CdA list

[oldtamiyaphile]

Originally Posted by munkitkat

The Cd of a Scion xB is 0.32? Pardon me if I don't believe that the brick of bricks has a Cd under 0.45.

0.32 is nothing special today, most European vans quote CDs from 0.31-0.33.

[Hersbird]

the 2016 Chrysler minivan is reported at .30 Cd, I don't see the frontal aera but now also has active grill shudders.

from Allpar "Chrysler spent 1.2 million CPU hours for fluid dynamics development and over four hundred hours in the wind tunnel to bring the 2017 Chrysler Pacifica out with a drag coefficient (cD) of 0.300, the top rating among its primary competitors. The minivan includees a minivan-first active shutter system, cutting drag by an average of 10%; when closed, air is redirected around the van. The shutters are usually closed at high speeds but open at low speeds or if the coolant gets hot.

A steeper windshield angle channels air off the front portion of the upper canopy; aero-shaped mirrors were designed with the extra load of the closed shutters in mind. The rear angle was optimized to cut turbulence; sill claddings and aesthetic “blister” channel air away, particularly from the wheel openings. The roof taper channels air to the spoiler, whose trailing-edge design shapes the air wake. The design of the rear pillars have an offset edge to push air off the rear upper corners of the minivan. A front-fascia close-out panel prevents air from channeling into the engine compartment and cuts “air swirl;” the engine shield pushes air down for the same reason. Front tire spats work like air dams, kicking air from the tires. Mid-floor belly pans on both sides, around 7 ½ feet long, are used on Touring and higher models; a rear suspension shield over the rear axle deflects air down, while a rear air diffuser panel channels air between the rear wheels. A hood seal cuts turbulence and noise. Even the wiper blades were optimized.
2017 Chrysler Pacifica minivans: Chassis and handling
I think we may lease one, but I kind of want to see what deals will be on the Hybrid version if any.

[bikeprof]

As for me..., I'd like to see these two options:
1. Hybrid
2. Turbo Diesel hybrid

Then "we're" talking...!

[Frank Lee]

Sure was a lot of that description that made no sense. "shudders" LOL

Like, "aero-shaped mirrors were designed with the extra load of the closed shutters in mind"- What?

I liked that first pic- the front view. Looks low enough to be a.... STATION WAGON. But the rest, aft of the "A"-pillar... yeeecchhh. Oh well, as long as it works.

[NeilBlanchard]

Grill shutters have nothing to do with frontal area; only Cd.

[aerohead]

perhaps they increased the drag of the mirrors to offset the drag reduction of the grille shutters?

[kyledamron]

The Cd for the 2008-2011 Ford Focus Sedan is .32

Surprisingly high considering that the whole thing is aerodynamically shaped and everything.

[Jack-Lee]

@kyledamron : big wheels and a "fat ass" destroys everythink

[aerohead]

Originally Posted by RobertSmalls

Two other independent lists:
Automobile drag coefficient - Wikipedia, the free encyclopedia
Automotive aerodynamics - Wikipedia, the free encyclopedia

What I really want to see is CdA data on modified cars. So, in .csv format:

Make,Model,Year,Cd,Height (In),Width (In),Frontal Area (ft^2),CdA
Aptera,2e,prototype,0.15,,,19.9,2.98
Volkswagen,1L Concept,,0.15,39.6,49.2,11.0,1.63
Aerocivic,Civic Hatch,1992,0.17,50.9,66.9,19.9,3.38
GM,EV1,1996,,,,,3.95
Subaru,Legacy Wagon,1995 - 1998,0.32,57.1,67.5,22.5,7.19

Aerocivic data from aerocivic.com. I'm sure the coastdown testing generated CdA data, which was then divided by a guesstimated value of A. I then multiplied the reported Cd by my own guess of A. I would love to know if this matches the CdA from the coastdown testing.

If so, then the conclusion is powerful: Most compact cars have very similar CdA, and I would only gain a 14% improvement in aerodynamics by trading my Subaru wagon in for a Civic hatch. Even the Insight is only 30% better than my car, but the Aerocivic moves through the air with 49% the effort of the Subaru.

If you want a slick car, you have to build it yourself?

If anyone has measured the CdA of their cars before and after aeromods, I'd love to see your results.

The '70 VW bus was estimated at Cd 0.285 vs 0.43 based upon 55-mph mpg.
The '84 CRX was estimated at Cd 0.235 vs 0.32,based upon top speed and 55-mph mpg.
The T-100 was measured at :
*Cd 0.268-0.267 vs 0.44 as driven
*Cd 0.251 with mirrors folded
*0.24 with mirrors deleted
The DARKO tunnel's numbers are 8.77% higher than the A-2 tunnel.
If the T-100 had been measured at A-2,the Cds might have been:
*0.244 as driven
*0.229 with mirrors folded
*0.219 with mirrors deleted
*At Cd 0.268,the top speed would be 123-mph vs 109 mph for a re-geared T-100.
*mpg at 65-mph was 34 vs 25.

[aerohead]

Originally Posted by Old Tele man

...what's the "consensus" thought on the "round-off" number (0.80-0.84, etc.) that's applied to compensate the "rectangular" area value (width x height - gnd clearance)?

...I've seen anything from 0.80 through 0.90 being used, but 0.84 seems most common.

...also, anybody know the CdA for the original Studebaker Avanti that turned 171 mph at Bonneville?

So far,no one's published a Cd for the Stude.I'd like to know as well.