[Phase]

Originally Posted by aerohead

I've explained many times about cross-sectional area, and how it can be morphed back-and-forth, just like Jaray did, and just like every ASHRAE HVAC design engineer does, going from round-to-square-to-oval.................. it doesn't matter as long as the overall sectional area does not vary any more than the original semicircular section of a streamline half-body, from station to station.
On the IONIQ, the process would be purely additive. Nothing would ever be removed from the existing body, only added.
A full boat tail would add 84-inches.
Hyundai 'removed' it in the IONIQ specification. We'd just be restoring it. As Lay's Model# 22. As Carl Breer's DeSoto Airflow aero mule ( long-tail ) As Kamm/Fachsenfeld's ( long-tail ) research models. As Buchheim et al. VW Flow-Body (long-tail ). As Mercedes-Benz C-111 III ( long-tail )
As NASA shoebox ( long-tail ). As Porsche's 908 ( long-tail ). As GM's EV1 LSR ( long-tail ). As GM's Aero 2002 ( long-tail ). As Robert Cumberford's Cd 0.16 ( long-tail. As GM's Oldsmobile AEROTECH ( long-tail ).
Phase may elect to lower his mpg expectations.
I'm indifferent as to the outcome.
But if 60-mpg @ 80-mph is the target, the aft-body of the IONIQ 'MUST' look something like CUER. None of the other vehicles which share a Cd like this are as efficient in their use of materials.
If the length is an issue, then you just ( Kamm/ Fachsenfeld ) truncate it, at whatever length you desire, and live with the drag increase.

the 60mpg at 80 is just a dream goal. even if its 57-58mpg at that speed, i wouldn't complain too much. I'm just trying to make my car more aerodynamic without making it ugly as junk.