Making the Ioniq slippier

[Drifter]

Originally Posted by aerohead

As to 'CITY' driving, see if the pure electric Hyundai's use a lower rolling resistance tire. I know GM does this.

Some manufacturers make EV-specific tires of existing LRR models. These are built to withstand the higher weight & torque of the EV and often prioritize lower road noise (which is more noticable in an EV).

As a result they're much heavier, a bit harsher, and can roll worse than standard LRR tires on lighter cars.

[Phase]

Originally Posted by Drifter

Using the coefficients that matched the MPG vs speed from clean mpg I come up with:



MPH Est MPG stock Est MPG -0.05Cd
5 31.83 31.85
10 55.6 55.78
15 72.47 73.16
20 83.12 84.75
25 88.37 91.28
30 89.28 93.62
35 87.03 92.74
40 82.73 89.59
41 81.71 88.76
42 80.65 87.88
43 79.56 86.95
44 78.44 85.99
45 77.3 84.99
46 76.14 83.96
47 74.97 82.9
48 73.78 81.82
49 72.59 80.72
50 71.4 79.61
51 70.2 78.49
52 69.01 77.35
53 67.82 76.21
54 66.64 75.07
55 65.46 73.93
56 64.3 72.78
57 63.15 71.64
58 62.01 70.51
59 60.88 69.38
60 59.77 68.26
61 58.67 67.15
62 57.6 66.05
63 56.53 64.96
64 55.49 63.88
65 54.46 62.81
70 49.6 57.7
75 45.19 52.97
80 41.23 48.65
85 37.68 44.72
90 34.51 41.16
95 31.67 37.94
100 29.14 35.04
105 26.87 32.42
110 24.84 30.06
115 23.01 27.92
120 21.36 25.98
125 19.88 24.23
130 18.54 22.64
135 17.32 21.19
140 16.21 19.86
145 15.21 18.65
150 14.29 17.55
155 13.45 16.53
160 12.68 15.6
165 11.97 14.74
170 11.31 13.95
175 10.71 13.22
180 10.16 12.54
185 9.64 11.92
190 9.17 11.33
195 8.72 10.79
200 8.31 10.29

https://ecomodder.com/forum/tool-aero-rolling-resistance.php?Weight=3200&WeightUnits=lbs&CRR=.00 7&Cd=.25&FrontalArea=25&FrontalAreaUnits=ft^2&Fuel Wh=33557&IceEfficiency=.36&DrivetrainEfficiency=.9 1&ParasiticOverhead=1500&rho=1.225&FromToStep=40-65-1

thanks for that. surprisingly in the real world with warmer temps, i get about 42-43mpg at 90 miles per hour. even this winter, cruise control in idaho going 90 mph and 18 degrees outside near twin falls at 5 am with a slight head wind hurting me, my car was averaging 37 mpg versus the 34 on that chart

[Phase]

Cut out ABS sheets abd sanded edges to fit where the old housing went. Got weather stripping too that’ll be the next install step

Will drill one hole in them to connect a mirror. So far it’s looking like gorilla gluing my blind spot mini mirror onto an eyebolt screw sticking out

[Phase]

Can anyone explain this area? Why not put a hard separation edge? Seems like airflow would go into the wake and wrap behind the car. Girlfriends new Corolla also has the same type of thing. Would there be a benefit of putting a hard edge here? There’s got to be an explanation for the smooth curve allowing air to go back

[aerohead]

Originally Posted by Phase

Can anyone explain this area? Why not put a hard separation edge? Seems like airflow would go into the wake and wrap behind the car. Girlfriends new Corolla also has the same type of thing. Would there be a benefit of putting a hard edge here? There’s got to be an explanation for the smooth curve allowing air to go back

Might just be a concession to styling. If Luc Donckerwolke, or whoever did the design for the IONIQ was more focused on drag reduction, they would have done what Mercedes-Benz is doing with their concepts.
Cd 0.24, for an ICE-EV hybrid isn't too shabby if you consider what it could be as a pure BEV. You're probably ahead of most TESLAs if you think about it.

[Phase]

Originally Posted by aerohead

Might just be a concession to styling. If Luc Donckerwolke, or whoever did the design for the IONIQ was more focused on drag reduction, they would have done what Mercedes-Benz is doing with their concepts.
Cd 0.24, for an ICE-EV hybrid isn't too shabby if you consider what it could be as a pure BEV. You're probably ahead of most TESLAs if you think about it.

So should I add a light strip there for a harder separation edge?

[aerohead]

Technically, yes. You'd be approaching the simple K-form truncation M-B has been flirting with.
Be mindful of the taillight, stoplight, turn-signal, backup-light visibility of other motorists near the car. You don't want to accidentally obscure any visual information the IONIQ is giving the public.
And watch for back-soiling of the taillight lenses. That gap between the burst edges may have allowed side-wash to spill in, helping to purge jetsam in the wake area from the plastic.
I used clear Plex on SPIRIT.

[Phase]

Originally Posted by aerohead

Technically, yes. You'd be approaching the simple K-form truncation M-B has been flirting with.
Be mindful of the taillight, stoplight, turn-signal, backup-light visibility of other motorists near the car. You don't want to accidentally obscure any visual information the IONIQ is giving the public.
And watch for back-soiling of the taillight lenses. That gap between the burst edges may have allowed side-wash to spill in, helping to purge jetsam in the wake area from the plastic.
I used clear Plex on SPIRIT.

The back area gets completely dirty anyways. Even with a little airflow going back into it. If I go to a ski resort, I have to get a car wash afterwards because the back is completely covered with road grime and dirt or salt

[Phase]

I’m assuming I’ll have to add a harder separation edge flare after the wheel spats are put on? The lower part is rounded. Wonder why they did that too…

[aerohead]

Originally Posted by Phase

I’m assuming I’ll have to add a harder separation edge flare after the wheel spats are put on? The lower part is rounded. Wonder why they did that too…

When you do the rear skirts, the rear bottoms should be spaced out enough to allow for full-depth clearance to the wheels.
If you add a short tail, it will integrate directly to the trailing edge of the new skirts.
If you do a short box cavity, it's trailing edge will have to address a phantom aerodynamic integration to the back of the skirts.