Adapting Basic Hypermiling Techniques to the HCH-II

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

  1. tigerhonaker

    tigerhonaker Platinum Contributor


    I could make this a much longer reply to this question you ask:

    I'm just trying to see if the HCHII can dog it out with a prius II in 1 or 2 miles gridlock traffic jam.[/quote]

    However the Short Reply is: NO The HCH II is never going to match up to the Prius II in the City Stop and Go Traffic. They are different designed Drive-Trains:

    Terry (tiger)
    BTW, Sorry if you were looking for a more Lengthy Exotic Reply. The answer in short is, NO.
  2. hobbit

    hobbit He who posts articles

    That's too bad, and I still think could have been solved with
    a relatively simple means of decoupling the IMA from the engine.
    I *love* what the Prius does in traffic jams -- only in the
    very longest ones or uphill do I ever have to light the ICE at all.
    Some of the people around me don't understand the pace time-
    averaging game I usually find myself playing, but these days I
    see other people doing some of that too. And the long gaps really
    do help straighten out the flow and leave plenty of room for
    those who need [or think they need] to maneuver.
  3. philmcneal

    philmcneal Has it been 10 years? Wow

    aw tiger you got me excited for a bit there! since tarbell says she can move the car with just ev assist if your lucky enough, but I guess that's not a move you can do anytime unlike the prius.

    Just godda keep saving my pennies ;)

    thank you for the replies tarabell and msantos, you have killed any delimma I had about the car ;) in all honestly though in the hands of the hypermiler I think the hchII can give it a good fight... well for a good reason too since its cheaper to buy a hchII than a prius at the moment ;) I mean c'mon how often do you get stuck in stop and go anyhow ;)

    Even in my worse stop and go, I find it easy enough to get up to the minimum speed that is required autostop to work, i guess what really wastes the hchII gas is when you use a high ratio to get the CVT going (as opposed to the prius relying on pure EV but that EV came from somewhere.... the ICE!)
    Last edited: Sep 14, 2006
  4. tarabell

    tarabell Well-Known Member

    Hi Phil, finally getting time to type out my 2 cents here.

    Basically Tiger said it all. But here's a few ways the HCH-II would react in your situation, just so you know.

    If you can build a big front buffer and maintain constant speed of at least 12mph, yes you can glide in EV w/assist pretty continuously. But it takes a bit of attention/care from the driver to keep it up. For a mile or so it won't be a big hit on your battery, but after 2-3 miles it would.

    If you're talking going 5-8mph it's harder because the car stutters and jerks right around there, and you can't really do EV.

    But if it's truly stop and creep, you're hosed because the autostop won't repeat unless you've reached some min speed (I forget, like 7mph). So you'd have to let enough of a gap form in front of you each time so you can get up to speed. Otherwise, I've just turned my engine off a few times rather than let it idle.

    So in all the situations above the Prius definitely wins AND would be easier on the driver ;)
  5. msantos

    msantos Eco Accelerometrist

    Hi all;

    I second Tarabell's comments in regards to the duration of crawling traffic and the impact on your FE.

    In my case, I incur most (if not all) of my milleage in city only streets and the stop and go traffic can definitely sink our FE to disapointing numbers. Keeping a buffer with the traffic ahead and reducing the forward advances helps a great deal especially if we do it to ensure that the autostop feature kicks in. I also try to minimize the EV assist because quite frankly, I use A/C (in Auto) throughout the year (cooling and defogging) and I prefer it to operate solely on the electric scroll compressor side only. Opening the windows is not an option because of the dust, smoke and pollen. :eek:

    So far however, I have managed to somewhat offset the negative impact of stop and go traffic but it is alot of work. I do cheat too! I often tune the radio to a local station to listen to traffic hot spot annoucements. When one is reportedly ahead of me then I will try to pick an alternate route. If I can't then it is time to take it easy and work on that buffer, watch at the traffic ahead and manage my accellerations.

    On a somewhat related note:
    I stopped responding to another thread concerning an HCH-2 mod that I'm involved in. Mostly because I did not want to hi-jack the thread. In any case this appears to be a better place for this (at least contextually).

    As soon as we get our IMA inhibit module working well on my colleague's HCH-II, I will put up some pictures of the module and foot switch (no schematics at this moment ;) ). Please PM me if you need additional details.

    For those that are not aware of the previous conversation, we are attempting to develop a user installable IMA assist inhibitor kit. This kit will allow the driver to temporarily cancel the IMA assist at will therefore promoting a better SoC among other things. Since we're both engineers (my friend is a professor at a local university) we've fancied this and other features for a little while. We are also using it as a project for a set of his students. It's his son's car actually :rolleyes:

    Anyhow, as a set-back, we blew his MCM and the part is now on order. I suspect that we'll have to monitor more IPU inputs not just the MCM's. After talking to our contacts at Honda Canada, we'll probably have to add OBD monitoring, but we're also trying to avoid scope creep - after all, this is supposed to inexpensive and fun.

    In any case, these are all little tricks that could help those of us that drive mostly in city traffic. And yes, for now the Prius is the better vehicle for stop-and-go city traffic. ;)


    Last edited: Sep 13, 2006
  6. tarabell

    tarabell Well-Known Member

    I made some (mostly) minor updates to the article. One addition is in the Foot Pressure section, with my observations of greater pedal sensitivity when driving shoeless. While it felt strange at first, after many weeks I can say I feel more normal driving without a right shoe than I ever did with it. I would worry more about my ability to make sudden stops safely if I was doing higher speeds, but since these days I drive in the right lane with max speed=55mph, this no longer seems an issue. Not only that, there’s a {{ lot }} to be said for the fun factor. Still I warn that it’s not for everyone, and to consult your physician, lawyer, state police, insurance agent, priest and maybe your mother before trying this at home.
    Last edited: Oct 8, 2006
  7. bear15

    bear15 Well-Known Member

    Just a quick question. Where is your updated article?
  8. tarabell

    tarabell Well-Known Member

    Hi Ed & Drew--

    You can either go to the top of this thread (page 1) -- or go to the homepage and click on the first article "Adapting Basic Hypermiling Techniques" in the right column, under the "articles" bar.

    Also, welcome to the site from me. :)
  9. diamondlarry

    diamondlarry Super MPG Man/god :D

    LOL! Thanks for the laugh. The problem is, it's probably not that funny to some people.
  10. dalew75

    dalew75 New Member

    Hi Tarabell,

    Great article! I've already used a lot of your techniques. I am a new owner of a 2006 HCH for about 3 weeks now. I started out getting around 43-45 MPG, but am now learning to get around 50MPG for my commute (which has some significant hills, and takes place in fall in New England - about 50 miles round-trip).

    Over the last few days, I've noticed a big improvement by using a pulse and glide technique. Basically accelerating quickly, so the assist meter jumps high or maxes out, and then coasting on my newfound momentum.... I've been able to get right around 50MPG for my commute over the last 2 days now.

    In your article, you described the technique to go from Regen to Glide to EV-Assist mode. I am able to employ this technique, but for me the most EV-Assist bars I can get doing this, without engaging the ICE is about 3-4 bars. From what I can tell, this assist isn't doing anything to help me along more than a normal glide does.

    Sometimes my issue is not being able to utilize the assist mode (and battery) enough, and my battery is often near maxed out. The quick acceleration helps to utilize it, but I'm wondering if there are other techniques to utilize it more without having to also use a lot of power from the ICE?

  11. xcel

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

    Hi Dale:

    ___Although assist can reduce your Fuel consumption for a given accel, the payback to bring the pack back to the equivalent SoC is not parity. It costs a ton and your 50 mpg - 50 mile segments are telling a story here. Stay out of the pack as much as possible. When in EV-Glide, minimize the number of bars of assist by slowing or gliding without assist as best you can.

    ___The whole point of P&G which was not emphasized in this article is to minimize the conversion of energy to/from the pack. Hidden charging is not a bad thing to bring her back up to 7 of 8 or to maintain the normal overhead of running the electronics but charging to replace what was consumed by an overaggressive assist regiment will see your FE sink overall. Reread Tarabell’s article carefully as she is not promoting the use of Assist except to show you what is and is not available under very specific regiments as well what you will see during the various modes on your HCH-II’s instrumentation. Use your HCH-II’s assist capability sparingly. I cannot emphasize this enough. Dropping the hammer and using all she is worth is not the best way to receive the highest FE.

    ___Good Luck

  12. dalew75

    dalew75 New Member

    Hello Wayne,

    Thanks for the reply. Here's the thing with me.... I've never been hit with the scenario of getting a forced charge, so to me it seemed like I wasn't able to utilize the assist mode enough. And so I've never had the FE hit of a forced charge. On occasion my SOC gets to 5 bars, but never any lower so far in my first 1200 miles or so.

    My question centers around getting good mileage in a hybrid versus any normal ICE car. Sure, I can glide without assist and get better mileage, but I cannot always maintain speed, and mainly, I'm not doing anything different than a coast in a normal ICE car (except for the fact that you can do so without any fuel reaching the cylinders?)

  13. xcel

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

    Hi Dalew75:

    ___If you can maintain 5 bars or above SoC throughout your commute, you are doing great! Using assist is more a performance addition then a FE one. Filling that pack back up is not free although it may look like it is under a hidden charging scenario. Hopefully you see the SoC slowly climb one bar at a time w/ no bars of Charge showing while driving down the freeway at 55 mph +.

    ___Gliding is not about maintaining your speed but slowly bleeding it off while waiting for the best opportune time to re-engage and bring her back up to a target speed. Let us consider a DWL scenario. The HCH-II can be used far different then any other hybrid in that you can re-accelerate on the back side of the hill/overpass under EV or let gravity take over while you are in a full blown glide at highway like speeds depending on the length and angle of the slope you are coming down. Coasting is the key to much higher FE and if you can hold onto a Glide without regen or assist, you are gaining the best of both worlds by comparison to either a hybrid or non-hybrid in fuel cut with regen or ICE-braking in either. Try and use this sentence as a guide. The further you can glide ICE-Off/Fuel Cut, the higher your FE will be. Place this statement in your head under all driving conditions and scenarios and you will find the HCH-II paying you back with 70 mpg type segments once warm and traffic allows some leeway with your newly learned techniques.

    ___Good Luck

  14. mistyz23

    mistyz23 Active Member

    Thank you so much for this amazing write up! I read it once over a couple of days when I first got my HCHII 2 months ago. I was a little confused simply because it was all new to me. I was so excited when I got my first 52mpg avg tank! Well, I revisited this article and it CLICKED. :woot: I concentrated hard on my gauges and didn't care if even truckers were passing me up while going 55-60. The result-- 74 mpg avg over 70 miles!!! Holy cow, what a change. The segment in question has a huge valley and hills with an intimidating incline on the 580 freeway just before the 205 junction (SF Bay area, California, nearing Tracy). I managed to get a 4 mile glide going downhill! The return segment I managed 50mpg, but my previous trips avg'd about 41-43 on this hill. Still a massive improvement.

    I'm really looking forward to re reading this article again and again until it is second nature. Thanks for taking so much time, Tarabell!
  15. ngzcaz

    ngzcaz Member

    Well done article... if you have the bucks to have that type vehicle. How about the rest of us that are relagated to the real world driving 8 to 15 year old vehicles ? Is there a forum that specifically deals with older vehicles ??

  16. tarabell

    tarabell Well-Known Member

    Hi NGZ and welcome to the site. I counted 14 pre-1990 non-hybrid vehicles in our mileage database and there are many more nonhybrid cars there at least 10 years old there, so somebody is hypermiling them. Try also doing a search of posts using your vehicle model as keyword to find some tips. Or post your question in the appropriate automobile forum here:

    Hypermiling feels most effective and productive when you have instrumentation/feedback gauges, otherwise it can be frustrating driving 'blind'. That's why for non-hybrids we recommend you get a scan gauge. It's an investment and not always suited to certain older vehicles but if interested check out the scangauge forum for more posts and details. Its certainly cheaper than shelling out for a new car.

    This is also a helpful article:
  17. Asystole

    Asystole Member

    Great article, have read it more then a few times and passed it on to other that are giving some thought to purchasing the HCH II. At least one so far will be purchasing on at the end of this month, plus the city I work for gives us $2000 for doing so. It is a win-win situation.
  18. 2008 Civic Hybrid

    2008 Civic Hybrid Serious Hypermiler

    Wow! Fantastic article. I wish the HONDA sales know their product half as well. Well done and a BIG thank you.

    I have just got delivery of my new 2008 Hybrid. Will apply what you mentioned in the article back in June 2006. I am sure it will work.

    I have a question. I read about the wear and tear on the engagement and disengagement of the auto transmission when we use PULSE & GLIDE. Will this apply to the CVT as well? Has anyone out there having transmission issue? Or is the Civic Hybrid build with CVT to handle the PULSE & GLIDE mode more effectively than the normal transmissions? I know CVT uses steel belt that does not shift gears as in manual or other auto vehicles.
  19. koreberg

    koreberg Junior Member

    All my cars are over 10 years old. I consistently get 5-7mpg better than my wife when driving our minivan, luckily it has a builtin fe gauge. I'm still working on my first tank in my del sol. I have found that a vacuum gauge helps some, once you learn how to read it. There is also older posts about a supermid, but its installation looks a lot more daunting to me than simply plugging in a scan gauge.
  20. st_judas

    st_judas New Member

    I wanted to drop by and say thanks, Tarabell! This article helped finally put me over the top to buy an '08 HCH. Well written, and very informative. Thank you.


Share This Page