E10 and lower MPG

[daschrier]

First off, not sure if this is the right forum for this topic....feel free to move.

Anyway, ever since the Boston area switched over to e10, 10% ethanol feul, my milage in my 04 sentra has dropped, a lot. Everything I've read says that MPG with E10 shouldn't go down more than 2% or so, which is like 1-2 mpg. I used to average 30-32 mpg driving around boston, but now I'm getting 24-28 at best.

Could just be a coincidence, but what has everyone else experienced with E10 fuel? My gf told me the other day her car has been getting worse mileage too, and she knows nothing about cars or E10 fuel, so it isn't just me.

Maybe I just need some sea foam, car does have 40k on it now.

 

[T-Keith]

quote:

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Originally posted by Kestas:

If my 60% BTU value is correct, this makes E85 have only 66% the BTU value of straight gas, and $1.98 of E85 is equal to $3 of straight gas.

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Not sure if I get your numbers there, did you mean 1.98 gallons of gasoline is like 3 gallons of Ethanol? 1 gallon of gasoline(E10 actually) was $2.89 this morning, which would be equivelent to 1.45 gallons of E85(currently $2.44) or $3.55. So currently in MN E85 is money behind.

I get 24-28 with my old Lesabre, so I'd consider that bad for a 4 banger. Sorry no non ethanol to compare it to.

 

[sunruh]

the whole ethanol movement is a bad idea.
it takes more diesel to till, plant, harvest, truck, and then mash the corn than the alcohol produced. to only then get a lower mpg in the vehicles it is put in.
bad math backing bad science. or should i say, good pr from the press backing stupidity.

 

[sifan]

Ever since using E10 this summer my 2003 Toyota Echo has been getting 45-47 MPG with daily commute mostly on back roads. My earlier summer gas mileages rarely passed 45. I am not sure the increase in gas mileage has to do with E10 or the use of tachometer. I installed the tachometer this spring, and have been driving with no more than 2K RPM on engine, snd with speed less than 50 MPH, plus slow acceleration and lots of coasting.

 

[Kestas]

T-Keith, I apologize for not being clear with my post, now that I've re-read it. $1.98 for a gallon of E85 is equal to $3 for a gallon of straight gas. Your interpretation is correct also.

You calculated the the E85 is more expensive as-used in your car according to your local market. I wonder how many people will be duped by this pricing, and accepting of this new fuel before they realize they've been had?

It's like something out of the back page of the Consumer Reports periodical, where they compare the new and improved product with the old product so everybody can have a good laugh!

 

[GT Mike]

I notice no difference whatsoever running E10 vs. straight gasoline in my Durango. In fact, some of the best MPG averages that vehicle has delivered have been on E10.

Also, the whole thing about ethanol having less BTU/unit than gasoline is true, however, it doesn't impact MPG nearly as bad as some tend to think. Every FFV reacts differently to it, and GM tends to take the biggest drop in MPG, but Ford and Chrysler FFVs that I've driven have not varied all that much from the mileage they get on straight gasoline or E10. I had a '04 Stratus as a demo a while back, and had enough time to do some comparisons with it on gas and E85. Difference was less than 2 MPG. When you're saving a buck a gallon or more on E85 and only losing 2 MPG, it saves a lot of money.

Negative energy value: I hear the naysayers mention this a lot. My question to you...Where does the energy to refine gasoline out of crude oil come from? Ever do the calculations on that?
A smart farmer would run B100 in his tractors and other implements to harvest the corn that is sold to the ethanol plants.

 

[johnsmith]

(4.64MB, 24 pages):
http://www.fueleconomy.gov/feg/FEG2006.pdf

From page 18 (page 20 in Acrobat):

quote:

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This section contains the fuel economy and driving range values for ethanol flexible-fuel passenger cars and light trucks. These
vehicles are designed to operate on gasoline, E85 (a mixture of 85% ethanol and 15% gasoline), or any mixture of the two fuels.
Annual fuel cost is estimated assuming 15,000 miles of travel each year (55% city and 45% highway) and an average fuel cost of
$2.00 per gallon for E85, $2.20 per gallon for regular unleaded gasoline, and $2.40 per gallon for premium unleaded gasoline.
Fuel economy and driving range values are shown for both gasoline and E85. When operating your FFV on mixtures of gasoline and
E85, such as when alternating between using these fuels, your driving range and fuel economy values will be somewhere between
those listed for the two fuels, depending on the actual percentage of gasoline and E85 in the tank.

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We've had E10 here in my part of Illinois long enough that I honestly can't remember if it made my fuel economy drop or not.

FWIW though, most of the people I hear that are just starting to get E10 in their area report a drop of something like 1-2 mpg. I also remember people in Canada saying they got fewer mpg with US fuel than they did back home. Don't know what they meant, but might want to check into that too if you're interested in all this stuff.

 

[Kestas]

I remember doing some calculations some time ago, figuring out how much BTU is in gas, alcohol, and E10. If I remember correctly, ethanol has 60% the BTU value of gasoline. This means you should get roughly 4% less gas mileage with E10 than with straight gas.

Assuming 30-32 with straight gas, you should be getting 29-31 mpg with E10. There may be something else affecting your gas mileage... e.g., air filter, O2 sensor.

My experience roughly matches the 4% I calculated. This is rather hard to pin down for the average motorist because of the driving variations that can occur with each tankful.

On a political note, imagine all the people who bought into the E10 years back (myself included), and who have no idea what they lost with this fuel, and how it will be even worse to those that buy into E85, without realizing what they lose in gas mileage, even with E85 considerably cheaper at the pump.

If my 60% BTU value is correct, this makes E85 have only 66% the BTU value of straight gas, and $1.98 of E85 is equal to $3 of straight gas.

 

[Kestas]

quote:

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Originally posted by GT Mike:
Negative energy value: I hear the naysayers mention this a lot. My question to you...Where does the energy to refine gasoline out of crude oil come from? Ever do the calculations on that?

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I've been to a number of talks given by engineers from Federal government, whose job is to make these calculations. So, yes, the calculations have been done. They all pretty much agree on what has been historically posted in BITOG.

Methanol has a net negative energy value (not by much).

Ethanol production requires 70% of the energy found in the final product.

Gasoline production requires only a tiny fraction of the energy found in the final product. I forget what the number was, but I have the impression it's at least an order (or two orders) of magnitude less than ethanol. This includes the energy used for exploration, pumping, refining, and transportation to user.

So on a grand scale, gasoline is the better value for energy. The reason were hearing so much noise about it is because of the geopolitical issues that affect gasoline use.

Personally, I think people will be totally oblivious to the real cost of E10 & E85, even if it was priced properly at the pump. It's simply the nature of most people to be narrow-minded and only see the dollar value at the pump. Imagine what the price will be of foods that are based on corn. The food industry will be competing with the ethanol industry for corn product. This can only drive the price of corn upward. The rise in food prices will be a hidden cost for the purchase of E85. We're gonna pay for it one way or another - either at the pump or at the grocery store.

 

[bob_ninja]

quote:

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I used to average 30-32 mpg driving around boston, but now I'm getting 24-28 at best.

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That is a large drop. I don't see E10 alone being responsible. As others said, engine's fuel injection system (how good/smart it is (not)) will have the greatest impact. It is possible that your system doesn't recognize lower energy density and doesn't adjust air/fuel mixture properly. Newer engines (such as flex fuel) actually pay closer attention to what sort of fuel is coming in (don't assume pure gasoline).

I use E? (not sure what it is, guessing no more than E10, perhaps E5) in a bike (carbs) and cars (fuel injection) and didn't notice a significant difference, perhaps 1-2 mpg worse.

Perhaps you could research Nissan documentation to see if you car is capable of adjusting to ethanol mix.

 

[JackFish]

I just went through two tanks of this stuff.
I don't check my milage meticulously, but the seat of the pants performance drop was noticable in my old, carb'ed, straight six 200. This was 90 octane, and the car seemed to lack the power it normally gets.

 

[Ray H]

quote:

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Originally posted by sunruh:
the whole ethanol movement is a bad idea.

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The whole imported petroleum idea is even worse - depending on the goodwill of five sheiks and an immam.

 

[Ray H]

quote:

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Originally posted by sunruh:
the whole ethanol movement is a bad idea.

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The whole world-wide reliance on imported middle-east petroleum is an even worse
idea - depending on the goodwill of five sheiks and an immam. (the spirit of the Barbary Coast pirates lives on...)

 

[sunruh]

while you have a point Ray, consider this:

would you rather use up your own oil, or theirs?

 

[XS650]

quote:

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Originally posted by sunruh:
while you have a point Ray, consider this:

would you rather use up your own oil, or theirs?

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I have long maintained that we should be using up their oil while we work towards weaning ourselves from using so much oil.

 

[Jimbo]

JakFish,

A carbed engine is going to notice a difference because of fixed jetting for mixture control. You are running leaner on E10 than straight gasoline and that is actually the intent. The oxygen in alcohol should improve emissions at the expense of power and mileage.

 

[thooks]

Kestas,

Very good. Your numbers are about as good as they get.

 

[Black Thunder]

ha i wish that 2 percent thing was true


my mileage drops like a rock when i use anything with ethanol.

 

[LARKBILL]

XS650
Right on, right on.

BTW, what year XS650? I owned an XS1A and XS2, both bought new. There were faster bikes and better handling bikes around, but I loved the way they rode and sounded.

 

[old farmer]

Here's what I've noticed. I live in Canada and use Shell V-power 91 octane, without ethanol, and usually get 19-20 mpg (I'll use US gallons for consistency) on hiway driving, speed of 65 mph.
We recently went to Pennsylvania and filled up with Sunoco 93 E10.
My mileage went to 23 mpg.(US)
I think it was the octane allowing the engine management system to optimize the engine for the octane.
When running 91, the knock sensor was probably sensing a slight knock and making the computer retard the timing to a level below what I can hear. So fuel economy dropped.
Higher octane allowed more timing, so fuel economy increased, even with ethanol.
The vehicle is an Aviator with the 4.6 liter 32 valve engine.
I once experimented and filled with 87 octane just to see what would happen. The engine ran fine and had no knock, but mileage went to 10 mpg(US).
Also I don't see the need for E10 in modern cars, their O2 feedback systems will run them to a certain emission level regardless of fuel. If E10 is used, the O2 sensor will see the extra O2 in the exhaust and richen the mixture to get within it's programmed limits. So economy drops.
E10 will probably lower emissions in older carbureted engines, and mileage too.
My vehicle would probably have got even better mileage on the 93 octane gas if it had no ethanol in it.
I think the way to get the best mileage out of ethanol is to use it to make a high octane fuel and build engines with really high compression to take advantage of it's high octane, about 113.