E10 fuel at QuikTrip

[YoungTulsan]

How many people have noticed a difference in gas mileage since QuikTrip started diluting their gasoline with ethanol?  In the second half of last year (I'm sure there was a thread about it with the news stories) QuikTrip and Murphy USA (the gas pumps in front of Wal-mart) started using a 10% Ethanol 90% gasoline blend.  As far as I can see, there is no visible labeling or signage accompanying the switchover.  QuikTrip's website does have an ethanol FAQ up telling you why you love ethanol and why it is good for your family and America.

My gas mileage has gone down, which I usually just brush off as me not taking good care of my car like I should - but it has noticeably been down.  I'm about to do some comparisons between QT gas and the 100% gas sold elsewhere (the station at 21st & Lewis is very vocal about it, with signs talking crap about E10, and labels on the pumps saying which choice has what blend) - to see if I really get an improvement by switching back to 100% gas.

What other places in town sell 100% gas?  Is it all Phillips 66 stations, or just some?

[cannon_fodder]

A gallon of ethanol has only 80% of the energy by volume as a gallon of gasoline.  With a 10% ethanol blend your mileage will probably go down.  Plus some numbers in...

(Gas Fuel Economy * % gas) + (ethanol economy * % ethanol)  
(100% * .9) +  (80% * .1) = .90 + .08 = 98%.

So you lose about 2% of your fuel economy with standard 10% ethanol blend.

Feel free to correct my math (I think it's right) or fill me in on physics based energy conservation crap that I may not know.  But 2% seems right to me.

[YoungTulsan]

If the 80% figure is true, then the math is right.  You lose 20% of energy on 10% of your fuel, so you would lose 20% of 10%, or 2%, leaving 98%.

Real world figures, thats what I am wanting to find out.  I've seen a few internet posts claiming there was a 2mpg difference between QT E10 gas and Phillips 66 100% gas.  I know internet posts are not scientific, or even necessarily true - Here is a sample (the comments at the bottom) http://www.tulsaworld.com/business/article.aspx?articleID=071003_238_E1_hSome27283

Dropping from 17.5mpg to 15.5 mpg is around an 11% drop.

I'll do my own comparisons.  What I think I'll do is a 3 tank average for each type (since my driving habits could differ on the short term, and throw the stats off for one tank).

[TeeDub]

Personally I just stopped going to QT as I don't appreciate being told one thing and sold another....    But then again, I am an a**hole.


Here are some other numbers:

Using EIA numbers, an approximate gallon of E10 gasoline should have about 118,285 Btu, 3.2 percent less than regular unleaded gasoline. How that affects fuel mileage in various model cars is disputed by proponents and opponents of ethanol production and consumers of the product.

According to the Renewable Fuels Association, the trade association for the U.S. ethanol industry, fuel injected cars may experience a decrease of approximately 2 percent in fuel economy using E10.

http://www.dailygazette.com/news/2008/feb/03/0203_Ethanol/

[inteller]

A.  76,000  = BTU of energy in a gallon of ethanol (E100)
B.  116,090 = BTU of energy in a gallon of gasoline
C.  .655 = 2/3 = GGE of energy in a gallon of ethanol.  A / B.
D.  1.53 = Gallons of ethanol with the energy of 1 gallon of gasoline.  D = B / A.

[inteller]

quote:Originally posted by TeeDub


Personally I just stopped going to QT as I don't appreciate being told one thing and sold another....    But then again, I am an a**hole.


Here are some other numbers:

Using EIA numbers, an approximate gallon of E10 gasoline should have about 118,285 Btu, 3.2 percent less than regular unleaded gasoline. How that affects fuel mileage in various model cars is disputed by proponents and opponents of ethanol production and consumers of the product.

According to the Renewable Fuels Association, the trade association for the U.S. ethanol industry, fuel injected cars may experience a decrease of approximately 2 percent in fuel economy using E10.

http://www.dailygazette.com/news/2008/feb/03/0203_Ethanol/

yeah, but they won't tell you what older carbuerated cars lose.  And there are plenty of those still out on the road.  I've had one person report a 30% drop in his old ford.

newer cars have been tuned to run on pee water gas, but a lot of cars, some within the last few years are not.

I was at 30+ mpg before Tulsa markets foisted E10 on us, now I'm down to 27-28 depending on how much I use the loud pedal.


but here is a little secret, find out when a station takes delivery.  Then be the FIRST person at that station in the morning the day BEFORE they take their delivery. (this won't work with 24hr places obviously) Ethanol has a tendancy to separate (especially if there is any water in the tank) and is lighter than gas so it settles to the top of the tank.  So what you get is a tank that is closer to E5 because the fuel hasn't been agitated yet.  You don't want to get gas the day of delivery though, because that'll contain high ethanol content, something approaching E15-E20.

[YoungTulsan]

quote:Originally posted by inteller

A.  76,000  = BTU of energy in a gallon of ethanol (E100)
B.  116,090 = BTU of energy in a gallon of gasoline
C.  .655 = 2/3 = GGE of energy in a gallon of ethanol.  A / B.
D.  1.53 = Gallons of ethanol with the energy of 1 gallon of gasoline.  D = B / A.

I'm no physicist.  I've seen it spun that ethanol "burns cooler" (to explain the BTU) - But doesn't heat = energy?  Combustion engines, do they not require HEAT to operate?  If you go purely by BTU, wouldn't that mean Ethanol contains 35% LESS energy for all intents and purposes?

By the 35% theory tho, you're still losing less than 1mpg at 25mpg starting point with a 90/10 blend.

edit - forgot an important "LESS"

[inteller]

quote:Originally posted by YoungTulsan

quote:Originally posted by inteller

A.  76,000  = BTU of energy in a gallon of ethanol (E100)
B.  116,090 = BTU of energy in a gallon of gasoline
C.  .655 = 2/3 = GGE of energy in a gallon of ethanol.  A / B.
D.  1.53 = Gallons of ethanol with the energy of 1 gallon of gasoline.  D = B / A.

I'm no physicist.  I've seen it spun that ethanol "burns cooler" (to explain the BTU) - But doesn't heat = energy?  Combustion engines, do they not require HEAT to operate?  If you go purely by BTU, wouldn't that mean Ethanol contains 35% LESS energy for all intents and purposes?

By the 35% theory tho, you're still losing less than 1mpg at 25mpg starting point with a 90/10 blend.

edit - forgot an important "LESS"

well, that is all in theory with all conditions being perfect....that is in a BEST case scenario.  What you get in the real world is hardly close to that, due to loss of energy at other points. Those numbers are for a lab environment where the burn is controlled, not mimicking the varying degrees of spark that a car provides.

You certainly can't do BETTER though.

[inteller]

required reading:

http://zfacts.com/p/436.html

[YoungTulsan]

quote:Originally posted by inteller

quote:Originally posted by YoungTulsan

quote:Originally posted by inteller

A.  76,000  = BTU of energy in a gallon of ethanol (E100)
B.  116,090 = BTU of energy in a gallon of gasoline
C.  .655 = 2/3 = GGE of energy in a gallon of ethanol.  A / B.
D.  1.53 = Gallons of ethanol with the energy of 1 gallon of gasoline.  D = B / A.

I'm no physicist.  I've seen it spun that ethanol "burns cooler" (to explain the BTU) - But doesn't heat = energy?  Combustion engines, do they not require HEAT to operate?  If you go purely by BTU, wouldn't that mean Ethanol contains 35% LESS energy for all intents and purposes?

By the 35% theory tho, you're still losing less than 1mpg at 25mpg starting point with a 90/10 blend.

edit - forgot an important "LESS"

well, that is all in theory with all conditions being perfect....that is in a BEST case scenario.  What you get in the real world is hardly close to that, due to loss of energy at other points. Those numbers are for a lab environment where the burn is controlled, not mimicking the varying degrees of spark that a car provides.

You certainly can't do BETTER though.

Some of the real world claims I have seen people make equate to the 10% virtually being nonexistant, a total loss in mileage.  When they are selling supposedly 90% gas, it starts to really puzzle me when people are claiming to see losses of OVER 10% (the claims from the TW forum are 11% losses).  I know they can't just put water in the gas, because that would actually disrupt the engine and performance - but it is almost like they've found a filler that causes no discernable difference in operation, yet allows them to sell a "gallon" of gas that is diluted down, only containing 90% or less of actual fuel.

[YoungTulsan]

From that zfacts site:

quote:
How much should you pay for E10 and E85?
If regular gas is $3.00/gallon you should pay
     $2.90 / gallon for E10 (10% ethanol).
     $2.13 / gallon for E85 (85% ethanol).
If regular gas is $2.00/gallon you should pay
     $1.93 / gallon for E10 (10% ethanol).
     $1.42 / gallon for E85 (85% ethanol).

Shouldn't that read: "If regular gas is $3.00/gallon,  meat, dairy, grain, and all other food commodity prices remain the same, and the tax burden remains the same instead of increasing with subsidies, you should pay..."

[inteller]

quote:Originally posted by YoungTulsan

From that zfacts site:

quote:
How much should you pay for E10 and E85?
If regular gas is $3.00/gallon you should pay
     $2.90 / gallon for E10 (10% ethanol).
     $2.13 / gallon for E85 (85% ethanol).
If regular gas is $2.00/gallon you should pay
     $1.93 / gallon for E10 (10% ethanol).
     $1.42 / gallon for E85 (85% ethanol).

Shouldn't that read: "If regular gas is $3.00/gallon,  meat, dairy, grain, and all other food commodity prices remain the same, and the tax burden remains the same instead of increasing with subsidies, you should pay..."

yes again, this is just looking at it from a sterile lab standpoint.  Of course all the other factors come into play too.

[Conan71]

I've noticed I'm getting about 25 miles less a tank than what I used to.  Not sure if it's the age of my truck or the ethanol.  QT seems to be the only 87 octane which does not ping in my engine, so I stick with it when around town.

Personally, my favorite car was the one in the avatar, about two miles per gallon of pure methanol.  But what a rush! A great use of dead trees. [8D]

[MichaelBates]

I used QT gasoline almost exclusively for years. Within the last few months, I noticed that the mileage on my 18-year-old Toyota dropped from about 28 MPG around town to around 22 MPG. I wondered if it might be a mechanical problem, but when I heard that ethanol could affect mileage, I filled up at the 31st & Yale Phillips. I won't know for sure until my next fill-up, but so far my mileage appears to be back where it used to be.

[custosnox]

quote:Originally posted by YoungTulsan

quote:Originally posted by inteller

A.  76,000  = BTU of energy in a gallon of ethanol (E100)
B.  116,090 = BTU of energy in a gallon of gasoline
C.  .655 = 2/3 = GGE of energy in a gallon of ethanol.  A / B.
D.  1.53 = Gallons of ethanol with the energy of 1 gallon of gasoline.  D = B / A.

I'm no physicist.  I've seen it spun that ethanol "burns cooler" (to explain the BTU) - But doesn't heat = energy?  Combustion engines, do they not require HEAT to operate?  If you go purely by BTU, wouldn't that mean Ethanol contains 35% LESS energy for all intents and purposes?

By the 35% theory tho, you're still losing less than 1mpg at 25mpg starting point with a 90/10 blend.

edit - forgot an important "LESS"

Actually, while heat plays a factor with internal combustion, it's not the key factor.  Compression plays a much bigger part in energy transfer.  Still, the less energy stored in a fuel, the less your going to be able to release.  

I've never really thought of the energy loss in ethonal blended gas, but since I drive an SUV that sips a mear 15 miles out of the gallon, I think I just might try running some pure gasoline.  Now if I can just find some handy from a place I feel I can trust (the little mart down the road boasts 100% gas, but they just don't inspire confidence in me)