Experience driving with E85

Looking at the history of sci.chem I see that the major debate here
about ethanol as a fuel is around two years old. There was a lot of
misinformation then, some of which can now be refuted by
experimentation by an individual -- not a lab.

I have access to four E85 fuel stations (gas stations that sell E85
also) in Albany, NY. I took the risk of mixing E85 with E10 in my
1999 Subaru Outback, well beyond the age at which the warranty
matters. I found that if I mixed half and half, my check-engine light
came on after a few days. The code was "fuel trim", as one would
expect, since the ECU in my car had hit the limit trying to increase
the richness of the mixture required for stochiometric burning.

I diluted the mix in the tank to 30% ethanol and the light went off in
only 7 miles of driving. I found that my car had better performance.
I could feel the acceleration in this old heap, unlike before. (No,
my fuel pump did not crumble into bits. Misinformation point 1)

That was encouraging. So I bought a converter, inspired by a Brazilian
invention, that stretches the electrical pulse to the fuel injectors
and quickly installed it. And I filled up with straight E85. That
was a month ago.

So here is how it has worked out. (This is personal experience, which
happens to agree with others one can find on the internet, and which
trumps the calculations of the armchair observers.)

It was written in this newsgroup that ethanol is much less efficient
than gasoline. It is true that the energy density of ethanol is about
30% less than that of gasoline. My 16-gallon tank can't take me quite
as far with E85 than with gasoline. I can live with that.

But the MPG penalty between E85 and gasoline is only 15%, not 30%, in
my experience. Some physicist is going to write me that this violates
the conservation of energy. But as a physicist myself, I am familiar
with the concept that (Energy Out) = (Energy In) x (Efficiency), which
defines the kind of efficiency I am talking about now.

The chemical energy of ethanol is Energy In to an automobile. But
what counts in life is Energy Out. Ethanol burns more efficiently in
an internal combustion engine than gasoline. From the MPG numbers, I
have to conclude that the efficiency (in the current sense) of E85 is
twice as high as that of gasoline. Hence the much smaller MPG
penalty. (It is explained in terms of ignition timing and burning
rate.)

But what concerns me more than MPG is MPD, or miles per dollar. E85
today costs $3.05 per gallon; Gasoline (regular) is $4.20. I am
getting about 7 miles per dollar, versus only 6 with gasoline.

My conclusion, subject to change as we careen toward the disater ahead
of us in Peak Oil, is that E85 is a much better fuel than regular
gasoline. (It's even better compared to premium. The octane rating of
E85 is 105, compared to 95 for super-premium IIRC.) The emissions of
E85 are much cleaner too. (Google it yourself.)

So E85 is cheaper, cleaner, hotter, and not imported. I am a happy
driver.

Uncle Ben
.

Relevant Pages

  • Re: Experience driving with E85
    ... about ethanol as a fuel is around two years old. ... And I filled up with straight E85. ... It is true that the energy density of ethanol is about ... 30% less than that of gasoline. ...
    (sci.chem)
  • Re: Ethanol (The Corn Lobby Corn Holes America)
    ... 15 years ago I put in a 1000 gallon fuel storage tank to get me ... supporters of ethanol had argued that the volatile organic compound ... ethanol in our gasoline supply will alleviate our need for foreign oil. ... its energy salvation is at hand. ...
    (rec.outdoors.rv-travel)
  • Re: Experience driving with E85
    ... about ethanol as a fuel is around two years old. ... since the ECU in my car had hit the limit trying to increase ...  And I filled up with straight E85. ... 30% less than that of gasoline. ...
    (sci.chem)
  • Para levantar um pouco a moral das cobaias
    ... Flexible-fuel vehicles are seen as a way to cut our use of gasoline because ... they can run on a fuel that is mostly grain-based ethanol distilled in the ... E85 or any mix of gasoline and ethanol in between. ... But you risk ruining a conventional vehicle if you ...
    (soc.culture.brazil)
  • 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)