I am new to this forum altough I have been lurking for a few weeks now. I have read about the pulse and glide (PG) technique and am trying to put it into practice. I do not need any information about how to use PG at speeds under 41 mph, I think I have that down fairly well. In many cases I have to travel on two lane roads where the speed limit is about 45 to 55 mph, how effective is PG at speeds over 40?
In one post (Tour de Sol) someone suggests 40-50 mph is not a good speed range for the prius to maximize FE, but that 50-60 mph might be better. Can other Prius II hypermilers confirm this, has anyone either experimented or run simulations or is this more of an impression. I seemed to notice that acceleration felt stronger in the 50-60 mph range vs 40-50. Is it more effective to just use cruise control at these higher speeds, or does PG gain some FE over 40 mph. Thanks.

 

Hi,

We are discussing that technique in "Prius Technical Stuff" under the terms "warp stealth." Just today, another poster confirmed having achieved it in another NHW20.

I'm the guilty party based upon my MPG vs MPH charts:

http://hiwaay.net/~bzwilson/prius/

The data from my NHW11 suggests that in the speed range around 42 mph, something is causing a dip in the MPG. I verified this by repeating a weekly commute with 42 mph as the target speed and the MPG hit the dirt. Yet when I repeat the test without speed variations, I can not reproduce the dip. This suggests there is an accelleration / decelleration componet to the performance impact. I continue to investigate the phenomina.

The "warp stealth" mode is new but one early report suggests it is useful in hilly areas. It may also be useful on flat areas but that remains under investigation.

Bob Wilson

 

Thanks Bob,

I will check at Prius technical stuff .

Dennis

 

As you know, the ICE is always spinning above 42mph.
Prius uses a lot of energy just to spin the ICE on warp stealth.
The below chart is came from...
http://priuschat.com/index.php?showtopic=15285&st=26

If your road consists of small up hills and down hills, it'll be easy.
Just pulse on up hill, then glide on down hill.
However, if it is a flat road, you'll be very tired to do P&G to control the sensitive accelerator, then you'll get very few or zero mileage gain.

My bet to drive above 42mph is...
Define your target speed, say 60mph, then set CC at that speed on flat road.
When you drive uphill, cancel the CC, then maintain your speed 56-58 mph manually.
When you drive downhill, maintain your speed 62-64 mph manually.
When you return to flat road, resume the CC for 60 mph.

Anyway, it's up to you.
We don't know how is your terrain and traffic. You can do your own test and you'll find yourself what technique is the best for you.

Good Luck!
Ken@Japan

 

WOW! Where did you get this great chart? Which model is it for? Under what conditions (standard day?)

I've been making my own but never could find anything like it:

http://hiwaay.net/~bzwilson/prius/

It is wonderful to find independent data that correlates with what I'm seeing.

Thank you! Thank you! Thank you!

Bob Wilson

 

Hi,

I am new to this forum . just joined, since I got a call from the Toyota delaer where I had registered for getting a Prius, that the vehicle that I ordered will be in the lot in the first week of June.

I am trying to read the threads now to gain some knowledge on how to increase the Fueld Efficiency of my future Prius. I had heard about the pulse and glide technique. Can someone please give me a detailed explanation (I am sure there is already a place holder for this article .. please send me the link!). I have a conventional mid-size sedan now, and I usually coast on it by turning the engine to neutral as often as Ican without disrupting or causing inconvenience to the fellow drivers on the road. I am sure, Prius will take care of that on its own.

I saw that Bob had referred to a "warp sstealth" mode .. what is that??

Also, he said that he was discussing the Pulse and glide technique in the "Prius Technical Stuff" .. where is that on the website?

Some help to a newbie like me will be greatly appreciated!

I see a very good community here .. and I am very excited to be a part of it!

Regards,
Kamran.

 

Hi,
I'd recommend mastering the FAQ techniques and getting used to the car first. "Pulse and glide" is a lot easier to master after you begin to feel comfortable with the vehicle. It is even better if you get an OBD scanner so you can monitor the critical signals.

"Warp stealth" mode is a new driving technique that maximizes low-fuel consumption at speeds above 42 mph on gentle down slopes. The recommended technique is to have a rapid response, current meter to monitor the battery charge/discharge rate and feather the accellerator to get on a low-current plateau. But this is just a high level synopsis.

The "Prius Technical Stuff" group is found in the http://yahoogroups.com/ area and has folks who like to dig into the engineering details. It really is a technical group as most of them would be a positive member of any engineering team. But if they answer a question, it might not be what you'd expect. For example, if you asked, "How do I change my oil?" You would might get answers citing international oil standards, the molecular weights of various oils and recent lab oil testing results. Many have their own copies of the Prius maintenance manuals with margin notes and OBD scanners or home made instrumentation.

Another group aimed more for lay folks is:

http://priuschat.com/

These folks know where the oil filter and drain plug are located and how much to put in and when. They also know how to program that dang radio and are operator oriented. It is also a place to find after-market products.

Bob Wilson

 

I think I did mention that as follows...

| The below chart is came from...
| http://priuschat.com/index.php?showtopic=15285&st=26

It is for 2004 Prius, and the conditions are posted there as follows...
"This simulation is for 68F, sea level, 40% RH, 29.92", 225 payload, no AC, no wind."

Ken@Japan

 

http://hybridcars.about.com/od/owner...seandglide.htm
Ken@Japan

 

Hi all and thank you for your replies ..

I went through the Prius FAQ posted on this website by Bob and they are indeed very helpful. I like Bob's advise about getting to know and feel your car initially before attempting to perform the FE bettering techniques. I have been reading on the chat forums that people who get used to do PG technique do it with the sound of the engine and by experience, etc. It becomes like a second nature to them .. something like rolling to a stop light so that I dont have to waste gas to haul my current mid-size sedan to bring it up to speed from zero; and other techniques like coasting when I reach a comfortable speed on the road and there is no other traffic trailing behind me and I have to take a turn at the end of the coast (so I have to slow down anyways .. so I dont break very much at the end .. sort of like preserving the momentum ..)

I get between 27-29 mpg in the city. The EP numbers for my car is 24 in the city and 33 on the Hwy. I got 36 (at times 38) mpg when I drove on the hwy last week. I am hoping that some of the techniques that I already know with my car will come to my use with my future Prius also ...

Thank you Ken for posting the link from hybridcars website. i had already read that, but I dont undestand what is siad inthe following lines from that link:

"The speed range that at is best for the Pulse and Glide technique is between about 30 and 40 miles per hour. Below 40 mph the Prius engine can remain off when Gliding. When Gliding above 40 mph, the Prius’ engine spins, even when it is off, which creates extra drag that reduces the distance the Prius can Glide."

Specifically, I don't understand the part about the Prius' engine spinning above 40 mph and that creating extra drag to the car.

On the same point, I read it is in another chat that PG technique can be practiced between any given range of speed .. the writer of that article recommended that the driver should determine the minimum acceptable speed limit and a maximum and practice the PG technique in that range? Now, is there any experimentation done to determine whether this "range" that is being talking about here is best when it is 30 - 40 mph, as done by the famous team of four drivers getting 109 mg!

Also, I dont understand much about the warp stealthtechnique, but as Bob said that I will concentrate of getting to know my car first, and may be the PG technique. I will get to the new technique once I feel comfortable with the car and PG .. By the way, how long do you think is the period of getting to know the car and mastering the PG technique?

Also, thanks Bob again for referrign to priuschat.com I will keep a tab on the chats on that portal as well ..

Thanks people again for your valuable time and suggestions for me!

Cheers!