Ecomodding an automatic '04 Civic Sedan

[mpg_numbers_guy]

Some more questions here...

Other than the lower engine cover that comes standard on the 7th gen Civic Hybrids here) what other aero mods were done to the Civic Hybrid that can be incorporated into my Civic EX? From what I've read, the 7th gen Civic has a drag coefficient of 0.36 but the same gen hybrid has 0.28. Seems like a lot of possible gain here.

And also, does anyone know of a tool somewhere to calculate the minimum speed of each gear? My Civic seems to shift into final overdrive between 40 and 42, but my tach is broken so I can't verify (one of those things I need to fix when I have time). Is there a way to calculate minimum cruising speed for each gear? Maybe using gear ratios or something? Or is it purely a vehicle by vehicle basis?

[Daschicken]

Originally Posted by mpg_numbers_guy

Some more questions here...

Other than the lower engine cover that comes standard on the 7th gen Civic Hybrids here) what other aero mods were done to the Civic Hybrid that can be incorporated into my Civic EX? From what I've read, the 7th gen Civic has a drag coefficient of 0.36 but the same gen hybrid has 0.28. Seems like a lot of possible gain here.

I was considering posting a new thread analyzing the differences between car models/generations. I have pictures for an 8th gen civic vs civic hybrid, but not 7th gen.



The differences visible in the hybrid here are the smooth wheels and the trunk lid spoiler.




Both cars seem to have rear wheel spats, so no improvement there.

Originally Posted by mpg_numbers_guy

And also, does anyone know of a tool somewhere to calculate the minimum speed of each gear? My Civic seems to shift into final overdrive between 40 and 42, but my tach is broken so I can't verify (one of those things I need to fix when I have time). Is there a way to calculate minimum cruising speed for each gear? Maybe using gear ratios or something? Or is it purely a vehicle by vehicle basis?

In your auto, minimum speed is decided by the computer, there is nothing to calculate. You could find out which speeds each gears work for by driving up to a speed where it locks the TQ in 4th, then just let off the gas and listen/feel for each downshift if you can. That being said, you can see what RPM you are at for the minimum speeds of each gear by using the engine rpm calculator I posted above and plugging in the other gear ratios, assuming your TQ doesn't just drop the engine to idle when you let off the gas...

[mpg_numbers_guy]

Originally Posted by Daschicken

I was considering posting a new thread analyzing the differences between car models/generations. I have pictures for an 8th gen civic vs civic hybrid, but not 7th gen.

Attachment 23638

The differences visible in the hybrid here are the smooth wheels and the trunk lid spoiler.
Attachment 23639

Attachment 23640

Both cars seem to have rear wheel spats, so no improvement there.
Attachment 23641

That would be a good thread to start, especially since many hybrid versions of regular cars have lower drag coefficients.

Originally Posted by Daschicken

In your auto, minimum speed is decided by the computer, there is nothing to calculate. You could find out which speeds each gears work for by driving up to a speed where it locks the TQ in 4th, then just let off the gas and listen/feel for each downshift if you can. That being said, you can see what RPM you are at for the minimum speeds of each gear by using the engine rpm calculator I posted above and plugging in the other gear ratios, assuming your TQ doesn't just drop the engine to idle when you let off the gas...

I've been trying to do that, and I think I have it sort of figured out. Too bad there isn't an actual calculator.

[mpg_numbers_guy]

So while waiting for circumstances to give me the ability to start ecomodding my car, here are is what I've come up with to do:

- Smooth coroplast wheel covers. Easy to restore to stock by cutting a few zip ties.
- Pipe insulation to block upper grille.
- Coroplast to effectively block portions of the lower grille. Coroplast "fan blades" to cover fog light area to increase aero.
- Possibly use coroplast to duct incoming air into the radiator.
- Air Dam - lawn edging mounted onto front bumper.
- Possibly see if I can obtain the engine bay belly pan from a same gen Civic Hybrid to install.

Attached is a rough idea of what I'd hope the final product to look like (thanks to Microsoft Paint):



What do you think? Any tips, suggestions, or improvements? Should I paint it black or try to match the silver? I'm also considering automated grille shutters if I ever become knowledgeable enough to wire them up.

All mods must be easily restorable to stock (unless I replaced the part such as with the bumper and grille, but kept the original bumper and grille).

[teoman]

Looks promising.

An automated grille block would not be hard to do at all.

[mpg_numbers_guy]

Originally Posted by teoman

An automated grille block would not be hard to do at all.

I want to believe that, but all the automated grille block mods I've found on here and other sites seem so complicated.

[California98Civic]

Originally Posted by mpg_numbers_guy

I want to believe that, but all the automated grille block mods I've found on here and other sites seem so complicated.

That is always the rub... What is simple for one modder, might not be so simple for another. Even objectively simple things are a little more complex for the relatively inexperienced. I just had a guy mention a "pigtail" for my directional signal light intermittent failure, and I had to look up what a pigtail is. "Pigtail" is obviously basic vocab, but my training and experience are elsewhere. We keep learning.

All that said, I agree with teoman that an active block is objectively simple. It is not like building an arduino or something objectively more complex. That means the learning curve is easier.

Good luck, hey.

[mpg_numbers_guy]

I guess. I suppose I should take it one mod at a time instead of trying to do everything at once that takes master ecomodders months to accomplish. One day though, I will figure it out.

[19bonestock88]

I’d focus on one mod at a time... you keep talking about resale value and returning the car to stock; do you intend to sell it soon?

[mpg_numbers_guy]

No, I don't plan on selling it for a long time. Car has 153K miles on it and Hondas should last well past 300K if properly taken care of, so the car has plenty of life in it since it's in excellent condition right now. I guess I'm just used to my family reselling cars when they reach the 250K mark and still getting $1K or so for them. I guess it really just depends on where I'm at when that time comes.

And as far as the returning to stock part goes, well, maybe someday I'll just get tired of hypermiling/ecomodding. I know, such a sacrilegious opinion to share on a forum like this, and I have no intentions of stopping anytime soon, but who knows.