The myth of pulse and glide

Discussion in 'Fuel Economy' started by Chuck, Jul 11, 2009.


Has pulse and glide worked for you?

  1. Yes

  2. No

  3. What is P&G?

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  1. JusBringIt

    JusBringIt Be Inspired

    Umm..there wouldn't be more cars...where did this come from?
  2. Chuck

    Chuck just the messenger

    I would like a concise answer - two sentences instead of a screen full one the for question I have for Gary and IamIan?

    What are you trying to accomplish?

    Until they reply, I can only assume it's to refute hypermiling as we advocate at CleanMPG and the objective they desire is:
    • That we will agree with them hypermiling is a total waste of time
    • If we do agree with that, shut down CleanMPG as there is no purpose in it
    • Wayne tells the media to forget hypermiling and swears it off
    • People like myself should stop hypermiling and conclude that when I was paying 30% less for gas I was deluded and somehow stealing from Shell...hypermiling is a myth along with the Moon landings (For some, moon landings were all a lie)
    Isn't that a reasonable assumption of Gary and IamIan's agenda?
    Last edited: Jul 17, 2009
  3. Right Lane Cruiser

    Right Lane Cruiser Penguin of Notagascar

    Gary, my route is just over 22mi one way and has 5 stop signs, 1 school crossing, 3 railroad crossings, and 33 stop lights. The posted speed limit varies between 30 and 50mph. I contend that my mileage would increase substantially because this is what happens on that route when other traffic keeps longer following distances and drives slower (as it did last summer with high gas prices):


    This wasn't on a test route or deserted loop somewhere (I don't have such a place around here) -- it was just my trip home from work one day, through traffic, with a moderate tailwind often blocked by trees and buildings along the route. I didn't make all the lights and I did have to come to stops at the base of a couple of hills. I was actually up around 156mpg until I got to the stop-light-every-block 3mi Anoka trek at the very end to reach my house.

    Note also that the SoC is at 18 bars -- right where it had been for a week. The distance is under 22mi due to the amount of FASing done; I don't bother trying to calculate what it would be with that taken into account.

    If you're wondering, the entire tank was done that way and here is where I was at the same time I snapped that photo:

  4. Nevyn

    Nevyn Well-Known Member

    On the highway, yes. But in reality, what is the whole trip average speed? I'm willing to bet it's MUCH lower.
  5. PaleMelanesian

    PaleMelanesian Beat the System Staff Member

    It sure seems to me that this is exactly what you're doing. :eyebrow: Argumentative from day 1, and HUGE pages of text. What's your point?
  6. R.I.D.E.

    R.I.D.E. Well-Known Member

    Post a single quote from any of my posts on this thread that show me commenting negatively about P&G.
  7. PaleMelanesian

    PaleMelanesian Beat the System Staff Member

    How about YOU show us a post of yours that is positive and not argumentative?

    And you didn't answer the question. What are you trying to accomplish?
    Last edited: Jul 17, 2009
  8. cpeter38

    cpeter38 Right Lane Dweller

    I'm confused - you purchased a car without noticing low profile, mag wheels with a 65 PSI fill or the $1800 bill for tires and wheels? I'm also confused about the "sidewall max of 44 PSI" versus the "could be inflated to 65 PSI". Would you please explain?

    I'm trying to come up with the scenario where a hypermiler's "overinflated" tires would be a root cause of an accident. I can come up with some, but they all involve some bad non-hypermiling habits. Even though I can come up with these fanciful scenarios, none of them reach the level of being "illegal".

    While the additional vibration may be unpleasant (and that is certainly the best argument for not "overinflating" your tires), I know every Ford vehicle I have owned would not have an issue with it. Perhaps Mercedes SLKs or Honda Insights are not built with the same high quality parts and careful assembly as Ford vehicles.

    I have to admit that I am a bit surprised - I thought that Honda built almost as good a car as Ford does.

    I have to admit that I am starting to have the same questions as others. Is the point of this to pick at some of the things that hypermilers do to get better fuel economy? If not, why not let those who chose to "overinflate" their tires or travel a bit slower than PSL to do as they legally chose to do. Why spend time on a "hypermiling advocacy" forum when your actions are starting to have the appearance of trolling?

    I know I spend my time here because I have learned a lot, saved a fair amount of money, and am doing my own little part to help the country I love achieve energy independence.

    Why are you on this forum???

    Edited to add: I see other people are also wondering and asking the same questions as me. Have you thought about this? I am serious when I suggest that you spend a few minutes thinking about this ...
  9. diamondlarry

    diamondlarry Super MPG Man/god :D

    Craig, I definitely agree with you there. I'd be willing to bet that my car will handle (when driven by me) better than most cars out there with sidewall max or under inflated tires. Also Craig, I'm having those same questions as you are.;)
  10. Chuck

    Chuck just the messenger

    Maybe not, but it's a bit hard reading thru so many l-o-n-g posts....earlier in this thread it was discussed making things shorter and concise. ;) ;) ;)

    So perhaps you are not that directly negative about P&G or hypermiling, but your assertion it's done in a manner to (1) greatly annoy other drivers, (2) greatly lengthen commutes is exaggerated. While IamIan says it does not work, you are saying it works but is not worth it - not exactly a lot more positive.

    And as Andrew pointed out, you completely dodged my question: what is your objective?

    Doing so is not flattering to you.

    P&G has worked for so many members, so it is strange to be told we should avoid it.
    Last edited: Jul 18, 2009
  11. lightfoot

    lightfoot Reformed speeder

    Not a lot lower. It's about 130 miles from Boston to my house, and it usually takes me almost exactly three hours = 43mph avg. The first ca 8 miles are in Boston traffic, then I have to slow for a few tollbooths, then ca 3 miles of local roads on this end.

    Lower speeds on the Boston end aren't helping my mpg: I was at 45mpg when I finally got onto the Mass Pike today, and at 93.5mpg when I got home. PSL in my town is 25mph, and I usually gain 0.5mpg or so on the local roads at this end. Last week's trip over the same route was similar only I got up to 97.5mpg at home.

    So, no, you don't have to drive 20-25 mph to reach 90-100mpg in an MT Insight-I in the summer.
    Last edited: Jul 18, 2009
  12. Right Lane Cruiser

    Right Lane Cruiser Penguin of Notagascar

    Agreed -- I drove from Coon Rapids, MN to Elkhart, IN last summer with two passengers and a full hatch at targeted speeds around 52mph (faster on downhills, a little slower uphill) and achieved 100.1mpg doing it.

    Blue Swayed loves DWL in the low 50mph range! :D
  13. cpeter38

    cpeter38 Right Lane Dweller

    Here is some objective data:
    Google maps quotes a "normal" daily round trip commute time of 94 minutes for me (not including my gated parking lot. Most of my best days average 102 minutes total commute time. The trip home on weekdays is always 6 minutes longer due to traffic (.8 hours in, .9 hours home). As I calculate it, I am sacrificing 2 minutes a day to reduce my fuel burn from 2.439 gallons per day to .985 gallons per day. That is a savings of 1.454 gallons ($3.635 @ $2.50 per gallon) per day.

    Even if you don't care about the conservation aspects of hypermiling, $109.05 per hour after taxes is pretty good money :D
  14. JusBringIt

    JusBringIt Be Inspired

    I sacrifice MAYBE a minute each my cha ching totals about $48/hr.
  15. cpeter38

    cpeter38 Right Lane Dweller

    I'd be pretty happy with that rate of earnings after taxes too!!
  16. Chuck

    Chuck just the messenger

    Summary: Many have found P&G works and does not cramp their lifestyle or annoy others, yet we are being told it does. May I suggest the naysayers give P&G a more serious try?

    I find the rationale of the opposing points telling us it just does not work very odd while we still go about our lifes saving money at the pump and the this some kind of exercise that if they tell us "the sky is falling" hypermilers will suddendly find themselves paying more to the gas stations, mechanics, and in hosipitalization bills? Kind of sounds like voodoo.

    Again to the naysayers: clearly and concicely state your objectives for this thread.

    To admit we are lunatics, swear off hypermiling and shut down the site maybe?
    Last edited: Jul 18, 2009
  17. iamian

    iamian Well-Known Member

    I agree.

    Congratulations ... those are some great results :woot:

    The kind of results anybody can be proud of... and would be nice if we all can make those kinds of improvements.

    Thank you ... I enjoy some of the discussions as well ... :)

    Don't let some of the others bother you too much ... they mean well ... they just sometimes don't care how and why things work ... It is enough for them just that it works ... the how and why just don't matter to them ... and they sometimes get overly defensive when flaws , errors , or the negative effects are pointed out to them ... don't let it bother you too much ... if you want to discuss the down sides and the plus sides ... me and a few others like me are still floating around here to discuss them with you ... some of us enjoy talking about how and why things work ... some of us don't mind discussing the negatives we currently tolerate... just because there is a down side doesn't mean it out weighs the good /benefits... and identifying the negatives or down sides I think is a good thing.... all the better to then try and figure out how to minimize them.

    Agreed ... and well said :D


    For me there are a variety of costs ... $ , Time, Effort , Environment , etc...etc...

    Sometimes that means a different job has been a better option for me.
    Sometimes that means me selling a house and or moving has been a better option for me.
    Sometimes it means different driving methods.
    Sometimes it means a different vehicle will result in a larger net benefit ...etc..

    Only He knows the answer ... and I think he should feel free to drive any vehicle he wants... it is his money after all... his time ... and his choice to drive any vehicle he likes.

    I suspect that the new vehicle required more money than just continuing to drive the old Insight ... I suspect there are many trips ( like on the highway over the Rockies ) he takes that his new vehicle choice causes him to get lower MPG ... I suspect he could have converted his old Insight to an EV for less $ than he spent on the new car... but... it still doesn't matter ... no matter how much extra $ or gallons he spends to drive his new ride ... he can drive any car he likes... and he seems to do a good job with his new vehicle too.

    I think you should add some other missing requirements ... Wayne would have to obey all traffic laws ... and never drop bellow a set minimum MPH speed... and he isn't allow to push or pull the car.

    Personally I'm not much of the betting type... and I don't know the conditions of the route you have in mind ... so I don't know if 140 or even 200 MPG might be possible ... I don't know enough about the conditions to say one way or the other ... and I think the conditions always matter.

    I also don't think it matters if Wayne can get even 200 MPG on the route you give him using that specific vehicle ... it doesn't affect to me that I still like learning how and why things work ... I like discussing the technical details of how and why things work ... and I like discussing what methods can be used to minimize some issues and maximize others.

    Nice results ... but still cherry picking the situation & it isn't the vehicle challenged to use ... the bet is for him to do it in a specific location, with a specific vehicle .... So If Wayne wants to take the bet and travel there great ... and if Gary looses his bet ... sucks to be him, Wayne can make $2,500 to easily pay for the trip... or if Wayne looses the bet great for Gary he gets $2,500 and didn't have to go anywhere.

    I don't think they have an 'agenda' ... I just think they just don't care how and why the details cause things work the way they do... and maybe they get a bit overly defensive when the negative sides are pointed out.

    That example of using battery alone to travel still stands as a MPG benefit to the use of assist... because no gasoline is less than any tiny amount of gasoline... but I think using that as a Pulse and then Glide down a bit ... then use conventional P&G methods would only gain ~3km or so of no gasoline usage to someone's commute... and it would require them to make the modification to allow the IMA stock battery to be charged from an outside source like a solar panel or something... which to be fair ... can be dangerous considering the high voltages... and that kind of modification is not for everybody.

    But don't worry about it.


    Both... isn't that great :D

    Even +2 pounds of addition weight at the wheel will add unsprung weight issues , due to mass amplifying affects of rotational inertia.

    This is not to say that those issues of unsprung weight are a show stopper ... or that they can not be dealt with ... of course they can be dealt with ... a H2 Tire at 60MPH has significantly more unsprung weight than a Civic Tire at 60MPH... yet the H2 has used methods to compensate for that additional unsprung weight issue.

    You can deal with it... but it just adds something to consider.

    For instance electric wheel motors also add to the unsprung weight ... one option to deal with this additional unsprung weight is what Bridgestone did in 2003 with there:

    Bridgestone Dynamic-Damping In-wheel Motor Drive System
  18. iamian

    iamian Well-Known Member

    Accomplish with what ?? a bit vague of a question ... With my car ??? ... With my testing ?? ... in this thread ???

    But anyway ... Here goes:

    To share & discuss some of the information we each have, ( including the technical details of how and why things work ), so that we each can learn from each other, that which we do not already know.

    To discuss with others how some of those details involved can be minimized and maximized as we wish to achieve whatever goals we might have.


    Is that concise enough ( bad grammar and all ) ?
    Or , did you want to expand on it out more than such a limited form allows?

    I'm sorry you made this incorrect assumption.

    Especially sense, I have never made any such claims.

    I have claimed that attacking A&E or anyone based exclusively on his posted MPG social ranking does not address the post he made. It is a very poor forum etiquette. It only serves to attempt to discredit and put down the person making the claim. I myself find it ethically questionable to rank the value of the ideas , opinions , and personal character of forum members by their MPG social ranking.

    To me personally, it doesn't matter if what he wrote had false conclusions or was misleading. Those would only be reasons to find the flaws in how the data was collected. To find the flaws in the data not collected. To find the flaws in the math used to crunch the data. To find the flaws in the conclusions made from that math... etc... in short, explain where he went wrong... not attack him personally ... explain how and why the details of things work the way they do ... by explaining where it went wrong ... instead of the personally attacks ... new things can be learned and shared and discussed.

    Or said another way... explain why and how you disagree with him and what he or anyone posted... If your only disagreement is that his posted MPG ranking is less than you or less than me or less than Wayne ... as far as I am concerned that is a very poor logic... and fails horribly to address anything being posted.

    I have been doing great ... I have learned lots and lots... which is what I hope to get from experimentation , testing , and studying... and I've had great fun along the way while doing so. :D

    And there is still tons more out there yet to learn :D

    I've tried to relay some of that data and information to others... when they are willing to discuss that information at least.

    You've made it clear you have no interest in discussions about any of the details involved ... and I have many times said I like to discuss those details... so if you just don't care to know or discuss the details of how and why things work the way they do... then just don't .... I fail to see why others like me should be discouraged from discussing the details of how and why things work ... and the details of how and why we might be able to address those details.

    Why? ... Has something changed ??? Do you now want to discuss some of those finer technical details?

    I have not been keeping my results to myself at all... I have offered the data and collection of information I have been massing freely to anyone.

    Why? ... Would you like to discuss some of those finer technical details and issues?

    We can talk like I was before about some of the methods of getting some of the benefits of P&G, without the negatives of the vehicle P&G....

    We could discuss as I started to before some of the variables involved in getting certain types of results when people like A&E did the number crunching... what was missing from his analysis ... how does the ratio of pulse to glide effect the results ... how does the vehicle average speed affect the achievable ratios ... how does different types of routes affect the ratios ...etc...etc...

    We can talk about what factors are effected by changes in the temperature ... things like how does it affect rolling resistance... how does it affect aerodynamic resistance ... how does it affect combustion ... how does it affect the fuel itself ... how does it affect battery behavior ... how do each of these change of time while the vehicle continues to be used ... which of these can affect P&G ... which will benefit it ... which will act negatively ... what are some things that can be done to minimize some of those negative impacts ... what are some things that can be done to maximize some of those positive impacts.... etc...etc...

    Just some people just have no interest in any of the results and details that has been recorded or were trying to be discussed.

    For example:
    The Gen-I Insight ICE's highest efficiencies of converting gasoline energy to mechanical energy are had in the learn burn window ... If the Pulse phase method used brings you out of lean burn ... you will convert less of the gasoline energy into mechanical energy... That is just the truth of that specific ICE... that is not saying that P&G doesn't work... I have never said it does not work ... But details like that still remain correct and true ... at best they might lead us to want to dive into the technical details in P&G in an effort to try and discover what benefits P&G might offer that are countering this known and correct negative issue of any Pulse phase that leaves Lean Burn... if we can discover the how and why it works despite this waste , we might be able to devise strategies to include those P&G benefits without this waste.

    But that is still a specific technical detail ... it doesn't apply to every vehicle or every method of driving... it is only that which it is... nothing more... nothing less.

    If you are tired of it ... ok ... have fun ... best of luck.

    I have no interest in getting into a MPG pissing contest with anybody... if that is all you care about ... then oh well... you wont' get it from me .... if that means you ignore what I write ... ok... feel free.... have fun ... best of luck .. no hard feelings here... :)

    As long as I hold this opinion ... the MPG number anybody gets day to day by itself ... is too limited ... and does not alter or affect the accuracy of any of the data or issues being presented... no MPG number I could post would affect the accuracy of anything I have written... Thus to do so has no value to me in a discussion of what I have written.

    If you have no interest in looking at the technical details of the discussion ... fine ... but that isn't me.

    If someone is just agreeing or disagreeing with someone else based exclusively on a posted MPG number ... or some kind of MPG social ranking system ... that isn't me either.

    Plenty of people can just not care about how or why anything works ... and just keep on driving ... that's fine too ... but it isn't enough for some of us ... some of us .. like to learn and talk about why and how things work ... how they might be improved ...we like to conduct tests and experiments ... we like to learn about things and share some of that knowledge with others... I'm not asking you to start wanting to learn about the details of how and why things work ... and there isn't much point in you trying to convince me to not want to learn more about how and why things work ... To each their own.

    Maybe that is enough for some people ... others want to know more ... some of us like to learn about how and why things work... I admit I don't really understand why you fight against that so much?

    So, sense MPG results are the bottom line ...

    How goes your efforts to travel few miles per year?
    After all 31 MPG traveling 3 miles uses less gasoline than 200MPG traveling 20 miles.

    How goes your efforts to ditch your car completely and do 90% of your travel by bicycle and/or walking?
    After all walking and/or bicycling are so much drastically more energy efficient & cheaper at moving you per mile, than any ~2,000 lbs vehicle is or ever will be.
  19. Chuck

    Chuck just the messenger

    The two opposing points that prompted this question dodged it, then defied it by giving us more chapter-length replies - one of them making an attack on Wayne. Since this is coming from a couple of intelligent people, I'm ruling out they could not understand the question as they continued their business as usual replies.

    The thread ceased to be a discussion long ago - it's behavioral being fed on by a couple that are bent on injecting negativity on something that has been proven to work by many members....makes as much sense as debating heavier-than-air flight in 1904. ;)

    I've heard many complaints of fatigue....we have been patient....if this was face-to-face do you think this topic would have been this extended?

    I don't know if this thread will be reopened....pessimistic given the cooperation after my question.
    Last edited: Jul 18, 2009
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