Civic Hybrid -- gas/electric usage

Does software control the switching of the power source between
gasoline and the battery pack? Or is it more of a mechanical element
that controls it?

Is it possible for Honda mechanics to "adjust" how much battery power
is getting used? I'm happy with my 2005 Hybrid, but I'd like to
average more than the 43.5 mpg that I'm currently getting. My driving
is 90% city (start and stop traffic). I watch the gauges closely, and
it seems that the battery doesn't get used as much as it could during
acceleration. In fact, very rarely does my overall battery power ever
dip below the 80% mark. I was wondering if they could adjust the
threshold/configuration of when the battery kicks in so that it gets
used more.

 

The first mechanic that offers to do any twiddling with the system, run
screaming from the shop. While it isn't rocket science, it isn't "use a
bigger hammer" technology either.

 

If it's like the Hybrid Accord, the battery power mostly goes to
accessories. Turn on the A/C and it will drain to empty in heavy
traffic.

 

ok, if the batteries were to be discharged to 50%, where is the energy
to recharge them going to come from? [that's a rhetorical question.]

unless you discharge them & keep them discharged, there is no "net
gain", so you're still going to run the motor to recharge those
batteries, and that's what consumes the gas. your software, based on
extensive research, knows how to optimise fuel consumption based on the
driving you're doing. try & believe that the millions of $'s & years of
research that preceeded your purchase were not wasted by incompetents.

 

The point is that the batteries in Honda's systems frequently hit 100%
full or empty. The hybrid system does assist a little more on a full
battery and regenerate a little more on an empty battery, but the
adjustment isn't enough.

On empty city streets, my HAH battery fills up because there's more
regeneration than assist. In dense stop and go traffic, the battery
empties because there's more assisting than regeneration. In both cases
the car stops being a hybrid after a few minutes because its not
adjusting to conditions. I have no idea how the EPA came up with the
HAH's high milage numbers.

 

Small clarification: Maybe the Honda's instrument panel's dial
shows it at "100%" and "empty", but the battery itself is
operating in a rather narrow State of Charge (SOC) range of
perhaps (I don't know exactly what Honda is using) 50-80%.
Probably an even narrower range. They *could* use it over a wider
range, but then they'd be compromising battery life.

EPA doesn't come up with them, Honda does. Honda tests the car to
a specific EPA-given drive schedule. EPA may check the
results. I'm sure Honda tweaked the battery control strategy in
part to give about as high a number on this test as they could
(presumably also with consideration to: battery durability,
emissions, drivability, real-world mileage ...). The lack of
correspondence of this EPA cycle to "real-world" driving, does
have a significant role in the EPA numbers being higher than most
people's experience.

And back to the main Q: I'm sure it is controlled electronically.
But you'd be well-advised to not muss with it!!

 

NO; However I suppose Honda's engineers could "tweak the IMA"
usage. Rest assured that the IMA system is highly optimized as, you are
using it day to day.

One tip: Use Econ mode for the AC system so the engine stops at
idle. That's going to be good as it gets.


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Which Honda do you have? I have a 2003 Civic Hybrid.
I see my batteries hit 100% full on a long downgrade, after which there is
no regenerative braking, obvious from the lack of little green bars when
braking. There are other times when it looks full on the gauge, but
stepping on the brake gives the green bars. I have never had this happen
in traffic on moderately hilly or flat terrain.

I have never seen less than two bars on the battery gauge. Somewhere just
below half, the engine starts charging, noted by four green charge bars,
even when I am headed up hill. This happens fairly frequently in the
hills.

The early Insights did not do engine charge, but I thought that wa changed
in the second model year, and maybe even by recall on the older IMA
programming.

I just received a recall notice. My IMA is going to be reprogrammed to
avoid some potential catalytic converter damage.

 

Good night! I've had my 2004 now for 18 months and am getting
32 mpg. Dealer says that's about the expected mpg - excuse me?
I think I should get at least 40 if they advertise 48. Had the recall
computer update done last week, but they say not to expect any
better -


POLL - What mpg is everyone getting on their hybrid civics?

 

That's not so good. I've heard a few stories about mpg like that in
strictly city driving in snow country.
edmunds.com has forums where people post their mileage.

I get 46 overall, with 50+ at 70mph on the freeway.
2003 CVT. 50,000 miles.

 

Wow.

A buddy of mine, on a complete lark, went and bought a used Beetle
diesel. 47K miles on it.

His first full tank, in town, with the AC blowing hard, was 47mpg.

I have yet to hear what his first highway drive did.

I'd think a Toyota Corolla could come close enough to that 46 overall
number, and that without having any black magic software/hardware that
no one but the dealer can fix.

 

you know, this whole economy thing has really gotten me interested.
especially as you mention the diesel thing. on the one hand, diesel is
more thermodynamically efficient, so it's going to give better economy
anyway, but diesel fuel also doesn't offer the same degree of latitude
for, er, "variance" that gasoline does because it can become smoky, hard
to start, or worse, ruin injection equipment.

since that recent octane thread we had, i've been doing a little more
reading around on the subject of calorific content for gasoline, and
there really is a /huge/ reluctance by anyone [in the california market
at least] to quote figures for the energy content of their fuel. i find
this interesting because all other consumer goods are subject to
performance standards, not least of which is natural gas which is sold
by the therm, not the cubic foot. even gasoline is subject to rigorous
weights & measures inspection with state inspectors certifying pump
calibration at regular intervals. but, think about it, if you're
selling energy not by actual calories [therms in the case of natural
gas] but by volume [gallons], the relevance of the volume measurement is
somewhat questionable if the energy content is variable.

so, what do we have here?
http://api-ec.api.org/about/index.cfm?objectid=4218DF26-FFDF-4A44-90410F150BF14E4E&method=display_body&er=1&bitmask=001002001000000000

and to repeat the most interesting paragraph in the whole page:
"Conventional gasolines also can contain oxygenates. They are added to
help meet octane number specifications and/or to extend the product volume."

extending product volume??? if using ethanol "volume extender", it has
about half the calorific content of gasoline meaning you need to burn
/more/ gas gallons to travel the same journey.

hopefully, the cost impact of this is obvious, but in case it's not,
consider this. imagine you're flying to tokyo from san francisco,
[about 1000 miles] against the jet-stream all the way. the pilot &
engineer carefully calculate their fuel requirement for the journey
based on their payload, known winds, distance, etc. imagine now that
they were buying fuel in gallons and that unknown to them, the energy
content of their fuel had been reduced by 10%. that could leave them
stranded in the ocean by nearly 100 miles. so, while i don't know this
for fact, you have to assume that either there is a base minimum energy
content for aviation fuel, /or/ that the energy content is known at the
time fuel calcs are done.

if there is a base energy content for aviation fuel, why not for cars?
it affects the amount of money i spend at the pump each week. if the
energy content is known, why not for cars? it affects the amount of
money i spend at the pump each week!!!

i'm now /definitely/ interested in this whole oxygenation thing. fwiu,
oxygenates are irrelevant for modern closed loop injection systems, so
could it be that the emphasis on oxygenates are actually the result of
the opportunity to use "volume extenders"???

 

It is true they vary. Diesel is denser than gasoline, and thus
has about 12-13% higher energy content (and about 12-14% more GHG
production) per gallon. Thus that part of the MPG benefit is not
about efficiency, just energy density.

Ethanol has about 2/3 the volumetric energy content of gasoline.

If one uses as much as 10% ethanol, I calculate roughly a 4%
decrease in energy content overall. That's just an approximation.
I'm not sure of the exact value. And I suppose most reformulated
or oxygenated gasoline uses less, so less deviation from "pure"
gasoline (which varies in itself). So yeah, there are energy
density differences, but not huge.

 

you know, this whole economy thing has really gotten me interested.[/QUOTE]

That's the goal: get people thinking and educated.

BTW, my buddy tells me that he gets 52+ mpg with that Beetle on all
highway miles.

I'd *much* rather have a diesel than a hybrid, if mpg is the same and
the fuel is roughly the same cost.

 

a) what are your driving habits like?
b) did you do any research on the hybrids before buying?

 

eh. kinda bores me. seeing all these people shelling out beaucoup bucks
on a new toy trying to justify it by saying itll save a few cents on
gas, and then getting all sentida when it doesnt work out as planned.

wanna save money? buy any small honda or toyota. new or used. wanna be a
little different? get some form of VW diesel, new or used. IIRC them
advertising over 500 miles on a tank, but diesel might take a little
effort to find. and then you have to deal with the VW quirks, like loose
engine tolerances and oil burning.

 

That's the goal: get people thinking and educated.

BTW, my buddy tells me that he gets 52+ mpg with that Beetle on all
highway miles.

I'd *much* rather have a diesel than a hybrid, if mpg is the same and
the fuel is roughly the same cost.
[/QUOTE]

im glad people are buying hybrids, but i think too many get their hopes
up too high. hearing people complain that they arent getting 50mpg, but
only 40 or whatever is as annoying as the guy at work bitching that it
took $80 to fill his suburban.

 

Mine is the Accord Hybrid.

Which would happen if the engine was venting unburnt gasoline on it.
That's not good for milage.

 

That's the goal: get people thinking and educated.

BTW, my buddy tells me that he gets 52+ mpg with that Beetle on all
highway miles.

I'd *much* rather have a diesel than a hybrid, if mpg is the same and
the fuel is roughly the same cost.
[/QUOTE]
i used to do a lot of maintenance work on diesels. in many respects,
they're great, especially for towing. and interesting to drive too - a
huge contrast to a honda where it's all about the revs.

but i /hate/ diesel fuel. i hate it on my hands. i hate it on my
clothes. i especially hate it if i get it on my shoes because it stinks
& you can't usually throw them in the washing machine like practically
everything else.

i'd also regularly see cracked cylinder heads. maybe the newer direct
injections are less problematic, but the older indirect injection
engines would always crack around the pre-combustion chamber. there's
massive thermal cycling & very high pressures in that location so it's
/going/ to happen. depending on the vehicle, many would last well over
100k miles, but even so, cracked heads were pretty much inevitable and
/very/ expensive to replace. old diesel indirects with cast iron heads
often last much better, but they're not immune by any means and i can't
imagine they're used much any more because of weight & emissions.

 

"im glad people are buying hybrids, but i think too many get their
hopes
up too high. hearing people complain that they arent getting 50mpg, but

only 40 or whatever is as annoying as the guy at work bitching that it
took $80 to fill his suburbanan."

If Honda is advertising it at 47/48 mpg, I'd like to know if something
can be tweaked to reach that mark. Should I just sit back and say
"well, 40 isn't too bad"? Hell no. If I'm going to pay the extra few
grand to get the Hybrid over the standard Civic, I want a return on my
investment.

And hearing someone complain about 40 mpg is not even in the same
ballpark as listening to a suburban or better yet, a Hummer owner,
complain about their gas bill. Apples and oranges.