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
"Mike Hardiman" wrote: | 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
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.
-- Dominic Richens | snipped-for-privacy@alumni.uottawa.ca "If you're not *outraged*, you're not paying attention!"
"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
Science is bent, farmers profit, ADM profits, politicians profit - we lose ;( Frank
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?
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)
-- Dominic Richens | snipped-for-privacy@alumni.uottawa.ca "If you're not *outraged*, you're not paying attention!"
It will forget radio stations, reset the ECU, and zero the trip odometer.
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
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..
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!
On my 2003 WRX, battery disconnect will only affect radio stations, ECU, and the trip odometer. On my car, nothing else is affected.
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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.
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There is a ton of stuff on the internet about gasahol, e.g.
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.
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