Fuel efficiency

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

  1. Mouse

    Mouse I'm only smelly

    Joined:
    Nov 1, 2005
    Oddometer:
    13,652
    Location:
    Byron Bay
    :scratch

    ^ Point?

    Mercs bigger trucks use a mix of gps/predictive shifting and Angel gear to achieve economy targets too.

    Guess the guys manually shifting bypass those benefits though...
    #81
  2. AUSSIEADV

    AUSSIEADV Long timer

    Joined:
    Sep 5, 2006
    Oddometer:
    6,457
    Location:
    Ned and Wild's fight site
    Blank!
    #82
  3. BradventureRider

    BradventureRider Power to rip yer bloody arms off!!!

    Joined:
    May 8, 2015
    Oddometer:
    352
    Location:
    A little bit North West of Toowoomba
    If they want to break the existing record then get a faster truck :lol3
    #83
  4. Warin

    Warin Retired

    Joined:
    Aug 30, 2012
    Oddometer:
    4,828
    Takes time for bike and truck to get up to speed .. so you need a long length of tar (salt = dust = bad lungs for the rider).

    EFI systems have been doing that for decades. No news here.
    #84
  5. abhibeckert

    abhibeckert Long timer

    Joined:
    Feb 15, 2010
    Oddometer:
    1,948
    Location:
    Cairns, Australia
    Those just shut off fuel delivery. The engine is still "running" in that all the moving parts are still moving around.

    The idea is to shut it down and shift into neutral — so the engine stops completely, with a battery or capacitor topped up by regenerative brakes that slow you down as drivers expect when they're not accelerating.

    Then you can use the power collected to accelerate again. It won't get you all the way back to your previous speed, but it should get more than half way there, saving a ton of fuel.
    #85
  6. farqhuar

    farqhuar Human guinea pig

    Joined:
    Mar 3, 2008
    Oddometer:
    2,247
    Location:
    Islands in the sun, Oztralia
    Existing bike speed record is just shy of 270km/h, :eekers achieved 23 years ago. The 130k record (now upped to 144k) was for a rider without a slipstream.
    #86
  7. Warin

    Warin Retired

    Joined:
    Aug 30, 2012
    Oddometer:
    4,828
    So it needs some kind of auto transmission ... or a manual clutch override. And then an electric motor/generator. May as well go all electric drive like the diesel trains.

    No photos .. https://en.wikipedia.org/wiki/List_of_cycling_records#History_of_unpaced_records
    Photo of aero bike https://www.popularmechanics.com/technology/a22946/human-powered-speed-record-aerovelo/
    #87
  8. abhibeckert

    abhibeckert Long timer

    Joined:
    Feb 15, 2010
    Oddometer:
    1,948
    Location:
    Cairns, Australia
    I reckon you could do it with slightly modified manual gearbox, all it'd take is a computer controled clutch and most cars already use that for the accelerator and brake pedals.

    The electric motor is already there for starting the engine. It needs to be bigger if it's going to accelerate the car, but not bigger — they assist the petrol engine rather than replace it entirely. This isn't new technology, nearly all current stop-start systems use the electric motor to get the car moving off the line until the petrol engine starts and takes over. The only change would be to keep the electric motor running alongside the electric motor until the capacitor or battery is drained.

    The real complexity (and cost) is having a regenerative braking system to collect power while slowing the car down. But the fuel saved over the life of a car is probably enough to cover that easily.
    #88
  9. Mouse

    Mouse I'm only smelly

    Joined:
    Nov 1, 2005
    Oddometer:
    13,652
    Location:
    Byron Bay
    Eh? The Merc start stop I've had experience with doesn't use an electric anything to get moving.

    Main diff is it uses electric drive for aircon and power steering so they continue to work even while sitting still. Car might restart and stop again stationary to help out aircon. Push the accelerator, the car starts and off you go.
    #89
  10. BergDonk

    BergDonk Old Enough to Know Better

    Joined:
    Nov 15, 2010
    Oddometer:
    8,273
    Location:
    Snowy Mountains Oz
    Another tangent. Some years ago BMW reckoned that one reason for diesel being more economical was that it had no intake air flow restriction, like a throttle butterfly. Their testing found that full throttle acceleration of a EFI petrol engine to a given speed, then steady throttle, was more efficient than gentle acceleration.

    Has anyone noted that cars have got a lot heavier over the years? A Kingswood was about 1200 kgs, now a Corolla weighs that much. Mind you the last HX Kingswoods were shit, flat out at about 120 and used about 12 mpg doing it, all in the name of emissions.

    Accelerating a mass to a greater speed takes energy, the bigger the mass, the more energy is required, basic physics.
    #90
    GodSilla likes this.
  11. diabolik37

    diabolik37 Deadly Gubba

    Joined:
    Jan 15, 2008
    Oddometer:
    2,035
    Location:
    Down Under QLD
    Maybe is time to rename this thread "Electrical efficiency", but that is going to possibly put Troy and myself out of business...

    Oh well... :muutt
    #91
  12. BergDonk

    BergDonk Old Enough to Know Better

    Joined:
    Nov 15, 2010
    Oddometer:
    8,273
    Location:
    Snowy Mountains Oz
    If you don't like the start stop engine thing, the ones I've tried won't shut down if you don't push too hard on the brakes. Easing off as you come to a stop, as we all should, then just enough pressure to remain stationary, and the engine keeps running, at least on those I've played in.

    #92
  13. farqhuar

    farqhuar Human guinea pig

    Joined:
    Mar 3, 2008
    Oddometer:
    2,247
    Location:
    Islands in the sun, Oztralia
    Wow, this grumpy old bastard sure is full of himself. To me, he sounds like he is straight out of the stone age! :rofl

    My experience of stop/start is quite the opposite - I think it makes a significant improvement to fuel economy in the city. I have been commuting on a Burgman in Melbourne traffic for over 10 years and have experimented with shutting off the ignition at lights (yeah, I know, I'm a tight arse :lol3) and find I can easily reduce my fuel use by around 15% - from 18km/l down to 21km/l.

    Interested to hear of other's experiences?
    #93
  14. Mouse

    Mouse I'm only smelly

    Joined:
    Nov 1, 2005
    Oddometer:
    13,652
    Location:
    Byron Bay
    Hard for me to directly compare. Merc went to start stop plus held a gear longer/lower in the rpm, result was real world economy improvement to about 6L from 9L over a distance of about 80k km with a fair mix of urban and rural driving.

    And that was in a ML, their mid sized 4wd thingy. First version ran the 3L v6, second version the 2.2L sprinter engine, but both pretty much same tune, don't drive sparingly, don't speed but don't slow down either.
    #94