Post your BMW Airhead fuel economy

Discussion in 'Airheads' started by BrokenR80RT, Jun 18, 2011.

  1. caponerd

    caponerd Kickstart Enthusiast

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    Maybe I should send you a copy of my milage records.

    My extremes on the RT are 32 at the bottom and 40 at the top. Both extremes are rare. Usually, I see 34 in town and 38 on the highway.
    #41
  2. supershaft

    supershaft because I can

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    I agree that a larger sample than by the tank might be informative but I have no real need for the info. Mileage varies SO much from riding technique and wind and what not that after a certain point it is mostly about innumerable varying conditions. That's bad science. I personally pick some other fires to piss on. :lol3 Besides, I think doing simple division in your head is good exercise!
    #42
  3. supershaft

    supershaft because I can

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    Have fun with it. I only hope you got out your lab coat and pipe out while making the graphs. Penny loafers with no socks? And a sharp haircut! Oh the horror! :freaky
    #43
  4. Lornce

    Lornce Lost In Place

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    I like to think of it as a more holistic way to approach building a performance engine. Any idiot can build a crude gas pump and spin it up to high revs with no regards for efficiency. KTM's been doing that for years. :rolleyes :csm

    Start with building a motor to higher standards of efficiency that makes good torque and then find a way to spin that to higher revs for improved power.

    It's the approach Rotax appears to have taken with their 800 twins. Compare them to 950 KTM's which make slightly higher peak power while using more than twice as much fuel.

    That's just dumb. :scratch

    :dunno
    #44
  5. fishkens

    fishkens Long timer

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    Nice. Can you show the y axis as % of total? This would show the differences between ADV and MOA more clearly.
    #45
  6. BrokenR80RT

    BrokenR80RT But I'll fix it.

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    Thanks for your input, Supershaft.:super Completely invaluable.
    #46
  7. bush pilot

    bush pilot Long timer

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    My old r90s was pretty consistent about getting 47-49 mpg at reasonably sane speeds (65-70). Those slide carbs and the tall rear axle ratio were great.
    #47
  8. Carrizojim

    Carrizojim Still stumblin along

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    +1... 45mpg usually... it will go way over that if I'm milking it along at 65 or less... My sweet spot is right at 69-70 mph, great mileage, smooth as glass...
    Pretty fresh carbs rebuilt in in Dec 2010, carefully synched and tuned by Renner... 130,000 original miles, no engine rebuilds or "restorations".
    #48
  9. Big John Sny

    Big John Sny Been here awhile

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    I don't know how this affects your results, but the fuel here in Dallas and many other large metropolitan areas in the US has changed quite a bit in recent years. I am getting significantly lower fuel milage numbers in all of my vehicles. Any additives they add will add volume of fuel without adding energy (some of these additives are seasonal). The addition of ethanol adds less energy per equivilant volume of gasoline it is replacing.

    I was getting a consistant 31mpg till I moved the needles back to the factory setting and started getting 35. I would really love to get 40, but my car that used to get 34 is now getting 30 and my minivan that was getting 25 is now getting 20 (both get slightly better when I get gas outside the metroplex), so I don't see that happening. I have used my wifes 250 ninja to go to work that should be getting 65 and I get just over 50, so maybe it is just me (although my wife says both cars get 2 mpg better when I drive them than when she does).
    #49
  10. pit0rz

    pit0rz Off on a bimble...

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    84 R100RT (currently nekkid) - 36MPG spirited back road riding w/ VERY limited Interstate jaunts. VM38 Mikunis and K&N Filter in stock airbox and Epco pipes (kinda loud)
    #50
  11. Rapid Dog

    Rapid Dog bikes, booze, broads...

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    Saturday, 49.5mpg average. 164 miles of freeway, canyons, open road, slow rough stuff.
    #51
  12. Bill Harris

    Bill Harris Confirmed Curmudgeon

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    I check the gas mileage once or twice a year. Mileage has been typically in the 47-49 mpg range over the years. A bit lower with spirited/high speed riding, and a bit higher with a light throttle. I've not seen much change with the introduction of ethanol-laced fuel, although cold starts are most affected.

    "YMMV"
    #52
  13. BrokenR80RT

    BrokenR80RT But I'll fix it.

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    Next time you are filling up instigate that pump and let us know how much ethanol your fuel has. That is one bad additive which will scalp your fuel economy. Gallon for gallon, ethanol has about 25% less potential energy than straight gasoline. :huh
    #53
  14. bgoodsoil

    bgoodsoil Dare to be Stupid

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    40
    #54
  15. Uncle Pollo

    Uncle Pollo Long timer

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    45/50 r80
    #55
  16. Stagehand

    Stagehand Imperfectionist

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    its 10% here. :sad
    #56
  17. Lornce

    Lornce Lost In Place

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    That's 60mpg imperial on a 2.91 equipped RS. :thumb

    I knew short gears was the only thing holding me back.

    :evil
    #57
  18. Mr. B.

    Mr. B. Climate Controlled

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    I just did a 1700 mile trip on my 1978 R80/7. Based on my sloppy book keeping records I averaged about 47 mpg.
    #58
  19. Gimmeslack

    Gimmeslack furthur

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    G/S usually 2-up.
    Varies according to type of riding I'm doing, but generally around mid-40's. Call it 45mpg.
    #59
  20. Stagehand

    Stagehand Imperfectionist

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    Good god. Do I just ride like an asshole? Sometimes I forget which crowd I'm hanging out with :lol3
    #60