Gas Mileage FAQ - Page 19
+ Reply to Thread
Page 19 of 19 FirstFirst ... 910111213141516171819
Results 271 to 278 of 278

This is a discussion on Gas Mileage FAQ within the Everyday Impreza Talk forums, part of the Community - Meet other Enthusiasts category; Thanks for the replies. I was a bit surprised because at fuelly.com my mileage is one of the worse and ...

  1. #271
    Registered User
    Join Date
    Feb 2014
    Posts
    7
    Thanks for the replies. I was a bit surprised because at fuelly.com my mileage is one of the worse and I was thinking "how the hell does these people do that mpg"? That's why I thought something was wrong.
    Anyway, I enjoy my ride everywhere I go, so screw my mpg.

  2. Remove Advertisements
    ClubWRX.net
    Advertisements
     

  3. #272
    UnBanned Sinister's Avatar
    Join Date
    Nov 2006
    Location
    Denver Metro Area
    Posts
    17,641
    I Support ClubWRX
    Pepezeta. Published city mileage for your year is 17-19mpg. Glad you're having fun with it though!
    Kevin
    Moderator
    Sinister's Blowoff Valve FAQ
    WRX Gas Mileage FAQ
    Sinister's Progress Thread - 430whp 429wtq - Sold
    Firearms Enthusiasts Thread

    The Sheriff's Star at the bottom left corner rates a user's reputation.
    If you found a user's post to be helpful or quite the opposite, please make it known to them by clicking the Star!

  4. #273
    zax
    zax is offline
    \_(ツ)_/ zax's Avatar
    Join Date
    Nov 2008
    Location
    Neverland Ranch, Maryland
    Posts
    13,454
    I Support ClubWRX I Support ClubWRX
    Quote Originally Posted by Sinister View Post
    Tricky question. Short side of it, if you drive conservatively now... You'll improve mileage. If you drive aggressively now... It'll get worse. Below are my explanations.


    Cold air intake brings in colder air, colder air means leaner condition which the ECU compensates for by injecting more fuel. (that's why we have an IAT bulb in the MAF housing).

    The cold air intake is less restrictive. That means less resistance, which means more power at lower RPMs with less throttle.

    So... With conservative habits, the mileage should be better. With aggressive habits, it should be worse.

    Less restrictive exhaust means more flow, more scavenging and therefore more volumetric efficiency. More efficiency means more gas mileage. But, it also means at higher throttle percentages, more air and fuel can be injected.
    Sorry Kevin, this is where I disagree. While improved flow does indeed increase VE, warm air increases fuel atomization which (in term) leads to a more complete burn. A CAI reduces air temps (at the injection point), reduces the fuel atomization, and should net worse economy.
    2015 CWP WRX STi ... But how did I get roped back into an EJ motor?!
    Zax's utterly unimaginably stock 2015 STi build thread
    Zax's Shaggin' Wagon Build Thread Now tuned for 99% pure Unicorn Jizz!

    Zach | Moderator -- Mid-Atlantic States, Tech & Modifying & General Repairs
    Rollin' with the Bugeye Mafia #302 | N.E.R.D. Subject Zero
    Facebook me here

    Your Mid-A local board: http://www.clubwrx.net/forums/mid-atlantic-states/

  5. #274
    UnBanned Sinister's Avatar
    Join Date
    Nov 2006
    Location
    Denver Metro Area
    Posts
    17,641
    I Support ClubWRX

    Gas Mileage FAQ

    Quote Originally Posted by zax View Post
    Sorry Kevin, this is where I disagree. While improved flow does indeed increase VE, warm air increases fuel atomization which (in term) leads to a more complete burn. A CAI reduces air temps (at the injection point), reduces the fuel atomization, and should net worse economy.
    I'll bite. You're wrong.

    Your cold air goes through a hot turbo. Our coolest intake temps (after warm-up) are still higher than the highest intake temps that street driven NA cars make.

    The best drag times are in the late evening after a drag strip was heated up all day, but the air has cooled down from the sun going down. Or on a warm day that a cold front just moved in.

    The difference in fuel atomization from heat isn't enough to matter for anything. Within normal operating temps. If it were... Then the inter cooler efficiency wouldn't matter to us, or inter cooler sprayers. Nor would water and methanol injection, or "wet" nitrous injection.

    As far as fuel atomization... Age and condition of your injectors will matter a lot more than intake temps.

    Love you sweet-t!ts,
    Kevin
    Kevin
    Moderator
    Sinister's Blowoff Valve FAQ
    WRX Gas Mileage FAQ
    Sinister's Progress Thread - 430whp 429wtq - Sold
    Firearms Enthusiasts Thread

    The Sheriff's Star at the bottom left corner rates a user's reputation.
    If you found a user's post to be helpful or quite the opposite, please make it known to them by clicking the Star!

  6. #275
    zax
    zax is offline
    \_(ツ)_/ zax's Avatar
    Join Date
    Nov 2008
    Location
    Neverland Ranch, Maryland
    Posts
    13,454
    I Support ClubWRX I Support ClubWRX
    I will admit that winter-driving tends to have worse fuel economy for a variety of reasons:
    1. Increased ethanol content in fuel
    2. Lower pressure in tires OR softer winter tires
    3. More time spent in Cold Start enrichment

    However I do believe that lower intake temps will lead to reduced fuel atomization. You are correct about the TMIC, but since the compressor follows adiabatic expansion and radiative cooling, delta T in = delta T out (rough simplification).
    2015 CWP WRX STi ... But how did I get roped back into an EJ motor?!
    Zax's utterly unimaginably stock 2015 STi build thread
    Zax's Shaggin' Wagon Build Thread Now tuned for 99% pure Unicorn Jizz!

    Zach | Moderator -- Mid-Atlantic States, Tech & Modifying & General Repairs
    Rollin' with the Bugeye Mafia #302 | N.E.R.D. Subject Zero
    Facebook me here

    Your Mid-A local board: http://www.clubwrx.net/forums/mid-atlantic-states/

  7. #276
    UnBanned Sinister's Avatar
    Join Date
    Nov 2006
    Location
    Denver Metro Area
    Posts
    17,641
    I Support ClubWRX
    All I heard were a bunch of smart person words and "you are correct".

    Kevin
    Moderator
    Sinister's Blowoff Valve FAQ
    WRX Gas Mileage FAQ
    Sinister's Progress Thread - 430whp 429wtq - Sold
    Firearms Enthusiasts Thread

    The Sheriff's Star at the bottom left corner rates a user's reputation.
    If you found a user's post to be helpful or quite the opposite, please make it known to them by clicking the Star!

  8. #277
    zax
    zax is offline
    \_(ツ)_/ zax's Avatar
    Join Date
    Nov 2008
    Location
    Neverland Ranch, Maryland
    Posts
    13,454
    I Support ClubWRX I Support ClubWRX
    Womp womp
    2015 CWP WRX STi ... But how did I get roped back into an EJ motor?!
    Zax's utterly unimaginably stock 2015 STi build thread
    Zax's Shaggin' Wagon Build Thread Now tuned for 99% pure Unicorn Jizz!

    Zach | Moderator -- Mid-Atlantic States, Tech & Modifying & General Repairs
    Rollin' with the Bugeye Mafia #302 | N.E.R.D. Subject Zero
    Facebook me here

    Your Mid-A local board: http://www.clubwrx.net/forums/mid-atlantic-states/

  9. #278
    Registered User Jeff_34's Avatar
    Join Date
    Aug 2014
    Posts
    9
    I saw better gas mileage after I installed my AOS. I have a 2011 STi sedan stage 2+ Cobb OTS with 11.3 lb flywheel. Went from 22ish to 24ish city. Probably from the lack of degradation of the octane by cutting the oil vapor out of the intake air supply; sounds legit.


    Sent from my iPad using Tapatalk

+ Reply to Thread

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself. We strongly suggest that you stay away from using aol, yahoo, msn, and hotmail accounts. Sometimes the mail server blocks the emails from our server. As a result you will not receive any notifications including the confirmation email.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


Posting Permissions

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
  •