1. Welcome to Tacoma World!

    You are currently viewing as a guest! To get full-access, you need to register for a FREE account.

    As a registered member, you’ll be able to:
    • Participate in all Tacoma discussion topics
    • Communicate privately with other Tacoma owners from around the world
    • Post your own photos in our Members Gallery
    • Access all special features of the site

Decrease in Gas Milage Problems

Discussion in '1st Gen. Tacomas (1995-2004)' started by tacomabilly, Jan 30, 2012.

  1. Jan 30, 2012 at 12:03 PM
    #1
    tacomabilly

    tacomabilly [OP] Well-Known Member

    Joined:
    Jul 28, 2011
    Member:
    #60694
    Messages:
    65
    Gender:
    Male
    Over the past 4 months, my '99 2.7 taco has been slowly decreasing in gas milage. Over the summer I was averaging around 23. I keep very good care of it, changing oil regularly, align and balance, air filter, the works. It went over 150,000 miles when this decrease began but I cannot figure out what the root cause is. I have ran it with both the deckplate mod on and off, reset the ECU, and have driven it on and off road with no change in milage. I'm now running around 19 MPG no matter if I run it off road all weekend or if I drive 70 on the interstate all week. Could it be a problem with the fuel filter or something that needs to be serviced? Anyone else had this same scenario? As I said, I was getting 24 MPG highway pre-150k and now I'm getting 19 MPG highway post-150k. Please pm me with any ideas.
     
  2. Jan 30, 2012 at 12:23 PM
    #2
    1998tacoma4x4

    1998tacoma4x4 Well-Known Member

    Joined:
    Sep 23, 2009
    Member:
    #23202
    Messages:
    267
    Gender:
    Male
    First Name:
    Matt
    Orange County
    Vehicle:
    1998 Tacoma 4x4 3.4L Auto
    Deaver j59 pack 2.5 SAW coilovers, rear bilstein 5100's. Extened stainless rear brake line, deck plate mod, drop in K&N filter, Kenwood headunit & pioneer speakers, SnugTop Shell.
    Try this. Seafoam, clean MAF sensor, check/replace plugs, egg under the gas pedal mod.
     
  3. Jan 30, 2012 at 1:05 PM
    #3
    Madjik_Man

    Madjik_Man The Rembrandt of Rattle Can

    Joined:
    Dec 2, 2009
    Member:
    #26893
    Messages:
    13,102
    Gender:
    Male
    Boulder, CO
    Vehicle:
    1998 Ext Cab 4x4 TRD 5MT sunfire red pearl
    About 25 pounds of spray paint and vinyl dye
    Winter gas will alone will contribute to a 1-3 mpg decrease in efficiency. At least that's what I have experienced.
     
  4. Jan 30, 2012 at 2:00 PM
    #4
    jij0226

    jij0226 Member

    Joined:
    Jan 23, 2012
    Member:
    #71238
    Messages:
    12
    Gender:
    Male
    First Name:
    josh
    raleigh nc
    Vehicle:
    2004 tacoma base
    I have the same problem. It seemed to start when it began getting cold out.
     
  5. Jan 30, 2012 at 3:47 PM
    #5
    scotrinaf

    scotrinaf Well-Known Member

    Joined:
    Jan 24, 2012
    Member:
    #71311
    Messages:
    1,503
    Gender:
    Male
    First Name:
    Scott
    Blountville, TN
    Vehicle:
    04 PreRunner TRD SR5 4x2 2.7L
    Leer 100XQ, Yakima Roof Racks
    Actually, cold gas has more tightly compressed air molecules making it denser, which should yield better gas mileage... I'm thinking it's something to do with your Mass Air Flow Sensor or something similar...
     
  6. Jan 30, 2012 at 5:52 PM
    #6
    tacomabilly

    tacomabilly [OP] Well-Known Member

    Joined:
    Jul 28, 2011
    Member:
    #60694
    Messages:
    65
    Gender:
    Male
    Thanks for the help. I changed the plugs, wires, and belts less than 25k ago and I live in alabama. Trust me, the weather has been nothing but hot and humid all winter. I'll try the MAS cleaning, but again, no check engine light or any change in driving style to contribute to the problem
     
  7. Jan 30, 2012 at 5:55 PM
    #7
    TACOMABOSS

    TACOMABOSS Well-Known Member

    Joined:
    Jul 7, 2011
    Member:
    #59499
    Messages:
    4,302
    Gender:
    Male
    Vehicle:
    96 SR5 4x4
    Bilstein 5100s, Toytec AAL, Deck plate mod, Hella 500ff's, Sportsman Camo seat covers, Total Chaos 1" diff drop, JVC stereo, Painted bumpers and grille, Custom grille insert, HID projectors, Black spray paint
    X2
     
  8. Jan 30, 2012 at 6:05 PM
    #8
    Snowman

    Snowman I have a problem for your solution…

    Joined:
    Sep 8, 2010
    Member:
    #42917
    Messages:
    2,909
    First Name:
    Craig
    Somewhere in Canada
    Vehicle:
    Check out my build
    But winter gas blend is different than summer gas and it yields lower mpg. Not only does winter gas evaporate faster than summer (wasted into the air) it also has a lower energy value than summer gas. Which literally equals less bang for your buck.
     
  9. Jan 30, 2012 at 6:15 PM
    #9
    scotrinaf

    scotrinaf Well-Known Member

    Joined:
    Jan 24, 2012
    Member:
    #71311
    Messages:
    1,503
    Gender:
    Male
    First Name:
    Scott
    Blountville, TN
    Vehicle:
    04 PreRunner TRD SR5 4x2 2.7L
    Leer 100XQ, Yakima Roof Racks

    Try filling up at the same gas station every time if you aren't already... I fill up at my local Sam's Club and have gotten consistent mileage for the last 115,000 miles on my Honda Civic... Might just be getting crappy gas from the knock-off stations that buy whatever's next on the line or last off the truck which will have a lot of trash in it...
     
  10. Jan 30, 2012 at 7:31 PM
    #10
    Snowman

    Snowman I have a problem for your solution…

    Joined:
    Sep 8, 2010
    Member:
    #42917
    Messages:
    2,909
    First Name:
    Craig
    Somewhere in Canada
    Vehicle:
    Check out my build
    Its not a conspiracy theory or something. Winter gas is a different mixture than summer gas and is written right on the pumps. Maybe in TN the winter isnt "winter" enough to warrant the cold weather blend.

    I have got gas at the same Esso (Exxon) for the past 4 years. Only another station if I happen to be out of town.
     
  11. Jan 30, 2012 at 7:35 PM
    #11
    tacomaman06

    tacomaman06 Carolina Alliance: Enforcer

    Joined:
    May 1, 2007
    Member:
    #1475
    Messages:
    26,258
    Gender:
    Male
    First Name:
    Will
    York,South Carolina
    Vehicle:
    '16 Tundra TRD Pro
    getting there....
    Fuel filter definitely needs to be changed periodically.......I usually do around every 15k with mine. Another thing tho......and even tho it won't throw a check engine light.......your o2 sensors could be causing your mileage drop. If you haven't replaced them ever.....may be a good idea. With them not throwing a cel.......not necessarily bad,but they are nearing the end of their life as far as reading correctly.
     
  12. Jan 30, 2012 at 7:37 PM
    #12
    tacomaman06

    tacomaman06 Carolina Alliance: Enforcer

    Joined:
    May 1, 2007
    Member:
    #1475
    Messages:
    26,258
    Gender:
    Male
    First Name:
    Will
    York,South Carolina
    Vehicle:
    '16 Tundra TRD Pro
    getting there....
    Winter fuel as opposed to summer fuel definitely makes a difference as well. Also.....ethanol rich fuels(most are nowadays) don't help with mileage either.
     
  13. Jan 30, 2012 at 8:35 PM
    #13
    Norton

    Norton Well-Known Member

    Joined:
    Mar 10, 2011
    Member:
    #52729
    Messages:
    2,748
    Gender:
    Male
    First Name:
    Steve
    Monument, CO
    Vehicle:
    2013 Access Cab 4x4 V6 6MT, TRD OR & Tow Packages
    ARE Z-Series Topper, OME 885 Coils, Dakar Leafs, NitroCharger Sports; TRD Quickshifter; TRD Exhaust; aFe POWER Magnum FLOW Pro DRY S Air Filter; Goodridge SS Brake Lines; Cooper Discoverer A/T3s on FJ SE Anthracite Rims; N-Fab 6-Step Nerf Bars; MetalMiller TRD Skid; jsi's Locker Anytime & ramonortiz55's Always on Power Outlet Relay Mods; crashnburn80's Ultimate Headlight & Fog Light Upgrades (RallyLights Harnesses, Osram 85/80W H4 & Flösser 90W H11 Bulbs); ND4's Fog Light Anytime Mod; Interior & Reverse LEDs; AudioControl LC2i LOC, JL Audio XD200/2v2 Amp, Focal PS165V1 Spkrs, Sound Ordnance B-8PTD Sub, Hushmat & Foam Insulation; Ltd Auto-Dim/Compass/Temp/Backup Camera/Homelink mirror; 4Runner 4X4 & FJ Fog Light Switches; Husky Floor Liners; UltraGauge EM; Redline Tuning QuickLIFT Elite; Mobtown Offroad Locking Bed Storage Doors; Toyota Bed Mat; Toyota Bed Extender; Pop & Lock Power Tailgate Lock; SolarGard Tint; CravenSpeed Stubby Antenna; Amsoil Lubricants; Adam's Detailing Supplies
    X4 ^^. I've tracked every tank of gas through 6 vehicles driven by my wife and me over the past 15+ years. Winter gas (here in Colorado) causes about a 15% mileage redux while also killing performance, across the board. :mad:
     
  14. Jan 31, 2012 at 5:13 AM
    #14
    tacomabilly

    tacomabilly [OP] Well-Known Member

    Joined:
    Jul 28, 2011
    Member:
    #60694
    Messages:
    65
    Gender:
    Male
    Ha Ha this began to happen in late September; I promise its not the winter gas. I have tried different fuel stations and have also tried ethanol vs. pure to no avail. Any way to change or check the fuel filter without taking off the gas tank?
     
  15. Jan 31, 2012 at 5:41 AM
    #15
    A_Ninja_Racer

    A_Ninja_Racer Well-Known Member

    Joined:
    Oct 7, 2008
    Member:
    #9789
    Messages:
    761
    Tampa, FL
    Vehicle:
    08 PreRunner TRD Debadged
    lol I wonder if we even get winter gas down here in florida. I swear to god this has been the hottest winter I can ever remember. I just wanted to throw out my 2 cents about the O2 sensors. tacomaman06 is right. I read somewhere that O2 Sensors have an "Average" Life of 50thousand miles. Now I'm sure this is a highly shortened life span because I've had many O2 sensors that have lasted much longer then 50k. But they do tend to fade over time and wont throw a check engine light up until the point of complete Failure.
     
  16. Jan 31, 2012 at 6:11 AM
    #16
    tacomaman06

    tacomaman06 Carolina Alliance: Enforcer

    Joined:
    May 1, 2007
    Member:
    #1475
    Messages:
    26,258
    Gender:
    Male
    First Name:
    Will
    York,South Carolina
    Vehicle:
    '16 Tundra TRD Pro
    getting there....
    I believe your fuel filter is located under the intake manifold. Pain in the ass to change.....but doable.
     
  17. Jan 31, 2012 at 9:57 AM
    #17
    Adam Baum

    Adam Baum Well-Known Member

    Joined:
    Jun 13, 2011
    Member:
    #58194
    Messages:
    292
    Gender:
    Male
    PCS
    Vehicle:
    01 PreRunner SR5 debadged
    I am averaging 17.5 miles per gallon after I switched to 265/75/16's. Before that I was getting 20 MPG with the stock 265/70/16's. Is that bad?
     
  18. Jan 31, 2012 at 9:59 AM
    #18
    jeremy_283

    jeremy_283 Super Member

    Joined:
    Dec 14, 2008
    Member:
    #11569
    Messages:
    1,435
    Vehicle:
    08 TRD Offroad Access Cab 4x4 Auto 4.0L
    Hella Rallye 4000 Cornering Lights PIAA 510 Fog Lights All Pro Front Bumper All Pro Rear Bumper All Pro Transfer Case Skid All Pro IFS Skid All Pro Rock Sliders All Pro High Clearance Hitch OME Dakar Leaf Springs OME Rear Shocks OME Front Shocks OME 885 Front Coils Wet Okole Seat Covers WeatherTech Floor Liners Sony Head Unit JL XD600/1 Amp 2 JL Audio 10” Subwoofers Custom Subwoofer Enclosure Kenwood Front Speakers Sony Rear Speakers Sound Deadening Mats LED Interior Lighting Pop N’ Lock Tailgate Lock Viper Alarm System Extra D-Rings In Truck Bed Maglite Seat Mount Disable Seatbelt Chime Rear Differential Breather Relocation Hi-Lift Bed Mount Flexible Front Mud Flaps 110v Inverter Always At 400w ABS Kill Switch Locking Center Console Removed Sway Bar
    :rolleyes:

    Wouldn't this mean that more gas is needed to prevent a lean air/fuel ratio...????

    lol
     
  19. Jan 31, 2012 at 10:12 AM
    #19
    Opihiman10

    Opihiman10 Active Member

    Joined:
    Oct 17, 2011
    Member:
    #65329
    Messages:
    36
    Gender:
    Male
    Honolulu, Hawaii
    Vehicle:
    2011 double cab 4x4 TRD SR5
    Nerf bars
    have you run a fuel system cleaner....something like proguard or the like? some fuels will leave deposits and resins which will present it self as gradually dec power and eroding gas mileage...

    Good like

    OPI
     
  20. Jan 31, 2012 at 11:33 AM
    #20
    scotrinaf

    scotrinaf Well-Known Member

    Joined:
    Jan 24, 2012
    Member:
    #71311
    Messages:
    1,503
    Gender:
    Male
    First Name:
    Scott
    Blountville, TN
    Vehicle:
    04 PreRunner TRD SR5 4x2 2.7L
    Leer 100XQ, Yakima Roof Racks
    We typically don't get below the teens in the winter although we'll have an occasional single digit night here and there... May be something to that, I've never seen the "Winter Fuel Mix" signs on our gas pumps that I recall...

    By the way, we do have stations around here that are known for buying the undesirable gas that is last off the trucks, or whatever is next on the line just to save a buck... And you can tell it if you fill up there... Low price isn't always a good thing to look for on a fill-up...
     
To Top