No ethanol in our gas

May 13, 2006 6:29 PM

Is regular unleaded gasoline made with only petroleum-derived compounds better than gasoline containing ethanol?

Two of the three filling stations in my neighborhood have signs up that say "No ethanol in our gasoline." The third has signs up that their gas may contain up to 10% ethanol. Is gasoline using MBTE as its oxygenate better or more efficient than gas containing ethanol? My understanding was that within a region, all gas is formulated to some standard, regardless of which specific compound is used as oxygenate. I know that fuel with a higher level of ethanol will be less efficient per volume, and that ethanol can harm plastic fuel-line components in engines not designed for it. Do the stations that advertise "no ethanol" have a point, or are they just blowing smoke?

posted by ackptui to travel & transportation (8 comments total)

I think the issue is political. Ethanol is supposed to be better for the environment, but costs more per litre than other methods.

I find it ironic that the push to remove ethanol in the name of cheaper gas will actually *increase* demand for oil (by 10% — the typical mix ratio) and so cause the price to go even higher.
posted by clord at 6:34 PM on May 13, 2006

ethanol can harm plastic fuel-line components in engines not designed for it

for newer cars, this is largely not true. most manufacturers have switched to teflon and other plastics that are fine with ethanol. nearly all cars made since the 1980s can handle oxygenated fuel with no problem. consider that 10% ethanol (or MTBE) has been legally mandated for many years in many states that by now anyone who still manufactures cars that could be harmed by ethanol would be swamped with warranty problems.

you should check with your car's manufacturer, but unless you have some non-spec components in your fuel line, ethanol is perfectly safe. in fact, gasoline is (for most plastics) a much stronger solvent than ethanol.
posted by sergeant sandwich at 7:15 PM on May 13, 2006

Connecticut banned MTBE because of groundwater pollution, so ethanol additives are now in every gallon sold in the state. Lost of information here including this:

"Replacing MTBE with ethanol will result in a decrease in formaldehyde emissions, and an increase in acetaldehyde emissions"
posted by smackfu at 7:37 PM on May 13, 2006

Ethanol contains half the energy per gallon that normal gasoline does. It also costs more per gallon.

Fuel with ethanol added costs more, but gives you worse mileage.
posted by Steven C. Den Beste at 8:03 PM on May 13, 2006

Fuel with ethanol added costs more, but gives you worse mileage.

i think this depends to some extent on location. i was driving through iowa last summer and the 15% ethanol gas was quite a bit cheaper. i think in, like, brazil the ethanol is much cheaper than gas. i'm not sure to what extent government subsidies for farmers influence these prices though. i think clord is right in that there's a lot of politics involved.
posted by sergeant sandwich at 10:03 PM on May 13, 2006

i think this depends to some extent on location.

The fuel was cheaper because the tax payers had been paying for it.
posted by bigmusic at 12:15 AM on May 14, 2006

Gas with ethanol is cheaper in Iowa because there is (or at least was) a 10 cent/gallon subsidy on it.

While it is true that ethanol is more expensive to produce than gasoline, the costs are starting to come WAY down as more ethanol plants are being built all over the midwest. You know...where all the corn is to begin with...
posted by achmorrison at 9:40 AM on May 14, 2006

Production costs of ethanol are becoming competitive given such expensive oil (although there is probably a reckoning to come regarding corn's overall deflated price, although hopefully by then we'll be making ethanol from crops that require less cultivation than corn).

But in a market where gas with and without ethanol cost the same per gallon, the gallon with ethanol nets you slightly less miles per gallon for your dollar. But it's a safer oxygenate than MTBE, which has been banned in a few markets. Mostly, however, those "NO ETHANOL" boosters have a political stake against alternative fuels.
posted by blueshammer at 2:06 PM on May 14, 2006