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

Why the sucky MPG?!

Discussion in '1st Gen. Tacomas (1995-2004)' started by kuntry09, Feb 27, 2012.

  1. Feb 27, 2012 at 8:38 PM
    #1
    kuntry09

    kuntry09 [OP] Well-Known Member

    Joined:
    Jun 12, 2011
    Member:
    #58140
    Messages:
    54
    Gender:
    Male
    First Name:
    Cam
    Douglas, Georgia
    Vehicle:
    '99 extended cab Tacoma Prerunner
    I've looked through the MPG thread and it's got me to wondering...why does it seem like I don't get near the gas milage these guys do!? I do all regular maintenance (oil 5-10k with synthetic, air filter every/every other oil change), my fuel filter was replace just a few months ago and my spark plugs were replaced about a year ago. My truck is a '99 extended cab auto with 284k miles and 4.5" lift (3" suspension, 1.5" body) BUT right now I'm running on stock 15's with 31x10.5 because I got tired of paying for gas with 305/70/16s. These days even with the stock tires I only get about 250 miles between fill ups (I fill up with 1/4 tank left) Now I could be wrong but it seems like when I first put the lift and tires on (then running 285/75 with only 3") I could still get closer to 300 miles between fill ups.....far as I can recall anyway that's been about 3 years ago. So what's the deal? Am I missing a simple maintenance thing that's hurting me or what? Oh I forgot to mention that I've seemed to have a loss of power too (not that there was much anyway lol). Few weeks ago it had trouble backing up with a trailer in tow up a slight grade....no make that a bump. Now when I say trouble I mean I had to get a running start to just get over it. So what's going on?! Any suggestions? I would LOVE to put my 305s back!
     
  2. Feb 27, 2012 at 8:56 PM
    #2
    slickyd

    slickyd Well-Known Member

    Joined:
    Jun 7, 2009
    Member:
    #18130
    Messages:
    303
    Gender:
    Male
    First Name:
    David
    Alex City, AL
    Vehicle:
    03 PreRunner SR5
    Im doing good if I get a tank to last me 250 miles. I have tried evertything. Even took it to the dealer and they can't figure it out
     
  3. Feb 28, 2012 at 5:10 AM
    #3
    Yamaha Dave

    Yamaha Dave Well-Known Member

    Joined:
    Mar 27, 2010
    Member:
    #34080
    Messages:
    2,677
    Gender:
    Male


    You also want to do the MPG number x3 times, add those together, and divide by three to give you a mean average. MPG can be factored by many variables, some can be controlled, other cannot. Obviously things like weather, density, barometric pressure, you can't control so you want to focus on your truck and specifically whats on it. Things like light bars, grill guards, ranch hand bumpers, CB antennas, off-road lights can all create Parasite Drag. Basically any device, item, product, that deflects or interferes with the smooth airflow around the vehicle. Once the airflow over the vehicle is spoiled it is no longer laminar or smooth. This also creates form drag which is a by-product of the turbulent wake caused by the separation of airflow caused by let's say that new light bar with x4 "6 inch off-road lights you just installed. Even a muddy truck can create drag from skin friction drag which is caused by the roughness of the surface. Also many other things affect your MPG, the weight of your tires, the load rating, the tread design etc. Obviously if MPG is your goal you want the lightest tire possible that will work with your application. The stock tires weigh in around 35 lbs. So any increase in weight x4 creates rolling weight and combined with something like an all terrain tire contributes to the rolling resistance of the tire. It takes force and energy to move the tire, and the harder and heavier it is the engine has to work harder to put out, which takes more fuel. Your poor MPG may also be contributed to something entirely different, something mechanical. Airfilters, fuel filters, clean injectors, the type of gas you use, or simple by the way you drive. There's so many variables, but my suggestion would be to remove what you can of aftermarket equipment, stay with the lightest tire possible you can run for your needs, keep the vehicle maintained properly, and get a Scan Gauge so you can test and measure your driving habits and find out where your wasting fuel.
     
  4. Feb 28, 2012 at 5:11 AM
    #4
    Stubbs95tacoma

    Stubbs95tacoma Well-Known Member

    Joined:
    Dec 12, 2010
    Member:
    #47604
    Messages:
    3,281
    Gender:
    Male
    First Name:
    Blake
    Wichita
    Vehicle:
    07 SR5
    6 Inch Lift
    Lol dont complain 200 miles and im on empty
     
  5. Feb 28, 2012 at 6:12 AM
    #5
    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
    Start tracking your mileage on fuelly.com

    Using a tank or two isn't suffice data.

    And if I thinking right, 250 miles on 3/4 of a tank is pretty damn good.

    Figuring a "full" tank fill up is 16 gallons. 3/4 of a tank is 12 gallons. 250 miles divided by 12 gallons yields over 20 mpg.
     
  6. Feb 28, 2012 at 6:54 AM
    #6
    Hillingdoner

    Hillingdoner Well-Known Member

    Joined:
    Jan 9, 2012
    Member:
    #70273
    Messages:
    458
    Gender:
    Male
    Rio Rancho, NM
    Vehicle:
    95 LX xtracab 3.4L 4x4 5spd
    140 amp Cadillac alternator, Audio system in progress, 4Runner map light mirror conversion, foot well lamp addition, buckets and console from 99 Tacoma regular cab, big three, tint
    Sorry all, another long Hillingdoner post to follow.

    I'm pretty focused on mpg. I've run into this not only on Tacomas, but a loads of other vehicles I've had (camry I own now for example). You have to take SOME reported mpg posts with a grain of salt. There are those that change wheels and tyres to different sizes or change gearing and then report incorrect numbers for mpg as they have not taken into account the effect these changes have made on the accuracy of their speedo/odo.

    I say SOME, there are those on the board that are very sharp on this and you can get real numbers. Not pointing fingers at anyone. I've seen this on other sites for different cars (don't get me started on the mpg numbers some Camry board members put out to others). Just a matter of something you have to keep in mind.

    You also have to look at the spec of their trucks, year model changes, are they geared different from the factory than yours, weigh different, are you seeing numbers that are actually a 5 lug standard cab stripped down model that are not being identified as such and you are comparing to a loaded out xtra cab 4wd or something? You need to compare apples to apples.

    Even then mpg will vary between vehicles. Driving style, route, location, temps....there are many factors. That is before you even get into each vehicle varied from the factory to some extent. The factory has an allowable percentage they are allowed to work within for speedo accuracy. Some will be pretty well spot on, but most will be off. You may be showing that you are going a certain speed, but actually you are going slower in most instances. This is within tolerance for accuracy in production and is allowed. If your speedo is clocking say 55 miles in an hour and you are actually travelling 53 you will have a bit of inaccuracy in that the odo will be showing more miles covered than actual. As such your mpg will be a little inflated.

    Get a good gps and test out the gps accuracy to mile markers. I generally test the gps on a 4 mile highway drive. I've found my Garmin spot on with indication mile marker wise. I use the same circuit and stop at the first mile marker. Set the GPS odo miles to zero and write down the speedo odo reading including tenths as well as set the trip to zero. I then start out and drive at least 10 miles up the highway (so I get a decent average and better accuracy) with a passenger jotting down what the speedo odo reading is including 10ths compared to when the GPS and mile markers say we've been a mile. They do this each mile. I then compare the vehicle miles to the gps miles. You can then calculate differences and get an average error factor to your odo to true miles. Bit nerdy I know, but that is how I am.

    Good info about drag above. That lift will not help drag. Neither will any added weight to the truck.

    A real potential issue and probably a good factory in your poorer mpg is your loss of power. You could have general wear in the engine, blow by, leaking head gasket, transmission issues etc. that are causing you to have lower mpg as well.

    I'd start with verifying where you are actually miles, indicated speed and actual mpg with a gps. Looks like a scan gauge can be used too to do this as well.

    Once you are accurate then start looking at what you can do to better your mpg. With that loss of power I'd be interested in what your compression is like. Any low cylinders. How is the shifting on the truck. Does the trans slip. How old are the O2 sensors. General condition of engine. Heck, even jack up each wheel (with stands under it) and see if you have any brake drag or wheel bearing issues.

    As I said, loads of factors to take into account. Best of luck with it!

    Cheers
     
  7. Feb 28, 2012 at 12:08 PM
    #7
    scocar

    scocar Scouting the perimeter for weakness

    Joined:
    Nov 11, 2009
    Member:
    #25814
    Messages:
    31,431
    Gender:
    Male
    First Name:
    Dick
    In close proximity to an undisclosed location
    Vehicle:
    2015 DCLB 4x4 SR5
    Back to square one after the 2001. So...
    ^^^ This, plus clean your throttle body. And when you do this, disconnect the battery so the ECU resets. This will help set a good baseline and eliminate more variables.
     
  8. Feb 28, 2012 at 12:26 PM
    #8
    lil J

    lil J Well-Known Member

    Joined:
    Dec 10, 2011
    Member:
    #68544
    Messages:
    163
    Gender:
    Male
    First Name:
    Jacen
    Louisville
    Vehicle:
    99 Tacoma 4wd V6 Horizon Blue
    Old Man Emu Suspension
    Different people drive different speeds, somebody who drives 55mph is going to get better mileage than someone who drives 70mph. It's hard to compare your mpg to someone elses when you don't know their driving habits. Plus your truck is lifted which effects the mpg.
     
  9. Feb 28, 2012 at 3:44 PM
    #9
    monoman

    monoman Time to get dirty!

    Joined:
    Aug 18, 2008
    Member:
    #8607
    Messages:
    997
    Gender:
    Male
    First Name:
    Dave
    Exotic, San Jose, Cal.
    Vehicle:
    2003 Tacoma Dbl Cab 4X4
    I usually get over 18 MPG, but A couple of weeks ago I noticed that my MPG was starting to go way down too, like 16 or so, so I did a check on my tires & low & behold, I found one that had gone down to 25 pounds. I usually check them often but I guess it had been a while since the last check.:confused: Pumped that sucker up and went back up to 19 MPG!:D
     
  10. Feb 28, 2012 at 4:03 PM
    #10
    Honey badger

    Honey badger Honey badger hits whatever tree he wants to hit!!

    Joined:
    Oct 22, 2009
    Member:
    #24735
    Messages:
    2,191
    Gender:
    Male
    First Name:
    Bon
    Kinder, Louisiana
    Vehicle:
    02 DC BLACK 3.4
    You are lifted and was running larger than stock tires. If you want good MPG's go back to stock. On a tank I am lucky to get 250 and I'm talking about running it down to E. I stopped paying attention to my MPG's a long time ago I knew once I put the life and tires it was going to shit. Like I said go back to stock problem solved.
     
  11. Feb 28, 2012 at 4:10 PM
    #11
    jandrews

    jandrews Carolina Alliance Southwest Region Ambassador

    Joined:
    Jun 7, 2009
    Member:
    #18122
    Messages:
    12,180
    Gender:
    Male
    Vehicle:
    '09 FourDubDee TRD OR
    A-TRUCK, Fat Kid in the Bed, Custom Pinstriping, Ported and Polished Muffler Bearing, Hi-Performance Bed Mat
    You have 284k miles on the motor, that's why.
     
  12. Feb 28, 2012 at 4:37 PM
    #12
    kuntry09

    kuntry09 [OP] Well-Known Member

    Joined:
    Jun 12, 2011
    Member:
    #58140
    Messages:
    54
    Gender:
    Male
    First Name:
    Cam
    Douglas, Georgia
    Vehicle:
    '99 extended cab Tacoma Prerunner
    I understand I'm in a lifted truck so I'm going to get a little less but I've gone back to stock 31x10.5x15s. Even when I first put the lift on with 285/85 tires it seems like I used to get closer to 280-300 between fill ups.


    I've recently come across fuelly so I'm going to start using it to see how it comes out then. I thought a "full" fill up would be 18 gallons so that would make it 13.5 though?

    I am back to stock except for the 4.5" lift.

    I understand there are variables from person to person how the MPG will be such as driving habits, type of driving, tires, gears, etc. The lack of power I've seemed to have lately though has made me wonder if something else isn't wrong. I've also had to have my transmission replaced and I wasn't sure if there was more than one tranny for the v6 that could account for a little less MPG.
     
  13. Feb 28, 2012 at 4:42 PM
    #13
    Konaborne

    Konaborne Pineapples on pizza Hawaiian does not it make.

    Joined:
    Nov 21, 2010
    Member:
    #46536
    Messages:
    31,748
    Gender:
    Male
    First Name:
    Cody
    Kealakekua, Hawaii
    Vehicle:
    Lifted 00 TRD Off-Road
    fox extended travel remote resivoir coilovers, 14" eibach 600lb coils, All Pro tubular chromoly 1" uniball upper control arms, All Pro expedition leaf packs, 10" bilstein 5150 piggyback reservoir shocks 265/75r16 Goodyear wrangler MT/R kevlars wrapped around 16" Helo 791 gloss black, Mini H1 retrofits with 6000k bulbs, 18" magnaflow w/custom exhaust reroute various decals, Sockmonkey retro hood stripes
    Your engine has 5x more miles on it, and you get better mpgs than me....

    Clean your MAF and dont stomp the skinny stick
     
  14. Feb 28, 2012 at 4:49 PM
    #14
    maineah

    maineah Well-Known Member

    Joined:
    Mar 24, 2011
    Member:
    #53641
    Messages:
    4,145
    Gender:
    Male
    First Name:
    Tim
    Maine
    Vehicle:
    4X4 SR5 V6 6spd
    This^
     
  15. Feb 28, 2012 at 5:08 PM
    #15
    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
    Maybe, technically, but early this month I ran it down to fumes and thought I was going to have to coast into the gas station... the fill up was 15.77 gallons.

    The 2 or 3 gallon reserve probably never gets tapped into because most of us fill up when the gas warning light has been on consistently.
     
  16. Feb 28, 2012 at 5:09 PM
    #16
    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
    That and noticing winter gas.

    btw - gas is no where near $5 a gallon here. It hasn't even broken $4/gallon
     
  17. Feb 28, 2012 at 5:15 PM
    #17
    scocar

    scocar Scouting the perimeter for weakness

    Joined:
    Nov 11, 2009
    Member:
    #25814
    Messages:
    31,431
    Gender:
    Male
    First Name:
    Dick
    In close proximity to an undisclosed location
    Vehicle:
    2015 DCLB 4x4 SR5
    Back to square one after the 2001. So...
    Do not even worry about tank capacity. You are making it too confusing.

    First, you should never run your tank down to E. You'll kill the fuel pump eventually.

    Second, just focus on miles since your last fill-up. You should run it down to 3.4 tank consistently, because as you lose fuel weight, mileage increases. It also helps to do the same with your washer fluid (I keeed). When you fill up, always do it the same way; by this, I mean never top off. on your fuel receipt, write down how many gallons it took to fill, then divide by miles on the odo. Average this over several tanks at least to get a number that is somewhat meaningful.
     
  18. Feb 29, 2012 at 11:18 AM
    #18
    monoman

    monoman Time to get dirty!

    Joined:
    Aug 18, 2008
    Member:
    #8607
    Messages:
    997
    Gender:
    Male
    First Name:
    Dave
    Exotic, San Jose, Cal.
    Vehicle:
    2003 Tacoma Dbl Cab 4X4
    Lucky bum!:rolleyes:
     
  19. Feb 29, 2012 at 3:31 PM
    #19
    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
    Just went 313.3 miles on 14.965 gallons (20.9 mpg)

    Cost per gallon: $3.229
     
  20. Nov 4, 2012 at 12:03 PM
    #20
    TheDaves00

    TheDaves00 Member

    Joined:
    Jan 14, 2011
    Member:
    #49255
    Messages:
    9
    Gender:
    Male
    Washington
    Vehicle:
    '15 AC 4WD 6 spd. Manual
    YUP!
     
To Top