I got the Glide part, but how do I Pulse?
#1
12-09-2005, 12:14 PM
I got the Glide part, but how do I Pulse?
In the 92.2156 mpg thread, in one of Wayne's posts (quoted below) he describes in detail how to pulse, but I can't get my Prius II to accelerate using only the ICE to power the wheels. Can Wayne or someone provide more details?
Basically, after I glide to 31-33 mph, I start pressing on the gas pedal and I first get only orange arrows (from the battery to the MGSet then to the wheels). If I push a tiny bit harder, I get a combination of pink arrows (from the ICE to the wheels) AND orange arrows. So then I let off a bit on the gas, and I'm able to get pink arrows (from the ICE to the wheels) and a green arrow (from the MGSet to the battery), but the Prius isn't accelerating, it's just maintaining speed.
How do I get the magical pink arrows-only stage AND accelerate? How many seconds (or minutes??) would you say it takes you to accelerate back to 41 mpg on a proper Pulse? And what color arrows would you see on a proper Pulse?
Wayne wrote:
Basically, after I glide to 31-33 mph, I start pressing on the gas pedal and I first get only orange arrows (from the battery to the MGSet then to the wheels). If I push a tiny bit harder, I get a combination of pink arrows (from the ICE to the wheels) AND orange arrows. So then I let off a bit on the gas, and I'm able to get pink arrows (from the ICE to the wheels) and a green arrow (from the MGSet to the battery), but the Prius isn't accelerating, it's just maintaining speed.
How do I get the magical pink arrows-only stage AND accelerate? How many seconds (or minutes??) would you say it takes you to accelerate back to 41 mpg on a proper Pulse? And what color arrows would you see on a proper Pulse?
Wayne wrote:
Originally Posted by xcel
___The “Pulse” phase is a lot trickier imho because so far, I have performed the technique improperly given the multiple back and forth E-Mails I have sent and received today. What you want to attempt to do during a “Pulse” phase is to let the ICE send all of its energy ONLY to the wheels during an acceleration and nowhere else. This phase of operation in a Prius II is called the dead band state and it simply means all power flows from the ICE to the MGSet, the MGSet to the wheels, or MGSet to the pack have been diminished to 0 or as close to this as practically possible with the instruments available in the Prius II for one to view. I have not yet achieved this dead band state because I always had flow to both the wheels and the pack during all Pulse attempts I held. I need some more experiment time or direct coaching which is what I will hopefully receive from Krousdb next Tuesday afternoon. To get there … In my time behind the wheel of Carl’s loaded - NAVI equipped Prius II, I just gently stepped on the accelerator enough to get the ICE to spin up and provide propulsion with the energy screen showing ICE power to the wheels (and power to the pack) while the digital readout was showing between 30 and 55 mpg for the acceleration back up to 41 mph.
___To put it all in a nutshell, you want to accelerate up to a maximum 41 mph, begin the “Glide” phase and slow to no less then 31 - 33 mph. Once the 31 - 33 mph target has been hit, you want to begin the “Pulse” phase and re-accelerate back up to a maximum 41 mph.
___To put it all in a nutshell, you want to accelerate up to a maximum 41 mph, begin the “Glide” phase and slow to no less then 31 - 33 mph. Once the 31 - 33 mph target has been hit, you want to begin the “Pulse” phase and re-accelerate back up to a maximum 41 mph.
#2
12-09-2005, 03:10 PM
Pretty Darn Active Enthusiast
Join Date: Jan 2005
Location: Eastern Washington State
Posts: 443
Re: I got the Glide part, but how do I Pulse?
This is why I'm not doing, nor am I concerned about pulse and glide. The deadband he is describing happens quite a bit naturally based upon the speed and power demands you are making out of the vehicle and what the vehicle believes it needs to do to maintain the ground speed you wish. However, the descriptions of the pulse and glide action seem much more complicated than I woudl desire and as such it would take a lot of fun out of the driving experience for me.
#3
12-11-2005, 08:26 PM
Re: I got the Glide part, but how do I Pulse?
Hi StevenAlice:
___When I wrote that up, I had just a few hours on my own behind the wheel of the Prius II so forgive me of my inexperience. You want to see the ICE to the wheels and the ICE to the MGSet back to the pack on the pulse for best results as described.
___Let me ask how your car is setup (tire pressures, oil type, and oil level), have you had the ECU update, and what kind of temps are you performing P&G’s in? All of these can and will make a difference as to the P&G’s FE capabilities.
___JeromeP, it is everybody’s right to skip a particular technique, setup, or general driving habit(s) but if you want to maximize your FE, the P&G technique in the Prius II is about as easy as it comes. After an hour or so, it will become second nature … if you want it too! Given the Prius II’s ICE can take acceleration rates from 17 mpg’s all the way up to 50 + mpg’s during the pulse for an honest to goodness 100 + mpg cycle, segment, or tank in warmer temps, you can use it in any slow down and just about any heavy - congested traffic tie up for accelerations as long as you are below 41 mph. Even above 41 mph, you can still use regen down to 41 mph and Glide down the rest of the way when coming to a stop. The technique as taught to me by Krousdb is really that good in the Prius II and I highly recommend that you learn its nuances ASAP. Your FE will skyrocket afterwards.
___Good Luck
___Wayne R. Gerdes
___When I wrote that up, I had just a few hours on my own behind the wheel of the Prius II so forgive me of my inexperience. You want to see the ICE to the wheels and the ICE to the MGSet back to the pack on the pulse for best results as described.
___Let me ask how your car is setup (tire pressures, oil type, and oil level), have you had the ECU update, and what kind of temps are you performing P&G’s in? All of these can and will make a difference as to the P&G’s FE capabilities.
___JeromeP, it is everybody’s right to skip a particular technique, setup, or general driving habit(s) but if you want to maximize your FE, the P&G technique in the Prius II is about as easy as it comes. After an hour or so, it will become second nature … if you want it too! Given the Prius II’s ICE can take acceleration rates from 17 mpg’s all the way up to 50 + mpg’s during the pulse for an honest to goodness 100 + mpg cycle, segment, or tank in warmer temps, you can use it in any slow down and just about any heavy - congested traffic tie up for accelerations as long as you are below 41 mph. Even above 41 mph, you can still use regen down to 41 mph and Glide down the rest of the way when coming to a stop. The technique as taught to me by Krousdb is really that good in the Prius II and I highly recommend that you learn its nuances ASAP. Your FE will skyrocket afterwards.
___Good Luck
___Wayne R. Gerdes
#4
12-12-2005, 10:33 AM
Re: I got the Glide part, but how do I Pulse?
Wayne, thanks so much for the further details. I think I know what to look for now (pink arrows from ICE to wheels and to MGSet, single green arrow to battery). I have seen that before when trying to Pulse, but it doesn't seem like the Prius is accelerating. Maybe if I push on the gas a tiny bit more while keeping the pink/green combination of arrows, it will Pulse.
My commute is mostly on the freeway, but sometimes I drive on a stretch of surburban expressway that has timed stoplights, and the speed limit is 35 so I practice my P&G there. Actually I practice P&G during my non-freeway commute as well, but those are much shorter stretches of road.
I keep my tires at 42/40 (though now that it's colder, I need to check my tires). I use Mobil-1 and use 3.5 quarts. My climate this time of the year is 45-50 degrees during the morning commute and 55-60 in the evening.
Oh, and I had the ECU update two weeks ago, and have noticed that the battery level indicator goes up from blue to green more often, and stays green longer. Also, my daily commute FE is now consistenly 1-2 mpg higher. I don't know if what I'm noticing is pyschological because I've been reading the "post-ECU update" threads on priuschat, or if in fact it has made some difference.
My commute is mostly on the freeway, but sometimes I drive on a stretch of surburban expressway that has timed stoplights, and the speed limit is 35 so I practice my P&G there. Actually I practice P&G during my non-freeway commute as well, but those are much shorter stretches of road.
I keep my tires at 42/40 (though now that it's colder, I need to check my tires). I use Mobil-1 and use 3.5 quarts. My climate this time of the year is 45-50 degrees during the morning commute and 55-60 in the evening.
Oh, and I had the ECU update two weeks ago, and have noticed that the battery level indicator goes up from blue to green more often, and stays green longer. Also, my daily commute FE is now consistenly 1-2 mpg higher. I don't know if what I'm noticing is pyschological because I've been reading the "post-ECU update" threads on priuschat, or if in fact it has made some difference.
#5
12-16-2005, 10:21 AM
Re: I got the Glide part, but how do I Pulse?
I am not the hypermiler Wayne is, so take these comments accordingly ..
I think there is a wide range of pulses that can be used with minimal differences, so I focus on staying below 42 mph, gliding, and anticipating the road.
Sending energy to the battery during a pulse incurs transduction losses, so unless my SOC is low, I avoid it; and instead, particularly if a long incline is coming up, deadband (meaning no arrows to or from the battery).
In my city of Albuquerque in warmer temperatures this approach is good for mid 70's fuel economy.
I think there is a wide range of pulses that can be used with minimal differences, so I focus on staying below 42 mph, gliding, and anticipating the road.
Sending energy to the battery during a pulse incurs transduction losses, so unless my SOC is low, I avoid it; and instead, particularly if a long incline is coming up, deadband (meaning no arrows to or from the battery).
In my city of Albuquerque in warmer temperatures this approach is good for mid 70's fuel economy.
#6
12-16-2005, 12:59 PM
Re: I got the Glide part, but how do I Pulse?
After the marathon, I havent worried too much about deadband. The main thing to focus on is the glide. After reaching the desired speed, let off the gas to get the green arrows only and then ever so slightly give it enough gas to make all of the arrows go away. It becomes second nature after doing it for awhile.
Dan
Dan
#7
12-16-2005, 04:48 PM
Re: I got the Glide part, but how do I Pulse?
I have a question. What is the maximum speed that can be used at? I have had difficulty as it has gotten colder (yes even here in North Texas) to send the car into glide, even under 41 MPH. My understanding is under 41 MPH since the ICE runs consistently over that but I have noticed small bursts of EV only mode or no arrows at all on cruise control at 55 mph, especially with a high SOC. I have tried manually at 55 MPH to no avail however.
#8
12-16-2005, 05:26 PM
Re: I got the Glide part, but how do I Pulse?
Originally Posted by abowles
I have a question. What is the maximum speed that can be used at?
http://hybridcars.about.com/od/owner...seandglide.htm
As Dan commented, please do not worriy too much about deadband, no arrow from/to the HV battery.
However, it is not good to see a yellow arrow from the battery when accelerating.
Ken@Japan
#9
12-16-2005, 11:06 PM
Re: I got the Glide part, but how do I Pulse?
Thanks Ken. I believe Xcel and others have said this before and it just didn't take. I know get that even though the indicators may not show charge at 55 mph the engine is spinning, even if freely. I'll keep practicing gliding as well. I am doing fairly well thoughas I am getting mostly 50+ mpg, even with morning lows of 30 F (0 C) and highs around 50 F. This makes me an extremely satisfied Prius owner. If some are right about peak oil between now and 2007 I will be ecstatic.
#10
12-17-2005, 09:24 AM
Re: I got the Glide part, but how do I Pulse?
Originally Posted by ken1784
40MPH.
http://hybridcars.about.com/od/owner...seandglide.htm
As Dan commented, please do not worriy too much about deadband, no arrow from/to the HV battery.
However, it is not good to see a yellow arrow from the battery when accelerating.
Ken@Japan
http://hybridcars.about.com/od/owner...seandglide.htm
As Dan commented, please do not worriy too much about deadband, no arrow from/to the HV battery.
However, it is not good to see a yellow arrow from the battery when accelerating.
Ken@Japan
While I agree that using the HV battery during acceleration leaves less charge to glide with, I think that if I had to choose which was more fuel economical overall: ICE on, arrow to the battery, or ICE on, arrow from the battery, I would choose the latter. The Prius is very adept at keeping the ICE in an optimal power range when power demands are high by pulling from the battery, but less adept at dealing with low power demand conditions. I think.
If the HV SOC is low, the conclusions change. Also, it is possible to place power demands on the car that force the ICE into an inefficient range. So I am not saying that the gas pedal can be floored with impunity, but that I strive to avoid low power demand, ICE on situations.
