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

Horrible Gas Mileage with KM2's

Discussion in 'Wheels & Tires' started by dysfunctnlretard, Sep 1, 2009.

  1. Sep 1, 2009 at 12:19 PM
    #1
    dysfunctnlretard

    dysfunctnlretard [OP] Hi

    Joined:
    Jun 5, 2009
    Member:
    #18080
    Messages:
    3,760
    Gender:
    Male
    First Name:
    Manny
    CA
    Vehicle:
    2010 FJC
    55w HIDs, 16" Countersteer Offroads, Yokahama All Terrains, Demello Sliders
    I just purchased some 285/75/16 BFG KM2's last week and have noticed a dramatic decrease in my MPG's. My trip to work in the morning consists of about 10 HWY miles and 3 miles on the street and I have noticed a decrease in this area.

    I also took a 110 mile-trip to Big Bear this weekend which consisted of a 7,000 ft elevation gain. I had a full cab plus some minor luggage in the back which totaled to about 800-1,000 lbs. Total driving this weekend was about 280 miles which left me with 1/4 tank after it was all said and done. This comes out to ~14MPG!!!

    I'm running my tires at 32psi. I know they are heavier than stock and my 2.5 inch lift plays a role in the decrease as well, but was wondering if you guys are experiencing similar symptoms?
     
  2. Sep 1, 2009 at 12:38 PM
    #2
    jdkeller

    jdkeller How many words can be fit in this s

    Joined:
    Nov 26, 2008
    Member:
    #11040
    Messages:
    12,983
    Gender:
    Male
    First Name:
    Jonathan
    Inland Empire, Ca
    Vehicle:
    2008 Tacoma Prerunner TRD Offroad
    Dome light LED, 6000k HID Headlights and fogs, Grillcraft black mesh, rear 5100's, Total Chaos UCA's, 285/75/16 BFG KM2's, Spidertrax spacers, Blacked out emblems, cb,kenwood tm270 ham radio, All Pro 3" leaf pack, Fox 2.0 coilovers, Revenge Fab Sliders, u bolt flip kit, Pioneer avh4200, bed bar with light and antenna, Wet Okoles, Weathertech Mats, Wet Okole Armrests, Rear KR Fab bumper, bed mat, N-Fab spare tire carrier with full size spare on 16" TRD rim, Bedlinered flares and grille. Camburg Spindles, All Pro front fenders.
    I think im running mine at like 40 psi. I dont know my gas mileage but my light comes on at like 275 miles. It is worse than stock obviously. I have the same size tires as you.
     
  3. Sep 1, 2009 at 12:40 PM
    #3
    dysfunctnlretard

    dysfunctnlretard [OP] Hi

    Joined:
    Jun 5, 2009
    Member:
    #18080
    Messages:
    3,760
    Gender:
    Male
    First Name:
    Manny
    CA
    Vehicle:
    2010 FJC
    55w HIDs, 16" Countersteer Offroads, Yokahama All Terrains, Demello Sliders
    wow. well if my calculations are right, I should be getting ~350 miles per tank, which is a bit better than yours so maybe I shouldnt be complaining. When putting the tires on I didnt expect such a noticeable difference in MPG.
     
  4. Sep 1, 2009 at 12:41 PM
    #4
    jdkeller

    jdkeller How many words can be fit in this s

    Joined:
    Nov 26, 2008
    Member:
    #11040
    Messages:
    12,983
    Gender:
    Male
    First Name:
    Jonathan
    Inland Empire, Ca
    Vehicle:
    2008 Tacoma Prerunner TRD Offroad
    Dome light LED, 6000k HID Headlights and fogs, Grillcraft black mesh, rear 5100's, Total Chaos UCA's, 285/75/16 BFG KM2's, Spidertrax spacers, Blacked out emblems, cb,kenwood tm270 ham radio, All Pro 3" leaf pack, Fox 2.0 coilovers, Revenge Fab Sliders, u bolt flip kit, Pioneer avh4200, bed bar with light and antenna, Wet Okoles, Weathertech Mats, Wet Okole Armrests, Rear KR Fab bumper, bed mat, N-Fab spare tire carrier with full size spare on 16" TRD rim, Bedlinered flares and grille. Camburg Spindles, All Pro front fenders.
    350 til light comes on or all of it?
     
  5. Sep 1, 2009 at 12:55 PM
    #5
    dysfunctnlretard

    dysfunctnlretard [OP] Hi

    Joined:
    Jun 5, 2009
    Member:
    #18080
    Messages:
    3,760
    Gender:
    Male
    First Name:
    Manny
    CA
    Vehicle:
    2010 FJC
    55w HIDs, 16" Countersteer Offroads, Yokahama All Terrains, Demello Sliders
    IM guessing all of it? I never let my light come on and the 350 MP tank assumption is based on the fact that I'm getting about ~90 miles per 1/4 tank.
     
  6. Sep 1, 2009 at 12:58 PM
    #6
    drew02a

    drew02a Rocking your mom's world Since 1997

    Joined:
    Jan 26, 2009
    Member:
    #13005
    Messages:
    3,179
    Gender:
    Male
    San Antonio, TX
    Vehicle:
    2006 Regular Cab 2.7L 4x4
    Are you accounting for speedometer error?
     
  7. Sep 1, 2009 at 1:02 PM
    #7
    hillbillynwv

    hillbillynwv Well-Known Member

    Joined:
    Jun 25, 2008
    Member:
    #7555
    Messages:
    1,066
    Gender:
    Male
    Fairmont, WV
    Vehicle:
    08 Tacoma 4x4 TRD V6 SR5
    Rear Leaf Spring TSB, Front Bilstein 5100's set to 1.75, Goodyear Wrangler DuraTrac 265/75/R16 tires, Black WeatherTech Floor Liners, aFe Pro Dry S air filter, lighted 4x4 switch......
    I've checked my mileage 3 different times since I have had my truck and I just turned over 12K miles. I'm only getting 14.5 MPG and that was with stock 265/70/R16 BF Goodrich Rugged Trail tires. I'm now running the Goodyear Duratrac's 265/75/R16.....I'm probably getting worse MPG now.....to afraid to check.....I don't want to know!
     
  8. Sep 1, 2009 at 1:02 PM
    #8
    jdkeller

    jdkeller How many words can be fit in this s

    Joined:
    Nov 26, 2008
    Member:
    #11040
    Messages:
    12,983
    Gender:
    Male
    First Name:
    Jonathan
    Inland Empire, Ca
    Vehicle:
    2008 Tacoma Prerunner TRD Offroad
    Dome light LED, 6000k HID Headlights and fogs, Grillcraft black mesh, rear 5100's, Total Chaos UCA's, 285/75/16 BFG KM2's, Spidertrax spacers, Blacked out emblems, cb,kenwood tm270 ham radio, All Pro 3" leaf pack, Fox 2.0 coilovers, Revenge Fab Sliders, u bolt flip kit, Pioneer avh4200, bed bar with light and antenna, Wet Okoles, Weathertech Mats, Wet Okole Armrests, Rear KR Fab bumper, bed mat, N-Fab spare tire carrier with full size spare on 16" TRD rim, Bedlinered flares and grille. Camburg Spindles, All Pro front fenders.
    I just figure i burn 15 gallons at the light. So if i take my 275/15 thats about 18mpg
     
  9. Sep 1, 2009 at 1:07 PM
    #9
    Canadianboy

    Canadianboy Taco love in East Van

    Joined:
    Jun 11, 2009
    Member:
    #18308
    Messages:
    892
    Gender:
    Male
    First Name:
    James
    Vancouver, BC
    Vehicle:
    09 TRD Sport S/B 4x4 Auto in Mag Grey
    Icon Stage 3, Goodyear Duratracs and KMC Addicts!
    I'm only getting 320 miles per tank on a stock setup, but with a pretty new truck
     
  10. Sep 1, 2009 at 1:10 PM
    #10
    drew02a

    drew02a Rocking your mom's world Since 1997

    Joined:
    Jan 26, 2009
    Member:
    #13005
    Messages:
    3,179
    Gender:
    Male
    San Antonio, TX
    Vehicle:
    2006 Regular Cab 2.7L 4x4
    If your truck had 265/70/16s stock then putting 285/75/16s will make your speedometer and odometer read 7.31% too slow. To correctly calculate fuel economy, multiply your mileage by 1.0731, then divide by the number of gallons.
     
  11. Sep 1, 2009 at 1:14 PM
    #11
    jdkeller

    jdkeller How many words can be fit in this s

    Joined:
    Nov 26, 2008
    Member:
    #11040
    Messages:
    12,983
    Gender:
    Male
    First Name:
    Jonathan
    Inland Empire, Ca
    Vehicle:
    2008 Tacoma Prerunner TRD Offroad
    Dome light LED, 6000k HID Headlights and fogs, Grillcraft black mesh, rear 5100's, Total Chaos UCA's, 285/75/16 BFG KM2's, Spidertrax spacers, Blacked out emblems, cb,kenwood tm270 ham radio, All Pro 3" leaf pack, Fox 2.0 coilovers, Revenge Fab Sliders, u bolt flip kit, Pioneer avh4200, bed bar with light and antenna, Wet Okoles, Weathertech Mats, Wet Okole Armrests, Rear KR Fab bumper, bed mat, N-Fab spare tire carrier with full size spare on 16" TRD rim, Bedlinered flares and grille. Camburg Spindles, All Pro front fenders.
    then im getting 19.6 :confused:
     
  12. Sep 1, 2009 at 1:15 PM
    #12
    DeeKay21

    DeeKay21 Lieutenant Dan.

    Joined:
    Nov 11, 2008
    Member:
    #10651
    Messages:
    14,188
    Gender:
    Male
    Nevada/Utah
    Vehicle:
    06' TRD Sport 4x4
    I am also running 32 psi in all 4 of my tires but I am running 285/65-18"s with a 3" lift kit. I know I lost mpg for sure, I just never looked into it. I figure that's the price I am going to have to pay for wanting to modify my truck. So I just suck it up and live with it!!:eek::D
     
  13. Sep 1, 2009 at 1:17 PM
    #13
    derekabraham

    derekabraham Living vicariously through everybody

    Joined:
    Jul 8, 2008
    Member:
    #7822
    Messages:
    29,052
    Gender:
    Male
    First Name:
    TW'S Hippy Liberal
    Portland, OR
    Vehicle:
    2002 4x4 4Runner
    Stick on hood scoop from Autozone.


    x2. :cool:
     
  14. Sep 1, 2009 at 1:24 PM
    #14
    drew02a

    drew02a Rocking your mom's world Since 1997

    Joined:
    Jan 26, 2009
    Member:
    #13005
    Messages:
    3,179
    Gender:
    Male
    San Antonio, TX
    Vehicle:
    2006 Regular Cab 2.7L 4x4
    If you calculated correctly, then yes.

    There are alot of people who complain about how much their big tires have killed their gas mileage, but fail to take into account speedometer error.
     
  15. Sep 1, 2009 at 1:29 PM
    #15
    DeeKay21

    DeeKay21 Lieutenant Dan.

    Joined:
    Nov 11, 2008
    Member:
    #10651
    Messages:
    14,188
    Gender:
    Male
    Nevada/Utah
    Vehicle:
    06' TRD Sport 4x4
    Yeah thats very true. I know when it says 75 on my speedometer, the GPS reads like 78.9 or something like that.:rolleyes:
     
  16. Sep 1, 2009 at 1:40 PM
    #16
    drew02a

    drew02a Rocking your mom's world Since 1997

    Joined:
    Jan 26, 2009
    Member:
    #13005
    Messages:
    3,179
    Gender:
    Male
    San Antonio, TX
    Vehicle:
    2006 Regular Cab 2.7L 4x4
    That small difference adds up when calculating fuel efficiency, :)
     
  17. Sep 1, 2009 at 1:44 PM
    #17
    DeeKay21

    DeeKay21 Lieutenant Dan.

    Joined:
    Nov 11, 2008
    Member:
    #10651
    Messages:
    14,188
    Gender:
    Male
    Nevada/Utah
    Vehicle:
    06' TRD Sport 4x4
    Yeah understood. I dont know. Maybe one of these days I will calculate my mpg and see where I'm really at.:rolleyes:
     
  18. Sep 1, 2009 at 1:53 PM
    #18
    Canadianboy

    Canadianboy Taco love in East Van

    Joined:
    Jun 11, 2009
    Member:
    #18308
    Messages:
    892
    Gender:
    Male
    First Name:
    James
    Vancouver, BC
    Vehicle:
    09 TRD Sport S/B 4x4 Auto in Mag Grey
    Icon Stage 3, Goodyear Duratracs and KMC Addicts!
    For me, it doesn't really matter. I didn't buy the Tacoma for good gas mileage, otherwise I would have bought a Prius. Its a truck for crying out loud!
     
  19. Sep 1, 2009 at 1:55 PM
    #19
    DeeKay21

    DeeKay21 Lieutenant Dan.

    Joined:
    Nov 11, 2008
    Member:
    #10651
    Messages:
    14,188
    Gender:
    Male
    Nevada/Utah
    Vehicle:
    06' TRD Sport 4x4
    X2 on that one!!!:D
     
  20. Sep 1, 2009 at 1:55 PM
    #20
    derekabraham

    derekabraham Living vicariously through everybody

    Joined:
    Jul 8, 2008
    Member:
    #7822
    Messages:
    29,052
    Gender:
    Male
    First Name:
    TW'S Hippy Liberal
    Portland, OR
    Vehicle:
    2002 4x4 4Runner
    Stick on hood scoop from Autozone.
    Ask OakleyTRD about gas mileage. ;)
     
To Top