BMW i3 - Low Hanging Fruit (improving aerodynamics)

[Snax]

I recently watched a video where it was mentioned that the cd for the i3 is rather high at 0.30. Looking for some low hanging fruit to improve upon that.

Obviously the mirrors are an easy target. One owner has already done a delete and camera retrofit to that end and it is probably going to be my first step.

I may go so far as to put fairings over the rear wheel openings as well.

That said, a boat tail per-se is out. The car already looks funky enough as it is.

Got any other suggestions likely to produce a measurable result?

https://www.youtube.com/watch?v=UvZrizh4Q4E

[redpoint5]

Sounds like you've already done your homework and decided what you're willing to mod. I'd simply drive slower if the ability to make a trip were in question. If the ability to make a trip is often in question, I'd get an EV with more range.

How does the undercarriage look?

[NeilBlanchard]

Frontal area is totally independent from the Cd, and vise versa. Cd is the overall shape, and that can be scaled up or down in size, and the Cd would remain the same.

[Snax]

Originally Posted by NeilBlanchard

Frontal area is totally independent from the Cd, and vise versa. Cd is the overall shape, and that can be scaled up or down in size, and the Cd would remain the same.

Good catch. Edited my OP.

[Snax]

Originally Posted by redpoint5

Sounds like you've already done your homework and decided what you're willing to mod. I'd simply drive slower if the ability to make a trip were in question. If the ability to make a trip is often in question, I'd get an EV with more range.

How does the undercarriage look?

It's not horrible. The front subframe area seems like the opportunity for greatest improvement however.

https://www.bmwblog.com/2014/11/11/l...i3-underneath/

[California98Civic]

Can it be lowered? Doing so, even one inch, will somewhat lower your effective frontal area and thus your CdA, total drag area (the mirror delete does that too). But the rear wheel cover is your lowest hanging fruit, I would bet.

[Snax]

I have installed springs that drop the front 1" and rear 0.8", giving a touch more rake as well. I am currently examining possibilities for going lower, but that is already pretty limiting on travel and ride quality already. Thinking about the potential to make that dynamic however with air suspension.

[redpoint5]

My money would be on mirror delete, but what do I know. Rear wheel covers could be it.

[Tahoe_Hybrid]

Originally Posted by Snax

I recently watched a video where it was mentioned that the cD for the i3 is rather high at 0.32 if I recall correctly. Looking for some low hanging fruit to improve upon that.

Obviously the mirrors are an easy target. One owner has already done a delete and camera retrofit to that end and it is probably going to be my first step.

I may go so far as to put fairings over the rear wheel openings as well.

That said, a boat tail per se is out. The car already looks funky enough as it is.

Got any other suggestions likely to produce a measurable result?
]

aero civic front end swap

[Snax]

Originally Posted by Tahoe_Hybrid

aero civic front end swap

Ha ha, yeah . . no . .

I was just looking under the rear area ahead of the bumper, and it looks like they did wrap everything up like a diffuser, but it lacks side dams. I might try hot gluing something on down there to test out as that seems like one of those things they would likely have compromised out of the design for durability considerations.

All else on the car is otherwise so clean that substantial gains seem most likely to be with either my driving or the boat-tail I am so against.

Anyway, unless people have other suggestions, I will probably stick to this thread for whatever mods and testing I do.