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Old 01-11-2018, 06:33 PM   #1 (permalink)
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Honda Insight 2019 Aero

Once again it appears the Aero Template II has been validated by the new Insight. Funny how 99.9999% of the people in the world haven't a clue about the significance of how it's shaped...but we know better huh?



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Old 01-11-2018, 06:55 PM   #2 (permalink)
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Notice how the back window goes slightly steeper than the template, bending the airflow down at the risk of inducing instability... but it all lands on the spoiler which still slopes down, but not as steep. That creates a high pressure area over itself and the lower part of the glass, reducing drag.

In the ideal shape the angle reduction is limited to prevent instability, which would mess up the airflow over the tail. But the tail isn't there in practical road cars...

This is why the modern sedan shape beats the classical kammback. It uses the fact that it is hatched to full effect while the kamm shape is just a truncated ideal shape, and therefore no longer optimal.
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Old 01-11-2018, 07:20 PM   #3 (permalink)
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Quote:
Originally Posted by RedDevil View Post
Notice how the back window goes slightly steeper than the template, bending the airflow down at the risk of inducing instability... but it all lands on the horizontal spoiler to have a high pressure area at the lower part of the glass, reducing drag.
I think you need to reconsider whether a very slight variation from the template is "Risking Instability". It is really a matter of being 98% perfect or 100% perfect in slight variations such as this. It isn't as if "The shape isn't 100% right, therefore it is going to only yield a 50% gain because the airflow is spoiled."

The air will barely notice this compared to if the shape followed the template perfectly, you'd need instruments tuned to very high level of sensitivity in order to detect a difference. And with all the subtle nuances with aerodynamics, that slight shift may even be a teeny tiny improvement.

My hunch is that they sloped the window a bit steeper to get the rear window a bit more vertical in order to function better for rear visibility. Possibly. Maybe.
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Old 01-11-2018, 07:50 PM   #4 (permalink)
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Well... The Insight is not unique in this. Many new sedans have this shape.

I wondered why some sedans got better Cd values than cars that followed the template more strictly, like my own Insight. But this may be it.
The air flow over the back slope of the template breaks when the flow gets disrupted. Any negative pressure area will enhance any instabilities in the airflow to create just such a disruption. So the template feeds down very diligently.

The sedan shape goes down steeper, deliberately for practical reasons, but also because the instability it creates has no time to get out of bounds; it meets the boot lid and flows out in the wake.
This is all by design, not just a subtle nuance. It is not a 50% improvement; none such is possible. But 3%, yes definitely.
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Old 01-11-2018, 08:11 PM   #5 (permalink)
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Note that the hard points on this car are the same as the Civic sedan. Same shape, just slightly differently style sheetmetal & fascias.

They could have just callled it the Civic hybrid.
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Old 01-12-2018, 01:05 PM   #6 (permalink)
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Quote:
Originally Posted by MetroMPG View Post

They could have just callled it the Civic hybrid.
Hmmm....Motor Trend may think you're on to something.

You're spot on, there is no Civic Hybrid anymore, so this is it. And it looks like Honda wants to position this car between the Civic and Accord. Sounds like it is going to use the same drive train as the Clarity which has a large electric motor next to a 1.5 Liter Atkinson engine able to drive the wheels directly, or be just a generator. This will start in the mid level trims and have deluxe trim models available.
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Old 01-12-2018, 02:21 PM   #7 (permalink)
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Unfortunately for Honda, unless gas prices spike, they're only going to sell about 10 or 20 of these.

That's regardless of how much nicer it's styled (to my eye) than the Civic sedan.

Prius sales were at their lowest point (last year) since the debut of the 2004 model.
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Old 01-12-2018, 03:21 PM   #8 (permalink)
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Frankly I wouldn't pick this car. No hatch, no deal. Despite this car being twice the size of my 1st gen Insight, I'm certain I can move larger pieces of furniture or construction materials.
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Old 01-12-2018, 06:11 PM   #9 (permalink)
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Is this more like a Civic Hybrid than a Clarity Hybrid?
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Old 01-12-2018, 06:24 PM   #10 (permalink)
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Quote:
Originally Posted by MetroMPG View Post
Unfortunately for Honda, unless gas prices spike, they're only going to sell about 10 or 20 of these.

That's regardless of how much nicer it's styled (to my eye) than the Civic sedan.

Prius sales were at their lowest point (last year) since the debut of the 2004 model.
I do sense your humor.

If you want to find the reason for anything, follow the money.

With gas prices being low now for about 3 years, off-lease trucks and Suv's have now reached to the used market where they are being snatched up instead of gas sipping cars. So with a growing number of vehicles in use returning relatively low mpg numbers, it is the PERFECT time (for the oil industry) for gas prices to rise.

Supply and demand, supply may be high but demand is rising and any slowdown in supply will have a greater effect.

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