Aerocivic - how to drop your Cd from 0.31 to 0.17

[Xist]

Nobody figured out how to tell Honda engines to enter lean burn? I understand the engineers probably had good reason for programming conditions.

[Ecky]

It's pretty easy in my G1 Insight:

Once the engine coolant temperature is above around 140F, I simply let off the throttle until the FCD reads ~100mpg, and it starts lean burn and the FCD jumps up. I can then stay in lean burn until around 90-95% load, which equates to ~70mpg on the FCD. If I push the pedal down any further, it drops out of lean burn, the FCD drops from ~70 to ~50mpg, and it begins electric assist. So far as I can tell, that's all there is to it.

Lean burn seemingly exists so that the Insight can cruise at peak BSFC RPM and high load, but also have power on tap for climbing hills, also at peak BSFC RPM and high load.

I'm under the impression that later model year Insights have more difficulty entering LB but I've never driven another one to confirm.

[slipknotsv]

really serious aerocivic 0,17 CD ? have confirmation ? about that....evidence

Best Hucho 0,140 CD template

[freebeard]

The Hucho example has an unsophisticated wheelwell treatment. That could account for the 0.03 difference.

[Cd]

Originally Posted by slipknotsv

really serious aerocivic 0,17 CD ? have confirmation ? about that....evidence

Best Hucho 0,140 CD template

Slap that template on this one. The mid 2000s ( 2003 - 2005 ) Lexus LS-430.
The car has a point two five drag coefficient with the optional air suspension.

"
The body was also more aerodynamic than previous LS sedans (Cd 0.26; 0.25 with air suspension),[76] and was the product of wind tunnel testing at facilities used for Shinkansen bullet train development.["

Source : https://en.wikipedia.org/wiki/Lexus_LS#XF30



Just because a car does not meet the template, does not mean it is that is is not low drag.

Worst case scenario is that the .25 Cd is off by about 5 counts - which is huge. Even if it were that high, just look at the angle of the rear glass on the Lexus.
I'd love to see how they did it !

BTW, My neighbor just bought a used one. I was just outside talking to him about the aerodynamics of the car ( The arrow what ???? huh )
If any of you would like some images of the cars aero features up close, let me know, and I will post some pictures.

The Aerocivic may or may not have a .17 Cd, but I applaud it's creator for following through with it.

[slipknotsv]

illustration

[seifrob]

Originally Posted by slipknotsv

really serious aerocivic 0,17 CD ? have confirmation ? about that....evidence
<snip>

I feel somehow offended by your post so I will react even if I am not basjoos.

1) the fuel log indicates very good fuel economy for that type of the car and is - although quite outdated - fairly consistent. If you input vehicle weight, frontal area and rest of parameters (you can google them) into the mpg calculator here on ecomodder, i think you will get close to the proposed Cd
2) Nobody is trying to fool you. The thread says about 0.17 Cd, but it is the title. It is supposed to be short.
On the aerocivic.com webpage is clearly stated that the Cd is tested out to be 0.17. That means - at least as my undoubtly poor english indicates - that the author believes it is 0.17 with some error given the test methodology (and the method is also described quite clearly). In the end - at least for me - it is not important if it is 0.17 or 0.19 or 0.21. The point is that it is achievable to get to these low numbers.
3) If you are really interested, I am almost sure that you wil find coast down test results somewhere here or on aerocivic.com. Or were you only trying to troll the thread?

rs

[freebeard]

It ain't rocket science: a spring scale and a long rope.

[user removed]

Fairly sure he (Basjoos) did coast down measurements. I'm fairly unoffendable after being on this forum 6 years. Your English beats the crap out of my Czech.


regards
mech

[aerohead]

*VW XL-1 Cd 0.189

*Schl'o'rwagen Cd 0.186

*GM Chevy Citation-IV Cd 0.186

*Renault Vesta II Cd 0.18

*Railton Mobil Special Cd 0.18

*Volkart Sagitta Cd 0.17

*JCB Dieselmax Cd 0.17 (full-scale)

*AeroCivic Cd 0.17 (estimated)

*Daihatsu UFE-III Cd 0.163

*GM Precept Cd 0.163

*GM Impact/EV1 LSR record car Cd 0.14


*CUER Cd 0.10

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Goro Tamai,who used to head the solar race team at MIT claims that wheel fairings can reduce wheel drag by 80%.
It may be that Mike's wheel treatment on AeroCivic over-compensates for concessions he had to make to other parts of the car,so as not to tear them off the car in traffic,and when ascending/descending parking ramps.
Cd 0.17 doesn't seem an inappropriate value to assign to a car with AeroCivic's mpg and coasting performance.