Gas mileage took a dive

Discussion in 'TFI Questions Answered By Dobeck' started by 11bdad, Dec 22, 2011.

  1. 11bdad

    11bdad Member

    Installed a TFI unit on my 2010 FXDC several months ago. Bike has Rush Slip-on's (1.75 baffles), and a Ness Big Sucker AC. Bike has run great since I installed the unit (still does), but my MPG has taken a dive over the last 3 tanks of fuel. The TFI is set to the recommended setting for the mods. My mileage has gone from 40-42 mpg to 36-38, with no change length of trips or riding style. Any ideas?

  2. glider

    glider Veteran Member

    You can lower the #1 and #2 pots just a bit but the decrease isn't drastic for openers. The engines are set so lean from the factory that the added fuel will make a slight difference in MPG.
  3. Bodeen

    Bodeen Well-Known Member Staff Member Moderator Contributor

    I cooler, great running bike is worth a few miles a gallon. Longevity alone is worth it. Dont worry, drive it like you stole it.
  4. dbmg

    dbmg Guest

    My thought is, now that it running great and pulling strong the amount of noise you are making do to the right wrist is indirect relation to less MPG.....
  5. 173ABN

    173ABN Active Member

    I think dbmg hit it right on the head. After I did the same upgrades I lost some MPG until I quit impressing myself with the new found power and sound. The MPG will come back some what. Injoy the new power and sound.
  6. 11bdad

    11bdad Member

    I guess I was a little vague in terms of the time frame. I installed the TFI probably 5 months ago. The pots were adjusted to the recommended settings and everything has been great. My gas mileage since installing the unit has been between 38-42, which is a combination of in town riding with 1 or 2 50 mile trips to Charleston a week. The drop in gas mileage has just occurred in the last 3 tanks of fuel. I'm not getting on the throttle any more than usual. I just don't understand why I've gone from an average of say 40 mpg down to 35 to 36. As good as the bike runs, I guess I won't worry about it.
  7. R. Lewis

    R. Lewis Senior Member Retired Moderators

    Did the last 3 tanks come from the same filling station? Have you put in any kind of fuel stabilizer - sea-form,MM,Iso-heet ?????
  8. cdyoung29

    cdyoung29 Member

    Winter blend petro. You will lose MPG in the winter.
  9. 11bdad

    11bdad Member

    Two tanks were Citgo 93 octane (no ethanol) and today was BP 93 octane. Normally all I run is the BP, but I thought I'd run some ethanol free in it since the station is pretty close. No additives have been added.
  10. DobeckTechSupport

    DobeckTechSupport Active Member Product Contributor

    11bdad - Glider's suggestion is correct to get a little fuel mileage back by turning the first 2 pots down just 0:30. Losing 4 mpg isn't real bad though for a stage 1 setup to get the torque and HP increase.

    Honestly though we will have to agree with a number of the other forum members about the quality of fuel more than likely being the culprit.

    Merry Christmas everyone.