Pulse and Glide or Not

[hdrygas]

Several Prius Chatters have commented on those occasions when it is very difficult or impossible to get the G3 Prius to glide below 40 mph. This happens to me every so often, and no matter how hard I try the ICE kicks in and I generally get a green arrow to the battery. Not every day but every second or third day.
I have been pushing the pulse and glide driving style as well as dead banding since August and have a great route to and from work all under 40mph. I am not completely convinced but I think that those occasions have occurred more often now that it did when I "just drove it" or was using cruise control a lot. As a result of doing this a lot I noticed that the SOC is always at 4 or 5 bars on the Energy Monitor. I have a ScanGage but not the CAN View as yet, so I have a good monitor on the ICE but not on the HV Battery and systems. Other than occasional long down hills going into downtown I rarely get to 6 or 7 blue bars almost never any green. I also am almost never below 4 bars. I also have noted that when I get into what I will call glide prohibited mode 2 other things. First I really have to put my foot in it to get a yellow arrow from the battery. Second if I am at all gentle on the gas I get a green arrow to the battery with ICE operation until the battery is at 7 blue bars then I can again pulse, glide and dead band. If I try to dead band in glide prohibited mode I get that green arrow most of the time. So that is what I have observed.
We know that the HV Battery and HV system will periodically go in to a recondition mode to improve and maintain the HV Battery. Given my observation that my SOC is somewhat lower when pursuing aggressive pulse, glide and dead band, is the battery reconditioning itself during those brief times when I can not get the car in glide mode with the gas pedal? What do folks think?

[Karkus]

I can't answer your question, but I've found an easier way achieve glide - just put it in neutral. Much less tiring on the foot, and guaranteed to stop energy flow from/to the battery. I've been doing pulse and glide that way for months, and its seems fine.
Note that a few people have expressed concerns about being in neutral for extended periods of time (and perhaps at very high speeds) but it's easy to avoid that. Also, some people contend that it is dangerous (and illegal), but I find that I can pay much more attention to the road in neutral than when I'm distracted by watching the arrows to achieve glide (of course the pros can do this without watching).

[hdrygas]

Originally posted by Karkus@Dec 28 2005, 11:52 AM
I can't answer your question, but I've found an easier way achieve glide - just put it in neutral.  Much less tiring on the foot, and guaranteed to stop energy flow from/to the battery.  I've been doing pulse and glide that way for months, and its seems fine.
  Note that a few people have expressed concerns about being in neutral for extended periods of time (and perhaps at very high speeds) but it's easy to avoid that.  Also, some people contend that it is dangerous (and illegal), but I find that I can pay much more attention to the road in neutral than when I'm distracted by watching the arrows to achieve glide (of course the pros can do this without watching).

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And yes you can force glide using Neutral when you encounter the glide prohibited mode, but if you put it right back in D you still can't get glide with the gas pedal, or at least on the one occasion I tried that. I will experiment more with that.

[LaughingMan]

Originally posted by Karkus@Dec 28 2005, 03:52 PM
I can't answer your question, but I've found an easier way achieve glide - just put it in neutral.  Much less tiring on the foot, and guaranteed to stop energy flow from/to the battery.  I've been doing pulse and glide that way for months, and its seems fine.
  Note that a few people have expressed concerns about being in neutral for extended periods of time (and perhaps at very high speeds) but it's easy to avoid that.  Also, some people contend that it is dangerous (and illegal), but I find that I can pay much more attention to the road in neutral than when I'm distracted by watching the arrows to achieve glide (of course the pros can do this without watching).

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I contend that it is dangerous because any transition out of the Neutral gear for emergency acceleration requires more time than stepping on the gas. In addition, for the Prius, you also have to add the additional disadvantage that when you are in Neutral gear, regenerative braking is not applied, so you are stuck with regular hydraulic braking.

That means that it is possible that heavy use of the neutral gear will result in worse efficiency if the brake is used often while in neutral, and more brake pad wear.