Gas Mileage

[Vimy101]

Since purchasing my 05 LGT limited MT wagon, I've averaged 23.1 mpg over 2700 miles of mixed driving. Long weekend 900 mile trek to DE, NJ, and CT with two nasty going nowhere traffic sits was 24.6. Best stretch was a mostly highway cruise in DE at 28+ when my son was driving. For that trip I was driving my Dad's 2006 VW Jetta TDI, loaded with nav, leather, sunroof, etc. That same trip notched 50.5 mpg without trying. The Jetta, while having only 100 HP, used its ample torque and well-matched 6 spd automatic to seem pretty sprightly. The Jetta is similar in size and weighs about 200 lbs less with its FWD. I wouldn't swap the sheer fun of my LGT, but the fuel economy of the Jetta was impressive. Nice interior too, one notch up from the LGT Limited's.

 

Deisel is the answer to decreasing the consumption of liquid hydrocarbons in the transportation fleet. My next car will be a deisel. My Spec. B? Oh, I'm keeping it, too.

 

BTW, I was going to pass on the LGT until I drove the Spec. B. It is a different car. Subaru is really on to something.

[LRegvall]

Vimy 101,

Most of the road tests in mags say the Spec B isn't that different from the regular LGT. What are the differences that you find so compelling? I would imagine that the better struts provide better damping which should be noticeable. Also the aluminum suspension should reduce unsprung weight also improving damping and reducing some of the suspension thump on bumps. Not using the M&S Bridgestones should also be an improvement. (I switched to 225/45-17 BFG Gforce KDWs with pretty dramatic results). But the increased ride height could be a negative by raising the CG of the car. The increased rolling diameter strangely seems to have improved acceleration times since most of the tests are showing better Spec B acceleration as against the standard LGT. Anyway, the changes don't seem to add up to a huge difference though I haven't driven the Spec B. I'd be interested in your thoughts.

[Vimy101]

Vimy 101,

Most of the road tests in mags say the Spec B isn't that different from the regular LGT. What are the differences that you find so compelling? I would imagine that the better struts provide better damping which should be noticeable. Also the aluminum suspension should reduce unsprung weight also improving damping and reducing some of the suspension thump on bumps. Not using the M&S Bridgestones should also be an improvement. (I switched to 225/45-17 BFG Gforce KDWs with pretty dramatic results). But the increased ride height could be a negative by raising the CG of the car. The increased rolling diameter strangely seems to have improved acceleration times since most of the tests are showing better Spec B acceleration as against the standard LGT. Anyway, the changes don't seem to add up to a huge difference though I haven't driven the Spec B. I'd be interested in your thoughts.

 

The Spec. B has a very poised feel to the suspension. I compare it to the ride of more expensive OEMs especially on the freeway.

[LRegvall]

That makes sense. The improved damping and lower unsprung weight would have the effect of improving the feel, taking out some nervousness. I don't think the existing set up is horrible, especially after changing tires, but those changes do sound like they would help the level of poise (good description). I suspect I'll be swapping out the rear sway bar first and then upgrade the struts at some point. Hopefully, Subaru (or someone) will offer the aluminum suspension components. Thanks for the feedback.

[belfer999]

I've got 9,000 miles on my LGT stg1 (auto). With mostly city driving and a 4 mile freeway commute each weekday (los angeles) bumper to bumper, I'm getting 18.3 avg mpg. I hit the boost a couple of times each time I drive. That stomp, wait-for-it, holy crap! acceleration is what sold me on the car. Only once, did I use an entire fill-up for a freeway trip / mpg experiment and I got almost 24mpg.

[RobE]

I've got 16,000 miles on mine of pretty much 50/50 (city/highway) and I have been averaging 19.8 mpg according to the trip computer and 19.3 mpg according to my calculations. Not bad, but not good compared to my old car's (BMW 330i) 26.7 mpg I managed over 34,000 miles.

[LRegvall]

RobE, sounds like you are in my mileage territory - 50%@16, 50%@22 = 19 weighted average (mine is actually more like 18 to 18.5). The searching I've done on this site (on various threads) seems to say that most people are getting closer to EPA levels 19/20 city and 25/26 hiway. Some are doing better. To me it reads like a technical problem not a driving style problem. My mileage doesn't vary much with speed or style. I've got an '05 wagon. My brother has an '06 sedan and he consistently gets 20 city 25 hiway. I'm just getting my car back from the dealer after the second round of diagnostics that show that the fuel management is working fine. Tomorrow I call the factory rep. Anyone have any ideas of where the problem might lie?

[forestir]

RobE, sounds like you are in my mileage territory - 50%@16, 50%@22 = 19 weighted average (mine is actually more like 18 to 18.5). The searching I've done on this site (on various threads) seems to say that most people are getting closer to EPA levels 19/20 city and 25/26 hiway. Some are doing better. To me it reads like a technical problem not a driving style problem. My mileage doesn't vary much with speed or style. I've got an '05 wagon. My brother has an '06 sedan and he consistently gets 20 city 25 hiway. I'm just getting my car back from the dealer after the second round of diagnostics that show that the fuel management is working fine. Tomorrow I call the factory rep. Anyone have any ideas of where the problem might lie?

 

From watching the instantaneous mileage readings, you can see that the worst fuel consumption is during acceleration. So when defining "city" driving, think less about where you're driving and more about how much stop'n go you are doing. To really test if there's a problem, find a time when there's little traffic and get on the highway on cruise control for a decent distance (say, 50 to 100 miles). Do this right after filling up, take the steady speed drive, and fill up again to calculate mpg. You should easily hit or exceed the EPA hwy number.

 

Also, make sure your tire pressures aren't low.

[Scooby2.5]

I tried some things to test the nav fuel calculator as I was finding that it always seems to read high.

What I did to cure this is to NOT continue to fill the car after the pump kicks off.

I used to go to the nearest dollar. If it kicked off at 15.33 i would always go to 16.00. When I quit doing this the nav calculator has been on the money.

Now when I fill up and it kicks off automatically I hit the handle one more time and when it kicks off I leave it. Best milage I have gotten is 28 highway and worst with a combo of city and highway is 21. Cobb stage 1 91 oct.

[HAMMER DOWN]

my 100 mile round trip to work 50\50 split highway\city I get 25 to 26 mpg.

[LRegvall]

I haven't used the averaging computer too much for determining gas mileage other than to test it against reality. It does seem to be consistently just shy of 2mpg off of calculated mileage. I occasionally use the instant computer to monitor my driving. It fluctuates so much though that it's hard to get much useful info but it does give some feedback. But as Forestir says, it is start and stop that does the most damage to mileage. The EPA city cycle uses 23 starts/stops over a 31 minute period over 11 miles averaging 20 mph with a top speed of 56. This is an average of 1.3 minutes per start/stop. This sounds like fairly typical city driving, though I may have a slightly lower start/stop duration. The highway cycle covers 10 miles at an average of 48 mph and a top speed of 60 with only one start and one stop. I only see this in rural driving, not highway driving. My rural driving (which usually includes hills) delivers around 20mpg and my highway around 22mpg. My conservative city driving (up shifting quickly at around 2500 rpm, pretend-egg on both accelerator and brake, use momentum as much as possible, use the mpg monitor, reserve boost for emergency use, etc.) is still around 15mpg. Pretty much what my more agressive and fun driving delivers. Clearly the start/stop process (i.e., using the accelerator pedal) is the culprit but I'm still convinced that some of the LGTs wouldn't get close to 20mpg with 23 start/stops in 31 minutes. I am going to try the the steady state cruise mileage test that Forestir suggests this weekend on my drive up to Laguna Seca to test the highway mileage.

[HuskerScooby]

Let me preclude by saying I drive a 2.5i

 

Guys, take this for what it's worth. I drive my car A LOT for work, hundreds of miles a day, so I'm filling up my tank nearly every other day or a couple times in one day. In six weeks time I put on 5,000mi.

 

I used to get about 25-26mpg (highway only) filling-up with whatever gas station was nearest when I needed it. I decided to switch out my stock filter with a drop-in K&N. Which did NOT help out...at first. But after a few tanks I saw about 1-2mpg increase in combination with using only Shell fuel per my brother's advice. Since doing so, I've been consistently seeing 28mpg minimum and last couple tanks 29, 30, and even 31mpg.

 

I was stuck in a smaller town without a Shell station and filled up with Sinclair gas, only to drop to 25.6mpg avg on that tank!

 

As far as the octane rating, I was using E89

 

edit* and my test conditions include FLAT Nebraska interstate at about 81mph on cruise control.

[LRegvall]

HuskerScooby, those miles are some tough duty. But it sure does give you a chance to test gas mileage. And with that many miles, it really makes a difference. Did you notice the difference with Shell right away or after a few tanks or...? In spite of all the things I've done to test mileage with driving style changes, my mileage has been pretty consistent. Any difference I get from fuel type should be noticed. Thanks.

[stillen]

06 legacy wagon 4 banger automatic tranny, 6500 miles, saw 32mpg high way while cruising up to maine, speedo never went abot 65 though........ around town shes averaging 27-28...... much better than my GMC 3/4 ton which gets 9 mpg

[Legasee]

stage 2, getting 21-22 mpg daily LA traffic driving to work and home, and going outta town on weekends.

[deadeye]

Hi All. Have 05 Gt Ltd Wagon with about 8K miles on it.. Drive it from Fl. to Ont-Canada 2-3 times per yr. I run about 76-78 mph when able.. Have avg about 25.8- 26.2 an all trips. I have used mid- range since day one.. 89 Octane. A Subie die-hard sends.. Deadeye

[VTGT]

stage 2, getting 21-22 mpg daily LA traffic driving to work and home, and going outta town on weekends.

 

Damn stage 2 daily la traffic and you get 21-22. I have tdc stage one on my 5eat and in all city i hardly see over 15 mpg. I drive passively 80% of the time. I think its normal because i did some logs and they checked out, but still seems screwy.

[LRegvall]

VTGT, I think you're the first beside myself to report 15mpg in town. And I get that whether being conservative or aggressive. Maybe 16mpg if I'm real soft on the pedal. If I get any help from Subaru, I'll post it.

[Legasee]

Damn stage 2 daily la traffic and you get 21-22. I have tdc stage one on my 5eat and in all city i hardly see over 15 mpg. I drive passively 80% of the time. I think its normal because i did some logs and they checked out, but still seems screwy.

 

I'm just off the shielf AP stage 2, 5EAT also, I drive pretty easy on the gas, and I'll gass it 1/2 throttle a few times a day...but other than that ya...21-22 mpg on the car's cubby computer...

[laneygirlid]

I am awaiting the arrival of a 2007 Legacy GT that has the new control on the turbo called SI (Subaru Intelligence) which gives the driver 3 controls over how much of the turbo you're using. It's supposed to add 10% boost to mileage. I am looking forward to experimenting with that and hoping that it really works. It's cool that I'll have access to the turbo when I want it, but can turn it off for situations when it's not needed.

 

I have read that the same affect can be achieved by staying off the throttle, but I like the fact that I can effect the fuel economy in more than one way.

[AWD_Rules3830]

5900 miles, 24 mpg at 80 mph.

[forestir]

I am awaiting the arrival of a 2007 Legacy GT that has the new control on the turbo called SI (Subaru Intelligence) which gives the driver 3 controls over how much of the turbo you're using. It's supposed to add 10% boost to mileage. I am looking forward to experimenting with that and hoping that it really works. It's cool that I'll have access to the turbo when I want it, but can turn it off for situations when it's not needed.

 

I have read that the same affect can be achieved by staying off the throttle, but I like the fact that I can effect the fuel economy in more than one way.

 

...or, get a 2005 or 2006 with a Cobb Accessport and stick it on an Economy map. Of course, it's not as easy as SI-Drive to get back to a normal or sharper map...

[oberth1]

I dont know what kind of highway your doin... Im gettin 29mpg highway with a passenger and a full load of luggage in the car. Hell i even get 23.5 mpg with my local driving. Take your foot off the gas! Oh and you might want to change your gas station, try a BP or Mobil gas station. Another saver is a K&N filter/intake. im getting 2mpg better with that... Enjoy!

[mwr]

Another saver is a K&N filter/intake. im getting 2mpg better with that.

What does that replace? Are there any drawbacks to it?

[VTGT]

VTGT, I think you're the first beside myself to report 15mpg in town. And I get that whether being conservative or aggressive. Maybe 16mpg if I'm real soft on the pedal. If I get any help from Subaru, I'll post it.

 

I guess its because i am in a lot of stop and go and my trips are only 2-3 miles a day. I think the car uses up more gas when it is not warmed up yet. So my car really is just warming up once i get to my location. Just a thought.