Lo-Drag: Cd < 0.2

[doubeld]

I'm no engineer, but I would suspect that anytime you narrow your contact points on the pavement you increase body roll which has an obvious impact on handling.

 

[JRP3]

I've been thinking of this in recent weeks. Given the astonishing ability of automotive computers nowadays to gather information from all four tires and respond as appropriate, does anyone think that a front end that had a narrow wheelbase might become workable? That is, if a car had its front wheels brought in just enough so that at full turn, the tires still remained inside that which we're all calling wheel covers, could it still be a stable, safe, properly-handling vehicle?

http://www.deltawingracing.com/

 

[1208]

Maybe at the press of a button a tail could extend out the back.

 

[JRP3]

Like this: https://youtu.be/qaR20sGX9ik?t=2m56s

 

[ohmman]

I think AudubonB's discussion about wheels applies directly to an extremely aerodynamic shape as well. We're accustomed to seeing vehicles appear in a certain aesthetic. Over time, if designers can push our comfort zone ever so slightly, we can be normed toward a shape we might consider "odd" today. This happens all the time in style and art.

 

[jkk_]

I think AudubonB's discussion about wheels applies directly to an extremely aerodynamic shape as well. We're accustomed to seeing vehicles appear in a certain aesthetic. Over time, if designers can push our comfort zone ever so slightly, we can be normed toward a shape we might consider "odd" today. This happens all the time in style and art.

Fair enough and I can get behind that. However, one thing that troubles me is that I have gotten the impression (which can be wrong) that people are advocating for covered wheels / wheel wells / etc from the standpoint of "we can shave off 1% of drag and gain 2% of range" while at the same time forgetting that more likely than not, these solutions will cause significant concerns and issues in places where we get plenty of snow (including wet snow when it's around just above 0C degrees, which is very heavy and sticky).

And yes, I'm probably too cautious regarding this issue, but for me reliability is more important than the gains that might be achieved via this method. And in any case, all of this is just pure speculation anyway, Tesla has surely made their mind already and we will see "which side was right" soon

 

[wdolson]

Fair enough and I can get behind that. However, one thing that troubles me is that I have gotten the impression (which can be wrong) that people are advocating for covered wheels / wheel wells / etc from the standpoint of "we can shave off 1% of drag and gain 2% of range" while at the same time forgetting that more likely than not, these solutions will cause significant concerns and issues in places where we get plenty of snow (including wet snow when it's around just above 0C degrees, which is very heavy and sticky).

And yes, I'm probably too cautious regarding this issue, but for me reliability is more important than the gains that might be achieved via this method. And in any case, all of this is just pure speculation anyway, Tesla has surely made their mind already and we will see "which side was right" soon

The aero wheels for the Model S that were only available for a short time increased range by about 7%. Completely covering the wheel well would improve range even more. However I agree with you on the practical aspects with getting packed with snow as well as other gunk collecting under there.

 

[JRP3]

Fair enough and I can get behind that. However, one thing that troubles me is that I have gotten the impression (which can be wrong) that people are advocating for covered wheels / wheel wells / etc from the standpoint of "we can shave off 1% of drag and gain 2% of range"

It would be much more than that.

while at the same time forgetting that more likely than not, these solutions will cause significant concerns and issues in places where we get plenty of snow (including wet snow when it's around just above 0C degrees, which is very heavy and sticky).

And yes, I'm probably too cautious regarding this issue, but for me reliability is more important than the gains that might be achieved via this method.

Optional and removable, i.e., if you don't want them you don't have to have them.

And in any case, all of this is just pure speculation anyway, Tesla has surely made their mind already and we will see "which side was right" soon

I don't actually expect wheel covers on the 3.

 

[S3XY]

The aero wheels for the Model S that were only available for a short time increased range by about 7%. Completely covering the wheel well would improve range even more. However I agree with you on the practical aspects with getting packed with snow as well as other gunk collecting under there.

Sounds like the aero wheels are a good compromise between reduced cd and aesthetics. They just need to design ones that look good and make them standard rather than an option. Then they can include the added range in their EPA rating.

 

[Twiglett]

All of these sleek body shapes look the part.
But does anyone remember the Mythbusters episode where they proved the the best performance came from the dimpled "golf ball" indentations along the body.
They got an 11% efficiency boost just by adding all those dimples.
Thats will the ugly grill, no wheel pants etc etc
Kinda makes the piddling 5% from adding wheel covers looks silly

 

[JRP3]

Of course all those dimples look great....

 

[physicsfita]

All of these sleek body shapes look the part.
But does anyone remember the Mythbusters episode where they proved the the best performance came from the dimpled "golf ball" indentations along the body.
They got an 11% efficiency boost just by adding all those dimples.
Thats will the ugly grill, no wheel pants etc etc
Kinda makes the piddling 5% from adding wheel covers looks silly

After seeing that episode, it made me wonder if something along the line of the riblets that are put on the hulls of race boats could be developed for cars (and could be made to not look awful). I'm guessing there must be some practical reason why not since we don't see anything like that on racing cars, and I would be amazed if some team out there hasn't given it a try.

 

[dgpcolorado]

All of these sleek body shapes look the part.
But does anyone remember the Mythbusters episode where they proved the the best performance came from the dimpled "golf ball" indentations along the body.
They got an 11% efficiency boost just by adding all those dimples.
Thats will the ugly grill, no wheel pants etc etc
Kinda makes the piddling 5% from adding wheel covers looks silly

Hmm... Does that mean that hail damaged cars get better mileage? That's an advantage I'd never have thought of!

 

[aronth5]

All of these sleek body shapes look the part.
But does anyone remember the Mythbusters episode where they proved the the best performance came from the dimpled "golf ball" indentations along the body.
They got an 11% efficiency boost just by adding all those dimples.
Thats will the ugly grill, no wheel pants etc etc
Kinda makes the piddling 5% from adding wheel covers looks silly

Of course all those dimples look great....

For those that never saw the episode

 

[David_Cary]

Aerodynamics will be good (hopefully). Style will eventually match function as it has to.

.2 will be normal within a decade I suspect. The best way to travel faster is with better aerodynamics. I want 100 mph as normal in a decade and doing that with a .3 Bolt is going to be silly

 

[aronth5]

Aerodynamics will be good (hopefully). Style will eventually match function as it has to.

.2 will be normal within a decade I suspect. The best way to travel faster is with better aerodynamics. I want 100 mph as normal in a decade and doing that with a .3 Bolt is going to be silly

100 mph, where? I didn't know they were planning on building an autobahn in North Carolina!

 

[Touring]

Would be good selling point for tech interested costumers with cd<0.20. Would look more futuristic, and will be good for marketing, efficiency and performance.

 

[Gerasimental]

After seeing that episode, it made me wonder if something along the line of the riblets that are put on the hulls of race boats could be developed for cars (and could be made to not look awful). I'm guessing there must be some practical reason why not since we don't see anything like that on racing cars, and I would be amazed if some team out there hasn't given it a try.

Most racing cars are designed for high lift, not low drag. Drag coeff of an F1 car is around 1.0 (depending on set up). Would be pretty awesome if this was what he meant by 'won't look like other cars'.

 

[cokata]

Most racing cars are designed for high lift, not low drag. Drag coeff of an F1 car is around 1.0 (depending on set up). Would be pretty awesome if this was what he meant by 'won't look like other cars'.

Your example is of the worst case scenario (open wheel, open cockpit) car. LMP1 cars have much more DF than F1 and are ~0.45.

Anyway i would take a smaller battery with better aero (for the same range) everytime, because it will reduce the penalty of more spiritual driving, also better aero means better performance at higher speeds, something that the Model S is really lacking (not that it's an aero issue)

 

[1208]