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I have been doing more calculations on the results I posted here. If you want to find out the optimal pressure for lowest rolling resistance then you should try to use slower test speeds. I used 100km/h as thats the figure I am trying to get lower consumption, but it causes problems for measuring RR as the wind has bigger impact to results. If you have little wind at 60 km/h its not so critical to get good results as most energy is used on Rolling resistance anyhow.
48km/h = 5725W
56 km/h = 6612W
64 km/h = 7650W
72 km/h = 8888W
On my ID3 at the moment air resistance becomes higher than rolling is at 70 km/h speed. If you keep test speed under that wind should not play so big role. I recommend that 60 km/h speed for RR measurements.
At 100km/h +10 km/h headwind means 2500W more resistance from wind.
When you have found your optimal pressure for lowest rolling resistance then you need to test which start pressure with cold tire gives you that in real world driving as when tires warm the pressures get 0,1 to 0,2 bar higher in general.
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