[aerohead]

1) The IONIQ was 'facelifted' for the 2020 model year.
2) MOTOR TREND tested the 'Limited' version, reported, page 18, October edition, by Nick Yekikian.
3) Los Angeles, CA, to Las Vegas, Nevada, @ 80-mph in 'calm' conditions outbound.
4) 41-mpg.
5) Return leg, into a headwind @ 80-mph.
6) 38-mpg.
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7) The mechanicals are identical to the 1st-gen.
8) Cd 0.24.
9) Frontal area ( Af ) approx. 24.223-sq-ft.
10) Length- 4470mm ( 176.0-inches ).
11) Length/ sq-root of Af = approx. 2.97999
12) Active grille shutters.
13) 15" Hybrid Blue Aero ( Eco-spoke ) alloy wheels
14) 195/65 R 15 tires
15 'Aero' wiper blades available from SEL version.
16) EPA test weight 3296- LBS.
17) No mention of climate control use.
18) No mention of following distance.
19) The dual-clutch automatic 6-speed transmission might not be able to maintain the engine as close to its best BSFC as a CVT.
20) With some working assumptions, and 4-pages of calculations, the headwind would have been approx. 4.8-mph.
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21) Use of the 'Instantaneous Fuel Economy' readout might be problematic.
22) Use of the 'AVE MPG' readout might help smooth the 'spikes.'
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23) It would be helpful if you'd select a target travel speed and capture an OEM mpg reading at that speed.
24) Then tell us what mpg you'd like to experience at that same speed.
25) From there, we can reverse-engineer the required Cd, if it's within bounds of attainable coefficients.
26) And from the archive of published Cds of that value, investigate other vehicles which have that Cd.
27) From those we can examine design features which culminated in that Cd.
28) It's all about shape!
29) A four-view image of the 1st-gen IONIQ is available @ the blueprints.com. I analyzed the car years ago.