New V&H Slip-ons and gas mileage

Discussion in 'General Harley Davidson Topic' started by DCLARKE, Aug 14, 2014.

  1. DCLARKE

    DCLARKE Member

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    I installed V&H Monster Round Slip -ons to my 2008 Road King Classic. The bike is all stock. I absolutely love the sound but my gas mileage has dropped about 6 MPG. Is this normal? I was told the ECM would adust to a minor mod such as slip-ons but not to more air. Overall the bike seems to have more get up and go and runs great. I will give up the gas mileage for power and sound but I am just curious. Thank you!
     
  2. 03HD883R

    03HD883R Active Member

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    I'm not too sure on FI bikes.

    But I do know sometimes why mpg drops sometimes... it's that impulsive need to twist that throttle hard to hear that fine engine roar out them newly modified pipes. :)

    And I'm sure it sounds really good too.
     
  3. dbmg

    dbmg Experienced Member

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    Here is the bottom line. With any change in exhaust you will tend to use the right wrist more to make noise. The negative effect is a drop in fuel mileage and excessive rear tire wear not to mention ringing in the ears in some cases.
    Do not ask me how I know. So if no check engine light and bike runs well as you have stated, then there is probably no problem at all with bike.:bigsmiley11:
     
  4. DCLARKE

    DCLARKE Member

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    You guys are right on. Ha Ha Ha. I have been paying more attention to my drivivg habits and it sounds so good I can't help but crank it up a little more than I used to. There goes my MPG's. I love the new sound. Thanks for the input. RIDE ON!
     
  5. insp.clouseau

    insp.clouseau New Member

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    Wait 'till you drop a nice performance cam in there...

    ...sure you could go for better fuel/mileage...? :s