Ioniq 6 cd of .21!

[aerohead]

Looks very familiar.
'Free-range kilowatt-hours'

[aerohead]

https://www.motorbiscuit.com/hyundai...ure-explained/

[freebeard]

Nice retrospective. Although, the 1986 Olds Aerotech is a stretch.

I'm putting the 2022 Tatra 77 Homage concept in the Interesting Aerodynamic Cars thread.

[aerohead]

' would have been nice for us if it was actually a self-powered, producible concept, that they'd road tested and run the numbers on.
The more comfortable consumers become with these uninterrupted 'single-bow' rooflines, the better.

[aerohead]

The latest issue of MOTOR TREND includes a brief road test of the car in South Korea.
Length-191.1" ( 4853.94mm )
Width- 74.0" ( 1879.6mm )
Height- 58.0" ( 1496.06mm )
Cd 0.21 ( compared to the Cd 0.29 IONIQ-5 )
Estimated Af 26.03- sq-ft ( 2.41826 meters-sq )
Est. CdA 5.4663-sq-ft ( 0.50783- meters-sq ) [ @ 86% of gross area )
The author believes that the aero will add 15-20% range, compared to the IONIQ-5.
@ 77.4 kWh, that's 2.29639-gallons-e
EPA COMBINED 130.639- mpg
Range about 273-miles @ 100% SOC.
I estimated a L/sq-rt of Af @ 3.121349
At this est. fineness-ratio, the Hyundai's body is more efficient than:
2006 Chevy Cobalt ECOTEC LSR
2020 LUCID AIR work-in-progress
2021 Tesla Model S Plaid
1989 Renault Megane concept
2007 Ford Fusion 999 LSR
1935 FKFS 5-PC K-form model ( lange-heck )
2014/2017 SPIRIT of Ecomodder.com ( w/ unibody/Viper windshield, grilleblock/ SCCA racing mirrors/ restored belly pan )
The 1984 Citroen ECO 2000 concept data remains unavailable to us.

[Cd]

Thanks for the cD figures. I just came across a test of this car and hung on to find out the cD.
After a moment or two of looking at the design from different angles, I just said to myself that this one was just another Nissan Leaf type design - stubby and no more aero than what we had nearly 30 years ago.
Thanks for proving me wrong ! .21 is pretty decent !

[Cd]

Originally Posted by aerohead

https://www.motorbiscuit.com/hyundai...ure-explained/

I notice they had to stretch it to fit the roofline of the Benz, which is closer to the template.

This is yet another car that puzzles me. It has too "fast" of a drop in the rear glass, yet gets a .21 cD.
I would have thrown up my hands and given up on the idea of templates and boat-tails, except for the fact that the Mercedes Concept IAA dropped it's cD lowest with the addition of a short tail section.

So, Aerohead - if this design had just left off that shelf spoiler, and instead followed the template curve, would the cD have been lower ?

[aerohead]

Originally Posted by Cd

I notice they had to stretch it to fit the roofline of the Benz, which is closer to the template.

This is yet another car that puzzles me. It has too "fast" of a drop in the rear glass, yet gets a .21 cD.
I would have thrown up my hands and given up on the idea of templates and boat-tails, except for the fact that the Mercedes Concept IAA dropped it's cD lowest with the addition of a short tail section.

So, Aerohead - if this design had just left off that shelf spoiler, and instead followed the template curve, would the cD have been lower ?

I believe so.
The Ioniq 6 ( pseudo-Jaray ), @ a fineness ratio of approx. 3.121349, and Cd 0.21 IS more efficient than some other Cd 0.21 cars.
However, if you consider the M-B Bionic Boxfish ( kammback ), which is 12.7% more 'bluff' yet Cd 0.19, or the Coventry University-modified Audi A2 ( kammback ) , which is 16.9% more bluff, and Cd 0.204, then the Ioniq doesn't shine so bright.
If you agree that the Ioniq 6 shares DNA with the 1968 PORSCHE 911 ( pseudo-Jaray / pseudo- Lange-car ), and the 911 had serious lift and drag issues, and the proper solution was a 'kammback', then it's not a reach of the imagination that a 'kammback' on the Hyundai would have improved things.
Since 1974, I've seen no evidence that a 'shape' exists, which can out-perform the 1930s 'kammback.'

[aerohead]

While a video at carscoops purports to explain all the aero tricks used on the Ioniq-6, it failed to do so.
---------------------------------------------------------------------------------------
PS:
As to the shape that's never been seen before, I'd recommend a look at the 2011, Mercedes-Benz F125 concept's roofline.

[aerohead]

I GOOGLED 'Ioniq 6 in wind tunnel, and this video came up.
This is all in Korean, with English sub-titles, by the CFD and wind tunnel folks who did the grunt work on the car.
All the tricks are discussed, however, no 'quanta' are provided.
https://insideevs.com/news/621207/hy...ic-efficiency/