Subaru Legacy/Outback: MPG-Real World Numbers

jccinoh · July 2010

Have had my 2009 Outback 2.5 now for about 18months. Mileage (90% city/10% highway) is currently standing at 25.2mpg.

stever · July 2010

I lost track of this discussion a couple of years ago.

Sorry to see you're still having mpg issues, Kidali. I'm way behind updating my spreadsheet on my '97 but I'll try to do that soon. Last April I was getting 23.10 lifetime. Got a bit over 78,000 miles on it now.

I've had about 5 tanks that have held over 13 gallons, but this week I set a (dubious) record, thanks to some poor planning. The Outback held 13.797 gallons. Hard to believe the tank really holds 15.9 gallons - I was sweating it a bit.

Steve, visiting host

stever · July 2010

Updated my spreadsheet.

Worst tank so far this year was 19.28. Best was 33.03 on a road trip. Lifetime average is up to 23.31.

I'm only driving ~6,000 miles a year.

kidali · August 2010

I have no idea how you managed 33mpg. That's insane.

Your lifetime average is a little under mine (had the car about 19 months now).
I'd still say mine is around 21. Though lately I've been having terrible mileage, even with 94 octane gas I'm around 20. Maybe it's the air conditioner running in this heat.

Still trying to figure out my throttle response issue right now. Maybe I'll start a new forum. As stated in earlier posts, check engine has been on for months. My guy decoded it as an 'engine knock' sensor. Reset it. It went out. But a week later came back on. That was in the winter. I'm just living with it. Some days though, it goes out, and the car feels like a rocket. It will come back on after 10 miles or so, and once it does, I almost have to floor the gas for the a/t to drop a gear or kick in at all.

Anyone else have this problem? My untrained analysis is there's a faulty computer on the car. Anyone?

PS> Anyone have an issue with spider cracking in the paint on the hoods of these 97's? Mine looks horrible, and worse after waxing. No real way to resolve it, just curious if others also experience this with the 97 outbacks.

stever · August 2010

That was on a California road trip, loafing along in mild May weather. Tanks were 21, 27, 30, 33 and 30. Then 24 a few weeks later back home. On a road trip in July '09 the best tank was 28 - probably got hammered by the AC.

Most of my driving is around town or 50 miles RT up to the ski hill in the winter, and those are the 21ish tanks. Worse tank ever was 13.16 one January.

Mine's red btw, and the paint looks pretty good. Dings and chips, but no spidering.

kidali · April 2011

For the last year or so, I've been hovering between 10.5 and 11 litres per 100km (or between 21.4 and 22.4 US MPG).

Since December though, I keep getting between 13 or 14 litres / 100k
(16.8 - 18 US MPG) !!! Horrible. 50/50 Highway/City, which means my CITY mileage has got to be atrocious.

Tires are inflated. Used injector cleaner. Rarely used my heated seats. (Obviously no AC this time of year in Canada). Use full synthetic oil. Often try the 91 Octane gas, and sometimes, stupidly, even the 94 Octane! No, I'm not made of gold. Just trying to make a perfectly fine car last longer.

Any suggestions? Can my mechanic (not a Subaru specific guy) diagnose if it's a PCV issue without taking the car apart?

Dom

xwesx · April 2011

If the PCV valve is old, that's an easy and cheap replacement. The part might cost $5 and the time perhaps as many minutes. It is absolutely the easiest DIY maintenance one can perform.

Another possibility is that the oxygen sensors are giving poor feedback so the car is not trimming the fuel/air ratio as efficiently. I noticed my fuel economy taper off somewhat once I was north of 150,000 miles on my '96 Outback. It used to give me between 22 and 28 mpg (or better!) except during periods of extreme cold (< -25F). In its later life (I had it to 220,000 miles, and it still ran great), the low dropped to about 17 with the tops at about 25. During periods of extreme cold, it would drop as low as 13-14 mpg.

I wish I could say I replaced the oxygen sensors and it made a marked improvement, but I planned to replace them in spring of 2007... yet fate had other plans.

pilot1226 · May 2011

I've had the new `11 Outback 2.5i CVT for a month now, here are my numbers:

Highway is about 36 MPG @ 55 MPH Cruise Control according to the dash computer. (To clarify, this is what's displayed after getting fuel and pulling right back out onto the highway. It actually goes higher - above 40 MPG - but because I typically only drive on a stretch of 5 miles of highway to/from work, it starts to go down when I idle at a light pretty rapidly)

Combined over the last 1k miles in the last month between about a 50/50 split of highway & city driving shows me between 26 and 28 MPG, depending on traffic. Not bad at all. Better than my 4AT 09 Legacy 2.5i.

I use Trip A for my current tank of gas, and Trip B for the time since last maintenance.

I was a big proponent of diesel-based Subarus coming over here and probably would have been one of the first to get them, since the MPG is significantly higher. We'll see what time brings.

ateixeira · May 2011

That's very good given the size and accounting for it being AWD. I bet you beat or match a tiny Suzuki SX4.

kidali · May 2011

Thanks, xwesx

I'll see if I can do the PCV valve myself, and ask my mechanic if he has a test for the O2 sensors before determining if they are the issue.

pilot1226 · May 2011

Well, I read somewhere that 55 MPH is usually close to the optimal MPG. Every 5 MPH over 55 MPH you travel I think you lose 10% fuel economy. Something along those lines, I think it was on some US Government website. Maybe Department of Transportation / Highway Safety.

Anyway, again, the 36 MPG is skewed because it doesn't take into account idling and things like that. For example, the day after when I turned the car on, I gave it about a minute to idle before I put it in gear, and the MPG decreased to around 32MPG. Granted, this also increases once I get the car back out onto highway.

I'll have to pen-and-paper some MPG next time I fill it up, since I use the same gas station on my way home from work and we'll see if it corraborates what my trip meter says.

Who needs a hybrid, just use your damn cruise control and try driving close to the speed limit!

robr2 · May 2011

Who needs a hybrid, just use your damn cruise control and try driving close to the speed limit!

On the highway yes. But in daily city driving, I'd take a hybrid any day. That's where they shine.

xwesx · May 2011

If your trip computer is anything like the trip computers on the Forester and Impreza, you'll likely find that it is between 1 and 1.5 mpg on the optimistic side.

ateixeira · May 2011

That is typical, but I had a Tribeca for a week, and oddly enough it read 0.6mpg LOW! Strange.

occking · May 2011

I have mad my 11 outback since Oct 1. For first 10,000 miles, I did not reset one trip odometer and it read 28.2 mpg. I am now over 9000 miles since then, and, again, it reads 28.2 mpg. I always fill the tank myself, and always "top it off", so I know my actual mpg per tank are very accurate. Probably cutting it too close, on three occasions I put in 18.5 gals, one time 18.9 and the tank is supposedly only 18.5 gals.

At any rate, when I have a chance I will add up all the gas I have purchased for this vehicle since new (I keep good records) and I believe it will come out to just about 27 mpg, actual. Yes, everyone's statements about mileage indicated on trip comuters being optimistic is correct. I have had many vehicles past 20 years or so, and every one of them is "optomistic, and this includes a 2005 outback, 2006 Tribeca, 2009 Forester, as well as my current vehicle. I would say the actual mpg usually 1 to 1.5 mpg less than computer indicates.

That being said, I have averaged, per trip computer around 31 to 32 mpg on a few occasions, but the best actual mpg I have ever attained (on mostly highway driving) has been 30. If, near the end of a long trip I must fill up, then continue home for another 30 - 40 miles, I have seen the computer go as high as 34 mpg. I think that's because the previous many miles were all highway, as well as the portion of the trip back home.

However, if I start up following morning & it still says 34 mpg, after just a few miles, it will drop very quickly.

ateixeira · May 2011

The tank may be that size. If you topped it off, portions of the rest could be in the fuel filler neck itself.

timadams · June 2011

**If your trip computer is anything like the trip computers on the Forester and Impreza, you'll likely find that it is between 1 and 1.5 mpg on the optimistic side. **

That's right on the button for my trip computer. My 2011 Legacy 2.5 has been in the 25-26 MPG range lately (30/70 city/highway - calculated as miles driven/gallons to fill up), and always about 1 to 1.5 mpg lower than what the trip computer says for that tank. I have been getting better mileage since the weather warmed up, but not as good as I expected based on EPA MPG figures. And I've been babying it, trying to get the MPG number up. I'd say the MPG is my biggest disappointment with the car.

easypar · July 2011

I really don't look at the MPG readout on the dash, but my '10 Legacy gets consistently over 30 MPG (34.4 more than once) when all freeway. When I mix in city driving it drops, but not as low as yours. I might not actually ever get as high as 30% stop and go drving on a tank so that might be part of it.

Recently took 2 long road trips, Colorado to Cincinnnati and Colorado/Austin TX. The first was with 2 adults, suitcases, one set of golf clubs etc, 2 tanks were above 34. The second was one adult, tools, golf clubs etc and the worst tank was 32 and a fraction. That's at 75 MPH with the cruise control.

Turned over 31,000 miles on the Austin trip.

kombi · August 2011

Is that with the Manual or the CVT?

almatti · August 2011

timadams, I disagree with your assessment of disappointing MPGs with the 2011 Legacy 2.5i. We have a 2010 2.5i CVT automatic, Premium, and although I haven't seen 33-34 mpg as some have posted even at higher speeds like 75 mph, I ususally consitently see on the car's computer 27.6 -27.8. The car now has 19,000 on the Clock, we bought it as a CPO in Feb 2011 with 7,400 miles it. And noticed that she settled in at that mpg level with 40% suburban/City and 60% Highway (with some traffic- NYC Metro area ) since we bought it. My 25 year son drives the car 95% of the time, and I know He's not practicing any "mileing techniques" [coasting, keep at 55MPH,no hard takeoffs] so compared to the 08.5 Mazda 3 s that we traded in, which would get overall average in similar driving conditions of 22-23mpg, The Subbie is Larger, it has AWD, a much better City riding car, than the Mazda, albeit, the Mazda does have sports car class type handling that the Subbie can't match, but we Love the Subbie much more than the Mazda - much more car for the money IMO...and overall very content with the mpgs. It's too bad that when we bought it that they didn't have a Limited on hand.

timadams · August 2011

If you're getting 27 MPG with 40/60 city/highway, you're doing about like I am. I get better than 30 MPG all highway, but when I add in suburban/country driving, it drops considerably.

My MPG is much better this summer than last winter, which may be due to some combination of a) better efficiency in warmer temps; b) summer gasoline and c) more miles on the car. We'll see how it does this winter. Disappointment is too strong a word as of now, but last winter I was getting only 23-25 MPG with the same 30/70 country/highway driving. We'll see if it is better this winter with more miles on the car.

I really believe the winter gasoline was horrible last winter, as everyone I talked to complained about poor fuel mileage, as in substantially worse than during previous winters.

xwesx · August 2011

Winter blends are killers on economy, as are the cold temperatures themselves. This is especially true for Subaru vehicles due to the extra differentials. Fuel economy on our Forester drops from about 27 combined during the summer to around 20 in the winter. Even during open highway driving, we won't break 25-26.

timadams · August 2011

I suppose that makes sense about the two differentials and extra friction in an AWD system being more pronounced in cold temps. I know my MPG always went down in winter, but not to the extent as last year (in my Subaru and other vehicles). The MPG drop was significantly greater than usual last winter.

xwesx · August 2011

If the winter was not harsher, then it is highly likely that there was a new blend being used. In what part of the country do you live? If winter temps are significantly cold (less than +20F on a regular basis), you can improve winter economy by switching out the stock gear oil with a synthetic 75w-90. Replacing the power steering fluid with a synthetic can also help.

boxerpluscvt · May 2012

My 2010 Subaru Outback (4 Cyl AWD CVT) has been averaging 29.2 MPG for the last 9 weeks / 3,500 miles. This has been in 50 - 70 degree Spring weather with 80% - 85% highway driving through three northern NJ counties and one trip to midtown Manhattan.
I don't rely on the built-in computer for this data. I run out each tankful of the cheapest "no name" Regular gas and zero the trip odometer each time. I'm writing this entry after getting 31.16 MPG - 561 miles on 18 gallons of Delta Regular.
By the way, after these 561 miles the MPG mid-dashboard computer said I had averaged "33.0" miles per gallon for this tank of gas. Having tracked dozens of tankfuls, the Outback's MPG computer makes sense only if you subtract 6% from its number. ("33.0" x .94 = 31, the actual mileage I was getting.) For the Outback owners out there, after filling the tank the Range computer displayed 620 miles which computes to 33.5 mpg. (Maybe one of you wants to attempt that?)
I drove as conservatively as possible to get my 31 mpg. I also run on Mobil 1 Synthetic oil and had the emissions software update that came out last year. Though some bloggers said the update hurt fuel efficiency, it has had no effect on mine.
I've had some great cars in my life - at least a dozen - and this one is my favorite. I test-drove all the small SUVs and wagons - from Cayenne to TSX - and I made the right choice buying the Outback. At 35,000 miles it's been a pleasure to own and drive.

Subaru Legacy/Outback: MPG-Real World Numbers

Comments

Helpful Tools

Most popular vehicles