Does anyone know the owner of this Prius?

that would be me

 

Nice try at gaining some more respect, @bisco, but the car has a PA license plate. I'm not buying it.

 

caught me

 

It looks a bit over-designed in the rear. They eliminated the Kamm-tail and threw away decades of aerodynamic theory. Here's an excerpt from Wikipedia at Kammback - Wikipedia The key here is that "cutting off the tail resulted in minimal increase in drag." Everyone does it now.

"The ideal shape to minimize drag is a teardrop. However researchers including Kamm found that abruptly cutting off the tail resulted in minimal increase in drag.[3] The reason for this is that a turbulent wake region forms behind the vertical surface at the rear of the car. This wake region mimics the effect of the tapered tail in that air in the free stream does not enter this region (avoiding boundary layer separation), therefore smooth airflow is maintained which minimises drag.[9]

Kamm's design is based on the tail being truncated at the point where the cross section area is 50% of the car's maximum cross section,[3][11] which Kamm found represented a good compromise—by that point the turbulence typical of flat-back vehicles had been mostly eliminated at typical speeds.

The Kamm tail presented a partial solution to the problem of aerodynamic lift, which was becoming severe as sport car racing speeds increased during the 1950s. The design paradigm of sloping the tail to reduce drag, carried to an extreme on cars such as the Cunningham C5-R, resulted in an airfoil effect lifting the rear of the car at speed, that could result in instability or loss of control. The Kamm tail decreased the area of the lifting surface while creating a low pressure zone underneath the tail."

 

Clearly inspired by Basjoos' Aerocivic:

Aerocivic - Honda Civic modifications for maximum gas mileage - aerocivic.com
The Aerocivic: Ugly as Sin, But Hey - It Gets 95 MPG
Basjoos Tells All About His "95 MPG" Aerocivic
Mike Turner's Awesome 95 MPG AeroCivic

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BTW, since this is a Gen2, shouldn't this thread be moved to Hypermiling Beastmode caught in the wild | PriusChat ?

 

Porsche tried it with their Langheck tail racers.

 

I'd say with all those mods the owner probably hangs over on Ecomodder.com

 

He or she isn't throwing away any aerodynamic theory; Kamm's design (actually invented by Koenig-Fachsenfeld for buses three years before Kamm published his first description of the design in 1939) was intended to maximize usable interior volume while minimizing drag, not to be the lowest-drag form possible at any cost. As Wolf-Heinrich Hucho described it in his monumental Aerodynamics of Road Vehicles:

"In essence the result was as follows: Beginning at the maximum cross-section, the downstream contours of the body are carefully tapered so as to keep the flow attached. This produces a steady increase of static pressure in the flow direction. Just ahead of the location where the flow would want to separate, the body is truncated vertically, resulting in a plane base whose cross-section is small in comparison to the frontal area. The wake behind the vehicle is narrow, and negative static pressure on the flat base is moderate due to the upstream pressure recovery. Both contribute to low drag. Looking at Fig. 1.34 the advantages of this so-called "Kamm-back" (or in an often used abbreviation, K-back) becomes evident at once. In comparison to the shape of Lay, the headroom in the rear is far higher; compared to the contour of Klemperer, a good part of the length is saved" (Hucho, W-H. Aerodynamics of Road Vehicles, 4th ed. Warrendale: Society of Automotive Engineers, Inc., 1998, 29).

Kamm's designs were still high drag by modern standards. He estimated his K3 (1939) at Cd .24, but testing the car (which still exists) in the VW wind tunnel in the 1980s indicated its actual drag coefficient is .37. The ideal length:depth ratio for low drag is somewhere around 4:1 to 5:1, much longer than K-form cars; this is evident when you look at low drag production and concept cars:


Mercedes C111 III, 1977: Cd .18


Volkswagen XL1, 2014: Cd .189


GM Aero 2002, 1983: Cd .14


Ford Probe V, 1985: Cd .137


Mercedes-Benz Concept IAA, 2015: Cd .19 (tail extended)

It's really, really hard--if not impossible--to get Cd numbers like that without a long, tapered tail.

 

One of my favorite cars ... it's original model to the U.S.. ... In addition to its hybrid drive system, the Insight was small, light and streamlined — with a drag-coefficient of 0.25. At the time of production, it was the most aerodynamic production car, ever.

 

I agree, and always compliment the owner when I have an opportunity.

 

I had one for a few years. Liked it but kept have smog equipment failures.

 

What was the issue?

 

That's a honda.

Posted via the PriusChat mobile app.

 

Smog senors would fail. Honda always covered the repair, but if I had to pay it was like $800.00. So that was the reason I sold it.

Original Honda Insight.

 

Someone asked on a board if you were to convert a car to a hybid what would you use. Well if I was under six foot tall I would choose a SAAB Sonett III. It had a .32Cd and weighed in around 1900 Lb's. The reason I said IF I was under six foot tall is this car is tiny.

 

How about a fiberglass bodies Bricklin SV-1?