librarygal Posted September 9, 2006 Share Posted September 9, 2006 Hello...purchased a 2001 2.5 automatic with 127K. Had everything gone over including flushing transmission, brakes etc...but sadly I have been tracking the gas mileage and today found that I had gone 98 miles on about 7.8 gallons. Not good news. The car seems to run fine...I checked my math and looked back over receipts and verified the gallons and mileage just to be sure...any suggestions? Thanks as always, Pam:-\ Quote Link to comment Share on other sites More sharing options...
Manarius Posted September 9, 2006 Share Posted September 9, 2006 Change air filter, spark plugs, plug wires, and possibly the front O2 sensor. Do cheap stuff first, then do the more expensive. Quote Link to comment Share on other sites More sharing options...
jon38iowa Posted September 9, 2006 Share Posted September 9, 2006 Hello...purchased a 2001 2.5 automatic with 127K. Had everything gone over including flushing transmission, brakes etc...but sadly I have been tracking the gas mileage and today found that I had gone 98 miles on about 7.8 gallons. Not good news. The car seems to run fine...I checked my math and looked back over receipts and verified the gallons and mileage just to be sure...any suggestions? Thanks as always, Pam:-\ Hi: I noticed a signifigant improvement in mileage after relplacing my front O2 sensor on my '99 Forester. I think I would start there. I hope its not the case for you, but my mechanic mentioned to me that a sure sign of a Converter failure is decreasing fuel economy; This would be unusual though as Converters last forever, unless a person gets really bad gas. Good Luck. John Quote Link to comment Share on other sites More sharing options...
The Dude Posted September 9, 2006 Share Posted September 9, 2006 Hi Librarygal. Mileage should be averaged over three complete tanks of gas. Subaru recommends that you stop filling the gas tank when the gas pump first "clicks" off. But different gas pumps "click" at different points. It's also possilbe to "stuff" over a gallon of gas into the gas tank after the first "click". So, try to fill the gas tank consistently, if you could use the same pump for all three tanks that would be a plus. Are you driving in city, open highway or mixed traffic? Heavy stop and go traffic will always result in very poor mileage. Moderate speeds on highways with little traffic will usually give the highest mpg results. I live in suburban/ rural South Carolina. I averaged about 24-25 mpg in my driving mix while driving my 99 Forester. Country roads usually yielded very good mileage with one exception. If the roads had slow moving vehicles, tractors for example, the constant passing absolutely killed my mpg. Quote Link to comment Share on other sites More sharing options...
librarygal Posted September 9, 2006 Author Share Posted September 9, 2006 Thanks to all who responded. For the record, when we bought the little green monster,(presently named Tortuga.. we had the following done: replaced engine coil and #3 spark plug wires, reset computer logics, flushed the transmission, replaced timing belt--I will check with them for the o2 sensors and see about the other suggestions such as the air filter etc. I have filled the car at the same station and never go beyond the click because I have had the experience of spilling and that is never fun. One thing I did notice, the actual reading on the gas indicator never goes all the way up to full...it stays down about 1 tick mark...the first time I thought the tank was full and drove home and saw that I went back to put in more gas (because the low mileage thing is bugging me and I wanted to be sure I had it full) and it took exactly .0158 which cost .12 cents and I was truly befundled. Anyway, I don't know if this is an issue or not. Over two tanks of gas we traveled 272 miles and the car used 16.7 gallons so that's about 16 miles per gallon... Also, I had the tires checked yesterday and apparently the rear back right tire is "new" and the other three are the same depth....the guy at the tire store said this can ruin the transmission...Is this true? Should I also go get new tires? Could this be affecting the mileage...sorry to be so long winded...and to not give all this info in the first post...guess it's the busy mom syndrome Quote Link to comment Share on other sites More sharing options...
Olnick Posted September 9, 2006 Share Posted September 9, 2006 First off, don't panic. Subaru fuel gauges are notoriously inaccurate. Best to keep handwritten records. Reset your tripmeter at each fillup and note milage and gallons added--then divide miles by gallons to get your mpg. And, as noted earlier, do this for at least 3 fillups before drawing any conclusions. By the way, your tire guy is sharp. AWD cars should have all 4 tires matching. Let us know how it goes. Quote Link to comment Share on other sites More sharing options...
jon38iowa Posted September 9, 2006 Share Posted September 9, 2006 Thanks to all who responded. For the record, when we bought the little green monster,(presently named Tortuga.. we had the following done: replaced engine coil and #3 spark plug wires, reset computer logics, flushed the transmission, replaced timing belt--I will check with them for the o2 sensors and see about the other suggestions such as the air filter etc. I have filled the car at the same station and never go beyond the click because I have had the experience of spilling and that is never fun. One thing I did notice, the actual reading on the gas indicator never goes all the way up to full...it stays down about 1 tick mark...the first time I thought the tank was full and drove home and saw that I went back to put in more gas (because the low mileage thing is bugging me and I wanted to be sure I had it full) and it took exactly .0158 which cost .12 cents and I was truly befundled. Anyway, I don't know if this is an issue or not. Over two tanks of gas we traveled 272 miles and the car used 16.7 gallons so that's about 16 miles per gallon... Also, I had the tires checked yesterday and apparently the rear back right tire is "new" and the other three are the same depth....the guy at the tire store said this can ruin the transmission...Is this true? Should I also go get new tires? Could this be affecting the mileage...sorry to be so long winded...and to not give all this info in the first post...guess it's the busy mom syndrome I would definately replace the tires(I don't know if they effect mileage)- perhaps the one new tire can be matched with three more; The transmissions in these cars are $4000. Just this week I put four new Unitoyal Tiger Paws on mine- awesome performance! I also recomend running a fuel cleaner( seafoam or other high quality) through your gas tank, and then change your fuel filter.When I changed my air filter I went with the new Air Hog, morever, it seems to run a little better with this kind. Even when everthing is perfect I have noticed these cars fluctuate in gas mileage, a little more then the average car. Mine for example: If I run the air conditioning it saps the mileage and alot, as will fast off the line driving, however if I take it slow then I can sometimes get upwards of 30 mpg. I have also noticed these cars are sensitive to the kind and grade of gas; Regardless of what the book says(and this is a high mileage car), I found mine runs much better on 89 or 90 octane, moreover it hated ethanol blend and this evident by poor mpg. John Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted September 9, 2006 Share Posted September 9, 2006 Some other things might if any of the brakes are hanging up that would reduce mileage. If you lift the wheels off the ground do they turn smoothly and freely or do you feel any binding, or if you drive for a few minutes and then kind of coast down and stop using the brakes as little as possible, do any seem excessively hot? overeager knock sensor could maybe knock it down a bit, as well as front o2 sensor. Tires circumference must be almost exactly the same or it can cause lots of heat in the AT center clutch thing and that heat doesn't come free - it costs gasoline. Quote Link to comment Share on other sites More sharing options...
librarygal Posted September 12, 2006 Author Share Posted September 12, 2006 New tires today and alignment.Had the oil changed and they checked the air filter which was fine. Checked around and saved $80 on 4 new tires and alignment. I truly think the car rides alot better! I talked to our Subaru Mechanics today and they said California gasoline isn't the greatest right now. They suggested a higher octane maybe..So, they will look at it on Friday and see if it needs tuned up. Since we mostly just putt around town, it would be good to get it out on the road for a couple hours...might try that this weekend. Now that it has new tires gotta try em out! Quote Link to comment Share on other sites More sharing options...
nipper Posted September 12, 2006 Share Posted September 12, 2006 Hello...purchased a 2001 2.5 automatic with 127K. Had everything gone over including flushing transmission, brakes etc...but sadly I have been tracking the gas mileage and today found that I had gone 98 miles on about 7.8 gallons. Not good news. The car seems to run fine...I checked my math and looked back over receipts and verified the gallons and mileage just to be sure...any suggestions? Thanks as always, Pam:-\ How are you measuring the fuel? you need to measure by what you put in the tank. If your gauge is off chevron has a additive that cleans gas gauges. It works really well. Next is the o2 sensors, and make sure none of your brakes are dragging. You may think about a set of plugs. nipper Quote Link to comment Share on other sites More sharing options...
librarygal Posted September 12, 2006 Author Share Posted September 12, 2006 How are you measuring the fuel? you need to measure by what you put in the tank. If your gauge is off chevron has a additive that cleans gas gauges. It works really well. Next is the o2 sensors, and make sure none of your brakes are dragging. You may think about a set of plugs. nipper Yep, I am going to probably get those plugs Friday...when I had the new tires put on today, they checked on the brake drag possibility and all was fine there...I am measuring the fuel by what I put in the tank. I am using the 15.9 full tank that the manual states...is that correct? Thanks alot! Seriously, a cleaner for gas gauges..who would have thought!:-p Quote Link to comment Share on other sites More sharing options...
nipper Posted September 12, 2006 Share Posted September 12, 2006 Yep, I am going to probably get those plugs Friday...when I had the new tires put on today, they checked on the brake drag possibility and all was fine there...I am measuring the fuel by what I put in the tank. I am using the 15.9 full tank that the manual states...is that correct? Thanks alot! Seriously, a cleaner for gas gauges..who would have thought!:-p what kind of driving are you doing? i mean they are rolling bricks to begin with, but unless you practice jet propulsion at the traffic lights, its hard to get milage that poor. Have you checked for codes? maybe a bad knock sensor? nipper Quote Link to comment Share on other sites More sharing options...
librarygal Posted September 12, 2006 Author Share Posted September 12, 2006 what kind of driving are you doing? i mean they are rolling bricks to begin with, but unless you practice jet propulsion at the traffic lights, its hard to get milage that poor. Have you checked for codes? maybe a bad knock sensor? nipper In town driving...3 miles here 5 miles there..but very conservative about taking off too fast etc...hardly ever run the a/c ... I know, it's hard to believe that it is getting such poor mileage. We have a 2002 manual trans forester and it does 23 at least in the same situations...and really good on long trips. Will have the subaru guys check for codes on Friday...it did past smog in CA in July and no check engine light comes on ever...maybe just the high mileage...Ha! Rolling bricks they are...but they are my favorite. Quote Link to comment Share on other sites More sharing options...
cookie Posted September 12, 2006 Share Posted September 12, 2006 The ox sensor on my 99 Forester was done at about 100,000 miles. I am in San mateo, where are you driving yours? when I drive in SF my mileage is terrible but the usual mix is down to the city to pick up my wife (24 miles each way) and the Forester does the shopping in San Mateo. Usually I average 25 overall. Quote Link to comment Share on other sites More sharing options...
BigMattyD Posted September 12, 2006 Share Posted September 12, 2006 Just checking your math regarding mpg... It doesn't matter what size your tank is (15.9 gallons) unless you already know your usual mpg, and you are trying to decide how far a full tank will take you. Fill your tank all the way full, and set your trip odometer to zero. Drive normally till it's time to fill up. When you fill up, record the number of gallons used (let's say 12.125.) Then look at your trip odometer (let's say 234 miles). Then divide your miles traveled by the gallons used: (234miles/12.125gallons) = 19.2 mpg. The tank size is not relevant to this equation. However, once you know your avg mpg (let's say 25 mpg), you can estimate your range till empty. (25mpg X 15.9 gallons) = 397.5 miles. Of course, you would not drive till empty, but give yourself a reserve, maybe 75 miles or so. Then if you reset your trip odometer every time you fill up, you can watch the odometer instead of a faulty fuel gauge. If you have been calculating correctly, please excuse me. It just seems too far off, and I know that there are others out there, anyway, who might benefit from this info. Not everybody is good at math... Matt D. Quote Link to comment Share on other sites More sharing options...
librarygal Posted September 13, 2006 Author Share Posted September 13, 2006 Dear Matt: Yep, I am doing it the correct way...thanks for checking up with me though... Quote Link to comment Share on other sites More sharing options...
librarygal Posted September 13, 2006 Author Share Posted September 13, 2006 We live in Chico...it is around town driving for sure. We do have another subaru forester that get about 23-24 around town (manual trans)..it is a 2002 with 68K. So, I will see about the o2 sensor and etc. on Friday when I take it to the Subaru guys. btw, these two guys are really good. They used to work for the dealership here and now have their own shop. So, they should have some kind of idea when they run through the code thingy..Thanks for the reply. Pam Quote Link to comment Share on other sites More sharing options...
BigMattyD Posted September 13, 2006 Share Posted September 13, 2006 I figured you were doing it right, but you never know for sure... I agree with everyone else that the next thing to work on would be the front O2 sensor. The ECU uses the output from the sensor to determine the air/fuel ratio. If it is reading incorrectly, the car may be running too rich. Here's another crazy thought: could you be losing fuel somehow.... a fuel tank leak, maybe someone siphoning it out, etc?? If that much fuel were leaking, you'd be likely to have noticed the smell already, or maybe spots on the driveway. matt Quote Link to comment Share on other sites More sharing options...
nipper Posted September 13, 2006 Share Posted September 13, 2006 By anychance you dont have a house trailer attached to this thing :-p nipper Quote Link to comment Share on other sites More sharing options...
librarygal Posted September 13, 2006 Author Share Posted September 13, 2006 Matt, Would the check engine light be on if this were the case with the os sensor? It did pass smog in June...should have some answers on Friday with the mechanics...thanks again... Quote Link to comment Share on other sites More sharing options...
librarygal Posted September 13, 2006 Author Share Posted September 13, 2006 ha... Quote Link to comment Share on other sites More sharing options...
brus brother Posted September 13, 2006 Share Posted September 13, 2006 Would this be noticeable with an OBD scanner or only in the rear view mirror? By anychance you dont have a house trailer attached to this thing :-p nipper Quote Link to comment Share on other sites More sharing options...
johnceggleston Posted September 13, 2006 Share Posted September 13, 2006 if the poor gas mileage was just one tank, i would suspect that you didn't fill it up the tank before . in other words it wasn't full when you started measuring your mileage. (there's one place where i fill up that my gas pump will click off when the pressure changes in the pump, like when the guy next to me "clicks off".) b ut if if this is continuing over several tanks, then that's out. the other thing is mpg is an average. i get 25mpg in my 95 2.2L leg. but 2/3's of my driving is hiway. if i go 200 miles at 30 mpg, i have to go 200 miles at 20mpg to average 25 for the tank. but realisticly, i go 200mi (weekly commute, one way) at 30mpg and 100mi at 15mpg to average 25mpg for the tank. this may not be the best round town gas mileage, and maybe should be improved, but the car is over 10 years old, 170k miles. keep us updated. and good luck. Quote Link to comment Share on other sites More sharing options...
cookie Posted September 13, 2006 Share Posted September 13, 2006 ox sensors can get lazy and not throw a code. Or they can go the other way and throw codes and still get average gas mileage. The little buggers do have a sense of humor. Quote Link to comment Share on other sites More sharing options...
librarygal Posted September 14, 2006 Author Share Posted September 14, 2006 Would this be noticeable with an OBD scanner or only in the rear view mirror? maybe THAT is IT!! I am pulling an invisible trailer!! Quote Link to comment Share on other sites More sharing options...
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