2010 Prius Rear Quarter Crease; Aero Aid for All?

[Rokeby]

In this video, at 0:50 -1:30, it is stated that the sharp crease at the
side/rear bodywork transition on the 2010 Gen III Prius is an aerodynamic
feature.

2010 Prius Aerodynamics

This "sharp edgedness" is also feature on current Cadillacs and Volvos,
presumably for the same reason

As the Gen III has one of the lowest Cds for mass marketed cars, there is
reason to believe that its designers and engineers paid particularly close
attention to even "minor details" with respect to drag reduction.

Good aerodynamics is the result of a number of interacting elements. It may
be that any benefit from the crease in the bodywork is dependent on the
"slab-sided" doors etc, upstream. That said,

Would adding this small detail make a diference on other vehicles with
rounded rear quarter/rear transitions? (Maybe even the 2004-'09 Gen II
Prius?)

Or is all this a bunch of hooey?

It wouldn't seem to be that difficult to make:
* Tape some plastic film to the bodywork where the addition will go.
* Form the crease from Bondo, epoxy filled w/lightweight micro-ballons), etc.
* Remove for final shaping and finish.
* Reapply with double sided tape.

[rgathright]

Great post. Hope it works!

[MetroMPG]

You can see this same feature discussed on the Chevrolet Volt as well:

Video: discussion of several GM Volt aero features

BMW and others have been incorporating similar airflow "trip" points to promote clean separation off tail light lenses, which typically have large corner radii.

I'd venture a guess and say this mod would be worth doing to any vehicle where the upstream flow is relatively unturbulent, and the transition at the end of the car has an ample radius.

The 1st gen Insight, with its skirted rear wheels and rounded rear bumper cover corner would be a good candidate.

The only catch is that the effect of this mod is likely so small it wouldn't be easily measurable outside of a wind tunnel or with CFD.

[NeilBlanchard]

Hi,

I wonder if this "crease" is preceded with a surface that has the proper tapering angle would increase the improvement?

In other words, a short(er) boattail -- for example, would a much shorter version of the Blackfly boattail be substantially effective?

[3-Wheeler]

Originally Posted by MetroMPG

...The 1st gen Insight, with its skirted rear wheels and rounded rear bumper cover corner would be a good candidate...

Hi Metro,

I've wondered about the large radiused shape of the Insight bumper the first time eyes were laid on a picture of the car.

A sharp edge here would do wonders.

Jim.

[Rokeby]

Here is a radical Gen II Prius implementation that is way more than an
"aero crease:"

The little circles are clear plastic to allow the tail lights to be seen from the side.

If a modder was particularly clever, this could be roughly reproduced with a
slightly curved sheet of coroplast (with the holes) or clear plastic. I suppose
they are intended to act like a vertical version of a rear deck-edge spoiler.

This feels like a super short version of the Geo Metro boat tail without a "transom."

While we're at it, here are a few more views of drool-worthy details on this car:

Rear wheel shirts

Front wheel covers

From what I've been able to uncover, this car is a one-off and none of these
parts are available for purchase.

[3-Wheeler]

Hi Rokeby,

Thanks for those wild Prius pictures.



Jim.

[Sean T.]

The current Dodge caravan has them too, there is a ridge that goes down the sides an inch or two behind the edge of the taillight. You can't see it in photos hardly, but next time you see one, look at the taillights.

[Piwoslaw]

In Knight Rider, episode Blind Spot, KITT has a crease in his tailquarters

[cfg83]

Piwoslaw -

And check out KITT's gorgeous wheel covers (that flew off a lot thank you very much) !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

CarloSW2