What If The Hch Was Not A Hybrid?

[EAKSE]

So let me start by saying that I'm pretty happy about my recent purchase of a used HCH. I'ts a pretty good automobile that handles well and has good fuel econmy with reasonable comfort.

I've been driving for about a quarter of a year on a commute of 60km and no hills ( a few light inclines). It's been wintertime although it's been one of the warmest ones on record. So far my best tank has been 52 MPG combined. I would think that a great success but really I feel I have had to work incredibly hard to achieve that. I've blocked the rad, bought a scanguage, rarely go aver 2000 rpm, glide on every opportunity and drive generally 10 kph under the speed limit (unless I find a truck to (safely) draft behind... even then I look for a slow one). I take an incredible amount of care to not engage the IMA so I don't lose by recharging.

I have not noticed any problems with recals which are fairly infrequent. However at the end of my return home I park my car with about 7-8 bars. In the morning I usually have 3-4 bars and I spend 20 km or so recharging with one green bar or maybe 2. obviously this is affecting the mileage negatively.

So I kinda wonder what the point is. Imagine that the HCH didn't have the weight of a battery or the weight of an electric engine. Sure the car would be down 20 hp and would slow down on every hill but I'm doing that on purpose now so I don't have to engage the IMA! I wonder what my mileage would be in this car would if I continued to drive using hypermiling techniques.

Does anyone else have the same thoughts I do on this?

[MaxxMPG]

What you are describing is the Honda 2012 Honda Civic HF.
The EPA says 29/41, but Wayne pretty much doubled those numbers.
The HF model has the wheels/tires of the hybrid, its aero tweaks and other enhancements, and an engine that has hidden Atkinson valve timing at steady speeds.

[lightfoot]

The SOC drop overnight is worrying. My Insight-I doesn't do that. Perhaps there is a current drain somewhere, or perhaps your battery is getting weak??

A few other thoughts that might help:

- You don't say how fast you are driving. On multilane highways slowing down a bit more than 10kph could help. I routinely run at 50mph on 65mph roads around here: that's roughly 25km/h under the PSL. I keep an eye on traffic behind me and if the road is fairly clear I may let the speed drop a bit more, until the next pack approaches. On two-lane roads it's best to run at the PSL if anybody is behind you - but if not, hey, do what you want!

- AC - I assume you aren't using it except on intolerably hot days? Around here, people cruise around with AC on in 70 degree weather!

- Tire pressures - I assume you've raised them?

- "to (safely) draft" is an oxymoron: if you're far enough back to be safe (3-4 seconds), the draft benefit diminishes to almost nil. It also locks you into whatever the truck is doing, which means you are locked out of most useful hypermiling methods. Around here trucks move right along, so my aero drag is lower driving at a lower speed than the net would be from driving at their higher speed and subtracting any draft benefit from the truck. Aero drag goes as the square of the speed.

- Are you using cruise control or are you letting your speed vary with the (limited) variations in terrain on your route? Basically DWL.

- Sounds like you're using DWB too?

- Here's a thread that may help: http://www.cleanmpg.com/forums/showthread.php?t=1306

Finally I looked up the weights of the current HCH and Civic HF: 2853 vs 2698lbs, or 155lbs heavier for the HCH. Yes the present HCH has a Li battery and yours is NiMH, so you'd have to look up the weight in your manual. But I think we're looking at the weight of one medium-sized passenger. I suspect the effect of that amount of weight on mpg would be minimal. Probably somebody here has tested that!

[lightfoot]

Originally Posted by EAKSE

I have not noticed any problems with recals which are fairly infrequent. However at the end of my return home I park my car with about 7-8 bars. In the morning I usually have 3-4 bars and I spend 20 km or so recharging with one green bar or maybe 2. obviously this is affecting the mileage negatively.

Your battery might be suffering from internal charge leakage (not liquids, don't worry!) and so might benefit from rebalancing. Mike Dabrowski (http://99mpg.com , (860) 935-5569) makes a hybrid battery grid charger and a harness for the HCH-II. He says the harness for the HCH-II is a bit tricky to install, so perhaps watch the installation video at: http://www.youtube.com/user/99MPG
The charger slowly brings the battery to 100% SOC (above the normal max Honda uses) to try to bring the cells into balance. It may also be helpful to cycle the battery using a discharger:
http://99mpg.com/Projectcars/packdischarger/
My Insight-I is on one of his chargers right now. No particular problems, just trying to keep it in shape because I use the car less now that I'm not commuting. The charger isn't cheap but it has all sorts of safeties built in (measures battery temp, runs the car's battery fan, etc) and is way cheaper than a new or rebuilt battery!!

[Mendel Leisk]

If this grid charging is beneficial, it's too bad Honda isn't taking the initiative and offering such a service through it's dealerships.

[EAKSE]

Originally Posted by lightfoot

The SOC drop overnight is worrying. My Insight-I doesn't do that. Perhaps there is a current drain somewhere, or perhaps your battery is getting weak??

OMG I hope not! Certainly it is a consideration but since I dont have re-calibration I think (hope) things are operating within specs for a car of this age. I am very new to this car and I doubt I can tell with any certainty without the IMA light coming on or frequent re-cals.

A few other thoughts that might help:

- You don't say how fast you are driving. On multilane highways slowing down a bit more than 10kph could help. I routinely run at 50mph on 65mph roads around here: that's roughly 25km/h under the PSL. I keep an eye on traffic behind me and if the road is fairly clear I may let the speed drop a bit more, until the next pack approaches. On two-lane roads it's best to run at the PSL if anybody is behind you - but if not, hey, do what you want!

My commute is about 95 % of my total mileage and it consists of approximately 95 % mutlilane highway and 5% urban stop and go.My highway speed varies between about 85 kph and 105 kph depending on if I have a long stretch with a down slope (there are 2 spots on the drive where I approach 105 kph each way).


- AC - I assume you aren't using it except on intolerably hot days? Around here, people cruise around with AC on in 70 degree weather!

I've only had the car since January so AC isn't a factor. If it is warmer (crazy warm weather this year) I just turn it off.

- Tire pressures - I assume you've raised them?

Yes I forgot to mention that. I'm running about 48 psi on both front and rear. stated sidewall is 44, They are tiger paw somethings but I dont see anything saying they are LRR


- "to (safely) draft" is an oxymoron: if you're far enough back to be safe (3-4 seconds), the draft benefit diminishes to almost nil. It also locks you into whatever the truck is doing, which means you are locked out of most useful hypermiling methods. Around here trucks move right along, so my aero drag is lower driving at a lower speed than the net would be from driving at their higher speed and subtracting any draft benefit from the truck. Aero drag goes as the square of the speed.

I'll give you this one. I experimented with this on the drive home tonight. By driving t a lower speed (about 90 kph) I was able to achieve a consistently lower fuel consumption.There are probably other factors like temperature and crosswinds but I have to agree that the trucks are making me drive faster. I reasoned that despite moving faster I would still gain. although I read it here before this it took this experiment to be certain.

My route is the second busiest in North America so I will tell you from experience that 2-3 seconds is an invitation to be cut off or just delayed. truck or car.... However I am slower and change lanes less then everyone else.

- Are you using cruise control or are you letting your speed vary with the (limited) variations in terrain on your route? Basically DWL.

Basic question...No to cruise

- Sounds like you're using DWB too?

Driving without brakes? Hell yeah.

- Here's a thread that may help: http://www.cleanmpg.com/forums/showthread.php?t=1306

Finally I looked up the weights of the current HCH and Civic HF: 2853 vs 2698lbs, or 155lbs heavier for the HCH. Yes the present HCH has a Li battery and yours is NiMH, so you'd have to look up the weight in your manual. But I think we're looking at the weight of one medium-sized passenger. I suspect the effect of that amount of weight on mpg would be minimal. Probably somebody here has tested that!

I still wonder if I wasn't recharging while using hypermiling habits in a car of this size and engine tech if I wouldnt be ahead.

That was an awesome reponse and thanks for your effort!

[EAKSE]

Originally Posted by lightfoot

Your battery might be suffering from internal charge leakage (not liquids, don't worry!) and so might benefit from rebalancing. Mike Dabrowski (http://99mpg.com , (860) 935-5569) makes a hybrid battery grid charger and a harness for the HCH-II. He says the harness for the HCH-II is a bit tricky to install, so perhaps watch the installation video at: http://www.youtube.com/user/99MPG
The charger slowly brings the battery to 100% SOC (above the normal max Honda uses) to try to bring the cells into balance. It may also be helpful to cycle the battery using a discharger:
http://99mpg.com/Projectcars/packdischarger/
My Insight-I is on one of his chargers right now. No particular problems, just trying to keep it in shape because I use the car less now that I'm not commuting. The charger isn't cheap but it has all sorts of safeties built in (measures battery temp, runs the car's battery fan, etc) and is way cheaper than a new or rebuilt battery!!

I'll check it out thanks!

[lightfoot]

Originally Posted by Mendel Leisk

If this grid charging is beneficial, it's too bad Honda isn't taking the initiative and offering such a service through it's dealerships.

Yes it is too bad. But offering this service wouldn't be simple:
- This charging uses a special programmable charger that monitors battery parameters (temp. voltage, etc) during charging and adjusts charging according to these variables and your presets
- Charging my Insight-I battery from "empty" (probably really 20%) to 100% yesterday took 10 hours. Discharging was relatively quick because I have MIMA and can drive with heavy assist while blocking regen. It might take longer to do in a shop. A few charge/discharge cycles could take a several days in the shop??
- A special harness with a circuit board, temp sensors, and taps into the IMA battery fan must be installed. Don't know about the HCH, but for the Insight-I the IMA battery must be removed (which involves unscrewing about a zillion fasteners). Probably a stretch for many dealerships??

Basically you're converting it into a PHV, minus the revised hybrid programming.

It would be great to see Honda build in grid charging capability to all its hybrids.

[GordonLightfoot]

I've asked the same question, and am going to run my HCH without the battery if/when it dies.
It is NOT the same as a new HF. I've checked them out. While the HF has LRR tires and some areo mods, it has the same 1.8 motor as the other Civics, not the 1.3 like we have. Big difference. The reason being is that the average buyer would not accept the slower acceleration of an unassisted 1.3. But slow is fine for most of us on here who drive efficiently.

GL

[lightfoot]

Originally Posted by EAKSE

My commute is about 95 % of my total mileage and it consists of approximately 95 % mutlilane highway and 5% urban stop and go.My highway speed varies between about 85 kph and 105 kph depending on if I have a long stretch with a down slope (there are 2 spots on the drive where I approach 105 kph each way).

Sounds good, but you don't HAVE to speed up on the downslope. You can simply maintain speed and get a bit more mpg and perhaps some regen.

Originally Posted by EAKSE

Yes I forgot to mention that. I'm running about 48 psi on both front and rear. stated sidewall is 44, They are tiger paw somethings but I dont see anything saying they are LRR

If they're not LRR that could cost you a bit of mpg. Insight-I is very sensitive to tires, don't know about HCH.

Originally Posted by EAKSE

I'll give you this one. I experimented with this on the drive home tonight. By driving t a lower speed (about 90 kph) I was able to achieve a consistently lower fuel consumption.There are probably other factors like temperature and crosswinds but I have to agree that the trucks are making me drive faster. I reasoned that despite moving faster I would still gain. although I read it here before this it took this experiment to be certain.

I did something similar with my old Subaru: ScanGauge showed I could do far better P&G 50-60mph than I could drafting a semi as close as I dared, unable to P&G, DWL, or even anticipate.
There's also mythbusters data showing that draft benefit declines rapidly with distance:
http://en.wikipedia.org/wiki/MythBus...ting_For_Money
11% at 100 feet, but they didn't get data for safe following distances of 2-3sec (80 feet/sec at 55mph, so 160-240 feet). For comparison, slowing from 65mph to 55 would decrease aero drag 28%. Don't know how much this would reduce tire resistance and frictional losses and don't know how ICE efficiency would be affected the lower power output needed at 55mph.

Originally Posted by EAKSE

My route is the second busiest in North America so I will tell you from experience that 2-3 seconds is an invitation to be cut off or just delayed. truck or car.... However I am slower and change lanes less then everyone else.

When someone cuts into my "cushion", I try to think of it as them handing me a "cookie": an excuse to slow a bit more and gain a bit of mpg.
As one of the slower vehicles on the road, it's pretty rare that I have to slow down for anybody. I almost never leave the right lane; when I do it's a Major Event!

Originally Posted by EAKSE

I still wonder if I wasn't recharging while using hypermiling habits in a car of this size and engine tech if I wouldnt be ahead.

Thanks! That might explain some of the problems Honda has been having with IMA batteries in their older cars. If they develop imbalances and internal leakage, the car may go into regen for a long period after startup, which would drop the mpg versus what the owner was getting when the car was newer. Forced recals and IMA lights might not be triggered by this condition.

Originally Posted by EAKSE

That was an awesome reponse and thanks for your effort!

Hey thank you for making me think about this stuff!