Fuel efficiency

Discussion in 'Australia' started by GodSilla, Jun 6, 2018.

  1. hunter_greyghost

    hunter_greyghost XS650 Allroads Traveller

    Joined:
    Sep 10, 2008
    Oddometer:
    10,928
    Location:
    Yass, Australia
    One of the reasons I sold the Aprilia Pegaso [20k/l], it couldn't compete with the old XS650 on fuel economy
    Both about the same weight [roughly], ridden by the same bloke but returned - Ape = 20k/l / Kenny = 25k/l
    Old school 20k/l=56.25mpg ? 25k/l=70.3mpg ? Had a GT750 triple with sidecar = 35mpg,
    Most of my life I've ridden 650 twins, [the reason = can't handle power !], although I had an 850T Guzzi back in '70's which was a miser @ 25k/l,
    start looking at any fuel economy testing and you'll find some surprising results, Harley Sportsters - Buells - old Guzzis - lots of twins and singles, all are up in the high marks 25k/l +
    As you lot have said;- power over economy, rather have the economy anyday
    BTW - had a '69 Corolla that would turn in 45mpg on highway speeds, and it was no slouch on power [for motor size - 1100cc]
    Did anyone mention water injection, knew a bloke in Tassy who did great stuff along these lines.
    Cheers
    Baza
    #61
  2. abhibeckert

    abhibeckert Long timer

    Joined:
    Feb 15, 2010
    Oddometer:
    1,955
    Location:
    Cairns, Australia
    Turbo lag isn't something we deal with on bikes though.

    I did a quick google search for dyno charts on various VW Golfs. For Diesel I found:

    100hp at around 1,600rpm
    sharp increase to peak of 200hp at around 2,000rpm
    gradual drop off to 100hp at around 4,500rpm
    then after that it falls off a cliff

    For the Petrol Golf R:

    100hp at around 3,000rpm
    nice fast increase to 200hp at around 6,000rpm
    a very gradual increase to 275hp at around 8,000rpm
    slight drop off in power before hitting the rev limiter

    So you've only got around 2,500rpm of "usable" power in the Diesel, while the Petrol one is usable for around 4,500rpm.

    Also, the steep increase in power from 1600 to 2000 rpm on the diesel would be terrible on a bike. You'd want some kind of traction control for sure to manage that, and maybe an automatic gearbox too.
    #62
  3. Mouse

    Mouse I'm only smelly

    Joined:
    Nov 1, 2005
    Oddometer:
    14,626
    Location:
    Byron Bay
    Peaky bikes are fun to ride... Nothing a bit of right hand discipline wouldn't address.

    I repeat that Merc have gone for much longer gearing recently. Someone mentioned something about lugging but clearly merc and Toyota don't see a problem.
    #63
  4. diabolik37

    diabolik37 Deadly Gubba

    Joined:
    Jan 15, 2008
    Oddometer:
    2,338
    Location:
    Down Under QLD
    How on earth you get Mercedes and Toyota on the same page???

    Mercedes has always offered the latest technology and it does win often in Formula One... Toyota just made Aircon standard on most of their model about 10 years ago and electric windows are still classified an accessory...

    They also couldn't compete in Formula One... Guess why... :lol3
    #64
    GodSilla likes this.
  5. poppy

    poppy Slow and Steady

    Joined:
    Mar 8, 2006
    Oddometer:
    3,268
    Location:
    G.C QLD
    Wonder how long it will be before we see cylinder cut out on multi cylinder bikes when cruising and engine cut outs at a standstill as per modern cars.
    #65
  6. gunnabuild1

    gunnabuild1 Long timer

    Joined:
    Sep 13, 2008
    Oddometer:
    3,520
    Location:
    Ipswich Queensland
    Hondas PCX150 already has the cut out at a stand still, I assume other modern scooters may have also.
    Don't have the numbers but was told the cut out was more about emissions than economy.
    Local NRMA guy was telling me the cars using the engine cut out at the lights were his best customers for batteries, claims they eat them.
    #66
  7. Cruz

    Cruz Lost but laughing.

    Joined:
    Nov 3, 2008
    Oddometer:
    9,796
    Location:
    Northside Brisbane, Qld Australia
    The cutout is all about emissions.
    #67
  8. abhibeckert

    abhibeckert Long timer

    Joined:
    Feb 15, 2010
    Oddometer:
    1,955
    Location:
    Cairns, Australia
    And also fuel economy. About 15% in heavy traffic.

    New systems are coming that will shut the engine off whenever you decelerate, combined with a regen braking system that will top up the battery (for your next start) instead of relying on engine compression to slow the car down.
    #68
  9. troy safari carpente

    troy safari carpente #501 Team f5oolery

    Joined:
    Nov 21, 2005
    Oddometer:
    30,309
    Location:
    "Swednavia" - f5ederation of scandwegia
    The Japs did not grease Bernie's palm enough...

    same as any team that has not tasted any level of success in F1 under his jurisdiction... :1drink
    #69
    Farmer Roy likes this.
  10. wairau

    wairau get in behind!

    Joined:
    Mar 29, 2011
    Oddometer:
    3,076
    Location:
    out the back of wainui there
    do you have any links to discussion/editorials on the topic? the tech side of that and motogp intrigue me although i admit i'm ignorant on the politics
    #70
  11. diabolik37

    diabolik37 Deadly Gubba

    Joined:
    Jan 15, 2008
    Oddometer:
    2,338
    Location:
    Down Under QLD
    The main reason for Toyota to exit F1 (as far as their explanation) was that the return based on the cost involved into racing was not as good as the return they got in Rallies....

    But the truth of the fact is that in seven years of racing, they were not able to either produce an engine powerful enough to stay with the rest and to finish within the point in a consistent manner...

    Toyota makes car but the company is cheap. They have always been cheap... The best part of it is that in Europe because of the competition with other brand Toyota sell their car much, much cheaper than in Australia, but for a reason unknown to me, Australian don't mind to pay say $70.000 dollar for a Landcruiser or a bit less for an Hilux...

    Oh... what a feeling :imaposer

    https://en.wikipedia.org/wiki/Toyota_Racing_(Formula_One_team)

    https://en.wikipedia.org/wiki/Toyota_in_motorsport
    #71
  12. Mouse

    Mouse I'm only smelly

    Joined:
    Nov 1, 2005
    Oddometer:
    14,626
    Location:
    Byron Bay
    Don't lose sight of the fact that for a car manufacturer the difference in cost to manufacture a real 4wd v a 2L fwd hatch was about $500 in mid 90s dollars....
    #72
  13. GTinAus

    GTinAus nutsplitter

    Joined:
    Jan 17, 2006
    Oddometer:
    1,428
    Location:
    Uralla
    I think a lot of you are forgetting that a bike does not have a flywheel. The kinetic energy stored in a flywheel, once it has gotten up to speed, will negate a lot of the throttle changes required on a bike to hold the same speed, up hill & down.
    (I once had a fairly catastrophic failure with a hay baler many years ago, and the flywheel broke loose & took off. It went through 3 fences and took out a couple of small trees before it stopped about a half a kilometer away).
    #73
    Cruz and Mouse like this.
  14. tomo8r

    tomo8r Been here awhile

    Joined:
    Oct 9, 2014
    Oddometer:
    401
    Location:
    Bathurst
    Bikes don't have flywheels?
    #74
  15. Big Willy

    Big Willy Gen. Italia

    Joined:
    Nov 28, 2008
    Oddometer:
    4,220
    Location:
    Sunshine Coast
    Not the ones he means...although Guzzis and Beemers do
    #75
    hunter_greyghost likes this.
  16. Ducksbane

    Ducksbane Quaaack!!!

    Joined:
    Dec 27, 2007
    Oddometer:
    1,260
    Location:
    Northern NSW
    For what its worth I have noticed over the years with my cars and bikes that give you a long term number for average speed the bikes seem to be about twice what the cars are. I'm talking 40's and 80's Km/hr. I assume this mostly reflects usage but I imagine that the bikes do higher speeds over rough roads, overtake more easily and get up to speed more quickly. Not sure what it all means, but definitely something I'm seeing.
    #76
  17. Warin

    Warin Retired

    Joined:
    Aug 30, 2012
    Oddometer:
    4,993
    Those are usually done behind a large truck... so the aero does not matter so much.
    #77
  18. tomo8r

    tomo8r Been here awhile

    Joined:
    Oct 9, 2014
    Oddometer:
    401
    Location:
    Bathurst
  19. ktmgeoff

    ktmgeoff Remember it's not a race!

    Joined:
    Jun 16, 2006
    Oddometer:
    1,984
    Location:
    Western Creek Tasmania ( sold the farmand moved)
    Our X3 Beemer has this system, but if you touch the brakes during deceleration the engine braking cuts in again. NB. the engine doesn't "shut off" but idles at about 1000rpm. NB again, this recharge system only operates in eco mode which has to be switched on every time you start the engine, but the shut off works in any mode unless you cancel it every time you start the engine.
    #79
  20. AUSSIEADV

    AUSSIEADV Long timer

    Joined:
    Sep 5, 2006
    Oddometer:
    6,754
    Location:
    Ned and Wild's fight site
    Listen to the likes of the loaded B double going up through the gears. The low revs, the extremely narrow rev range and the number of gears.

    Your typical street car, rev range, number of gears ( let’s keep this as a manual for comparisons sake).

    The modern motorcycle, rev range, number of gears.

    Different applications with different design characteristics requires different cam profiles, bore, stroke etc.

    So they want to rid the world of diesel. Back to that loaded B double with the torque benefits of a diesel. So does this mean we are heading back to the T charged 2 T with modern Tech ie FI, KIPS etc to try and emulate the diesel like torque?

    Combustion engines have a particular area of the rev range that is most efficient. This area size can change (fixed but manufacturered) significantly dependant on what’s required for the application. Keep a peaky cam (or 2T port timing) profiled engine in its narrow range and you have great power with efficiency. Either side of its most desirable range and power and efficiency drops off significantly. A reduction in economy is the result. More in burnt fuel.

    Fuel power shot for acceleration when winding on the throttle, booting the pedal. That’s a lot of fuel. An easy wind of the throttle can reduce/ avoid the power shot altogether.

    Then there is the B double doing it’s consistent speed with the fueling metered by a govenor.

    There are that many variables to consider when comparing the likes of bikes, cars and trucks etc.
    #80
    RussellM likes this.