Ethanol gas = Less MPG

[Liv]

So something recently I just came across because of my "new" car, that I've never really thought about, is the concept that, not all gas is equal. Okay, I have thought about it, I once posted about a co-worker who swore a station was watering down their gas, and called it hogwash. I always assumed gas is gas, despite some people suggesting, some stations, "watered down" the gas. Some people even have a gas allegiance because of this.

But talk to people who drive super economy vehicles, who track their mileage daily, and they'll tell you to stay away from gas stations with Ethanol in their gas. A fuel, congress and your government are touting as "green" and will lead to America's energy independence. But, you can lose 2-5 MPG simply by the fuel you use, choose the E10 blend and find your economy vehicle is less economic. Considering this fact, it would seem everyone would be careful of what station they use, especially when you see people drive miles out of the way to find a gas station that sells a few cents cheaper. Something I find counter-intuitive. (Driving more for cheaper gas.) Despite my conservative nature, I've never shopped for gas, I never knew there was that much of the difference.

The way I understand it, is the science of it, says, ethanol contains less energy than gasoline. Less energy, makes it less efficent, thus less MPG. So that full tank of gas you buy for the same price as regular gas, ends up costing you more, because you can't drive as far on it. Seems like a blistering good deal for gas station owners.

So how do you know. Apparently, gas stations are supposed to list fuel dispensers containing Ethanol to consumers by law. I also found this handy-dandy site:

pure-gas.org

Of course there doesn't seem to be any local to me, but I'm going to start hunting.

Corrections
Found this, apparently NC (my state) does not want us knowing:

If you want to stay away from the blends entirely, you may face some difficulties. North Carolina did away with labeling requirements on pumps carrying ethanol blends in 2002.

[A Person]

Ethanol has less carbon in it than gasoline (90% carbon) which is why it has less energy (30 vs 40 MJ/kg), it's also more expensive than gasoline to produce. however it does produce less CO2 per mile so there ought to be a net benefit to the planet, if not your wallet.

The argument for ethanol is a bit iffy though since it's produced from corn (in the US) and is quite energy intensive to produce, it's largely a subsidy to farmers right now. However since the carbon it contains came from the atmosphere in the first place it is still an improvement. There are much better ways to produce alcohol (methanol) that use waste products as feedstock (rather than food) and less energy to produce. Methanol has even less energy than Ethanol (23 vs 30 MJ/kg). Running cars from natural gas (methane) produces even less carbon per km and has 55 MJ/kg. And we get more methane every time thesumofyourfears opens the orifice in his face so we'll never run out.

[Liv]

Okay, that makes me feel better... but aren't you going to use more gas, transporting and driving on this fuel offsetting the "green" benefits?

Sort of the whole, more Co2 is created producing the batteries for the hybrid, than the hybrid will save argument?

[A Person]

It depends on what you mean by 'more gas' and 'green benefits'

We buy gas by volume and tend to assume that the smaller volume we consume the better. By that token gasoline is 'better' in that it has more energy per litre than ethanol or methane.

Another way of looking at is by weight. We buy liquified gas (propane and methane) by weight. And strange at it may seem Methane has more energy than gasoline by weight

But from the environmental perspective it's how much CO2 is emitted per km (or mile) that's important. The energy in fuel comes from oxidation of carbon to carbon dioxide and oxidation of hydrogen to make water. Water is harmless, CO2 isn't, so using a fuel with a higher hydrogen/carbon ratio means a higher (better) water/CO2 ratio.

Methane is CH4 i.e. 4 to 1
Ethanol is CH3CH2OH (C2H6O) i.e. 3 to 1
Gasoline is a mixture of alkanes from pentane (C5H12) to octane (C8H18) i.e. around 2.1 to 1

So for a given amount of energy production, methane is twice as good as gasoline, ethanol is 50% better

The trend in Europe is to implement a green tax on fuels to make the economics reflect the environmental cost of burning the fueal rather than the actual cost to mine/manufacture it. Thus gasoline would be taxed so that its cost per km would be more than ethanol, since its CO2/km is more.

Unfirtunately the USA has too many TSOYF's for a practical common-sense, science-based tax to work. It would be a commie socialist moonbat, unconstitutional, attack on Christianity.

[The Vicar]

Also, note that in countries closer to the equator than (most of) the U.S., ethanol is a much saner choice because they can derive it from sugar cane instead of corn -- corn yields much less ethanol per acre than sugar cane does, so you can make more of it and charge less.

[A Person]

Biodiesel makes more sense than ethanol since it is far less energy intensive to produce - no distillation required and the feedstock can be any vegetable oil: canola, sunflower, olive, palm, coconut

It's not as good in terms of CO2 per km but since the carbon is recycled each time it's carbon neutral

You can also use animal fat or liposuctioned body fat

[Liv]

You can also use animal fat or liposuctioned body fat

I'd volunteer for that one.

[Liv]

It's interesting I posted this. Apparently, the US government is ceasing their subsidy on Ethanol, so gas was predicted to increase about .04 a gallon this next week. Well it's gone up way more than that. I filled up with 3.19 earlier in the week. It's now a 3.39.
.20 cents? Wow.

[A Person]

They are removing the subsidy to corn ethanol producers, it ought not to have an effect for months. What you are seeing is likely just reflecting the steady increase in oil prices over the last quarter

oilprice.jpg (14.66 KiB) Viewed 1396 times

The 'good' news is that the price increase reflects an increase in demand i.e. economies are improving