fuel map to optimize the AFR for specific engine operating conditions. Ethanol contains oxygen, and when it is added to the gasoline and combusted, the oxygen content of the exhaust increases, indicating a “lean” AFR. The amount of injector on-time required changes for a specific operating condition.

During closed-loop operation of the ECU, the interaction of the oxygen sensor and fuel injectors is adjusted to the oxygen content of various ethanol blends to obtain the stoichiometric AFR. However, during open-loop conditions, the ECU varies the amount of time the fuel injector is turned on based on the target fuel map held in the ECU program. This program has been developed for gasoline and E10. Those values will not deliver the proper amount of fuel with higher ethanol blends. This is where the short-term and long-term fuel trim values come into play.

If more correction than normal is needed, as determined by the ECU target fuel map, the ECU uses the short-term fuel trim strategy option to compensate. The ECU short-term fuel trim programming allows the ECU to adapt and adjust the injection duration quickly, delivering the correct amount of fuel. When higher ethanol blends are used, the initial output of the ECU results in a lean mixture. When a specific injector on-time is commanded, the oxygen sensor signals a change in operation, by changing either to a rich or lean AFR. However, if the response is not what the ECU anticipates, the injection timing is adjusted until the expected response is observed. This phenomena is referred to as “learning.” Short-term fuel trim is a very fastresponding adjustment, while long-term fuel trim adjusts via the “target fuel map” stored in the ECU.

The procedure followed to “learn” each new ethanol blend involved starting each vehicle a minimum of three times, after the engine coolant temperature was below 160°F, and driving the vehicle on a predetermined test loop that had a variety of driving speeds and conditions. A diagnostic scan tool was used to monitor the short-term fuel trim values to ensure that they varied no more ± 3%, which is an acceptable range for emission testing."

With this in mind, lets see what can be done.


3.2.9. Using Ethanol Blends in E85 vehicles

Steve Vander Griend of ICM says, "Ethanol’s high octane level has been a limiting factor in most previous testing because the limits of the engine are reached before the octane is fully utilized. This is a particularly poignant issue with regard to E85, which is well-known to have more horsepower than regular unleaded, but as yet has been unable to achieve the same efficiency rates. This could likely be due to the fact that engines are simply not able to fully utilize the fuel."

Vander Griend continues "For the average FFV, you will put 28 percent less energy in the tank compared to gasoline, the average mileage loss is only 20 percent or with two studies, 15 percent. This is never mentioned by ethanol critics, they will only believe what they read on the internet".

"The reason for the gain is a combination of a few aspects. Ethanol’s cooling effect reduces pumping loss and some reduction in heat rejection. Ethanol does burn cleaner and has a faster flame front, meaning more energy is released at top dead center where it is needed. Ethanol’s cooling effect also reduces the octane needs of the engine which helps the vehicle in not needing to reduce timing. All this of course is overshadowed since the oil companies blend ethanol to a cheaper octane lower quality gasoline.

So what's to be done in the short run and in the longer term? Vander Griend says there is likely a small cost increase for auto manufacturers to make these modifications, but if the industry can guarantee a waiting market for those engines, manufacturers can make it happen. Therefore, the strategy to expand blender pump availability simply has to work if large numbers of the U.S. drivers can ever be expected to use E30 or another midlevel blend. We discuss Blender Pumps below.

However, Anderson of Ford writes: "FFVs could play an important transition role by providing compatibility with both E85 and future intermediate ethanol content blends, and could become desirable if higher ethanol blend fuels are attractively priced." Clearly if you filled a third of your tank with E85, and fill the remainder with E10, you will be running on ~ E30 and you can check your mileage. With a hand calculator you can change this ratio and find out with the optimum blend is for your vehicle. You should save money running on this optimum blend.

Anderson also writes: "While FFVs could be optimized for high ethanol content fuels today (published 2012), these vehicles would still need to provide competitive performance on the predominant fuel (currently E10) in order for them to be attractive to consumers at the time of purchase. An E85-optimized FFV that is fueled with lower- RON E0 or E10 fuel would show a considerable and unacceptable decrease in power and torque and a moderate increase in fuel consumption." But since our E85 vehicles are running in these conditions  from the day they are delivered, we don't know what we are missing. Its time to bring this to the attention of our auto manufacturers.

But there is potentially more good news, turbochargers. For example, E85 made from a 97-RON blendstock exhibited a total ON of 133 in a turbocharged DI (direct injected) engine. Many new vehicles have turbochargers, they on in the Ecoboost engine line of Ford and the Ecotec engines of GM. Clearly, for these engines the auto manufactures should be able to get more power out of these vehicles when using ethanol.


3.2.10. How can we use our E85 vehicles to test the intermediate blends of Alcohols?

There are three ways we can test our own F85 vehicles. First, making use of existing blender pumps to create our own Ethanol Blend Mileage Performance chart, similar to the charts in Section above. Second, using an Ethanol Content Analyzer, from Zeitronix you can measure the precise amount of ethanol in your fuel system. Third, without the need of an external meter, but just using the gas tank measurement indicator. % of ethanol on discrete segments (see picture below). Using a Ethanol Content Analyzer blender pumps are largely in the mid-west. They allow ethanol dispensed cheaply and easily Using your hand calculators.

3.2.11. Distribution via Blender Pumps

Blender pumps are shown in the photos above. The first indicates the octane being purchased for each blend, and in the second photo we can see the prices for the blends more clearly. These pumps allow a number of predetermined Blends of different fuels to be made and put into your gas tank.

Blender Pumps are increasing around the country. In North Dakota 60 were installed in 2010. But Blender pumps are expensive – maybe $30,000 a pop – and with all the flex-fuel manufacturing in the US, there are still around 8 million flex fuel cars out of a total US fleet of 250 million – which makes it difficult for a retailer to justify putting in a blender pump anyway. Not that, making 5-10 cents a gallon as they do, that they are howling for new fuels that bring new investment requirements, in any case.

Coskata responds with an interesting point. Pumps don’t last forever – they need to be replaced anyway, just around once every 10 years – why not simply replace a standard pump with a blender pump? That way, the conversion cost is absorbed into the normal capital replacement schedule. By 2022, you have blender pumps in broad distribution.

Should US manufacturers continue their commitment to, say, 50 percent or more of their fleet being flex-fuel enabled – by 2022, using a 17-year replacement cycle for the US fleet, perhaps as much as 33 percent of the fleet could be flex-fuel enabled, without changing the game on manufacturers.

Furthermore; “If we can develop a solid infrastructure and establish a blender pump network, within three to five years, we could potentially anticipate the pricing between regular and premium fuels to be cut in half through the availability of midlevel ethanol blends,” Vander Griend stated. “This can offer the auto industry the framework to increase compression ratio and in turn, enable the auto industry to manufacture more turbo-charged vehicles. Consumer education is paramount to this initiative. Consumers who understand octane does indeed matter because it improves mileage, provides savings at the pump, and mitigates adverse health effects, are consumers who will choose ethanol.”

So how does a Blender Pump work? In the figure below we see that there are two tanks underground, one with gasoline and the other with ethanol.

Reduced costs of ethanol blends:


The Rural Energy for America Program (REAP) offers grant and guaranteed loan funding for eligible rural businesses to assist with the cost of purchasing and installing flexible fuel pumps for mid-range ethanol blends (including E85).Rural areas are any areas other than: (1) A city or town that has a population of greater than 50,000 inhabitants; and (2) The urbanized area contiguous and adjacent to such a city or town, as defined by the U.S. Bureau of the Census using the latest decennial census of the United States.

USDA Rural Development is seeking applications via the Rural Energy for America Program (REAP). The program purpose is to fund renewable energy systems and energy efficiency improvements. Eligible applicants include rural small businesses and agricultural producers. Flexible fuel pumps remain among the list of renewable energy projects which are eligible for REAP Funding.

Grant requests can be made for up to 25% of total eligible project costs.

Grant/guaranteed loan combination requests can be made for up to 75% of total eligible project costs, typically 25% grant, 50% loan guarantee request.

Guaranteed loan only requests can be made for up to 75% of total eligible project costs.

Feasibility study requests can be made for up to 25% of total feasibility study costs up to a maximum of a $50,000 request. An independent third party must perform the feasibility study.

If you are a Rural Small Business or Agricultural Producer that is contemplating the feasibility or installation of the flexible fuel pumps, please contact your local Rural Development representative as noted below to explore their feasibility study and equipment installation programs.

Application deadline is April 30th for: Grant Applications to install technology, Grant/Loan Combination Applications to install technology, & Feasibility Study Grants.

Application deadline is July 15th for: Loan Guarantee Applications

BYO Ethanol to offer grant writing services through Sage Project Consultants to station owners for USDA REAP Flexible Fuel Pump Installations For the second year, the Blend Your Own (BYO) Ethanol Campaign, a partnership between the American Coalition for Ethanol (ACE) and the Renewable Fuels Association (RFA), is offering to offset costs associated with grant writing fees for these projects. The projects are designed for retail fuel station owners seeking assistance with the purchase and installation of renewable fuels infrastructure equipment through the USDA Rural Energy for America Program (REAP) . In FY2011, Sage wrote and helped submit a total of 21 USDA REAP applications representing 15 different states that successfully secured $1.3 million in total funding. For the 2013 funding cycle, we are poised to help retail fuel station owners across the country prepare and submit competitive applications to USDA that represent 25% of their eligible project costs associated with the purchase and installation of new blender pumps. The deadline (April 30, 2013) is rapidly approaching to submit grants for this year’s funding, so please act quickly if you are interested in taking advantage of this program! Contact or 605-728-5303 for more information and to discuss your project.

Learn more at

An application checklist is at:

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