Quote:
Originally Posted by kingsway
Could it be as simple as using a Scanguage/Ultraguage and going up the hill using various speeds and gears and identifying a sweet-spot that is a good compromise of rate of consumption and time elapsed?
|
If you have scan gauge, that should be able to tell it, also consumption over distance would work.
But if no Scan gauge, one have to figure it out with math or something.
Now I did read somewhere here that it is same amount of power needed to climb despite which gear you have selected.
That is not entirely so, it is true at the wheels, but lower gear has lower gear ratio and because of that engine needs to produce less power to achieve same amount of power at driven wheels.
Think about driving up a hill with bicycle on top gear, you need more power to overcome ratio. Or think about lifting something heavy, with 2:1 ratio you can lift more than with 1:1 ratio.
Then one must apply distance/time to that too also fuel used per power unit and amount of power used so one can calculate how much power is used for each second or each distance unit, then difference between gears and time and it should come clear when to use which tactic.
I think it should be possible to make a calculator that calculates it all, but it would need gear ratios and BSFC map to work. Lot of other parameters too, but it should not be impossible.
edit: Ah, it might be possible to get around of BSFC map issue, perhaps bit inacurate, but still, one just would need to estimate a bit.
Turbo diesel motor can be up to 40% effective, at part load that will drop, but not as much as with gasoline engine, I haven't found part throttle efficiency yet, but my guess is somewhere around 30%?
Gasoline engine was 26% and under 20 at part throttle?
One can use efficiency estimate to multiply consumption, it should give pointers to right direction then.