So i've been driving alot lately and i realized i get really crappy gas mileage with my Impreza... I know its a 1.8l and you need to keep the pedal pretty far in the ground haha ... but i get poor gas mileage lately even when i drive easy. i get like 15mpg ... Does anyone know why!?

well i've seen this topic come through here alot, but I'm just going to chime in and add my greivance since you've already started the ball.

I also get poor mileage. the last time i filled up i put in just over 14 gallons(it was really low) and I used 89 from Hess just for the hell of it even though i always use 87. I got 250 miles from that tank, which figures to about 18mpg. This is the worst gas mileage I've ever gotten out of a 4 cylinder. So in an effort to fix this I did the obvious.
-Oil and filter change (5w30 full syn)
-air and fuel filter change (OEM replacement)
-spark plug and wire change (NGK V-power, bosch 7mm wires)
-Tires are at 44psi
-Better flowing exhaust (Borlas, custom midpipe -1 resonator)

Mileage has NOT changed at ALL. It's actually worse because over the summer, before I made these changes I was getting 275-280 miles per tank.

My next steps are to:
-Get my alignment and balancing checked.
-Lightweight or underdriven pulleys. (still can't decide)
-Try to get my hands on one of the apparently hard to come by throttle body spacers.
-Lose weight
-Give it a good aerodynamic waxing.
-Drive as little as possible.

:(

On this car and my last Impreza (which was a 1.8) I get about 200 miles out of 7/8ths of a tank... Unless i'm doing all highway miles.

I have a '95 2.2L with 100k miles and I have noticed a small problem with mine too. I have just recently calculated mine to be 13mpg... which is basiclly horrible. I set the odometer every time when filling up (mainly because my gas gauge doesn't always work so well) and find I get about 160 miles, with little below a quarter left, before I fill up. Tonight, I was hitting 155 miles and it was on E. Given that it's a 50 liter tank, I figured I used about 45 liters approx (actually that could be a bit high).

45 liters = 11.89 gallons
155/11.89 = 13.03 mpg

And it's a 2.2 non-turbo....... like whoa? that bad? I do have to the last few days have been rather cold, in the teens. Generally in the morning, I let it warm up for about 5-10 minutes, but I've only done that twice on this tank. I use 87 fuel and drive no highway miles. Think that's just it? Probably with the addition, that both our cars are getting old, possibly they just arn't as efficient as they used to be. This would probably help both our problems.

try cleaning out the insides with some BG44K or seafoam. and 44 psi? what the hell? what tires are you running?

and for the original post, how many miles on the car?

running contis, can't remember which model right now and it's waayy to cold to run outside right now, says 44 psi right on the sidewall. i normally run them at 40 but, like i said i want to try every little bit.
I tried seafoam and drygas, should have mentioned that before. they made no difference.

i've noticed black residue on the tailpipe, no doubt i'm probably running rich. I don't know how to change that affordably.
any help with that?

not to toot my own horn or anything but, I have a 2.2 in a 97 OBS and the worst I have ever got was 19 mpg and that was getting on it everywhere I went and at an average of 6,500 ft elevation. best ever is 32 on a drive from Grand Junction to Phoenix and same on the way back going over mountains that were above 11,000 ft. I run 91 octane minimum and have 302,000 miles on the original heads and about 120,000 miles on the block. also running a 5mt and 18 inch wheels. I average around town about 24-25 even if I get on it a lot. If I don't get on it a lot I get about 27-28 around town.

running contis, can't remember which model right now and it's waayy to cold to run outside right now, says 44 psi right on the sidewall. i normally run them at 40 but, like i said i want to try every little bit.
I tried seafoam and drygas, should have mentioned that before. they made no difference.



yeah 44 psi is waaay to high to be running for daily driving... recommended pressure is about 32F and 29R.... the reason is says 44psi on the sidewall tires is b/c that should be your max inflatable pressure

not to toot my own horn or anything but, I have a 2.2 in a 97 OBS and the worst I have ever got was 19 mpg and that was getting on it everywhere I went and at an average of 6,500 ft elevation. best ever is 32 on a drive from Grand Junction to Phoenix and same on the way back going over mountains that were above 11,000 ft. I run 91 octane minimum and have 302,000 miles on the original heads and about 120,000 miles on the block. also running a 5mt and 18 inch wheels. I average around town about 24-25 even if I get on it a lot. If I don't get on it a lot I get about 27-28 around town.
Jesus! I have a 97 2.2 and I average ~20-21 around town. Most I ever got was 27 on a highway tank.

I got better gas milage when I was driving a friend's stock 99 2.5RS on the highway... sure, it was all highway, but a lot of that was at WOT (had to keep up with those damn turbo'd cars, :lol:)

running contis, can't remember which model right now and it's waayy to cold to run outside right now, says 44 psi right on the sidewall. i normally run them at 40 but, like i said i want to try every little bit.

44psi as in the MAX pressure PSI???

could it have anything to do with
your winter Gas you have up there??
I don't know but you are all from the
north. Please no flaming me it hurts :)

i have 225 40 18 Nexus tires and I run 36 psi onroad and 28 when offroad. I run the same pressure front and rear cause when I last had my car aligned they did a revolution per mile check on the tires and the rear was actually turning the same revs when the pressure was set the same. Could be the stereo and the full tank of gas at the time but I wouldn't think they weigh that much.
I have an aftermarket custom CAI and gutted cats so I get a lot of air flow, big reasoning for getting good MPG. When I was living at 6700 ft elevation I was getting about 21 mpg around town but now that I live at 4600 it runs a lot better.

update: still bad.
Just refilled today, 14.018 gallons, 268 miles driven, mostly highway. What little backroad driving i did I drove like 4k was redline because I was purposly trying to find my best mileage. 89 octane from Shell.

Yes i realize it's a bad idea to max out tire pressure but i was trying everything, they're down to 38F 36R, which I admit is lower than my usual 40 all around, I didn't realize they were supposed to ride that low on pavement.

I'm way to strapped to do the things I would like to help this, all i can think of is:
better flowing muffler (borla XS, I need QUIET dammit)
lightweight pulleys
TBS
I think i have a caliper dragging, passR. I wasn't applying the brakes and as i got off the highway and coasted to a stop i heard faint sqealing. THIS i can tackle for cheap, hopefully it helps. I heard it happens alot with these cars.

Oh yeah, I'm really interested in also reflashing the ecu to lean it down a bit. I hear good things about I-speed, anyone gain mileage with a reflash like that?

I just upgraded my front brakes from the 10.2 inch rotors, single piston calipers to, 11 inch twin piston calipers from a 99 legacy outback for 130$. came with rotors, pads, calipers and brackets, everything fit perfect. I also upgraded the rear brakes from drums to disc from a 98 legacy outback for 125$. What a huge difference that makes.

hahah all this info yet no1 knows the problem!

turbo it. The engine is so weak taht you have to go full throttle all the time. This uses a lot of gas. My mileage improved when i turbo'd my 1.8

turbo it. The engine is so weak taht you have to go full throttle all the time. This uses a lot of gas. My mileage improved when i turbo'd my 1.8

Actually, the fuel consumption is based on air flow (or mass air). So by making more power you're consuming more fuel. On my beater Legacy 1990 model, it was getting terrible gas mileage at first. After doing a full tune up including an AT trans kit, it still was bad. I read the ECU codes and it was getting a knock sensor code. I replaced it and the CEL indicator hasn't come back since (about 1500 miles). It's got better power etc. It's averaging 18-20mpg city now. It has 191k odo. Not bad really. I recently found the original window sticker for it in the glove compartment too. It shows city 20 and Hwy 26 :rolleyes: Pretty crappy mileage but I guess that's what this is all about = technology! What can we really expect with these old engines?

My wagon gets like 20MPG on a good week. Freeways MPG seems to be closer to 30. I think it is that you have bury your foot into the gas tank to get these 1.8's to move. I like turboL's thinking tho :D I was worried I would just get 10MPG with a turbo on it tho.

Oh 249k miles on original heads and block. Never rebuilt. he he he.

cheers

garrett

Yeah turbos don't hurt non-boost MPG necessarily. MPG usually goes down though because the driver now likes to mash the throttle more ;)

I consistently get 30-31 mpg in my 1.8L...but it's FWD so that may not apply to most of you. I'm never on the highway, but I wouldn't consider my commute "city" driving either - it's backroads driving where I'm usually in 5th gear doing between 45 and 55 mph for a few miles at a time.

So my 1.8L FWD Impreza is faster and gets better mileage than a 1.8L AWD Impreza...why would I want to do an AWD swap again? (haha)

Actually, the fuel consumption is based on air flow (or mass air). So by making more power you're consuming more fuel. On my beater Legacy 1990 model, it was getting terrible gas mileage at first. After doing a full tune up including an AT trans kit, it still was bad. I read the ECU codes and it was getting a knock sensor code. I replaced it and the CEL indicator hasn't come back since (about 1500 miles). It's got better power etc. It's averaging 18-20mpg city now. It has 191k odo. Not bad really. I recently found the original window sticker for it in the glove compartment too. It shows city 20 and Hwy 26 :rolleyes: Pretty crappy mileage but I guess that's what this is all about = technology! What can we really expect with these old engines?


well explain to me how im getting better mileage then? Ofcourse not on full throttle, but I can go heavy throttle for much less time now to get where I would have to go heavy throttle for a long time when I was N/A. After that its just coasting and light off boost throttle

well explain to me how im getting better mileage then? Ofcourse not on full throttle, but I can go heavy throttle for much less time now to get where I would have to go heavy throttle for a long time when I was N/A. After that its just coasting and light off boost throttle

I'm just saying that more air needs more fuel which is a fact (without water or any other type of injection). Going from NA to turbo on the same engine will certainly change the way the engine behaives. Your driving style would likely change too based on that. That could have something to do with it. Otherwise, I have no idea why you're getting better mileage LOL!

Try o2 sensors? I'm getting about 220 to the tank (ej22) and recently was getting very bad gas mileage, then came the CEL (p01130). I'm waiting on UPS as I type for the new sensor.