Seafoam and other additives...

[kimokalihi]

Depends. If you're hammering it all the time then that might be normal but if not that's quite low. I get 21-23 on my 20G swap with a much larger turbo and larger injectors and it runs a bit rich when I get on it. I have gotten as low as 19 a couple times with plenty of spirited driving though. 14 I think means something is certainly wrong. The stock specs I think are 17 city 23 highway. I used to get 27 mpg in my NA wagon with 4EAT.

[keithmoilanen]

yeah i get same mpg no matter how i drive it. and i get black smoke on my tail gate after driving a while. what should i do?

[kimokalihi]

Maybe you have an air leak in your intake after the maf. Or bad o2 sensor or temp sensor causing rich condish.

[keithmoilanen]

hmm i will have to take a closer look at the intake. o2 senser i could replace jsut because and see if that helps.

[Legacy777]

I'd suggest checking the ECU for codes. Instructions are on my site in my signature. Besides a vacuum/boost leak the coolant temp sensors play a big role in air fuel mixture, so if your coolant temp sensor is getting lazy, it may be telling the ECU it needs more fuel than it really does. They're cheap and pretty easy to replace. I will usually just replace them every 100k miles.

[keithmoilanen]

yeah who knows how old my o2 sensor is i bought the car two years ago. 250miles on the body 170 on motor 70 on wrx tranny.

[Alphius]

When I had the car I drove it back from Idaho when I bought it from Lee and got 27mpg. No boost the whole way. I'd say the advice in this thread is pretty spot on for pinpointing a mileage issue.

[91Beater]

The aerosol one is easier to use and definitely safer as the flow rate is limited enough to avoid hydro locking.
It's a better option for intake application in my opinion. The site does say its the same formula.

http://www.seafoamsales.com/how-to-use- ... .html#nogo

Read the Vortec version as well as it talks about Subaru H engines. Mine didn't come with the special 4-way spray nozzle. I held open the butterfly valve, then shoved the nozzle all the way into the plenum. I sprayed it for a bit.

I then used it as shown in the instruction video on their website by pinching the nozzle under the intake boot.

I think this is more effective than any other way. The contents sprays onto the butterfly valve and gets turned into a mist as the flow of air sweeps it into the manifold from the bottom of the throttle plate.

[Legacy777]

I've never seen the spray version.....that looks pretty cool!