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Realistic mpg

Discussion in 'Motorcycle Tech Talk' started by skull2007, Jun 7, 2007.

  1. skull2007

    skull2007 Active Member

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    my o6 heritage has V/H long shots with baffles and the old se ac. i was getting about 42 mpg with the 04 map (805.159) i've been doing alot of trail and error and have got it up to 43.5. my driving is about 85% highway. my avg speed is around 70. what can one real hope to ever get when it comes to mph. i weigh around 215:picked:
  2. voodoochild

    voodoochild New Member

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    I dunno what is realistic but i checked mine again today. I am getting around 44 mpg. I weigh 165 lbs and I have the stage 1 kit, and I'm not light with the throttle either. Most of this tank was basically cruising, not high speed highway. Hope this helps.

    BTW, 04 Dyna, TC88, S/E pipes, thunder monster baffles, stage 1 kit.
  3. skull2007

    skull2007 Active Member

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    :confused: am i wrong in thinking that we should get better mpg with a better air flowing engine?
  4. cowboy

    cowboy Moderator Staff Member

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    My 03 E glide got about 48 mpg when stock , added the PC lll se air cleaner & pipes drive it about the same most of the time & now down to 30 mpg :(
    :cool:
    I think it's more air more power less MPG
  5. Red Rider

    Red Rider Well-Known Member

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    Anytime you up the overall power you reduce the mpg unless the ride wasn't dialed in to begin with. That is why I am happy with my bagger being relatively stock...though I am getting V-H Pro 2-1 pipes for the better midrange were I ride it the most. It sounds like you are right there for your mpg/perfromance mods.
  6. Tomflhrci98

    Tomflhrci98 Active Member

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    More air flow is kind of a catch 22. If you reduce the air flow friction with the use of stg1 air cleaners and open exhaust pipe and port and polished heads etc. etc. you will get a more efficient engine and thus better gas mileage. HOWEVER, when you have more power from this you tend to use it (wrist twisties which is the whole point of doing it anyway) and when you do that you are using more gas.

    So, it is not an easy question to ask. You have to develop a riding style that is consistent and important to you. That could be a certain country road you like or high altitude riding or hwy riding at 80 mph or 70 mph etc. Then make changes that give you good MPG while riding like that. Of course, don’t lean it out too much.

    In theory the Power commander dyno centers should give you the best all around mpg if they know how to use their air/fuel ratio meter correctly. I think it is hard to find anyone that really knows how to use the stuff and calibrates there meters correctly.
  7. Cracker

    Cracker New Member

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    The only way to be certain that you are spot on is with a dyno tune that will read out your air fuel ratio.

    I get 38 with my carbed EG 95" at 65~70 but it will drop to 34 if I push it at 80mph.

    Cracker
  8. skull2007

    skull2007 Active Member

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    catch 22 makes sense

    the better sounding the exhaust, the louder we play it, and down goes the mpg:eek: we're domed
  9. Tomflhrci98

    Tomflhrci98 Active Member

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    Skull,

    I think your mpg (as you described) is about right. I think we should easily get 40 to 45 mpg if you are consistantly running 70 mph. Hell my 4 door honda accord gets 35.5 mpg at that speed.

    My bike gets 40mpg if I run 78 mph between fill ups. 78 to 80 is about where it seems the smoothest. When it is runnig right... but thats another issue.:cussing:
  10. Elrod on the V-Rod

    Elrod on the V-Rod New Member

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    I have an 04 Herritage w the V&H longshots,stock ECM and air filter.Yea yea,I know,use a tuner or a download or take a chance of burning a combustion chamber component,but at over 20k miles it hasn't missed a beat,not flaw 1 in performance at any throttle opening.

    I average close to 45mpg of combined riding,including loading the bike.
    One spring my wife and I left Daytona early in the morning,about 50 out and some fog.I rode like a grandpa and never went over 60mph,no blips for downshifting,very light and methodic on the throttle.We weigh about 300lbs between the 2 of us and had our stuff in the bags.It was 112 miles to the house and I got 60mpg! I've done this a few more times since.

    BTW my first vin # is 5.I've been told I have a different cam profile than #1 vin's.Maybe this is the reason for the mid 40's milage.I know my B engine idles way more smoother than any others I've heard or ridden.


    Elrod on the V-Rod
  11. skull2007

    skull2007 Active Member

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    getting there

    i leaned out my map a little in the 20% trottle 3000rpm range, getting around 44.5 mpg. or am i going easier on the trottle:picked: , also playing around with the timing advance in the 5%-10% trottle position by throwing in some 3's to see what effect it will have on take off:rolleyes: seems fine tuning would go better wth a tach:confused: do you guys think a tach would tighten things up with tuning these maps:drunk:
  12. chucktx

    chucktx Moderator Staff Member

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    yes........hard to fine tune without one.....
  13. HarleysLR

    HarleysLR Active Member

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    It seems to me the two Fatboys that we have get much better mileage than anyone has posted here.
    The 1990 80 inch EVO with 10:1 compresion, EV3 cam with early model Scream Eagle exhaust gets 52 + mpg no matter what speed it is ridden. It has a polished and modified CV carb.
    2005 FatBoy 88 has a Screaming Eagle ingition with VH Big Shot Staggered exhaust and a modified CV carb it gets 50+ mpg. These bikes are both ridden hard and fast and for long miles at a time. It's all in the way you tune them.
  14. cowboy

    cowboy Moderator Staff Member

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    I stoped & filled up last night , got 38.5 mpg , My new Big city thunder baffles should be here today , so if there all there cracked up to be I'll pull out the wife's lap top & retune finetune & go from there , I would like to get it back to the 48 it got before all the changes
    :cool:
  15. DKIN21

    DKIN21 New Member

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    FUEL mpg

    I HAVE 07 SCREAMIN EAGLE ROAD KING, 110 CU. IN., 6-SPEED, WE JUST RETURNED FROM JACK DANIELS RALLY IN LYNCHBUR4G, TN, FROM KNOXVILLE, TO CHATTANOOGA, TN I SET CRUISE ON 79 MPH. AVG. 48 MPG, FROM CHATTANOOGA, TN TO LYNCHBURG AND BACK TO TULLAHOMA, TN RIDING 2-UP (350 lbs.) ALL 2 LANE MOUNTAIN ROAD, ON AND OFF THROTTLE HARD, 119.9 MILES TOOK 2.60 GALS OF GAS AVG. 46.0 MPG. I'M RUNNING V&H SLIP ON WITH THE V&H FUEL PAK, BIKE JUST TURNED OVER 5,000 MILES ON THE WAY BACK TO KNOXVILLE.

    LIVE EASY, RIDE HARD:: :cheers: :rocket_bike:
  16. hotroadking

    hotroadking Super Moderator Staff Member

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    Lots of bikes built for performance are jetted rich, to make power and to cool the cyl.

    JMO carb tuning isn't as precise as EFI, you can set RPM ranges, throttle position and fuel/air at each increment. That way you can have a leaner AFR at 20% throttle, 3000 RPM 70MPH to get better mileage and still go rich under WOT for full throttle runs.

    Most S&S carbs get crappy mileage because they are over jetted, changed mine back a couple of sizes and fuel mileage went into mid 30's which is good for a 124.

    I have a daytona twin tech afr scanner that I have to finish putting together the sniffer to check the exhaust, then I'll be able to tune the carb even better.

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