Fuel mileage with upgraded cams

Discussion in 'General Harley Davidson Topic' started by JohnRKC06, Sep 28, 2011.

  1. JohnRKC06

    JohnRKC06 Member

    How does new upgraded/ high performance cams affect your fuel mileage.I know when I installed True Duals ( V&H slipons & Headpipes) along with a SERT my fuel mileage is not very good. The bike does runs like a Bear . But I was wondering how much more mileage I will be losing.Lets face it most of us didn,t get into this sport to save money on gas.My friends with the newer bikes along with the 6 gallon tank & the extra gear can go much longer than I ever could. Thanks in Advance
  2. sanec1

    sanec1 Active Member

    The mileage on my Road King was affected more by my twisting the throttle. The 21N cams gave the bike more "snap". The difference made with the combination of cams, K&N breather, Thunderheaders and TFI was significant. The bike was more responsive and I enjoyed riding it more. I get about 37 mpg compared to other riders who average 40.
  3. shaker

    shaker Active Member

    I'd like to know this myself. I dropped from about 42 mpg to 30 mpg after adding a Dobeck to my bike - this was on a highway trek with factory settings. This winter I'd like to replace the cam tensioners, and I thought about possibly upgrading the cam shaft, but am concerned about trashing my mileage. I was able to up my mpg's by backing off of the factory settings on the Dobeck, but performance is about what I had when stock. I need more time playing with it.
  4. 67wizard

    67wizard Junior Member

    I get about 40 - 43 with a 103 upgrade and 255 cams, TTS mastertune, no cats and reinhart slipons.
  5. sanec1

    sanec1 Active Member

    That seems pretty low to me. You can contact Dobeck through this forum in the Self Help section. I was able to get more mileage without compromising performance. Have you checked the condition of your plugs and air cleaner?
  6. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

    Anytime you get the beast breathing more air, and adjust the AFR so it is not too lean, you will use more fuel. Just the way it is.

    But you can fine tune the TFI or the Gen 3s to keep the performance and heat where you want them, and not be too big a hit on the fuel economy. However, freer breathing and lower AFR means more fuel. No way around that!

  7. wolffman

    wolffman Account Removed

    You would need to get a good dyno tune or some kinda Autotune ECM. Once you start changing things liek cams, pipes and airboxes it messes with your AFR.

    Buddy of mine has a built to the gills motor. Running a Thundermaxx AT and is getting 42-46 MPG. 04 Ultra.
  8. kemo

    kemo R.I.P

    My bike gets 42 to 44 mp US gallon. I have the Andrews N26 cams and A/N Big sucker air filter and low restriction mufflers.