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

Auto Transmission slowing truck down

Discussion in '2nd Gen. Tacomas (2005-2015)' started by auart, Jun 27, 2009.

  1. Jun 27, 2009 at 5:40 PM
    #1
    auart

    auart [OP] Well-Known Member

    Joined:
    Jun 21, 2009
    Member:
    #18734
    Messages:
    107
    Gender:
    Male
    First Name:
    ART
    Auburn, Alabama
    Vehicle:
    2009 Tacoma Prerunner TRD Off road 2wd
    TRD OFF ROAD, Tow Package, Scanguage2, Secure Tailgate Mod, OEM Tacoma Bed Mat, Stainless Side Step Bars, Extang Trifecta Cover.
    Have a BRAND NEW Tacoma 2wd AUto Trans w TRD Off road w Towing package.
    OK, I have had the Truck exactly ONE week. I have had several 4runners and have a 4runner now. This truck has me puzzled a little.
    When driving along at say 50 MPH and getting near a Turn or Stop,(I drive Light footed!) I let off the gas and want to sort of coast to the turn or stop light, especially if going slightly downhill, and the truck really starts to slow down much quicker than I am used to in the 4runner. IT doesnt seem to coast along, it seems to be downshifting and going into a lower gear or something and while it does have the feel of total control, it has got to be hurting the MPG's.
    The 4runner will coast when you take your foot off the gas pedal, the Tacoma seems to want to downshift.
    Is this simply a matter of the Truck being geared so differently it is setup more for Control and Towing? Seems the rear end is in constant control, no coasting at all.
    I am having to give it the gas going downhill toward an upcoming turn, which in the 4runner the vehicle would be gaining speed going downhill toward the same turn. Both have AUTO Trans. Both are 4.0 V6 and both are 2WD.
    The Tacoma is NEW with TRD Off Road package and Towing package.

    Just got my first fillup after 300 miles and my MPG is 17.1. The 4runner I have always gotten 20 to 22 MPG with the 6 Cyl, and it has more weight.

    I have read and searched and don't see a whole lot of discussion on this.

    Forgive me being such a Non-Mechanic with my description!!!

    [​IMG]
     
  2. Jun 27, 2009 at 5:57 PM
    #2
    Incognito

    Incognito μολὼν λαβέ

    Joined:
    May 25, 2009
    Member:
    #17626
    Messages:
    13,625
    Gender:
    Male
    First Name:
    Colton
    VA
    Vehicle:
    2012 Pyrite AC TRD OR
    See Build thread
    As for the mileage, give it some time and it should work itself out. Let it break in and you'll be ok there. ;)
     
  3. Jun 27, 2009 at 6:07 PM
    #3
    silversavage

    silversavage Active Member

    Joined:
    Jun 17, 2009
    Member:
    #18595
    Messages:
    25
    Gender:
    Male
    San Francisco, CA
    Vehicle:
    09 Silver Crew Cab TRD
    Don't know about that... As for the downshifting, the new tacomas are designed to help you brake so thats why it will slow down quicker. It's not designed for MPG's for that you want a Prius. :D

    EDIT: You'r MPG is better than my 14, I'd say 17 is about avarage and wont get much better unless you change your driving habits.
     
  4. Jun 27, 2009 at 7:04 PM
    #4
    auart

    auart [OP] Well-Known Member

    Joined:
    Jun 21, 2009
    Member:
    #18734
    Messages:
    107
    Gender:
    Male
    First Name:
    ART
    Auburn, Alabama
    Vehicle:
    2009 Tacoma Prerunner TRD Off road 2wd
    TRD OFF ROAD, Tow Package, Scanguage2, Secure Tailgate Mod, OEM Tacoma Bed Mat, Stainless Side Step Bars, Extang Trifecta Cover.
    Believe it or not... I traded a PRIUS to get a Tacoma!!! I used the Prius to Commute for 3 years and put 93000 miles on it. Due to Transfer I only have to drive 3 miles to the office now so I wanted a Truck!
    I know how to drive to get the best MPG's from driving the Prius... Basically light on the gas pedal and ease to your stops.

    I started this thread to hopefully get some insight to why the Tacoma feels like its downshifting into a lower gear while coasting downhill to a stoplight. The 4runner I have coasts down hill more and gets better MPG. I guess it doesn't make sense to me!
     
  5. Jun 27, 2009 at 8:30 PM
    #5
    jhodge83

    jhodge83 Any dog under 50# is a cat and cats are useless... Moderator

    Joined:
    Apr 27, 2007
    Member:
    #1432
    Messages:
    28,112
    Gender:
    Male
    First Name:
    Jamie
    Moncks Corner, SC
    Vehicle:
    09 Timberland Mica DC 4WD Sport
    wat?
    i still get 18ish mixed with mine after 15k miles and all my mods. stock most people are getting 18 city and about 21 highway. keepit under 2k rpm's PERIOD and u should see it increase as well as getting some miles on it
     
  6. Jun 27, 2009 at 8:50 PM
    #6
    Janster

    Janster Old & Forgetful

    Joined:
    Mar 25, 2007
    Member:
    #1138
    Messages:
    14,256
    Gender:
    Female
    First Name:
    Jandy
    Lancaster, PA
    Vehicle:
    2016 GMC Canyon SLT w/ LineX and....
    That's all normal.... give it time to break-in.

    What tire pressure are you running? The doorjam (atleast on mine) says to run 29psi. Personally? I think that's too low. I've bumped mine up to about 32-34psi. That might give a slight edge on the gas mileage.

    Nice Truck!!
     
  7. Jun 27, 2009 at 8:55 PM
    #7
    SilverStreakUSMC

    SilverStreakUSMC Member

    Joined:
    Jun 17, 2009
    Member:
    #18570
    Messages:
    22
    Gender:
    Male
    Charlottesville, VA
    the tacomas are made to slow down as soon as you let off the gas petal. everything is normal. as for me i like it, never driven anything that does it.
     
  8. Jun 27, 2009 at 9:36 PM
    #8
    brian

    brian Another Traitor

    Joined:
    Apr 15, 2009
    Member:
    #16011
    Messages:
    7,557
    Gender:
    Male
    Elizabeth City, NC
    Vehicle:
    2008 F-350 Powerstroke
    normal, and normal. Go easy on the gas and you'll get better MPG. Just needs to break in.
     
  9. Jun 27, 2009 at 10:13 PM
    #9
    WilsonTheDog

    WilsonTheDog Kylie's dad

    Joined:
    Nov 17, 2007
    Member:
    #3496
    Messages:
    4,837
    Gender:
    Male
    First Name:
    Eric
    Myrtle Beach SC
    Vehicle:
    07 Prerunner SR5 DC/SB V6
    Magnaflow 12576 muffler & chrome tip, Westin step bars, 27% tint, Pop N Lock, AFE ProdryS, bed mat, Husky liners, D-rings added, Access Literider tonneau, Pioneer 4-ways all around, GY Wrangler Duratracs 265/75/16, 5100's @ 1.75", 1.5" AAL
    ^I concur. Mine easily went up 2mpg over the first 10K.
     
  10. Jun 28, 2009 at 12:16 AM
    #10
    VancityCK

    VancityCK Well-Known Member

    Joined:
    Apr 14, 2009
    Member:
    #15995
    Messages:
    109
    Gender:
    Male
    Vancouver
    Vehicle:
    09 Magnetic AC TRD Offroad
    The Tacoma's and other new vehicles have a trick in that when you are coasting the ECU will shut off the injectors, so, yes, the revs are up, but fuel consumption is 0.
     
  11. Jun 28, 2009 at 4:26 AM
    #11
    JONNY TACO

    JONNY TACO Well-Known Member

    Joined:
    Feb 20, 2009
    Member:
    #13865
    Messages:
    151
    Gender:
    Male
    PA.
    Vehicle:
    DARK METALLIC GRAY -DOUBLE CAB SHORT BED
    ADVANTAGE TONNEAU COVER,TOYOTA BED LINER, POP&LOCK TAILGATE LOCK, SIDE TUBES, WIFE IN PASSENGER SEAT
    My wife's 09 Camry does the same thing. She likes it, especially when going down mountains.
     
  12. Jun 28, 2009 at 6:00 AM
    #12
    chris4x4

    chris4x4 With sufficient thrust, pigs fly just fine. Moderator

    Joined:
    May 8, 2008
    Member:
    #6497
    Messages:
    106,158
    Gender:
    Male
    First Name:
    FlimFlubberJAM
    Tenoe, AZ
    Vehicle:
    2013 Rubicon Unlimited,
    4.10 gears, sliders, and lots of buttons.
    Correct. The 5 speed auto tranny in the Tacoma is designed to emulate a manual tranny. The Torque converter can achieve vaious stages of partial lock up, to allow the truck to have engine braking

    Also correct. THe fule injectors "turn on" again at 1200 rpm when the throttle is not applied, and the vehicle is coasting.
     
  13. Jun 28, 2009 at 7:25 AM
    #13
    Snipe

    Snipe Well-Known Member

    Joined:
    Jan 9, 2009
    Member:
    #12421
    Messages:
    1,150
    Gender:
    Male
    Pacific NW
    Vehicle:
    08 TRD Off Road
    Mine being the 6 Spd manual it is different then what you are talking about but this is what I found about coasting under compression and fuel consumption.

    We have a highway with a rolling downhill grade here that runs between 1 an 5%, the other day I was coming down under compression doing about 50 mph and the scangauge real time showed I was getting between 46 and 64 MPG, I popped it out of gear and the scangauge immediately went between 69 and 84 MPG depending on how fast I was coasting.

    Out of gear my truck will never go below 1200 on the tach unless I am under 10 MPH


    So what I found it is using more fuel under compression then when rolling along out of gear
     
  14. Aug 3, 2009 at 8:35 PM
    #14
    carmellocafe

    carmellocafe Begin With The End In Mind.

    Joined:
    May 15, 2009
    Member:
    #17267
    Messages:
    2,266
    Gender:
    Male
    First Name:
    KEVIN
    N. California
    Vehicle:
    2014 TRD OR Access cab longbed
    Nah, I think Chris is right-- The injectors shut off for engine braking. This means your not putting fuel in the engine. At idle, in neutral you are still injecting fuel into the engine. (I think).
     
  15. Aug 3, 2009 at 8:40 PM
    #15
    chris4x4

    chris4x4 With sufficient thrust, pigs fly just fine. Moderator

    Joined:
    May 8, 2008
    Member:
    #6497
    Messages:
    106,158
    Gender:
    Male
    First Name:
    FlimFlubberJAM
    Tenoe, AZ
    Vehicle:
    2013 Rubicon Unlimited,
    4.10 gears, sliders, and lots of buttons.
    correct.
     
  16. Aug 3, 2009 at 9:05 PM
    #16
    Danzer

    Danzer Well-Known Member

    Joined:
    Mar 13, 2009
    Member:
    #14662
    Messages:
    502
    Gender:
    Male
    First Name:
    Derek
    Phoenix
    Vehicle:
    06 TRD Offroad 4x4 AT
    K&N 77 Series High-Flow Performance Kit.Rear Seat Covers.Rear TSB with 1.5" AAL and OME N182's. Front 5100's and OME 884's.Cobra CB.Painted mirrors, grill and powder coated rear bumper. Trail Gear sliders.
    I always wondered about this too. My old Ranger would coast forever. Thanks for clearing it up.
     
  17. Aug 3, 2009 at 9:34 PM
    #17
    TRDrew

    TRDrew Member

    Joined:
    Jul 21, 2009
    Member:
    #19981
    Messages:
    21
    Gender:
    Male
    First Name:
    Andrew
    San Diego
    Vehicle:
    06 TRD Pre Runner Sport
    I have a 06 TRD double cab 4.0L and never get over 20mpg. (38000K on motor). If I coast it for 18 gal then I can milk 400 miles on 18 gal. But driving under 2K revs takes a lot a patience and time. I have noticed that if I am light on the pedal and coasting down hill sometimes it will hold a lower gear until I hit the gas.(like a jake brake on a 18 wheeler)
     
  18. Aug 4, 2009 at 7:52 PM
    #18
    carmellocafe

    carmellocafe Begin With The End In Mind.

    Joined:
    May 15, 2009
    Member:
    #17267
    Messages:
    2,266
    Gender:
    Male
    First Name:
    KEVIN
    N. California
    Vehicle:
    2014 TRD OR Access cab longbed
    In my 06 I've noticed that while coasting if I just barely apply a little pressure on the gas pedal, and I mean "very light pressure," It will act as if its coasting in neutral w/o the braking effect.:)
     
  19. Aug 4, 2009 at 7:57 PM
    #19
    TacoTurd

    TacoTurd Defying Alliances since 2007

    Joined:
    Jul 19, 2007
    Member:
    #2160
    Messages:
    317
    Central Texas
    Vehicle:
    07 PreRunner TRD Sport
    TRD Exhaust, TRD CAI, Bull Bar, PIAA lights, Passport, Bed Mat, UWS Toolbox, Hood Struts, Rear TSB, TRD/Okole Seat Covers, Hellwig Rear Sway Bar, Burned Carpet, Nasty Dent in Roof
    Yer kiddin, right? :rolleyes:
     
  20. Oct 8, 2009 at 10:47 AM
    #20
    saf023

    saf023 Well-Known Member

    Joined:
    Aug 13, 2009
    Member:
    #21124
    Messages:
    734
    Gender:
    Male
    East Coast
    Vehicle:
    2nd Gen TRD Sport DCSB 4X4
    My 6 cyc, 4X4, automatic, TRD Sport truck now has 17K miles now. Until yesterday, the automatic trans did not downshift on its own.

    - For the first time yesterday, I was coasting down a hill.
    - The trans was in "D". I felt the truck downshift.
    - I looked at RPMs. They went from 1100 to over 2200.
    - While still coasting down hill, I manually shifted into "4". The RPMs did not change. I immediately shifted back into "D" and the RPM jumped from over 2200 to 1100.
    - The truck clearly downshifted on its own although the dash shift status does not indicate the trans has shifted from "D" to "4" (unless I shift it manually).
    - Same thing happened this morning.

    What appears to be happening is the trans is being shifted from its overdrive to 4th. What I don't know is if engine braking is an "undocumented Tacoma feature", or a problem. I can't find anything in the owners manual. I know if I call the dealer I'm going to get the patented "they all do it" response. Anybody know for sure?
     
To Top