From: G-S on 14 Feb 2007 04:18
> On 14/2/07 11:58 AM, in article
> bigiain-AE5D94.11581914022007(a)nasal.pacific.net.au, "Iain Chalmers"
> <bigiain(a)mightymedia.com.au> wrote:
>> In article <12t2uqtn9215g7c(a)corp.supernews.com>,
>> G-S <geoff(a)castbus.com.au> wrote:
>>> The 1 kilowatt of lighting on the coach (dual headlights, high power
>>> driving lights, fog lights, running lights and multiple rear lights)
>>> with the fixed fast idle engaged showed as a variation of 10ml a minute
>>> in the flow rate. That is down near sensitivity reading limit of the
>>> meter (which is rated at +/- 5ml per minute) so the real figure could be
>>> as low as 5ml per minute or as high as 15ml per minute variation on the
>>> total fuel usage (which was close to 350ml per minute). But the effect
>>> _was_ real and repeatable and could be triggered by turning the lights
>>> on and off.
>>> Your calculated figure doesn't seem unreasonable to me Ian.
>> Thats within (although admittedly right at the bottom end) of my 0.12L
>> +-40% for 120W figure, and it's pretty close to the figure the little
>> Honda genset gets at full load.
>> Taking both your stated major errors into account (+-50%) and mine
>> (+-40%), I'd say we're completely in agreement with each other...
> Sorry to ruin the party boys....
Don't worry you aren't :)
> I don't know of too many machines that "idle" every where.
I said 'fast idle' not idle. That term is used in the industry to
indicate a fixed rev situation above idle.
On the contrary I know of many engine combinations that run at
effectively fixed revolutions and then use that to run an electric
motor. I rode on such a train last week.
CVT transmission cars approach this constant revs (as an ideal) also.
Auto scooters are another example.
> Also, we were talking about headlights.
Not _just_ headlights.
From: Knobdoodle on 14 Feb 2007 04:19
"sharkey" <sharkey(a)zoic.org> wrote in message
> Knobdoodle <knobdoodle(a)hotmail.com> wrote:
>> IF you already have the action of the injector (and fuel pressure etc)
>> benchmarked so that the amplitude and duration that you measure with the
>> oscilloscope actually means something.
>> Other wise all you're measuring is "bigger/smaller" or "longer/shorter"
>> which, as you point out, can give you relative info but not actual "fuel
> Oh, yeah, but isn't this thread about using more fuel when you've got P
> plates on or something? I don't remember.
Yeah; my mistake!
It occurred to me at 6pm today as I was riding home that you're not using
the CRO to actually MEASURE fuel-flow; just to see a change.
I'm so used to ignoring all the Hamsturbation that I'm missing the rare
From: G-S on 14 Feb 2007 04:21
> On 14/2/07 1:18 PM, in article
> bigiain-DB0328.13183714022007(a)nasal.pacific.net.au, "Iain Chalmers"
> <bigiain(a)mightymedia.com.au> wrote:
>> In article <C1F8B385.26876%hbaj2006(a)aapt.net.au>,
>> Hammo <hbaj2006(a)aapt.net.au> wrote:
>>> Sorry to ruin the party boys....
>>> I don't know of too many machines that "idle" every where.
>> Look again Hammo, I don't even mention engine speed anywhere in my
>> calculations, just energy used over time - I don't care if you idle your
>> car for an hour or if you run it at redline in top gear up a hill for an
>> hour, the headlights will use an extra ~0.12L either way...
> No. Thanks for trying to bluff that one. Remember the discussion re:
> GS mentioned speed as a way to suggest that the figures were in agreeance.
> Perhaps you missed that?
I most definitely did not. I mentioned 'engine revolutions' and 'fixed
idle' but only as an aside and only to eliminate the issue of engine
revs varying being another effect not needing to be accounted for.
From: Hamish Alker-Jones on 14 Feb 2007 04:26
On 14/2/07 2:29 PM, in article slrnet50gs.33n.sharkey(a)anchovy.zoic.org,
"sharkey" <sharkey(a)zoic.org> wrote:
> G-S <geoff(a)castbus.com.au> wrote:
>> The 1 kilowatt of lighting on the coach (dual headlights, high power
>> driving lights, fog lights, running lights and multiple rear lights)
>> with the fixed fast idle engaged showed as a variation of 10ml a minute
>> in the flow rate.
> Nice one, centurion.
Actually, it is. So 1 kW = 1000 W
As BigIain reckons no further reductions/considerations of inefficiencies
need to be considered and there is already "fluctuation" in the measurement.
GS said what 50% based on his numbers. BigI said there was 35% difference
at peak efficiency.
A car with 120 W lights would use 120/1000 * 10 * 60 = mL / Hr
But the mean value being 7.5 mL min-1.
So it gets even smaller....and it is at idle with a an expected increase in
efficiency as stated by Big. So the 50 % is infact bigger than 50
percent!!(not yet taking into the 35 % error due to the efficiency when
running at peak, i.e. When most cars that actually travel somewhere do!).
Now the above is based on a "coach" and would not be hoping to get anywhere
near the fuel consumption rate of something like Nev's machine (or my little
What percentage of total fuel is being "claimed" here? We are talking about
From: Knobdoodle on 14 Feb 2007 04:26
"Toosmoky" <toosmoky(a)hotmail.com> wrote:
> sharkey wrote:
>> Also the air is slightly cooler (on average) at night, so engine is
>> more efficient.
> It's also more dense, thus increasing drag.
He heh; I'm sure the water-content in the air is higher too which would also
increase both of the above.
(and the air-con isn't on and the windows are up and the tyres are cooler
and the brake-parts have contracted further away from eachother and the
thermatic fan isn't running and you're calmer and less aggressive in your
lane-changing and accelerating and...and... your imagination is more