so i have a 87' subaru wagon all stock. carbed. new motor with less then 35,000 miles with perfect compression. no exhaust leaks new plugs and new cap and rotor. so what the heck!? i am getting only 19-21 mpg. y is not up around 24-28mpg like most subies?

Could be a million things, vacuum leak, running riich/lean, fule filter/ line leak. Try to find some leads. How does it idle, how does it run at top speed, what is acceleration like. Anything at all abnormal. What color suit is on your tail pipe? you will get more responses if you give as much relavent info as possible.

if you recently bought this soobi..check the trunk for a body... that almost always does it... ....2nd theory...does your girlfriend sneek out in the car late at night????

Improperly routed vacuum lines, bad tire pressure, incorrectly set choke, etc, etc. There's a ton of things that will do it. Want awesome mileage? Put 60 PSI in each tire, and run ATF in your manual tranny.

 

Mostly make sure the mechanic hooked up the carb correctly - those Hitachi's can be nasty. Vacuum advance for the disty, etc.

 

GD

I have the same year dl wagon and get 24 mpg mixed city/hiway and 28 mpg hiway. As GD says, it is very easy to have some vacuum hoses hooked up incorrectly. Also with an '87, many of the hoses will have become hardened with age and heat exposure, so they will be a source of vacuum leak.

 

Another thing to do is test for any brake drag - jack up each corner and see how easy each wheel spins in neutral.

I would start with the basics. Like others have said, get a vacuum diagram and check the routing. Check timing. Check your engine in the dark for any sparking that would indicate a problem with plug wires. Another possiblity is a clogged catalytic convertor. My carbed 86 averages about 25.5 MPG.

Along with what has already been posted, check air filter, tire pressure and....driving habit (weighed your right foot lately? ).

Could just be a crappy carb. My hicrappy even after pro rebuild never really ran right and i know it wasen't vacum because i only have three. Cat is poked out and i would only get 22mpg at best. Put on my rebuilt weber and i am up at 32mpg on the highway and 30 in town .( as long as i keep my foot off the secondarys all the time) Im still doing fine tuning so i think i can get a little better. I love the sound with the 2 inch air filter i put on. Allmost sounds like a four barrel when i stomp it! Can allso cruse around in fourth gear in town without lugging. In fith gear at 75 mph I can still pick up speed going up hill. I could go on about how much better my 86 wagon runs now but anyone who has done it knows what i meen! Does anyone know if freer flow exhaust helps gas milage with a weber?

for whatever reason....this just happened TODAY, again. last summer i did the brakes on my impreza OBS and gas mileage went up about 2 mpg. there were no problems with the brakes, they weren't way over due or anything. i just replaced them as preventative maintenance. and 2 mpg instant gain. same thing just happened today on my XT6. did the brakes yesterday and instant 2mpg gain??? this is all highway driving, very consistent comparison. i'm thinking cleaning and regreasing the slides each time helps the pads pull off the rotors or something...just a guess but i know it's fact.

26.5 mpg yesterday

28.5 today???

that's on a 6 cylinder XT6.

A lot of DIYers over look that bit when doing brakes, even some garages will just to get car done faster. One also wants to clean the backing plate and apply small dab of grease at the shoe contact points on the rear brakes.

i've heard of people that was having bad milage replacing their oxygen sensor and their milage improved. but i have never experienced it for myself yet. maybe some of the other board members have and can let us know if this is true ot not.

He has no O2 - 4WD 49 states carb.

 

GD

you are having bad mileage because the hitachi carb that comes on your car is most likely worn out. I've gone through 3 hitachi carbs in 6 years. I gave up on finding a good one, so I just stick with my 12-15 mpg that I get with it.

Still out pulls a SPFI EA82.. LOL

 

there is other factors that could be causing bad mileage. bald tires, over/under-inflated tires, bad alignment, weight in the back. Fuel filter could be pluggin up.

 

As for a free'r flowing exhaust, it helped my milage some, but then again, it sounds cool and I keep it rev'd up all the time so it canceled itself out.

Hey thanks for all the help. Well as for my exhaust. it is all new, 2.5" all the way to the back. the tail pipe has some black around the edges. does that mean anything? I am going to replace my wires and fuel filter tomorrow and see if that does anything. brakes are needing attention, but i dont understand how that can effect gas millage. but they are getting done next week anyway. tires are flatted properly, so Yeah i am leaning towards vaccum leak or carb. my idle is fine though. it does not jump around or anything, stay's consistent. last time i looked at my carb and cleaned it it looked really good. but who knows? any more help would be welcome. I will get back to you all, and hopefully i will see some progression.

I've gone through 3 hitachi carbs in 6 years. I gave up on finding a good one, so I just stick with my 12-15 mpg that I get with it.

 

You are lifted - that's not great mileage, but I usually get about 20 MPG with my lifted wagon and a Weber. The big tires suck the gas. Normal.

 

Danny - Get a weber.

 

GD

You are lifted - that's not great mileage, but I usually get about 20 MPG with my lifted wagon and a Weber. The big tires suck the gas. Normal.

 

Danny - Get a weber.

 

GD

ok give me about $300. lol whats up anyway GD. yup got her running

Did one for that POS sedan I got for $200 - actually a little less. I may have a friend that would sell you one for pretty cheap. Have to get an adaptor plate ~$38, and maybe a couple jets and a rebuild kit.

 

Glad you got it runnin - sounds like a nice engine.

 

GD

I am getting 22 to 23 MPG. I have a Hitachi carb. Does anyone have the part number to order a Weber? I would love to put one on my EA82. I also want to know if anyone has any 14" wheels for sale, I am doing that sometime this summer. I have decided that I am not going to lift this car, I am just going to put bigger tires, it is a daily driver.

On my last trip, with my 86 (stock) wagon with Hitachi carb, I traveled 600 miles round trip to Denver and got 41.5 mpg running 3 oz. acetone/10 gallons gasoline . I rebuilt my Hitachi about 4 years ago but other than that, it's original. The car has 280,000 miles on it. BTW I kept my foot out of the carb and stayed under 60 mph.

On my last trip, with my 86 (stock) wagon with Hitachi carb, I traveled 600 miles round trip to Denver and got 41.5 mpg running 3 oz. acetone/10 gallons gasoline . I rebuilt my Hitachi about 4 years ago but other than that, it's original. The car has 280,000 miles on it. BTW I kept my foot out of the carb and stayed under 60 mph.

Yeah i keep hearing about that whole acetone thing. I keep telling myself i am going to go try it. I mean what is the worst that can happen right? might as well try it. so that will be another thing i try.