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Many vehicles have a computerized system that displays the ratio between fuel consumption and distance traveled.
This is somewhat useful - as far as it goes - but doesn't take into account a number of factors that influence the resultant value; the terrain over which the vehicle is driven, the driving
style, and the amount of other traffic - more applicable to an urban setting.
What the user really wants to know is how much "value" they are getting from their fuel - is the engine operating efficiently ?
Since modern vehicles are extensively instrumented, it seems reasonable to use the data to provide a better metric. Distance traveled becomes irrelevant; what matters is how much energy (in MJ) was extracted from a given amount of fuel.
The torque delivered to the wheels can be measured, as can engine revs, and vehicle speed. These data, suitably integrated, reveal how much energy has been used by the vehicle.
The amount of fuel consumed to deliver that energy can also be measured (within normal error bounds).
Thus, the system knows what the fuel usage was to deliver a known amount of energy as usable propulsion. Even an engine simply left idling will give a figure for "fuel consumed to maintain nil usable energy output".
|| What the user really wants to know is how much
value they are getting from their fuel ... Distance
traveled becomes irrelevant
7, Oct 25 2020
||Distance traveled is the value received from fuel
spent. You can instrument it as much as you
like (and whatrock can obsesses about correcting
systemic errors) - but the only calculation you
need is how far did you go for a given amount of
||If the output of idling was completely unusable no one would idle. Idling provides safety and efficiency improvements when stopping in traffic or at stop signs. It provides energy for heat, air conditioning, headlights, and other uses of power. It promotes rapid egress when performing aggressive unscheduled bank withdrawals. I'm sure it has other uses as well. Of course none of that involves moving the car, but cars are expected to do all kinds of things these days.
||If the output of idling was completely unusable no
one would idle.
-Voice, Oct 25 2020
||Many hybrids do not idle. My cars engine shuts off
second of stopping at a light, and restarts instantly
when I put my foot back on the gas pedal. Never a
problem with heat, a/c, lights, etc...
||And for pure EVs, idling is a non-issue completely.
A non-starter. An idle concern. Next?