Making the Ioniq slippier
 

I want to make more hyundai ioniq more aerodynamic for better fuel economy on the highway while still driving fast. I don't want to remove the side mirrors, and lowering it is way too expensive.

Any advice on under trays, rear spoilers, and so on? How can i make an already low drag car have even less drag?

I would begin with these.

How to Do Good On-Road Aero Testing

Five Ways to Reduce Your Car's Aerodynamic Drag

Starting with a low-drag car like the Ioniq, you'll have a harder time improving it. But it is possible. Just remember to test not guess. (And I'll put in a plug here for my own website, Amateur Aerodynamics. You might find articles like this one useful).

Yeah I’ve watched every single one of his videos. That’s where I’ve gotten the idea about the rear spoilers, both trunk and under rear, along with better under body smoothing. I’ve seen some companies mod splitters and side skirts on the Ioniq, it looks cool and the claimed it helped with speed records or mpg, but then Julian’s channel is always saying those don’t work and are gimmicks

Spats front and rear on all four corners? Manufacturers seem to make their cars semi-offroadable.

If you can't lower it, maybe lift the rear [for a good angle of attack].

My understanding is the Ioniq is very streamlined from the factory, but I'm curious to see what you end up with. Is yours hybrid or plug-in?

Just the basic hybrid. The hubcaps are probably more aero than even a model 3. I get great mpg at low highway speed and city driving but fast interstate driving it tanks

The easiest way to determine your car’s potential for mpg improvement via aeromods is to find out how much your mileage improves when drafting. A removable Reese hitch mounted boat tail would the single biggest potential mpg improver (and can also be used for additional cargo storage space). Beyond that, wheel well covers, double side skirts in combination with wheel spats in front of each wheel and a mini-boat tail behind the back wheel. Since your car starts out with pretty good aerodynamics (0.24 Cd), check your grill opening size, airflow pattern through the engine compartment, and existing underpanelling for potential improvements over the OEM equipment.

I have the same problem with my 0.28 Cd Camry hybrid, great mileage below 60 mph, but big drops in 70+ mph interstate driving. I’m retired, so I don’t do much interstate driving, but if I still had a long interstate commute, I would be adding these mods to my Camry.

Can you send some photos of examples of a few of those things? And the front grill on the Ioniq opens and closes depending on how much cooling it needs, so a grill block isn’t necessary for the most part. In the winter, it stayed shut the whole time

Post some photos?

ecomodder.com: Aerocivic - how to drop your Cd from 0.31 to 0.17

Comments. no pix:

ecomodder.com: Comments from other sites about basjoos' Aerocivic

Some INONIQ quanta
 

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.