Hey Peter, I don't usually come on here, but a friend at Zero referred this to me as they knew I've been doing testing the past year, and while SOC isn't always accurate, at least before the latest firmware, the trip wh/mile is very accurate. But because of the way it calculates, the further you go the more accurate it becomes. As it only divides wh consumed by distance every half mile. So the wh/mile will tick up and up and then take a jump down. However after 40 miles this is unnoticeable.
Although it's pretty challenging to get the same number each time, even on the same route. The more you work on it, the better you will get. But I would suggest doing 10 identical runs and compare the results. However put a piece of electrical tape over the dash so you can't see the result until you get home, so you aren't tempted to adjust anything along the way second guessing that you might have done something different the first half and want to make up for it. Just don't let yourself see it until the test is over. But I would be willing to bet that if you do 10 runs, that your results from highest to lowest are 10% off. And because of that it will be impossible to tell the benefit of the fairing until you can get all your runs to be within 5% of each other. Until those results are repeatable, don't bother changing anything.
I'll give some pointers I've learned. Use the max speed in the ride mode, and then just hold the throttle wide open the whole test until you cross the finish point. Do a highway loop and accelerate to the max speed by turning full throttle from the side of the highway where you start the test after you have reset the trip meter. (if you don't like accelerating fast turn the torque down in the ride mode, but accelerate to max speed the exact same each time and then hold it there until you cross the same finish point and then hit the kill switch while you coast to a stop). Make sure wind is less than 5 knots (use windy.com), even though you will be doing a loop to negate wind. More than 5 knots will make the headwind trip use more energy than you gain with the tail wind and your wh/mile will be higher. Make sure the temperature is within 3 degrees each time you do a test. 5 degrees colder will increase aerodynamic drag 1%. Wear the exact same pants and jacket each time. Tighter clothing will give better wh/mile than looser clothing that flaps more in the wind.
Good luck, I look forward to your results. Someone tag me on facebook or post a link when there is a reply to this. I haven't logged on to EMF in over 4 years I think. Or at least since the narcissist-in-chief was elected in late 2016, I basically just stayed on facebook only, just in case he tried to do something completely nuts to try to destroy our democracy like he eventually ended up doing Jan 6th, and so I just got used to just staying on facebook to keep in touch with real time news which doesn't happen on this forum. Although things are so much better and safer the past few months, maybe it's time to come back here again