Re: Ethanol

On Nov 26, 8:02 am, "C. E. White" <cewhi...@xxxxxxxxxxxxxxxxxxxx>
wrote:
"Sarah Houston" <SHo...@xxxxxxxxxxxxxx> wrote in message

news:Xns9B626236C7D0SntzldfrdSntzldfrdco@xxxxxxxxxxxxxxxxx

You know, someone here mentioned that they took a hit in MPG from
ethanol, and I was wondering what happened to the car this fall. I
was
averaging about 26.5 MPG in my work, which is mostly city driving,
and
then all of a sudden I started getting about 23.5. In fact I even
took
it in about 10 days ago for them to check the timing, thinking
something
might be wrong.

If your car is running properly, you shouldn't see that sort of fuel
economy decline when using gasoline with ethanol. The highest
concentration that they can sell as gasoline is e10, that's 10%
ethanol. Ethanol has roughly 85% as much energy as gasoline, so e10
has about 98.5% as much energy as straight regular gasoline.

Actually, ethanol has about 70% of the energy of gasoline, so E10
should lower gas mileage by about 3% or, in your case, about 0.7 mpg.

At the
most your mileage should suffer a 3% decline - if you were getting
26.5 mpg on straight gasoline, you should be getting no worse than
25.7 mpg on e10, assuming all things are equal.

I buy a lot of gas at Costco. A few months back, they slapped on
stickers indicating that the gasoline could contain up to 10% ethanol.
I have always kept a gas log for all of my vehicles. For my Fusion, I
think I can see a very slight decrease, but nothing as drastic as you
are claiming (and I am not sure there is really a decline, just the
hint of one). For my Frontier, I've seen no change at all. For some
vehicles, the change in mileage with e10 is negligible because the e10
has a little higher octane (in some cases) and the vehicle's PCM can
adjust the parameters to take advantage of the change.

Do you keep a gas log? If you don't, I'd suggest doing so. I don't
think you can reasonably blame an eleven percent decline in fuel
economy on the switch to e10 gasoline (at least for a modern fuel
injected engine). Something else must be going on - either a real
problem with the engine, a change in driving style, or incomplete
record keeping. For sure you need to calculate your fuel economy
average over multiple tanks of fuel. It is very easy to get large
variations in fuel economy when doing single tank averages.

Ed

There are other differences in winter gasoline vs. summer gasoline.
The gasoline contains oxygenates (ethanol is one; MTBE was another -
but MTBE is no longer used) which help the gasoline burn completely,
so that there is less pollution. The oxygenates reduce gasoline
mileage as well. Other differences to make the winter blend may do so
as well.

In addition, in the winter, when the engine starts off colder, the
engine takes longer to run at full efficiency. This may be part of the
problem. Also, you need to check your tire pressure frequently,
because temperature changes result in tire pressure changes as well.
And, as Obama said, we can save plenty of gasoline by keeping our
tires properly inflated.

jeff
.

Relevant Pages

  • Re: Ethanol
    ... If your car is running properly, you shouldn't see that sort of fuel economy decline when using gasoline with ethanol. ... Ethanol has roughly 85% as much energy as gasoline, so e10 has about 98.5% as much energy as straight regular gasoline. ... I don't think you can reasonably blame an eleven percent decline in fuel economy on the switch to e10 gasoline. ...
    (alt.autos.toyota)
  • Re: Ethanol
    ... ethanol, and I was wondering what happened to the car this fall. ... If your car is running properly, you shouldn't see that sort of fuel ... economy decline when using gasoline with ethanol. ... Ethanol has roughly 85% as much energy as gasoline, so e10 ...
    (alt.autos.toyota)
  • Re: New ethanol production method uses far less energy than it creates
    ... Aside from the politics of it, is there a problem with E10? ... Ethanol has less energy than gasoline per unit. ... I think MTBA is less of an energy hit, but I'm not certain my memory is ...
    (misc.transport.road)
  • Re: For those with gasoline powered boats
    ... IMPORTANT UPDATE FOR BOATS WITH GASOLINE ENGINES ... ETHANOL-BLENDED GASOLINE AND YOUR BOAT ... Ethanol is primarily alcohol, and for years we have been ... advised not to use dry gas as an additive in marine fuel systems. ...
    (rec.boats)
  • Re: New ethanol production method uses far less energy than it creates
    ... Aside from the politics of it, is there a problem with E10? ... Ethanol has less energy than gasoline per unit. ... I think MTBA is less of an energy hit, but I'm not certain my memory is ...
    (misc.transport.road)
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