[dude987]

I've heard that you get lower MPG on E10 petro over 100% pure gas. Any truth to this statement? Also heard that the water content in ethanol can contribute to mechanical wear and tear over time. And lastely, that it produces more green house gasses than pure petro. Just wondering why we use E10.

[EJL]

Yes ethanol blended fuels reduce MPG. Ethanol has less energy in it than gasoline does. Ethanol attracts water, so yes it goes bad quickly http://www.fuel-testers.com/expirati...hanol_gas.html . And I believe we use ethanol because of the corn lobby. It can make sense in some circumstances, I'm sure people much smarter than me will reply, but corn based ethanol doesn't make much sense at all.

[RoundelM3]

Ethanol does have a higher octane rating, but as the poster above stated, it does have less BTUs than gasoline and thus less energy. Compared to pure gasoline, ethanol has only roughly 70 percent of the energy in gasoline, and the same amount of ethanol would give you 30 percent less mileage than gasoline.

The corn lobby may have something to do with it, but a lot of the energy companies call it "oxygenating" the fuel for better emissions in the warmer months. Personally, I think that's bunk and they're just finding yet another way to screw us out of more money per gallon by diluting gas with ethanol, which costs less per gallon.

[mike@x-ph.com]

Yes it will

[floydarogers]

Originally Posted by roundel335

...The corn lobby may have something to do with it, but a lot of the energy companies call it "oxygenating" the fuel for better emissions in the warmer months. Personally, I think that's bunk and they're just finding yet another way to screw us out of more money per gallon by diluting gas with ethanol, which costs less per gallon.

No, the energy companies don't have anything to do with "oxygenating". The use of ethanol to oxygenate gasoline and lower the emissions of CO, especially during winter months with stagnant air, was mandated by EPA circa 1990. It's no longer used for that purpose since more recent emissions equipment basically eliminated CO as a problem.

Ethanol does lower CO2 emissions, but corn alcohol is only slightly positive in that regard. Brazil's sugar cane alcohol does better; the grand dream is switchgrass cellulosic production of alcohol.

[casualDIYer]

Corn-based ethanol reduces mileage.

http://www.fueleconomy.gov/feg/ethanol.shtml

[RPM90]

Good luck finding an easy and ready supply of 100% gasoline.
In my area, Chicago, just about every station has 10% ethanol.

BTW, this 10% thing has been investigated and it's been found that some stations have suppliers filling them with gasoline that has more than the 10% limit allowed by law.
Problem is, there aren't enough people looking out for this, which means it'll continue.
I wonder if the cars emission sensors, like the O2 sensors, can be used to read how much of the fuel is ethanol? Program that into the computer with a screen to show us.
That way we can know and avoid stations playing games with us.
With enough people avoiding those stations they'll quickly come around and comply with the law.

This brings up a question, when EPA do their MPG testing, do they use 100% gasoline or 10% ethanol gasoline?
Hmmm....I'll have to look that up.

[sdhotwn]

Frankly most people's driving habits etc introduce more variance than the 10% ethanol does. It has roughly 60% of the energy content of gasoline, at 10%, math is easy so you you have a reduction of about 4% relative to 100% gas. So that means at 30 mpg you are losing about 1.5 mpg, which frankly is within variance for average driving.

The biggest issue with ethanol is the attraction of moisture, and ability to eat seals on older cars. Almost everything else is overblown. An issue yes, but small one.

[dude987]

The Ogallala Aquifer ground water is being depleted faster than its being replenished to grow corn for ethonal. Given the current usage rate it's only a matter of time before the ground water is depleted leading to direct social consequenses. Meanwhile the cost of food is increasing because the corn is being diverted to produce ethonal.

I dunno. Maybe I'm missing something but it just doesn't add up for me.

As a kid, lake Meredith near Amarillo, TX was a huge water reserve holding over 300,000 acre-feet of water. It was vast body of water used for recreational boating as well as irrigation and residential water. Today it, the lake, is completely gone. It is a pathetic sight and sadly, this may only be the tip of the iceberg.

The 1.5 MPG loss, up charge at the pump, and corresive wear and tear on mechanical components are nothing compared to the amount of energy and cost that went into producing ethonal in the first place.

The cost of depelating a life sustaing water source, to grow corn, harvest it, convert it to ethonol, and transport it to service stations all in the name of subsidzing farmers just doesn't make economic sense.

Just a rant.

[floydarogers]

Originally Posted by dude987

The Ogallala Aquifer ground water is being depleted faster than its being replenished to grow corn for ethonal.
...
The cost of depelating a life sustaing water source, to grow corn, harvest it, convert it to ethonol, and transport it to service stations all in the name of subsidzing farmers just doesn't make economic sense.

Just a rant.

IMO, a very good rant!

[sdhotwn]

Originally Posted by floydarogers

IMO, a very good rant!

In general I agree as well... the one area missed in there is the fact that ethanol is "better" for the environment (which the rant covered most of the issue there) and thus anything that fits that crusade gets pushed through/approved/chased. Regardless of where you come down on the arguments about global warming/climate change, more attention needs to be paid to the costs of the "green" initiatives that are pursued. The recent executive order regarding coal reduction is another one to pay attention to. Take a look at Germany's situation to see how poorly that has turned out (4-5 times higher energy costs than other European nations, turning back to the use of coal to compensate, etc)

[dude987]

Petroleum fuel is used to plow, till, and fertilize the soil, plant the seeds, pump and irrigate the crop, spray pesticide, harvest the crop, transport to a distillery, convert it into ethonol, and transported to retail outlets.

I'm not a scientist, but pound for pound how much petrol btu is expended to produce ethonol btu equalivant? 1.5/1.0? Just a wild guess.

If the energy depleted for getting petrol from underground to the pump is 6% per unit, the energy required for getting ethonol from corn to pump is maybe 90% per unit. That's of course before any discussions about water depletion, reduced MPH, higher costs at the pump, and general wear and tear on the mechanical components.

Not factual numbers but just a guess.

I had some good times boating and water skiing on Lake Merideth as a kid. Just sad to see it wasted away for no good reason.

[sdhotwn]

I'm with you.

[floydarogers]

Originally Posted by dude987

...
I'm not a scientist, but pound for pound how much petrol btu is expended to produce ethonol btu equalivant? 1.5/1.0? Just a wild guess.
...
Not factual numbers but just a guess.

Most studies show that there is around a 20% gain in corn ethanol - ie, for every gallon of oil used in production of corn ethanol, you get the equivalent (all this is in btu) of 1.2 gallons of oil out. See http://www.transportation.anl.gov/pdfs/TA/580.pdf, page 25.
It's also interesting if you scroll down a few pages from there and notice that diesel cars are clearly the best in "Well-To-Wheel" emissions, even compared to hybrid and electric vehicles.

[sdhotwn]

Originally Posted by floydarogers

Most studies show that there is around a 20% gain in corn ethanol - ie, for every gallon of oil used in production of corn ethanol, you get the equivalent (all this is in btu) of 1.2 gallons of oil out. See http://www.transportation.anl.gov/pdfs/TA/580.pdf, page 25.
It's also interesting if you scroll down a few pages from there and notice that diesel cars are clearly the best in "Well-To-Wheel" emissions, even compared to hybrid and electric vehicles.

Nice bringing a solid reference item in to the discussion it looks like.

[dude987]

Originally Posted by floydarogers

Most studies show that there is around a 20% gain in corn ethanol - ie, for every gallon of oil used in production of corn ethanol, you get the equivalent (all this is in btu) of 1.2 gallons of oil out. See http://www.transportation.anl.gov/pdfs/TA/580.pdf, page 25.
It's also interesting if you scroll down a few pages from there and notice that diesel cars are clearly the best in "Well-To-Wheel" emissions, even compared to hybrid and electric vehicles.

Interesting. So we emit 400% more green house gases just to delute petrol btu from 100% to 20% and deplete our water supply. Wow!!! Good info.

[floydarogers]

Originally Posted by dude987

Interesting. So we emit 400% more green house gases just to delute petrol btu from 100% to 20% and deplete our water supply. Wow!!! Good info.

You're reading it wrong, and not reading the entire reference.
1) the reference is in terms of BTUs. Oil that is used (fertilizer production, pumping water, transport, plowing, ethanol production/cooking, etc.) produces 1.2 BTUs of energy.
2) Since corn/ethanol is renewable, the burning of the ethanol produced reduces the amount of GHG by the 20% factor. In fact, since GHG per BTU from ethanol is smaller than from GHG per BTU from oil (less carbon in ethanol than in oil), the reduction in GHG is more than 20% (the figure is in the reference, can't remember right now.)

I totally agree that producing corn for ethanol using Oglalla Acquifer water is bad, but please don't confuse that fact (and the food market upsets) with the physics.

[dude987]

Originally Posted by floydarogers

You're reading it wrong, and not reading the entire reference.
1) the reference is in terms of BTUs. Oil that is used (fertilizer production, pumping water, transport, plowing, ethanol production/cooking, etc.) produces 1.2 BTUs of energy.
2) Since corn/ethanol is renewable, the burning of the ethanol produced reduces the amount of GHG by the 20% factor. In fact, since GHG per BTU from ethanol is smaller than from GHG per BTU from oil (less carbon in ethanol than in oil), the reduction in GHG is more than 20% (the figure is in the reference, can't remember right now.)

I totally agree that producing corn for ethanol using Oglalla Acquifer water is bad, but please don't confuse that fact (and the food market upsets) with the physics.

So if I understand correctly, you burn 1 BTU (petro w/GHG) farming to produce 1.2 BTU ethonol that will again emit GHG. So in the end, the total GHG emitted is 1 BTU from petro and 1.2 BTU from ethonol. Seems it would be more efficient if the petro BTU was used directly for fuel. With ethonol, you have burned the 2 BTU's of GHG to gain 20% efficiency in BTU and associated GHG.

[nicknaz]

What % of ethanol can our cars handle without causing issues to the fuel systems?

E30 ?

[RPS328ix]

I very recently made the switch to ethanol free gas with 91 octane rating, and over the last two tanks my gas mileage (mostly city driving) has gone up by at least 2-3 miles per gallon. The car seems like it drives a tiny bit smoother, but that could be in my head. The cost is about 30 cents more than E10 premium, so it is basically a wash in terms of savings, but if ethanol free is better for the engine then why not?

My question is this -- will I do any damage to the engine or fuel system by occasionally switching back and forth between regular E10 gas and ethanol free? I'm planning to fill up with ethanol free when I'm home, but If I'm traveling then I'll have no choice but to use E10 premium since ethanol free is nearly impossible to find.

[fujitashi]

it does have less BTUs than gasoline and thus less energy.

[sdhotwn]

Originally Posted by henryrumpole

My question is this -- will I do any damage to the engine or fuel system by occasionally switching back and forth between regular E10 gas and ethanol free? I'm planning to fill up with ethanol free when I'm home, but If I'm traveling then I'll have no choice but to use E10 premium since ethanol free is nearly impossible to find.

Will not cause any issues at all.