Yes I do understand basic aero stuff, bikes water & viscosity etc.
I'm trying to quantify effect vs velocity, I did look at that chart and the numbers seem to indicate a more significant effect than what I thought.
Just going by seat of pants accelerator position and coast downs at various speed, my personal experience does not seem to corrolate the same, when I pull the foot off the throttle to coast, deceleration seems to decrease at an exponential rate, once down to about 40mph it's like the only thing that slows her down is an incline, otherwise she just keeps rolling.
The thread below probably posed the question better:
http://ecomodder.com/forum/showthrea...ant-24813.html
Indications are that Cd does change with speed, i.e it should improve with speed, still counter to my perceptions, so am still trying to work through it and also wondering how the different types of aero drag interact at lower speeds.
Another thing I just thought of is BSFC maps and drivetrain mating to stock vehicle, the drivetrain is optimised for typically expected use patterns, so they are generally tuned for moderate to high speeds, therefore if you tend to use vehicle at low load only, it will be running less efficiently and hence any aero benefits at lower speeds may well be negated by reduced drivetrain efficiency, so unless vehicle intake and exhaust are tuned down for a lower rpm range there may be no improvement at the pump.