Fuel mileage

Discussion in 'Western Star Forum' started by Wmckenzi, Mar 18, 2014.

Page 1 of 3
  1. Mar 18, 2014 #1
    Wmckenzi

    Wmckenzi Bobtail Member

    8
    0
    Mar 18, 2014
    0
    Hello everyone. I am looking for some advice. I have three new 4900 sb with 500 horse cummins. We haul logs on short runs. We are only getting around 5 mpg on average. Average loads are 85,000 lbs loaded and 30,000 empty on the way back. Almost all back roads-stop signs, hills, etc. trucks have ten speeds and 3.90 gears. Think we can do any better? I was hoping to get 6 mpg, but may be dreaming. Any suggestions would be appreciated. I would hate to have to get rid of these trucks, but may have to if I can't get the mileage up. Thanks!
     
    Wmckenzi, Mar 18, 2014
    Wmckenzi, Mar 18, 2014
    #1
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.

  3. Mar 18, 2014 #2
    jameslawton

    jameslawton Light Load Member

    257
    65
    May 1, 2013
    Tulsa OK
    0
    I think you got to tall a gear should have went 4.11 or 4.56 your pulling alot of weight and a 13 or 18 speed would have been better choice but your not going to get much better then that if you stay on the back to much slow and go and 5mpg pulling full loads is not the worst fuel mileage I have heard of
    You might be able to put a tune in it and get a half or 1 mpg out of it but mybee not good luck
     
    jameslawton, Mar 18, 2014
    jameslawton, Mar 18, 2014
    #2
  4. Mar 18, 2014 #3
    rjones56

    rjones56 Heavy Load Member

    823
    486
    Jul 15, 2008
    staunton va
    0
    Winter blend of fuel is hurting your fuel mileage. Mine lost about 1/2 MPG. I doubt you will ever get any fuel mileage running short haul stop and go stuff. I would say 5 is pretty decent, considering.
     
    rjones56, Mar 18, 2014
    rjones56, Mar 18, 2014
    #3
  5. Mar 18, 2014 #4
    Wmckenzi

    Wmckenzi Bobtail Member

    8
    0
    Mar 18, 2014
    0
    I was wondering if I should have geared them lower. We are never on the interstate, so they may be too tall. We just put progressive shifting on them to try to get more. We'll see! Thanks for the reply.
     
    Wmckenzi, Mar 18, 2014
    Wmckenzi, Mar 18, 2014
    #4
  7. Mar 18, 2014 #5
    Wmckenzi

    Wmckenzi Bobtail Member

    8
    0
    Mar 18, 2014
    0
    I have a 2005 fright liner that gets 6mpgs doing the same thing. Has a Mercedes in it and 3.52 gears, I think. May be I need to go back to the freight liners!
     
    Wmckenzi, Mar 18, 2014
    Wmckenzi, Mar 18, 2014
    #5
  8. Mar 18, 2014 #6
    gokiddogo

    gokiddogo Road Train Member

    8,786
    14,769
    Mar 5, 2012
    Ontario Canada
    0
    Knock the emissions crap off it and let it breathe ...
     
    gokiddogo, Mar 18, 2014
    gokiddogo, Mar 18, 2014
    #6
    Cetane+ Thanks this.
  9. Mar 18, 2014 #7
    freightlinerman

    freightlinerman Road Train Member

    1,287
    536
    Mar 4, 2011
    Florida
    0
    The 'emissions crap' has little do to with it. The truck has been engineered with it. As far as progressive shifting, for most drivers its worth less.Most drivers know the correct RPM to shift to get the best fuel mileage. If you are an owner operator, having it on wont do much of anything. Lets be real here, you are hauling heavy loads and going up hill. You need to use all the horse power you have and some times shift at a high rpm to maintain speed when you get to the next gear. Progressive shifting would be helpful when you have an empty trailer and you have a driver that likes to mash on the throttle and hot rod through the gears. 5 MPG is pretty good given your circumstances.
     
    freightlinerman, Mar 18, 2014
    freightlinerman, Mar 18, 2014
    #7
  10. Mar 18, 2014 #8
    Wmckenzi

    Wmckenzi Bobtail Member

    8
    0
    Mar 18, 2014
    0
    I think I should have spec'd these trucks with 4.11 rears. What do u think the difference would be?Average top speed in high gear is only around 59mph, which I think is too slow for 3.90 rears. Wonder what it would cost to change one out and see.....
     
    Wmckenzi, Mar 18, 2014
    Wmckenzi, Mar 18, 2014
    #8
  11. Mar 18, 2014 #9
    freightlinerman

    freightlinerman Road Train Member

    1,287
    536
    Mar 4, 2011
    Florida
    0
    THese new engines really, really do like lower RPM's. For example, doing 50 MPH at lets say 1,400 RPM's, it seem's low. But, I shift into top gear and do the same speed at lower RPM's and the instant MPG's goes up. They are designed to run low RPM's unlike older engines.
     
    freightlinerman, Mar 18, 2014
    freightlinerman, Mar 18, 2014
    #9
  12. Mar 18, 2014 #10
    snowwy

    snowwy Road Train Member

    20,612
    13,333
    Jul 6, 2009
    0
    your not kidding about that, freightliner.

    wouldn't be so bad in the flatland side of the country either., but in the western mountains. where you gotta grab gears on every stinking hill. instead of cruising in a midrange rpm and only having to grab on half the hills.

    throw in an automatic and now your really lugging the engine. and literally crawling up the hills. cuz it won't run in the higher rpm range,
     
    snowwy, Mar 18, 2014
    snowwy, Mar 18, 2014
    #10
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.

    • Page 1 of 3