Lower gas economy in NM

[Mike Hardiman]

I just moved from Vermont to New Mexico and noticed that I've been getting
about 50 miles/tank less here with mixed driving on my 2000 Outback. I
suspect it is due to the ethanol they put in the gas here between October
and March, but someone also suggested the engine may need a tune up for the
altitude (about 3500' vs. 800' in VT). Anyone here know which of the two is
the most likely culprit?

-Mike

 

[john cline ii]

:
| I just moved from Vermont to New Mexico and noticed that I've been
getting
| about 50 miles/tank less here with mixed driving on my 2000 Outback.
I
| suspect it is due to the ethanol they put in the gas here between
October
| and March, but someone also suggested the engine may need a tune up
for the
| altitude (about 3500' vs. 800' in VT). Anyone here know which of the
two is
| the most likely culprit?
|
| -Mike

It's the gas. The engine management computer takes care of the
altitude change. There is no way to tune the engine mechanically for
higher altitudes. That went out decades ago. The someone who
suggested that hasn't kept up!

john cline ii, who hopes that helps

 

[Dominic Richens]

I just moved from Vermont to New Mexico and noticed that I've been
getting about 50 miles/tank less here with mixed driving on my 2000
Outback. I suspect it is due to the ethanol they put in the gas here
between October and March, but someone also suggested the engine may
need a tune up for the altitude (about 3500' vs. 800' in VT). Anyone
here know which of the two is the most likely culprit?

Yes, "gasahol" does have a lower energy density, so your fuel economy will
be 3-8% less. As for "tune up" - the most you can do is reset the ECU by
removing the negative battery cable and holding down the brake pedal (drain
the current) - it will "forget" the old timing and figure it out anew.

 

[H. Whelply]

"john cline ii," eh?! So we hang out in some of the same groups! I wonder if
that's significant and true of others? That is, is there a pattern here?!

Pensively yours,

HW

 

[Frank Logullo]

Yes, "gasahol" does have a lower energy density, so your fuel economy will
be 3-8% less. As for "tune up" - the most you can do is reset the ECU by
removing the negative battery cable and holding down the brake pedal (drain
the current) - it will "forget" the old timing and figure it out anew.

Science is bent, farmers profit, ADM profits, politicians profit - we lose
;(
Frank

 

[GTT]

Yes, "gasahol" does have a lower energy density, so your fuel economy will
be 3-8% less. As for "tune up" - the most you can do is reset the ECU by
removing the negative battery cable and holding down the brake pedal (drain
the current) - it will "forget" the old timing and figure it out anew.

I realize the Subie will also forget radio stations preset, as well, BUT
will it
forget the keyless entry/alarm settings, or other such neat stuff that will
be
sorely missed, after this cheap reset of the ECU?

 

[Dominic Richens]

Science is bent, farmers profit, ADM profits, politicians profit - we
lose ;(

Doesn't it burn cleaner? I thought that was the whole and only point to
adding ethanol? (okay, so in the US a few clever individuals came up with
some other reasons, but aside from that :0)

 

[2 Stroke]

It will forget radio stations, reset the ECU, and zero the trip
odometer.

 

[Brian McCloskey]

Mike,
Could be both. At 3500' the atmospheric pressure is ~ 10% less than in
Vermont. Your ECU will compensate, but you may be a little heavier on the
gas to get the same performance. That could also contribute to decreased gas
mileage.
Regards,
Brian

 

[mj]

Doesn't it burn cleaner? I thought that was the whole and only point to
adding ethanol?

The purpose is to provide subsidies for farmers and the industrial
providers of the gasahol by creating increased demand for corn products
& gasohol production - with the end payback being votes by the farmers
and cash paybacks by the gasohol producers..

 

[GTT]

Okay, I can understand those. Do you know if it resets or loses
ANY OTHER information?

I just sold a GMC pickup that lost it's alarm system when the battery
was replaced/died. I had to find a guy who knew how to reset it and
that was not a simple procedure. (hold one finger on your nose,
one hand on your butt, click the override button FIVE times, and
then press the remote button, or something close to that. It was one
strange procedure.) Cost me $25 to learn it, too!

 

[2 Stroke]

On my 2003 WRX, battery disconnect will only affect radio stations,
ECU, and the trip odometer. On my car, nothing else is affected.

===================================

 

[2 Stroke]

Sorry to double post, but if you have ever replaced the battery on
your Outback, you already have done the equiv. of an ECU reset.

=====================================

 

[Frank Logullo]

I just moved from Vermont to New Mexico and noticed that I've been getting
about 50 miles/tank less here with mixed driving on my 2000 Outback. I
suspect it is due to the ethanol they put in the gas here between October
and March, but someone also suggested the engine may need a tune up for the
altitude (about 3500' vs. 800' in VT). Anyone here know which of the two is
the most likely culprit?

There is a ton of stuff on the internet about gasahol, e.g.
http://www.perc.org/publications/opeds/ethnaol.php?s=2
Politics aside, what disturbs me is the bad science involved.
Frank

 

[David & Caroline]

The winter gas around here definitely bites - I generally get 1 or 2 mpg
less with the winter gas (20-ish vs 22-ish) in my WRX wagon (no highway...
some "spirited" driving ;-) etc.) - the fuel economy thing isn't a big deal
to me (I don't drive enough to have it make a difference to me) - biggest
difference I notice is a reduction in power - definitely can be felt on the
butt dyno... I don't think we are the only region using winter gas - they
must have used it up in the northeast (esp. with MA's somewhat restrictive
emissions requirements) - I am guessing you are feeling the combination of
the altitude and the winter gas - it will get a little better when the
stations have the good stuff (good being relative... they still call 91
octane "premium" here...). I am going to guess that the winter gas is the
biggest culprit - when I moved here (from sea level) in my old car, I hardly
noticed a drop off in performance (granted, it was an older Corolla...), but
I have always noticed the hit with winter gas...

whereabouts are you? Some stations seem to be slower about changing over
than others (though I think they all have by now) - I am in Abq. which is 5k
to 6k feet up. You will feel the altitude difference (in terms of reduced
power output) much more on a NA engine than you do in a turbocharged engine.