[aerohead]

eletrek.com has an article about Tesla's Model 3 Aero Wheels,which includes a link to a road test conducted by nextmove,car rental in Germany.
Three cars were rented and driven over a 94-Km circuit,with different hubcap configurations,at 150 km/h (93.205 mph).
The hubcaps improved range from 312 Km (193.867 miles),to 320 Km (198.838 miles),a 2.564% increase.
Following the velocity-cubed law,at 136.8 km/h (85 mph),(Most allowed in the USA) the advantage would be 1.944%.
At 104.6 km/h (65 mph [where cars may hit their EPA HWY rating]) the benefit would be 0.869%.
At the old 'double-nickel' 55-mph national speed limit,we'd see 0.526%,perhaps a rational for not obsessing over 'rotating wheels' by automakers for at least 20-years.