Obsessed with aero dynamics

I am sure there will be people trying this out in practice. A few years down the road at least.

I much prefer the 20 mile loss in range...

Why not make the Model S a bubble car? Oh yeah...that hasn't worked so well in the past, has it?

I think the science behind reducing the Cd is pretty easy. The hard part is making it aerodynamic without making it fugly, that is an art.

The aerodynamic wheels are a brilliant move, because they are a part of the car with significant impact on the aerodynamics, and are trivially swapped so the consumer can choose.

I want to know the impact of the side mirrors, I hate the archaic rule requiring real mirrors instead of cameras. I would love to mod my car and put cameras in place of the mirrors ( reversibly so I could put the mirrors back with no harm done )

richkae said:

I want to know the impact of the side mirrors, I hate the archaic rule requiring real mirrors instead of cameras. I would love to mod my car and put cameras in place of the mirrors ( reversibly so I could put the mirrors back with no harm done )

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Yes, I think this thought is shared by many. Also, regulations for mirror size/shape is different for Europe vs North America.
To save costs (and have only one mirror design) some manufacturers chose to make one larger side-view mirror design that satisfies both requirement.

richkae said:

I think the science behind reducing the Cd is pretty easy. The hard part is making it aerodynamic without making it fugly, that is an art.

The aerodynamic wheels are a brilliant move, because they are a part of the car with significant impact on the aerodynamics, and are trivially swapped so the consumer can choose.

I want to know the impact of the side mirrors, I hate the archaic rule requiring real mirrors instead of cameras. I would love to mod my car and put cameras in place of the mirrors ( reversibly so I could put the mirrors back with no harm done )

Click to expand...

...

+1

TEG said:

Yes, I think this thought is shared by many. Also, regulations for mirror size/shape is different for Europe vs North America.
To save costs (and have only one mirror design) some manufacturers chose to make one larger side-view mirror design that satisfies both requirement.

Click to expand...

I did some googling and all I could find was some high school science experiment with a "wind tunnel" with and without mirrors on a model car. Someone surely has done better than that.
Google powers activate!

richkae said:

I did some googling and all I could find was some high school science experiment with a "wind tunnel" with and without mirrors on a model car. Someone surely has done better than that.
Google powers activate!

Click to expand...

Found this
http://espace.library.uq.edu.au/eserv/UQ:120959/F._Alam__R_afmc_16_07.pdf

Audi e-Tron concept:

Cadillac Converj concept:

Yeah what I want to see is: CdA of X with mirrors and CdA of Y without mirrors, for an N% reduction in drag.

Side mirror drag effect on fuel economy - quantified - Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com

Instead of outside side mirrors, the car uses tiny cameras...a set-up similar to that seen on the Cadillac Evoq concept car unveiled at the 1999 North American International Auto Show. "We knew we couldn't afford the 30 counts of drag, so we went with camera mirrors," said George Claypole, Vehicle Integration Engineer for GM's Advanced Technology Vehicles. - Automotive Engineering International Online

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So there we have mirror drag quantified: "30 counts of drag" - which if I'm not mistaken means Cd ".03". Seems overly large to me, but there it is.

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why don't we have cameras replacing side view mirrors yet? - AnandTech Forums



http://web.archive.org/web/20060715051619/http://www.tfd.chalmers.se/~lelo/rvad/reports/rva2002_gr11_contribution-to-drag.pdf

"Contribution of different devices to the total drag"
...
Rear View Mirrors 3 - 6%
Engine Cooling 5 - 9%
Underbody 14 - 20%
Wheels, Rims and Wheel Housings 30 - 35%
Vehicle Body (Shape and Sealing) 39 - 42%

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...The problem with the rear view mirror is that its interaction with the flow around the car is very complex. For instance its combination with the A-pillar contributes to the creation of trailing vortices at the side front of the car, which are highly drag-consuming. Moreover, another very important problem is that it plays a major role in aerodynamic noise generation since the flow around it can be highly unsteady...

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Since the Model S needs vastly less "engine cooling" and the underbody is completely smooth because it doesnt have a bunch of exhaust pipes hanging down there, it seems likely that mirrors contribute much more than the 3 - 6 % they would in an ICE.

Nissan's chief engineer for the Leaf told us that the funny frog-like headlight bulge on the Leaf is to deflect airflow around the mirrors. The primary concern was not aerodynamics - but noise. In a car as quiet as a Leaf, the airflow over the mirrors was otherwise audible.

Yes, and the LEAF is remarkably quiet a freeway speeds. I enjoy that aspect on my daily highway commute.

Nissan Leaf

richkae said:

I want to know the impact of the side mirrors, I hate the archaic rule requiring real mirrors instead of cameras. I would love to mod my car and put cameras in place of the mirrors ( reversibly so I could put the mirrors back with no harm done )

Click to expand...

I don't think that rule is archaic; it exists as a failsafe in case of parts failure, much like the mechanical emergency brake (which apparently the Model S won't have). In fact, three semi-redundant mirrors are required. I guess if you had two redundant cameras, redundant batteries supplying them, redundant screens, and redundant sets of wiring, plus the center rear-view mirror, that would be an adequate substitute. But you're getting into "really complicated" at this point. I wonder if one could simply design a curved mirror for side view which could be mounted inside the car.

neroden said:

I don't think that rule is archaic; it exists as a failsafe in case of parts failure, much like the mechanical emergency brake (which apparently the Model S won't have). In fact, three semi-redundant mirrors are required. I guess if you had two redundant cameras, redundant batteries supplying them, redundant screens, and redundant sets of wiring, plus the center rear-view mirror, that would be an adequate substitute. But you're getting into "really complicated" at this point. I wonder if one could simply design a curved mirror for side view which could be mounted inside the car.

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Well you don't need redundant batteries. If the main battery is not working, you're not going anywhere any way

neroden said:

...I wonder if one could simply design a curved mirror for side view which could be mounted inside the car.

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Yeah, I had been pondering that one too. These days I tend to point my side view mirrors rather outwards to watch the "blind spot" and use the center rear-view mirror for looking at traffic behind. Newer cars with steeply raked windshields (for better aerodynamics) have started sporting a larger triangle window in front of the side view mirrors, so one could conceivably put an interior wide angle mirror to help you look out the sides instead of an external mirror. Some non-USA cars had side-view mirrors much further forward (even on the hood) which may have some merit as you can use the mirror without taking your eyes so far away from the road ahead.



Fender/hood mounted side mirrors - side mirrors cars | Ask MetaFilter

I know the conversation has moved on from the wheel fairings, but I feel like I should dissuade anyone from pursuing something like this for their model S. It's in our best interests as EV enthusiasts to promote our cars as a desirable alternative to ICE cars. I know the concept is beneficial to any type of car, but the instant people see an EV with fairings, they will see it differently. It may be efficient, but it's unsightly and will make others lust after the car less. As an F1 fan, I'm extremely interested in aerodynamics as well, but we should keep our cars as presentable and accessible as possible if we want more people to go out and buy these cars.