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Thread: F800 vs F650GS performance

  1. #1
    BrucePaul
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    F800 vs F650GS performance

    We just got back from a 4400 mile Western US tour, both bikes performed flawlessly. The gas tank on the 800 seemed to be 20% smaller than the 650. Odd? yes, only because the 650 got 20 to 25% better gas mileage than the 800. Every time we filled up the difference showed up. 800 running premium and the 650 regular. De- tuned 650 ? I sure would not re-tune it. Something must be wrong.
    Colorado, Wy, UT, ID,MT, ID, WA,OR, CA, NV,AZ, UT and back to CO, Great trip 25 days.
    If it is not broken, don't fix it

  2. #2
    172526
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    Quote Originally Posted by BrucePaul View Post
    We just got back from a 4400 mile Western US tour, both bikes performed flawlessly. The gas tank on the 800 seemed to be 20% smaller than the 650. Odd? yes, only because the 650 got 20 to 25% better gas mileage than the 800. Every time we filled up the difference showed up. 800 running premium and the 650 regular. De- tuned 650 ? I sure would not re-tune it. Something must be wrong.
    Colorado, Wy, UT, ID,MT, ID, WA,OR, CA, NV,AZ, UT and back to CO, Great trip 25 days.
    That seems pretty much normal. We travel with the same pair of bikes and the 650 always uses 10-15% less fuel than the 800. I run premium in both bikes.

    One reason is that the 650 is geared higher and the other is that I usually have the most weight packed on mine. Also I am probably harder on the throttle that my wife, so she gets better mileage, her chain will last longer, her brakes will last longer.....but we always arrive at our destination at the same time,

  3. #3
    wanderer
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    The 800GS has a hotter cam with a lot more overlap. This adds HP at high RPM but cause some amount of up burnt fuel to exhaust at lower RPM. To meet emission the 800gs has air injection so the unburnt fuel is burnt in the catalyst. All this means a fair amount of less fuel efficiency.

    This one of the reason why the 800 is geared to turn more RPM/mile...so it runs at higher RPM where there is less unburnt fuel exhausted....also that is where it puts out more power...ie above 5000 rpm.. over the F650GS.

    It has always been a puzzle to me why BMW would make their most dirt oriented bike the F800 the most peaky in HP and their road oriented bike the F650GS stronger at lower RPM. How much time does the average rider run his F800 above 5000prm in the dirt???

    Must be the same marketing guys who decided it was smart to name the road version the F650 or F700 vs what it is a 800.
    Have to hand it to the Bavarian Brain Trust???

  4. #4
    Registered User Rod Sheridan's Avatar
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    I have an F700GS and Diann has an F650GS.

    Her bike uses less fuel than mine also............Rod.
    Work is the curse of the riding class

  5. #5
    BrucePaul
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    Cool F650 - f700

    Quote Originally Posted by Rod Sheridan View Post
    I have an F700GS and Diann has an F650GS.

    Her bike uses less fuel than mine also............Rod.
    Strange, I thought the two were the same (except for minor things) & the reason they changed the name was to avoid more confusion.
    at any rate, I love the way it rides. Thanks for your input. Bruce
    If it is not broken, don't fix it

  6. #6
    Small road corner junkie pffog's Avatar
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    Quote Originally Posted by BrucePaul View Post
    Strange, I thought the two were the same (except for minor things) & the reason they changed the name was to avoid more confusion.
    at any rate, I love the way it rides. Thanks for your input. Bruce
    My guess on that is maybe a little more spirited acceleration, and larger frontal area contributing to wind drag.

    Couple weeks ago was riding with the wife in PA, I was riding spirited in the fun stuff, and conservative in the straights waiting for her to catch up. Got 67 mpg on the F800GS, her F650GS (the single) only used .2 gal more at fill up 2.7 gal for me 2.5 for her in 182 miles.
    2010 F800GS Full Ohlins package, '04 R1100S Replika
    '01 F650GS Wife's bike
    Maritime Alps and Vosges 2012
    Tuscany and Central Italy 2010

  7. #7
    BrucePaul
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    Quote Originally Posted by BOBZELIFF View Post
    The 800GS has a hotter cam with a lot more overlap. This adds HP at high RPM but cause some amount of up burnt fuel to exhaust at lower RPM. To meet emission the 800gs has air injection so the unburnt fuel is burnt in the catalyst. All this means a fair amount of less fuel efficiency.

    This one of the reason why the 800 is geared to turn more RPM/mile...so it runs at higher RPM where there is less unburnt fuel exhausted....also that is where it puts out more power...ie above 5000 rpm.. over the F650GS.

    It has always been a puzzle to me why BMW would make their most dirt oriented bike the F800 the most peaky in HP and their road oriented bike the F650GS stronger at lower RPM. How much time does the average rider run his F800 above 5000prm in the dirt???

    Must be the same marketing guys who decided it was smart to name the road version the F650 or F700 vs what it is a 800.
    Have to hand it to the Bavarian Brain Trust???
    Exactly.. does not make sense
    If it is not broken, don't fix it

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