Gas mileage and fill-up

[Subietonic]

The 98 GT Auto comes on right about the "E" but then, if I want to live dangerously, I can drive another 60-80 miles until the gauge is well below the "E" and still only put about 13 gals of gas in the tank on refill. On the 98 GT Manual, the light doesn't come on until the gauge is below the "E" line about 1/8 inch . It also takes about 13 gals of gas to fill at this indicated position. I don't like to get below a half a tank so I very rarely see the light on either car. The 01 Forester gas light comes on and stays on if the needle even brushes the "E" line and I start looking immediately for a fill up because its gas mileage stinks.

Br, Dale

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[Boxologist]

My '95 Impreza 2.2 L Auto AWD will get high 20s on the highway and mid 20s in the city. I typically get around 27 mpg.

I wonde what it will go up to with the intake iput on lastweek.

[Heather]

18.4 in City driving only. Well a city of 60,000 with no stop and go really. The 2001 manual Outback I drove on the same paths got 22 City. What's up with that?! I noticed Chewie likes to rev high. Driving 40 MPH in 3rd she is at almost 4,000 RPMs, whereas the Outback in the same situation, was at around 3,200 RPMs. Is this why? Or do I gas her too much because of the GT go fast badge?
Heather

[LewBob]

Heather, It is probably a combo of things. My GT had poor throttle response below 3600 or so until I added the Ganzflow and light weight pulleys. Now I can shift at lower RPM's and drive below 3,000 when in traffic. That should be helping my gas mileage even if I do have fun accelerating up to speed.

BTW, I sent back the DirectHits igntion system. I found that moving up to mid grade gas was what had improved my performance... More money to save for a Cobb muffler Lew

[rallysquirrel]

Just drove a friend to pickup his Aprilia (motocycle) this past weekend. I was good on the throttle and got rewarded with 27mpg, which has never happened before. I drove down and drove like my normal self, with my frined on the bike in front of me and I will probably get ~20mpg

It will be well worth it

[Subietonic]

Heather,

Me thinks it's because of the 4.11:1 axle ratios. More turns to the engine to go the same speed (= faster takeoff, i.e., go fast quicker badge) compared to the Outback which is turning at something like 3.73:1 IIRC

Bottom line is that the GT engine/drivetrain will turn at higher rpm, hence more fuel to go the same speed/distance. Upside is the wahoo affect and the downside is the decreased fuel mileage.

Br, Dale

[Heather]

Originally posted by LewBob
BTW, I sent back the DirectHits igntion system. I found that moving up to mid grade gas was what had improved my performance... More money to save for a Cobb muffler Lew

Hmmm.... I will try mid-grade fuel with the next tank! Thanks for the tip! Since we have to get Premium in the Bean, I figure to save $ I need to get low grade in Chewie, but if she needs a higher grade, she will get it! I only go to Chevron, since that gas is supposed to be good.

A Cobb muffler huh? Sounds good! I want one too!

With the shifting comment. Brooke shifts Chewie at 2500 RPM's (when I let him drive her that is) and I shift her between 3500 and 4000, so to keep her ECU trained right, I can't shift sooner or she will poop out on me, or that is my perception.

Heather

[rallysquirrel]

I believe it's good to switch around companies where you get your gas, bacuase they all seem to use different cleaning agents. This might help your engine be cleanest. I also use BG-44K once a year to clean my fuel injectors. Seems to work like a charm.

[jrlegac8195]

I was wondering if anyone else had this problem

Ever since I got the car 2 yr and 8 months ago. The gas gauge needle will out of nowhere go from where ever it is and quickly whip down to "E" and sometimes stay there or will quickly go right back to where it was. Had warranty but was too lazy to have it checked, it always went back and didnt happen for a while.

Anyone else??????????

[gavin]

On a related topic, you really should fill up at 1/4 tank, rather than on E. You'll extend the life of your fuel filter, and engine. You'll also have to clean your injectors less often.

[rallysquirrel]

Originally posted by jrlegac8195
I was wondering if anyone else had this problem

Ever since I got the car 2 yr and 8 months ago. The gas gauge needle will out of nowhere go from where ever it is and quickly whip down to "E" and sometimes stay there or will quickly go right back to where it was. Had warranty but was too lazy to have it checked, it always went back and didnt happen for a while.

Anyone else??????????

I had the same thing happen to me for about 2 weeks. Now it's gone. From the replies I got, it seems to be a common thing that noone can explain.

[Satellite]

Well, I experienced it today... the gas light. Honestly I didn't even know I had one. It didn't last too long, by the time i noticed it on, I knew i was low on gas but didn't look for a light i thought was non-existant, it took about 5 miles and it just turned off and I didn't see it since, I quickly filled up because my car was on E for about 20 miles. Suprisingly though, I filled it up and I only got 13.084 gallons into my tank. Aren't they suppose to be higher?

[gtwagon941]

I would run it like an 1/8th of a tank below the "E" and I never ran out. Only saw the light once or twice in three years. Anyways, like everyone else has said it doesn't take long to figure out where you can let the needle slip to before you better fill up. On my 98 GT the gauge is not super accurate either, but can't push it as far since when I tried that I found myself walking home and longboarding back to the car with some gas.

As for mileage I never get below 22/23 city or not, and I definitely am in the lead foot category.

Jared

[MrBean85]

1992 Legacy L AWD sedan
mixed driving conditions 21-25
no modifications
91 octane or better
I usually fill up at about 240 miles but have gone as far as 315/330, and yes 1st gens do have a gas light !

[subysouth]

I got a bit of info

94 L wagon 5-spd

Best average mileage 30.5

Worst average mileage 23.4

When I bought the car the were a number of repairs that needed to be done, CE light error codes, front main seal,etc. As I repaired each of these, serviced the car and added some mods, my mileage steadily increased from a baseline average of about 24 mpg. The best mileage was recorded two weeks after new plugs/wires and a new AmSoil air filter and (a bit ashamed to admit) a Zmax engine treatment kit. I saw a consistent 2mpg improvement after the zmax, I dont know what that snake oil does.

After all that was done I was averaging between 28-30 mpg(I religiously keep mileage records and I do quite a bit of highway driving.) Then Bam! my mileage dropped off almost ten percent to its current level of 25-27 mpg. And I know why. It was due to the simplest mod out there. Can anyone guess what it was?

Ok I'll just tell you. New wheels and tires. I went from 185/70-14 to 205/55-16(WRX-takeoffs.) I would never go back to those stock tires for numerous reasons but I was getting excellent mpg on them.

subysouth

Ps I have only seen that low fuel light once and man you got to really ignore that thing for a while after it hits "e." Took 11.9 gallons to fill up from there and the manual claims I've got a 14 gal tank.

[jezzarisky]

as far as the gas gauge goes, my first subaru never read the correct amount when i filled it completely full it went only half way, which from what was explained earlier my guess was that one of the two sensors was out, and the only way i could gauge when to fill up was by the gas light, and so i know subarus have them as far back as 91, they do work, and with my new one i have the same situation youre all in, it says its on empty and when i fill it up its only like 10-11 gallons, my guess as to the inaccuracy of the gauge is a safety thing, it will show empty and if youre out in the middle of nowhere then you know you have a few more gallons left, when the light actually comes on you know you only have about 2 gallons left, and after that youre on your own. btw the gas light is still a fickle thing, and will turn off and on and random times, best thing todo is if it comes on, fill up.

as for mpg, my first 4 calculations i was getting in the upwards of 30+ mpg, but the last two times it drastically dropped to about 24. the only main things i can think of is one, lower octane fuel (85-87) no used of gas treatments, and hard 'n fast acceleration (pulling 6,000+rpms before shifting) but i just cant see those making such a drastic difference.

[1320Fastback]

Originally Posted by jkyes

on my 99 legacy, 20-27mpg... usually 20-22 city.. i also usually get ~250-300 before E light comes on, and i usually fill with 12 or so gallons.

+1, I run Coscto 87 btw.

[monovich]

my fuel light works great on my 98gt. Its definitely non-linear (which I guess is normal). The first half of the tank moves slow and then it drops pretty fast after 1/2. The light always goes on when I hit empty and is pretty accurate. If I drive about 30 miles after the light goes on I risk running out of gas, which I've done. My biggest fillups are 14.6 gallons and supposedly I have a 16 gallon tank.

[Jonathan]

Originally Posted by jrlegac8195

I have some questions on the legacy gas mileage and what happens to other people on fill-ups.

I get about 18 - 20 miles to the gallon on normal city driving. Does anyone else get this low of a MPG?

Also when I go to fill-up at the gas station and my gauge is on "E". It always seems I only need between 9 - 11 gallons to fill-up the tank. In the manual it says that the tank holds 16 gallons. Is this common or is my fuel gauge gone. I have had this car for almost 3 years and it has always been the same.

Thank you
Ron

Like Ron's original post, my '96 4EAT 2.2 Litre Legacy gets a fairly consistent 18.5 to 19 MPG in a 12 mile (round trip) commute to and from work that involves a fair amount of idling at traffic lights. I would imagine it will do 25-28 MPG on the open road, although I haven't done this. The 4EAT tends to be rather innefficient on start-up & acceleration, IMHO.

I usually wait until the Gas Pump Icon warning light comes on before refueling. Typically it takes ~12 gallons +/-. I understand that it has a 16 gallon tank, so leaving the 4 gallons sloshing around doesn't hurt, and helps to keep the internal gas tank fuel pump cool, and means most of the dirt and sediment in the tank stays in the tank instead of being sucked in to the fuel filter and/or fuel injectors.

I would say that this is "common" and that your gas gauge is fine, and it is best to leave the gauge reading the way it is.

My '99 5-speed Legacy GT sees mostly light back road use and some highway use were I typically see mid 20ies fuel mileage.

[SubaruFan]

2001 GT SDN 5spd

19mpg towing 2000lb sailboat low wind profile
22-25mpg flat freeway towing 500lb sailboat also low slung/wind profile

25-26mpg mixed freeway city commute (note my commute I generally keep the revs pretty low no need to go fast in stop and go traffic)

Best ever milege 68mph cruise control setting - 35psi in tires front and back- tail wind with a few miles including some down hill 32mpg. The closest I've come to that since is 27mpg on the same trip/road years later.

[SubaruFan]

Should note that Summer gas tends to be a better blend for milege vs winter gas which has a bunch of crap in it to cut polution etc. California for ya

[fire_chimp]

I haven't seen my light, Ill have to give it a try and see just how far it goes below E. As for gas millage if i baby it i get 31 highway. 25 in town, and thats with 165K.