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HELP! Getting 7-8 miles to to gallon!

Low MPG Subaru legacy 1990s Problem Need help 7 MPG

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26 replies to this topic

#1 Ekstrandd

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Posted 26 October 2013 - 04:53 PM

I have a 1993 subaru legacy. It's an automatic 2.2 liter. It has 191,xxx miles on it, and it was well taken care of by the previous owner. I have owned it for about a month now, and mind you I am a BRAND NEW driver (2 months) and this is my 2nd car.

According to my mechanic husband I should get 20 miles to the gallon. Last time I filled up I reset my trip mile counter thing, and I am now at a quarter tank after 90 miles. Since it's a 15.9 gallon tank, 11.9 gallons for 3/4 of a tank, that is about 7.5 miles per gallon... I am hoping there is something obvious I am missing.

After I bought it there was an electrical wire problem with the starter, which was fixed, and then the alternator went out, which was also replaced with a brand new one. I use as little heat as possible to try to conserve gas (however I do live in Alaska), and I am NOT a speed racer whatsoever - I always drive the speed limit if not slower. (I hate driving) My check engine light HAS been on as long as I've had the car, and my car SUPER hates the cold mornings - I always have to start it a couple times to get it going.

Ideas? Suggestions? Help? Please? Pretty please?

PS - Why are the fuel tank measurement lines (on the dash) so uneven/disproportionate? Is that related?

#2 jp98

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Posted 26 October 2013 - 05:41 PM

Don't go by the fuel guage to figure the mileage.  Use the odometer and the number of gallons when you fill it back up and divide the number of miles driven by the number of gallons that you put back into the tank to figure the mileage. 

 

If you have a check engine light you need to get the codes read to know which way to go to fix it. 



#3 Dakotademon7

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Posted 26 October 2013 - 05:45 PM

Using the heater doesn't burn extra gas. The first thing is to see what code it is throwing. Get that fixed and do an oil change and tune up.

#4 cohophysh

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Posted 26 October 2013 - 06:29 PM

shoot, you should be getting upwards of 29 mpg



#5 Gloyale

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Posted 26 October 2013 - 06:38 PM

Using the heater doesn't burn extra gas. The first thing is to see what code it is throwing. Get that fixed and do an oil change and tune up.

 

Technically every electrical load will use very tiny amount more gas as the Alt loads up and takes power from engine.

 

So running the blower motor would technically use a tiny bit........I mean a tiny bit.  So little it would probably not make 1mile extra e on a tank let alone anything noticable.

 

I'm thinking that you need to read the codes.....but honestly, if it's running well then more likely the gauge is inaccurate. 

 

(there are 2 senders.....1 on each side of tank and the average between them is the level shown.  If one goes bad it does weird things to the range the gauge operates in)



#6 Gloyale

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Posted 26 October 2013 - 06:39 PM

shoot, you should be getting upwards of 29 mpg

 

LMAO

 

That's wishful thinking. 

 

The car was only EPA rated at 23-25 brand new.

 

19-22 is about average for these cars with high miles.  espescially the autos.

 

Here's the EPA page.

 

Look at the automatic, 4wd wagon. 

 

http://www.fuelecono...ubaru1990.shtml


Edited by Gloyale, 26 October 2013 - 06:44 PM.


#7 Cougar

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Posted 26 October 2013 - 06:55 PM

I didn't realize you had double posted this issue. Here is my previous post:

 

I haven't heard of a Soob with that bad of mileage before so I wonder if what you are seeing on the fuel gauge is really a true tank level. There are two fuel level sensors inside the tank and I suspect that one of them isn't working correctly. When you filled the tank did it show full? If not then that would be a clue to a faulty sensor. You could also refill the tank and see how much fuel it takes to fill it again and then calculate your mileage using the amount it took to fill the tank. Sometimes using a product called Techron in the tank has cleaned the fuel sensors for some folks.

 

There could also be a problem with the coolant temperature sensor for the engine which is making the engine run more rich than it should be.



#8 cohophysh

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Posted 26 October 2013 - 07:29 PM

LMAO

 

That's wishful thinking. 

 

The car was only EPA rated at 23-25 brand new.

 

19-22 is about average for these cars with high miles.  espescially the autos.

 

Here's the EPA page.

 

Look at the automatic, 4wd wagon. 

 

http://www.fuelecono...ubaru1990.shtml

Well I hate to tell you that my 90 wagon with 380,000 miles gets around 29.



#9 Gloyale

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Posted 26 October 2013 - 08:10 PM

Well I hate to tell you that my 90 wagon with 380,000 miles gets around 29.

 

Bullsheet

 

You're oddometer is off.



#10 cohophysh

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Posted 26 October 2013 - 08:14 PM

Bullsheet

 

You're oddometer is off.

nope, checked



#11 cohophysh

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Posted 26 October 2013 - 08:18 PM

nope, checked

I should mention that all I do is drive it on the freeway



#12 Gloyale

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Posted 26 October 2013 - 08:22 PM

nope, checked

 

Dude.

 

Even the Justy is only rated for 32.....with a full litre and one cylinder less displacement.

 

So if your odometer is off then your math is off or you aren't keeping acurate records or your just lying to yourself to feel better about your car.

 

Something is off.

 

And I'm sorry if I sound like a wongleflute but it's unrealistic and unhelpful to people to make them somehow expect they should eb getting near 30 MPG.

 

I am sick of people bringing me cars and complaining that they read they should get 25-30 MPG from their Legacy/Forrester/WRX etc.....

 

NO YOU SHOULD NOT!!!  So I'm sorry to be a wongleflute about this but look again at the EPA ratings for these cars and be honest with yourself.  You're NOT getting 29mpg



#13 cohophysh

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Posted 26 October 2013 - 08:27 PM

Dude.

 

Even the Justy is only rated for 32.....with a full litre and one cylinder less displacement.

 

So if your odometer is off then your math is off or you aren't keeping acurate records or your just lying to yourself to feel better about your car.

 

Something is off.

 

And I'm sorry if I sound like a wongleflute but it's unrealistic and unhelpful to people to make them somehow expect they should eb getting near 30 MPG.

 

I am sick of people bringing me cars and complaining that they read they should get 25-30 MPG from their Legacy/Forrester/WRX etc.....

 

NO YOU SHOULD NOT!!!  So I'm sorry to be a wongleflute about this but look again at the EPA ratings for these cars and be honest with yourself.  You're NOT getting 29mpg

whatever, say what you want but before I put it in storage it was consistently getting 29, the previous owner was getting 27-29 



#14 Gloyale

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Posted 26 October 2013 - 08:56 PM

whatever, say what you want but before I put it in storage it was consistently getting 29, the previous owner was getting 27-29 

 

So you get 400 miles to a tank?

 

Let me get this straight....you get 15-20% BETTER gas mileage after almost 300k miles than the car got new......yeah sure. 

 

Your math is wrong or your lying. Or maybe not so much lying as just pulling crap out of your arse to make yourself happier with your own choices.  Or your trying to impress the internets.



#15 Fairtax4me

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Posted 26 October 2013 - 10:08 PM

My 96 used to get 33mpg consistently. Ive done 435 on a tank and filled up at 13.5 gallons. Mind you, it's a manual, and that was with fairly conservative driving. Has struggled to get over 29 recently, at 225k miles.

To the OP, you should be getting in the 20-25 mpg range with the automatic AWD. But make sure to calculate fuel mileage based on gallons refilled at the pump, not by what the guage says. The fuel gauges in these are notoriously inaccurate.
Unless you have a cloud of black exhaust following you around I find it very hard to believe you're getting fewer MPG than my buddies 3/4 ton Chevy truck. (He gets 12 mpg downhill with a strong tailwind)

CEL on, you need to check the codes and see what it thinks is wrong.
More then likely you need an engine coolant temp sensor. And you may also have a bad O2 sensor.

#16 Gloyale

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Posted 26 October 2013 - 10:33 PM

My 96 used to get 33mpg consistently. Ive done 435 on a tank and filled up at 13.5 gallons. Mind you, it's a manual, and that was with fairly conservative driving. Has struggled to get over 29 recently, at 225k miles.

 

 

Even if those #s were accurate,( which I don't believe) that would be 32.2........so if that's your best "I've done blah blah blah" situation then you couldn't be "consistently" getting even better than that.

 

ONce again......the stats....and this is assuming your car is FWD, which I doubt because most if not all us 96 cars were AWD so the mileage would be even worse.

http://www.fuelecono...mes/12783.shtml

 

here's the AWD version

http://www.fuelecono...mes/12785.shtml

 

See what I mean about the tendancy to "puff up" ones own situations?



#17 Fairtax4me

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Posted 26 October 2013 - 11:05 PM

You can puff up all you want but that's what it did, multiple times.
96, 2.2, AWD, MT.

#18 WoodsWagon

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Posted 27 October 2013 - 12:05 AM

98 Outback with the 2.5l and auto could pull down 27 consistently on road trips loaded with family. Best was 29.8 across Nebraska. So I could see a 2.2l in a lower ride height legacy with less weight in it doing better no problem.

 

But for the original question, cold start issues and low MPG could be due to a failing coolant temp sensor for the engine's computer. There's two sensors, one for the gauge with just one flat spade connection, and one for the computer, with a two pin connector.

 

The first thing to do is to read the codes stored in the computer. It's easy to do on that car, there's a pair of connectors under the dash that you plug together and it will make the check engine light flash in a pattern. Decipher the pattern and you get two digit code numbers that you can look up to see why the computer is unhappy. That's your first step to figuring out what might be wrong.

 

Oh, and the gas gauge isn't 15.9 gallons from full mark to empty. There's usually a couple gallons left below the Empty mark as a "reserve". So when the gauge hits empty, and the low fuel idiot light comes on, there's still enough gas in the tank to drive it to a gas station. Only figure out your mileage based on full tank to refilled full tank divided by miles driven.



#19 Ekstrandd

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Posted 27 October 2013 - 12:47 AM

Okay guys, so update. I just put 5.5 gallons in and my fuel gauge went up half a tank. Fuel gauge off?

Edited by Ekstrandd, 27 October 2013 - 12:48 AM.


#20 heartless

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Posted 27 October 2013 - 07:25 AM

Yes, very likely the fuel guage is not reading correctly. This is a common issue with the older models.

 

My 1990 Legacy, with 237,000, auto, AWD, gets an overall average of around 24-25 mpg - both city & country driving - summer slightly more - winter slightly less. The guage works only when it wants to, so I dont go by the guage. I reset the trip meter at each fill up, and run to around 275 miles or so on that and fill again - usually in the 11 gallon range when I do.

 

You need to find out what codes are stored - that will tell you more about what is going on with the engine than us just guessing at things

 

 

 

@ Gloyal - statistics are just educated guesses - nothing more (in a statistics class right now). A sample range is taken, and an average is calculated off of that sample and applied to the entire "population". it is NOT carved in stone! If the samples are taken from an area that is different than where you are located (ie: above or below sea level, flat ground vs hilly, etc), it is VERY likely that your personal average may differ by quite a bit. Never mind variables such as tire composition, O2 sensor condition, tune-up, etc

 

The mileage that I just posted is based off of 6 - 7 years of driving this same car, under pretty much the same conditions over that time frame.

Individual fill-ups have varied by quite a bit, including a high of just over 30 mpg right after changing the O2 sensor, to a low of 23 mpg - right before changing the O2 sensor...

 

The tires I have on my car right now - Kelly Explorers - are softer, stickier tires that have reduced my average mpg by 2-3 mpg overall. The last set of tires I had - Cooper CS4 Tourings - were a harder compound, and I was getting an overall average of about 27mpg with those, with highway mpgs going into the 29mpg range - consistently.

 

The old 89 GL manual consistently got 32-33 mpg - and I didnt drive that car "nice" - it was way too much fun to play...

Madkow007 was getting around the same - 32-33 mpg out of his 1990 Legacy sedan, MT as well...

 

So just because the statistics say something, does not mean that ALL cars are going to be exactly the same. There are far too many variables involved to insist that every car is going to be dead on that statistical value.



#21 oregoncoast

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Posted 27 October 2013 - 07:45 AM

Even if those #s were accurate,( which I don't believe) that would be 32.2........so if that's your best "I've done blah blah blah" situation then you couldn't be "consistently" getting even better than that.

 

ONce again......the stats....and this is assuming your car is FWD, which I doubt because most if not all us 96 cars were AWD so the mileage would be even worse.

http://www.fuelecono...mes/12783.shtml

 

here's the AWD version

http://www.fuelecono...mes/12785.shtml

 

See what I mean about the tendancy to "puff up" ones own situations?

 

 

this-thread-just-went-full-retard.jpg



#22 Dakotademon7

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Posted 27 October 2013 - 08:01 AM

BbbbhaahhA. You guys are cool.

#23 MilesFox

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Posted 27 October 2013 - 10:05 AM

my cars range from 18-20 in town, 22-and 24 on the highway across 300 miles, , both 4eat (94 legacy, 95 legacy) and my 93 FWD would do 26-27 on the highway with its taller gearing, but still the same 20 ish in town.

 

I would average about 1225 mi between gas on the highway, but i couldn't trust the gauge as the car would run out before the yellow light came on.

 

If the gauge itself is inaccurate, the yellow low fuel warning light would still come on independent of the gauge sweep itself. The yellow light reflects about 2 gallons left in the tank



#24 Cougar

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Posted 27 October 2013 - 11:58 AM

Okay guys, so update. I just put 5.5 gallons in and my fuel gauge went up half a tank. Fuel gauge off?

 

It does indeed sound like one of the two tank level sensors isn't reading correctly. If you drove 95 miles on the 5.5 gallons of gas that would put your mileage at about 17.25 miles per gallon. This is a lot more what you would expect to see instead of the 7 or 8 you had originally thought you were getting. You stated that your husband is a mechanic so he should be able to fix the problem himself without much trouble. You can get at the sensors through some access covers above the tank, inside of the car. Sometimes you can just clean the contacts to fix the problem. Using some Techron in the tank might fix the trouble also. If you need some help with this let me know, the CAT roams near the Chugach mountains also.

 

One other thing to note in case you aren't aware of it. You should not try to fill the fuel tank all the way up in todays cars. There is a charcoal filter in the fuel system that is designed to remove fuel vapors but if it gets liquids inside it, it will damage the filter. 



#25 Gloyale

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Posted 27 October 2013 - 12:35 PM

Okay guys, so update. I just put 5.5 gallons in and my fuel gauge went up half a tank. Fuel gauge off?

 

1 of the 2 senders is dead.

 

Remove the plates under the rear carpet and access the sending unit connectors (one on each side of the tank)

 

Test resistance of each sender.  If nessecary, remove the senders and test them through the range for proper resistance changing.







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