Never thought I'd own a Hybrid Civic, but it seemed like the smart choice and we recently traded in to get a new one.

Couple of questions about the new Civic Hybrid:

- Anyone know the weight on the stock alloy wheels?

- Is there a good place to find more information on the parts and design of the IMA system and 1.3l SOHC mill?

- What value in terms of efficiency would there be in lightening the overall weight of the car or the wheel weight? Also, would it benefit the frontal area and coefficient of drag to lower the vehicle by 1-1.5"? I suppose the real question is - do any of the common aftermarket civic parts have economy benefits?

- What are all the acronyms used on the board. I know ICE is internal combustion engine; png = pulse and glide; but there were others in the discussion about PNG that I did not recognize. Is there a glossary?

- At speed, with a manual transmission, what is the safest way to glide and shut off the ICE? Is there a trick to getting it to Auto Stop above 5mph?

Thanks for the info. The car's pretty slow, but I like it. Had it two days and got 45mpg average yesterday for 36miles and 54mpg for 21mi today. It's substantially downhill to work and the opposite on the way home.

Jason / Griffith Coachworks
Drivers:
'05 Civic Hybrid
'02 Subaru 2.5 RS
'79 Alfa Romeo Spider Veloce

Projects:
'85 Jag XJS w/ 383cid SBC & Quad Sidedraft EFI
'78 IH Scout II w/ EFI & Eaton M90 Supercharger
'75 BMW 3.0 CS w/ T3/T04E Turbo

 

The weight of wheels is in a few recent discussions. Comes in around 30 lbs total
I think (tire + wheel).

Honda has decent info about the IMA, the video is good, I went looking for the link, couldn't find it, but it is in this forum somewhere. THere are links to both the 2003 and the 2006 HCH IMA videos, they are on www.hondanews.com I think so you might find them there.

Weight efficiency estimates come in around about 1mpg per 100 lbs, up or down.

Haven't seen much on aftermarket mods here, mostly people drive the cars stock.

There is no glossary, you are sort of on your own there.

For an MT (manual tranny), shutting off the key and putting it back into the II position is called a reboot or a Forced Auto Stop (FAS). The safety considerations are that the brake pressure will drop as you use the brake pedal, and the mechanical backup requires very strong legs to get significant braking, try it and you'll get a feel for it.

The power steering will also cut off briefly, it is electrical so it comes back, but a few seconds after you put the key back in the II (run) position. The mechanical backup for the steering isn't too bad, you can drive the car that way (I can even do it one handed). I have an MT and use FAS a lot, but not at freeway speeds, I tend to use it at low speeds and when the engine is cold (Auto-Stop doesn't come on until the engine is warm).

Enough brake pressure to come to a full stop remains during an FAS, and it is using the brake pedal that loses pressure so you can control it fairly well.

I think most people coast with the engine on at high speeds just because the efficiency gain is slight, and for cases like prolonged downhill grades you might as well charge up the battery as go FAS and risk reduced brake and steering control. That said some of the better hypermilers in this forum routinely reboot down big hills, it does help.

 

There is a glossary. Look at the bar above the ads at the top of the page. You will see the link to the glossary there.

 

Ignoring the cost to benefit ratio and the potential decrease in crash worthiness, a fiberglass/carbon fiber hood, rear lift, and front fenders, would probably provide a modest drop in weight, obviously resulting in better fuel economy. I see these parts frequently on enthusiasts' civics - HP enthusiasts, not FE enthusiasts.

 

I too am looking at perfomance mods that decrease parasitic loss and don't cost fe (fuel efficiency), so let us know if you find any!
I'd like to know if civic lowering springs will fit an HCH, I'm not sure it'd be enough to help fe tho.



Sounds like a K&N filter would help.
https://www.greenhybrid.com/discuss/...lter.3406.html

Similarly I'd guess a better exhaust system would help without causing the ECU to push in more fuel.
A warm air intake is a mod that a few people here are working on.

Here are the best selection for wheels/tires I've seen discussed. They save you a whopping 2lbs per tire!
https://www.greenhybrid.com/discuss/...tion.3360.html
https://www.greenhybrid.com/discuss/tires.3303.html

An acronym that stumped me for a few was DWL = Driving With Load.
Any other ones you're trying to figure out?

 

Lowering springs may fit. One thing to note is the hybrid needs stiffer springs in the back to compensate for the added weight of the battery pack.

 

Couple of replies...

Tire weight is a tough call - the decrease in weight may be due to less dense/softer rubber, which in turn means more coefficient of friction on the tires. The wheels I'd do just for looks, plus they're 7-8lbs each in 14x6.

The K&N Filter may boost the volumetric efficiency of the engine, but all that is going to do with any normal load sensing equipment in the fuel management system (MAF/MAP/Etc) is to demand more fuel to attain the proper stoichiometric air fuel ratio, which in turn might mean a little more oomph, a little more responsiveness but in the end a little more fuel.

The ride height and weight decrease benefits certainly don't outweigh the costs. Heck, I could personally lose more weight than I could take out of the hood, trunk and wheels.

And additionally, with swinging 52.8mpg over the last 100 miles, I'm pleased as punch as it is right now!

Thanks for the info from honda about the IMA system!

Jason Griffith
Griffith Coachworks
Woodland, WA