Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Subaru Legacy/Outback: MPG-Real World Numbers



  • mjrossmjross Posts: 3
    I recently moved from Colorado Springs, CO to the LA area and I've noticed that since then my 2000 Subaru Outback's mpg has noticeably decreased. It's still in the decent range (above 20mpg), but less than in CO. Could this be because of the drop in altitude (from ~6000' to sea level)? What (if anything) can I do about it?
  • ateixeiraateixeira Posts: 72,587
    Hmm, you do lose power at altitude, since the air is less dense. I'm surprised it had a noticeable effect on mileage when you started intaking denser air, though.

    Also, the octane is probably higher in LA, 87 vs. probably 85 I'd guess. That also should not cause a drop in mileage, though.

  • mjrossmjross Posts: 3
    I used 87 octane in Colorado too (it's "mid-grade" in CO, but regular here), because that's what the manual says to use.
  • I am guessing you are encountering a lot more conjested roads than in LA than in Colorado Springs. It also could be because the adaptive software that runs the ECU needs to be reset in order to compensate for the change in air density and driving style.
  • mjrossmjross Posts: 3
    The traffic actually isn't much worse here--I'm not in downtown LA or anything. I have a friend who told me I might have to reset the ECU, but I was hoping for some confirmation. He said all I would need to do is disconnect the battery for a while?
  • bkaiser1bkaiser1 Posts: 464
    California has notoriously bad gas and is the likely culprit in your mysteriously lower mileage. I moved to Sacramento from Reno but continue to work in Reno, so after years of driving the same "loop" and filling up in different places, I can attest to getting 3-4mpg less on any tank of gas that I filled in CA versus one that I filled in Nevada. This has held true on both of my Subarus, my Honda, and my pickup. For whatever reason, the gas that is supplied to CA stations is apparently formulated differently and is known to cause drivability problems in some cars.

    COBB Tuning, for example, had different ECU maps for CA cars to factor in the crummy gas that we receive here...the original map that they were using on to reflash the computers on WRXs was causing some noticable drivability problems (stumbling, etc) in CA cars.

    It's ironic that in a state so obsessed with emmissions and efficiency that they would supply gas that routinely delivers *less* efficiency than neighboring states.

  • ateixeiraateixeira Posts: 72,587
    Could it be a partial mix of Ethanol in the gas?

    Here in MD most pumps have switched over to E10, i.e. 10% ethanol. There is less energy in ethanol so most people will get a slight drop in efficiency.
  • jay_24jay_24 Posts: 536
    Don't blame the ethanol. Minnesota has a 10% ethanol requirement and Wisconsin doesn't. I get nearly identical MPG. In fact I tend to fill-up in MN because
    #1- it costs 15 to 20 cents less per gallon.
    #2- I get the best MPG from a Shell station in MN with 10% ethanol(29mpg in a 2001 Outback with 110K miles).

  • ateixeiraateixeira Posts: 72,587
    You should get a Shell credit card if you don't have one already. Get another 5% discount on that gas.

    Personally, I have not observed a noticeable change in MPG since MD went with E10.
  • subearusubearu Posts: 3,613
    Actually, several SE Wisconsin counties do have the 10% ethanol requirement thanks to being included in the Chicago metropolitan area which requires reformulated fuel.

  • grahampetersgrahampeters AustraliaPosts: 1,785

    There arer a fair number of possibilites. Try running the tank right down and then refill through several cycles using a good quality branded (eg Shell etc) fuel rather than supermarket or discount chain. The ethanol mix should not change economy much.

    Also consciously think about driving habits of those around you. I find my fuel economy changes between cities although ostensibly the traffic is about the same. This is probaby because of the need to drive differently in differnt traffic conditions. For example, here in Australia, the traffic in Melbourne is solid but fairly calm. Sydney is more aggressive although congestion is probably about the same at present. I find my usage leaps when I drive in Sydney because you have to be more pushy to retaing your place in traffic


  • hypovhypov Posts: 3,068
    altitude and climate change between CO and CA.

    You're running leaner in CO due to the altitude and richer in CA as the ECU adjust for condition.
    The ECU should settle in to CA conditions after a few hundred miles.

  • Looking for an idea of the all around mileage I should expect from a Outback 3.0 6 cylinder.

    I am looking at a 2008 Outback and like the 6 cylinder but might just buy the 2.5 if there is a huge difference in MPG.
  • I have an 07 LLBean. Averaging around 21, mostly suburban. Averaged 25 on a recent mostly highway trip. Using 89 octane. Tried 87 and it doesn't work well. Does run smoother on 93.
  • About what I expected. It wouldn't be too bad if you could get away with 89 Octane.

    Thanks for the info!
  • I've had an Outback XT with 5sp.MT and 11,900 miles on it for about 6 weeks.

    The one road trip so far (190 miles) yielded 22.9 MPG :(, mostly using the cruise control.

    Around town it gets 13 to 15 MPG :cry: , but I've been experimenting with the turbocharger's effect on acceleration :).

    I'm hoping that the engine will loosen over the next few thousand miles and the highway mileage will improve.
  • jfljfl Posts: 1,388
    Just a note: if you reset the ECU, I find the first tank or two gives very poor gas mileage as the computer re-learns your driving style.

    A battery failed on me just before a long highway trip, resetting the ECU. :cry:

  • I live in Reno and of course have noticed the same MPG differences of going back an forth "over the hill" with my 03 Forester. I've attributed some of the difference to be the drive from Reno to Sac is mostly downhill. Conversely, Sac to Reno is mostly uphill.

    FYI everyone, Reno sits at an altitude of 4,500 feet while Sac is virtually a sea level. In between is Donner Pass that rises to about 7,200 feet. The trip is about 120 miles depending on the exact door to door locations.

    Just my 1.5 cents.
  • xwesxxwesx Fairbanks, AlaskaPosts: 11,152
    That is a very likely reason for the difference. I even notice better mileage driving to Anchorage from Fairbanks than the other way around. The difference between the two is a total of about 500 feet elevation with, obviously, some dramatic increases between. We usually see 1 mpg better on the way down.
    2014 Audi Q7 TDI, 2008 and 2013 Subaru Forester(s), 1969 Chevrolet C20 Pickup, 1969 Ford Econoline 100, 1976 Ford F250 Pickup
  • cptpltcptplt Posts: 1,075
    first 2 tankfulls of gas on my 08 OB Ltd/PZEV 25mpg calculated and displayed, thats about 2 better than my 98 Legacy
  • After 2 tankfulls on my 2008 Legacy the computer shows I am getting 27.1 mpg avg. 2.5 non turbo/automatic trans.
  • radar1radar1 Posts: 25
    I have the 08 basic 2.5 auto, just returned from a 1,000 mile trip and was pleasantly surprised to get 28.2 overall, with most of the driving at about 72 MPH. The tank that had a long stretch of 60 MPH driving saw a 30.5 average. I was expecting worse because my Focus 2.3 ZX5 only got 28 on the same trips, and the label says to only expect 26 on the highway.
  • ateixeiraateixeira Posts: 72,587

    In CR this month they test a Legacy 2.5i and an Accord, the 177hp model.

    Surprisingly, the Legacy used a little less gas, saving about $20/year in fuel costs.
  • stantontstantont Posts: 148
    I have an '08 OB XT turbo, MT5. We just did the first really long trip after breakin (approx 2500 miles at start). Austin, TX to Raleigh, NC and back, crossed the Blue Ridge mountains several times. Two aboard plus maybe 200 lbs luggage. 75-80 mph on cruise control, winter time, so no a/c. Southern states; no ethanol AFAIK.

    TOTAL: 103.0 gallons for 2839 miles equals 27.56 mpg. Wouldn't be surprised to see it creep to 28+mpg by 20k miles.

    City driving, even during breakin, has averaged 22-23 mpg, but my "city" includes a fair bit of freeway at 65-70 mph. YMMV.

    The MPG indicator is about 10-15 % low; it read 25.2 mpg for the trip. At first I was pretty disappointed in "mileage" until I realized the trip MPG calculator was off. I assume the computer tries to estimate gallons from injector on time and fuel pressure, etc., so I shouldn't be surprised at 12% error. As always, actual fuel consumed and actual miles driven are the only way to get credible numbers; and trying to estimate mileage from 7 or 8 gallons in 150-200 miles is not very accurate either. If the pump shuts off 1/2 gallon earlier or later, you introduce +/- 1-1.5 mpg error.

    It seems the new EPA test protocol (18 city, 24 highway) is pretty hostile to the turbo, as my real-world experience is far better than EPA estimate. I'm quite pleased; our '02 Legacy L wagon with standard engine and MT5 got 28.5 -29 on the same trip two years ago; and our 2000 Honda Accord V6 automatic got about the same (but was boring to drive!). The turbo/stick car gives excellent performance with very little fuel penalty unless you really USE the power.

  • stantontstantont Posts: 148
    BTW, if it seems we have changed cars a lot, that is correct. I bought the Accord V6 hoping to get a successor to my 1990 Taurus SHO. Nope, the Accord was refined but boring. Then I bought the '02 Legacy L wagon used in '04 because I really needed a wagon to carry kayaks (on top) and bicycles (inside). Nice but a bit spartan, so I sold it to a friend at 103,000 miles and bought the '08 OB XT MT5.

    WOW! This is the first car since the SHO that makes me smile every time I get in and turn the key. Quiet, smooth, refined, luxurious, quick. Rides so soft you expect it to wallow on turns, but it really corners pretty flat. Plus it goes like stink when you nudge the gas pedal!

    27.5 mpg highway ain't too shabby, either, for a car with that much performance. Well done, Subaru!
  • xwesxxwesx Fairbanks, AlaskaPosts: 11,152
    Hah, well, you have done far better than me in the last 12 months... ;)
    2014 Audi Q7 TDI, 2008 and 2013 Subaru Forester(s), 1969 Chevrolet C20 Pickup, 1969 Ford Econoline 100, 1976 Ford F250 Pickup
  • I just bought a 08 SE Legacy 2.5 auto. and I am getting 23 miles to the gallon combined. I live in a rural area not a big city. It only has 2k miles on it and I am taking it easy so it will break in nicely.
  • paisanpaisan Posts: 21,181
    Just pulled 24mpg over a 1,000 mile trip including city, high speed highway, lots of idling, and some offroading. Not too shaby in my book.

    Motorsports and Modifications Host
  • steverstever Posts: 52,683
    I picked up my Outback used from a friend in March, '03. It had 34,513 on the odometer when I first filled it up. My lifetime mpg today, at 67,564 miles, is 23.08.

    I've had three tanks over 30 mpg, and three under 15 mpg, so I figure all of those are aberrations that cancel each other out.

    I can see a slight trend for better mpg in the winter, likely because it has a black leather interior and 105°F isn't all that unusual here in Boise in high summer.

    Most of those miles are interurban, and I'm a pretty relaxed driver usually, at least pulling away from the light.

    Steve, visiting host
  • tswitztswitz Posts: 3
    We just picked up our 08' Legacy Sedan SE this Thurs and are thrilled with it thus far! Our first tank of gas yielded 23.7 mpg on mixed city/highway driving - most of what I would call "suburban" driving.
Sign In or Register to comment.