Adapting Basic Hypermiling Techniques to the HCH-II

Discussion in 'Articles' started by tarabell, Jun 30, 2006.

  1. warthog1984

    warthog1984 Well-Known Member

    There is such a forum. Its called "the Daily Grind":D. Personally, my '94 Dakota gave me many good miles until I sold it this week for a more FE car- a 5 year old Civic.
     
  2. zehelmer

    zehelmer New Member

    Hi, warthog :woot:

    Is it a IMA/Hybrid?

    What's your mpg?

    joe
     
  3. kaumaal

    kaumaal New Member

    Thanks for putting this valuable article. Indeed, the contents in your article helped me a lot to improve my driving skills to obtain high fuel effieciency on my HCH-11. Thanks again!!.
    At present (After driving first 15000kms), my HCH- 11 works 4.0-4.3 L/100Km within city limits and 3.5-4.0 L/100Km on Highway. However, the efficiency seems droped during winter time (0 to -30C) to 5-6.2L/100Km within city limits. The overall efficiency was noted around 5.2 L/100Km before 1st oil change (ie. when milage is less than 10000Km). The article on SAHM (Super Atkinson Highway Mode) by msantos seem very interesting, and I guess my HCH-11 once obtained 2.9-3.5 L/100Km using this technique.

    -Kaumaal.
     
  4. jmelson

    jmelson Well-Known Member

    Thanks much, Tarabell, for your detailed article. I just got a 2008 HCH and am starting to learn how to best use it. My overall MPG has gotten up to 41 now, in about 800 miles of driving. (I know, it isn't broken in yet, and will do better.) Today I filled the gas tank for the second time, and reset the trip B odometer. When I got to work, I saw I had something wild like 57 MPG over about 9 miles of driving. I guess there must be a lot of downhill to work.

    Anyway, it seems like there ought to be a way to make it use the IMA more when driving. When I tought the brake pedal, it is easy to get 8 or 10 green bars, ie. a full-scale reading of regenerative braking. But, I've NEVER seen it go over 4 bars of assist. If the electronic drive can handle extracting 20 Hp out of the motor/generator, it should be able to supply 20 Hp to the motor. Tarabell mentioned the difference between gas pedal movement and gas pedal pressure. Are there truly two sensors in the pedal system? If so, it might be possible to tweak some springs or whatever to allow you to get more of the IMA assist before the engine cuts in. I find it extremely difficult to keep it at 3 bars of assist with the engine off. Just the slightest bump in the road, like a tar strip will cause the engine to start. I can easily tell from vibration when the engine is on or off in that mode, as I think it is running on two cylinders at very low throttle, and becomes very smooth when the engine cuts off.

    Anybody tinkered with the system to get more range of the electric assist before the engine comes on? Tarabell shows some stuff about 80 MPG instantanous milage with the engine running. I've never seen it hold over about 60 with the engine on, but maybe that's because the engine hasn't loosened up, yet.

    Thanks for all the hard work!

    Jon
     
  5. jmelson

    jmelson Well-Known Member

    I just retired a 19-year old Toyota Corolla station wagon with 5-speed. It got about 29 MPG in the city, and 39-42 on the highway. I recently started trying to hypermile with it, andf got the city MPG to 34 or 35. I shut the engine off and coasted down all long hills, and shut it off and coasted up to stop lights. On small cars, the manual transmisson makes a HUGE difference.

    Jon
     
  6. jmelson

    jmelson Well-Known Member

    The rules on when it will auto-stop and when it won't are obviously complicated. It is still a surprise to me every time it doesn't when I expect it to. On one occasion when it was at a light I knew would be a long one, I shifted to N and back to Drive and it autostopped. Other times this didn't work. I used to do this sort of stuff with my Toyota Corolla, but shutting the engine off turns off your turn signals and such.

    Jon
     
  7. jmelson

    jmelson Well-Known Member

    I'd be more interested in an IMA ENHANCER, not inhibitor. It seems to me the range where you can get the IMA working is WAY too small. I'd like the OPTION of making the range of IMA much greater between true coast and starteing the ICE. You can only get about 3 bars, which is maybe 1/4 or less of rated output. There are several series of small hills that I could run all in EV-glide if I could only keep the ICE from starting up on every uphill. The uphills are fairly short, so they shouldn't exhaust the battery.

    Jon
     
  8. Right Lane Cruiser

    Right Lane Cruiser Penguin of Notagascar

    Welcome, Jon!

    The real reason you want to stay away from using IMA is that you have to charge the battery back up -- doing this is ultimately an extremely inefficient conversion of energy from gasoline to electricity with a lot of lossy processes. You end up getting better mileage by avoiding using the battery so you don't have to charge it back up.
     
  9. 06hch2

    06hch2 Well-Known Member

    Welcome Jon,
    I had the same idea when i first got my hch: maximize assist, but i learned over time and with lots of reading here that with this hybrid, as Sean said, you will have better fuel efficiency by AVOIDING assist as much as possible. Its counterintuitive but true. Try it on your usual path tomorrow, and tell us how it went.
     
  10. jmelson

    jmelson Well-Known Member

    Well, I agree that in level driving, this would be true. Taking energy from the engine, through the motor/gen to the battery and back to the motor would be very inefficient. But, this route I drive has a LOT of hills where I can use 3 bars or more of regen. Otherwise I could just let the car accelerate, but then I might get a speeding ticket. On some of the hills I HAVE to regen or I'd really get flying.
    So, it seems that using the energy from the battery, in this hills situation, might be quite useful.

    Otherwise, I agree that as long as you can keep rolling within 20 - 35 MPH, you'd be best without the assist, and just switch the ICE on and off as needed.

    Well, I'll play with it and see if I do better with a lot of coasting.

    Jon
     
  11. Right Lane Cruiser

    Right Lane Cruiser Penguin of Notagascar

    Jon, search the forums for the SAHM mode for the HCH-II.
     
  12. 06hch2

    06hch2 Well-Known Member

    Regen (green bars) is your friend going down hills. Use it to recoup state of charge (soc) lost going up hill. Going up hill in traffic, you can't avoid using assist (white bars), and you can't really avoid it accelerating from a stop in traffic, but try to keep the number of assist bars you are using as low as possible, to slow the loss of soc.

    You don't have to drive only 20-35mph to avoid assist. You can avoid it at any speed, depending on the slope. After you accelerate to desired speed, just back off the accelerator just enough to make the white assist bars disappear. You should see the ifcd bars increase as you do this.

    Coasting, when defined as neither accelerating nor decelerating, is a major part of hypermiling. Just do it without using assist, and you will produce higher fe numbers without causing the dreaded, fe-killing forced regen.
     
  13. jmelson

    jmelson Well-Known Member

    Well, I found this info on another thread about the 2008 HCH having a "SAHM" (Super-Atkinson Highway Mode) and have been getting the feel of holding that mode. I don't have one of the expensive ScanGauge units yet, but I presume I am running in that mode when the instantaneous economy display is running in the 65-80 MPG region. One of the roads I travel has gentle hills for a couple miles, and I was able to hold the economy gauge up there over pretty much the entire length, at about 35 MPH. Quite cool!

    Jon
     
  14. jmelson

    jmelson Well-Known Member

    I did lots of coasting with my previous car, a stick-shift Corolla, and got ~29 MPG in city driving. When I got into more extreme hypermiling, I got that up to 35 MPG, so I do know how to coast.

    I think maybe the 2008 HCH-II has reduced the "affinity" of the assist over previous years, because I have to push pretty hard on the pedal to see any assist when the ICE is running. Mostly what I see is using assist ALONE, and then the white bars all go away when the ICE starts on a steeper hill.

    I've been practicing using the SAHM mode as much as possible around town. It takes a VERY sensitive feel, but sometimes I can hold it for quite a while.

    Jon
     
  15. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi Jon:

    ___35 mph at 1,100 RPM cruising is not SAHM but the std. slow speed gentle cruise as Tarabell has shown with pics of the same in the low speed tests at the beginning of the article. IGN timing is completely different down in those ranges and seeing 80 – 110 mpg should be the norm in a somewhat steady state while DWL low speed cruise.

    ___About your Corolla… 35 mpg using extreme techniques in a Corolla w/ a stick? There are beginner, intermediate and advanced techniques but extreme? Please define because it will not stand up to scrutiny around here and especially with just 35 from a Corolla with a stick. That would be a bad day in a Ranger P/U truck let alone in a Corolla.

    ___Remember that SAHM is a highway, higher speed technique. Holding high FE in an HCH-II from 25 to 38 mph is simply holding high FE at slower speeds due to the just above idling 1.3L ICE.

    ___Good Luck

    ___Wayne
     
  16. rev426

    rev426 Member

    goodjob dude
     
  17. Kacey Green

    Kacey Green Well-Known Member

    I think the coding may have been changed between '08 and '09 when the car has an affinity for assist seems to have changed based on my previous trips in similar conditions (weather and SOC) on the same trips.

    Also I've been down to three bars and have yet to see the "Forced charge" on my '09 (I think I saw it several times on the '08s), am I not looking for the right things? At three bars the car preferred to stick the one charge bar on the display, but by demanding more slightly power I could make it go away.
     
  18. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi Kacey:

    ___The one-Bar of charge showing is forced charging and when stepping into it, it will disappear. That is how I remember the 2008 HCH-II acting during our review of it two months ago as well. We have (2) 09 HCH-II's heading our way for the 48-contiguous states world record next month and I will try and make note of your observations as well.

    ___Good Luck

    ___Wayne
     
  19. Kacey Green

    Kacey Green Well-Known Member

    I see, I also looked back at tarabell's description again, I do see an iFE hit but the car doesn't always go back up to near full, once I did see 3 bars of charge and the car didn't let me cancel that.

    The terrain I drive on is very hilly, we also have some bad tailgaters, I've gone to just ignoring them completely unless they have more than two axles or if someone is hogging the passing lane, I go at or nearly at the limit on one or two lane roads b/c nobody can pass safely in that situation.

    I'd be glad for you to put my through its paces @ CincyMPG. (I also have the solution to the lack of a spinning tuner knob on the navi models for you ;) ) Please tell me more about the 48-contiguous states world record. Is it in competition to the couple with the VWs?
     
  20. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi Kacey:

    ___The 06’s and 07’s would usually force charge back up to six or seven of eight-bars after forced charging similar to the way the Insight and HCH-I’s would act if you let them do their thing. The 08 I dove in July did not do this. It would hang around four to five bars and every once in a while it would slide to four or three. A one to two bar forced charge would begin and SoC would climb back up to only 4 to 6 bars. It would than stop and stick there. It was a little maddening because you could be traveling down the Interstate running the lightest accelerator pedal while DWL and you would lose a bar and you know there was absolutely no assist expended. It appears that the Transverter drops out while the SoC is at a given higher percentage and when it falls back due to overhead, DRL’s, radio whatever, it fires off to bring SoC back up. I think there is current flowing thorough the Transverter all the time but if not, Honda chose a good strategy other than the force charge hit. That thing is nasty :(

    ___About that NAVI equipped radio. I began holding down the Tune button and it would accelerate through the list but it was not nearly as fast as a knob. What are you doing ;)

    ___Good Luck

    ___Wayne
     

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