How to Pulse and Glide with pictures...

Jack66 · Aug 20, 2008

JimboK said: ↑

OK, let's try to make this simple. Here are the rules:

Keep it on the Energy screen. I use the Consumption screen only to spot check my results via the five-minute bars.

During pulses, watch your instantaneous MPG and keep it at least half the vehicle speed. You're accelerating of course, so the relationship will constantly fluctuate. With a little practice you'll get a pretty good sense of a good acceleration rate, and then all you need to do is spot check the gauges to validate. Ignore the arrows and don't worry about RPM. Obviously you can't monitor RPM without add-on instrumentation. That's why I suggest watching the iMPG/MPH relationship; it's a suitable surrogate for this purpose for those without the instruments.

During glides, aim for the "no-arrows" condition shown in the first post. This takes a little practice to hit and hold, but it's not difficult once you get your foot "trained."

P&G is only one of many important tools in the box. To know when and how best to use it is just as important. Good hypermiling includes all the tools, using those that best fit the situation at the moment.

Anticipatory driving is critical -- knowing when best to begin and end a pulse based on traffic and terrain, learning the timing of red lights on your routes, watching for the lights and other slowdowns, and beginning a glide as soon as possible to the extent traffic behind will tolerate. The CleanMPG folks have coined the term DWB: driving without brakes. Every time you hit the brakes, you've wasted a little kinetic energy. Better is to let that energy go to work for you and allow the car to decelerate in the most efficient way possible for as long as possible -- i.e., gliding.

There is a balance on busy roads. On the one hand, I won't drive 20 MPH in a 35 MPH zone if heavy traffic has no chance to pass. My first guiding principle for hypermiling is to be safe, legal, and courteous. In heavy traffic, I often resign myself to just going with the flow. On the other hand, I won't give in to impatient tailgaters who insist through their actions that I drive 20 MPH over the limit and wait until the last minute to slam the brakes approaching a stop. A jerk will be a jerk, and I can't change that.

Route planning is important too. I seek out through mapping (Google maps) and experimentation which routes are favorable for P&G -- those with less traffic and lower speed limits. It could end up being a somewhat longer route, but I am careful to avoid a route that uses more total fuel. (I have a simple spreadsheet to calculate total fuel consumption.) Where I have a choice, I plan the time of my drives for periods of lighter traffic.

I should mention that even with a perfectly executed P&G, some conditions simply won't allow great fuel economy, including short trips that never allow the car to fully warm to efficient temperatures and lots of stop and go in weather extremes where cabin climate control is constantly running at high levels. There are tools and techniques that help with those conditions, but they're outside the scope of this thread.
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OK, definitely the best post and summary of the techniques I have seen to date for folks trying to get better MPG without having to understand the science of it all. Thanks, Jim!!!

Jack66 · Aug 20, 2008

sandman said: ↑

Yes my 13 year old went with me this morning and took the pictures..
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Sandman, I think it is great that you involved your 13 year old. What a great activity to do together. BTW, please tell your 13 year old that they take great pictures -- better than most of the PC posters.

9G-man · Aug 20, 2008

Jack66 said: ↑

OK, definitely the best post and summary of the techniques I have seen to date for folks trying to get better MPG without having to understand the science of it all. Thanks, Jim!!!
Click to expand...

Except for one important thing.... The speed threshold....... The glide can really only be achieved below 42 MPH. Above that the technique is the same, but the "glide" is really gonna be a warp-stealth (yellow arrows from batt). Usefull on downhills at any speed.

JimboK · Aug 20, 2008

9G-man said: ↑

Except for one important thing.... The speed threshold....... The glide can really only be achieved below 42 MPH. Above that the technique is the same, but the "glide" is really gonna be a warp-stealth (yellow arrows from batt). Usefull on downhills at any speed.
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Yes, very important. Thanks for the reminder. I'll add the speed constraint to my post to make it more complete.

ctbering · Aug 20, 2008

JimboK said: ↑

OK, let's try to make this simple. Here are the rules:

Keep it on the Energy screen. I use the Consumption screen only to spot check my results via the five-minute bars.

During pulses, watch your instantaneous MPG and keep it at least half the vehicle speed. You're accelerating of course, so the relationship will constantly fluctuate. With a little practice you'll get a pretty good sense of a good acceleration rate, and then all you need to do is spot check the gauges to validate. Ignore the arrows and don't worry about RPM. Obviously you can't monitor RPM without add-on instrumentation. That's why I suggest watching the iMPG/MPH relationship; it's a suitable surrogate for this purpose for those without the instruments.

During glides, aim for the "no-arrows" condition shown in the first post. This takes a little practice to hit and hold, but it's not difficult once you get your foot "trained."

P&G is only one of many important tools in the box. To know when and how best to use it is just as important. Good hypermiling includes all the tools, using those that best fit the situation at the moment.

Anticipatory driving is critical -- knowing when best to begin and end a pulse based on traffic and terrain, learning the timing of red lights on your routes, watching for the lights and other slowdowns, and beginning a glide as soon as possible to the extent traffic behind will tolerate. The CleanMPG folks have coined the term DWB: driving without brakes. Every time you hit the brakes, you've wasted a little kinetic energy. Better is to let that energy go to work for you and allow the car to decelerate in the most efficient way possible for as long as possible -- i.e., gliding.

There is a balance on busy roads. On the one hand, I won't drive 20 MPH in a 35 MPH zone if heavy traffic has no chance to pass. My first guiding principle for hypermiling is to be safe, legal, and courteous. In heavy traffic, I often resign myself to just going with the flow. On the other hand, I won't give in to impatient tailgaters who insist through their actions that I drive 20 MPH over the limit and wait until the last minute to slam the brakes approaching a stop. A jerk will be a jerk, and I can't change that.

Route planning is important too. I seek out through mapping (Google maps) and experimentation which routes are favorable for P&G -- those with less traffic and lower speed limits. It could end up being a somewhat longer route, but I am careful to avoid a route that uses more total fuel. (I have a simple spreadsheet to calculate total fuel consumption.) Where I have a choice, I plan the time of my drives for periods of lighter traffic.

I should mention that even with a perfectly executed P&G, some conditions simply won't allow great fuel economy, including short trips that never allow the car to fully warm to efficient temperatures and lots of stop and go in weather extremes where cabin climate control is constantly running at high levels. There are tools and techniques that help with those conditions, but they're outside the scope of this thread.

You seem frustrated but genuinely interested in improving your fuel economy. I will restate the challenge I made elsewhere: Contact Wayne at CleanMPG for a hands-on clinic. There's nothing like seeing it firsthand and having a coach. Did you receive the PM I sent you about that?

[EDIT: There may be an issue here of terminology being confusing. "Gliding" as I describe in rule #3 is for speeds of 40 MPH and below. Many of us limit our use of the term "glide" to these lower speed scenarios, whereas "warp stealth" is used to describe similar (but not identical) ICE-off deceleration at higher speeds. The pedal-feathering technique is the same, but warp stealth is a little harder to hit and hold (especially if state of charge is low) and its value more limited. "Pulse and warp stealth" may not be the best strategy at higher speeds, depending on speed, terrain, and traffic.

This is Sandman's thread so he ultimately can make the call, but with the title of "How to Pulse and Glide with Pictures," I suggest focusing the discussion on "true" sub-41 MPH glides to eliminate confusion. The subject of optimal highway fuel economy is more complex and there still is debate on best practices.]
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Jim, thank you for the great tips. Your the best! Terry

sandman · Aug 20, 2008

I am completely confused about what screen to have up, Consumption or Energy. I have used 'Consumption' but I don't seem close to breaking the 50 + MPG barrier. It could be from traffic behind me pressing me to go faster at start ups or approaching stop lights. I have had drivers riding me from behind if I don't race to a red light. I believe I am very good at hypermiing but I still have City and Interstate drivers that get frustrated with my hypermiling techniques. When in slow traffic some of these drivers get very aggressive while others appreciate me 'gliding' slowly in stop and go traffic.
If I switch to the Energy screen would I better monitor the systems in use versus Consumption screen? I have been trying to master exactly what color conserves the best without draining the hybrid battery. It's almost like I need to have a navigator monitor all systems for best MPG's while I drive. BTW, I saw he Energy screen thread, its incredible. I plan to study the colors and directional arrows. I have no idea what RPM's I am going so keeping the car at or below a certain range, other than my ear and feel, doesn't seem possible. I didn't know the colors slightly change based on the car's acceleration, I really don't believe most Prius owners understand the complexities of this car.
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ctbering: To do a true Pulse and Glide you will need the energy screen up. You can refer to post number one for what you will need to look for on that screen. But please don't think we go around P&G all the time you can only do it when there is no traffic or traffic is moving slow.Like jimbok said the main thing is be safe, legal, and courteous. When I am going to work or coming home I have certain spots I pull over and let traffic around then I am off to P&G some more..I now take the back roads for about 30 miles of my commute instead of the interstate and it has really help my MPG's.

Here is a pic I took before filling up yesterday..

sandman · Aug 20, 2008

Sandman, I think it is great that you involved your 13 year old. What a great activity to do together. BTW, please tell your 13 year old that they take great pictures -- better than most of the PC posters.
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Thanks, He loves my Prius he asks me every day when I get home what my MPG's are and when we are going somewhere he likes watching my scangauge and MFD coaching me. we went to town the other day its about 12 miles I P&G all the way there, when we hit the first light in town my scangauge read 101 MPG for my CFE he really liked that My six year old went by on his bike the other day and said look dad I am gliding..

nooaah · Aug 21, 2008

sandman said: ↑

You are welcome and good luck with it, let us know how much it helps you..
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I drove about 100 miles with a passenger and hundreds of pounds of furniture. It dropped my mpg for the tank down to about 44. 150-200 miles later I'm back up to 51mpg, so it looks like I'm getting a little better with the whole pulsing thing now.

It jumped up from 47-50.5 yesterday with all highway driving.

Neohybrid · Aug 21, 2008

We've only had our car for a few weeks, but I followed the advice on this thread for our first "trip" -- visiting family in Western MD. There are no lack of mountains on the trip through WV and Western MD. With two adults, a teenager, and three dogs (avg. 30lbs. ea.) plus stuff for two-day trip we averaged 56.1 MPG (375 mile round trip) with AC on. I have to say I was very impressed.

rz1 · Aug 22, 2008

I've been practicing P&G and starting to get better. I'm up to about 66 to 67 mpg/tank for the last few fill ups. Here is an issue I run into from time to time. Has anyone seen this?

Occasionally when transitioning from pulse to glide, no matter what I do I can't get into glide state (all arrows off). It does not seem to depend on speed or any other factor that I can detect. By experience, I have noticed that in such states if I forcefully tap on the go-pedal, the problem goes away and I can happily glide after that.

Any thoughts? Could it depend on the state of charge? Any other factor?

efusco · Aug 22, 2008

rz1 said: ↑

I've been practicing P&G and starting to get better. I'm up to about 66 to 67 mpg/tank for the last few fill ups. Here is an issue I run into from time to time. Has anyone seen this?

Occasionally when transitioning from pulse to glide, no matter what I do I can't get into glide state (all arrows off). It does not seem to depend on speed or any other factor that I can detect. By experience, I have noticed that in such states if I forcefully tap on the go-pedal, the problem goes away and I can happily glide after that.

Any thoughts? Could it depend on the state of charge? Any other factor?
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You're not in S4...and it'll happen. Usually just below 35mph, but rarely I've had issues above as well. The only other thing is that sometimes if you don't let up on the accelerator briskly enough it can keep running. IOW, when you want to go into the glide you should start with your foot on the pedal at whatever pressure you were pulsing at, then lift it up all at once, not gradually.

But I think the lack of being in S4 is probably the main issue.

fthorn · Aug 22, 2008

What about Gen 1 Prius?

efusco · Aug 22, 2008

fthorn said: ↑

What about Gen 1 Prius?
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Same concepts apply.

sandman · Aug 22, 2008

We've only had our car for a few weeks, but I followed the advice on this thread for our first "trip" -- visiting family in Western MD. There are no lack of mountains on the trip through WV and Western MD. With two adults, a teenager, and three dogs (avg. 30lbs. ea.) plus stuff for two-day trip we averaged 56.1 MPG (375 mile round trip) with AC on. I have to say I was very impressed.
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Congratulations just wait until you hit 60MPG(for a tank) you will be grinning from ear to ear, I know I was....Keep us posted on your progress..

kscableguy · Aug 22, 2008

so when you all are P&G'ing, you are basicly speeding up over the speed limit (5-10mph over) and then just taking your foot off the gas and letting the car coast until you are about 5-10mpg under the speed limit? Am I understanding this right????

sandman · Aug 23, 2008

so when you all are P&G'ing, you are basicly speeding up over the speed limit (5-10mph over) and then just taking your foot off the gas and letting the car coast until you are about 5-10mpg under the speed limit? Am I understanding this right????
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Well you don't let the car coast you glide with the car(no arrows on MFD) thats why its called Pulse and Glide..To do a P&G I pulse to 40 then Glide to 30 average speed=35mph..any higher speed P&G and you don't get a true glide you get a warp stealth glide(yellow arrows), but I always say any type of glide is better than no glide at all!!!

jps000 · Aug 23, 2008

kscableguy said: ↑

so when you all are P&G'ing, you are basicly speeding up over the speed limit (5-10mph over) and then just taking your foot off the gas and letting the car coast until you are about 5-10mpg under the speed limit? Am I understanding this right????
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I am not sure about the speed limit reference...

You can be at any speed, whether you were cruising along at that speed or had just glided down to that speed, say 12mph-35mph. You pulse (that is, accelerate) to a higher speed, from say, as an example 25mph to 35mph (don't go above 40mph). Then you let off the accelerator, regen (green/blue) arrows will appear, then you gently (feather) push the accelerator pedal back down, so that all arrows are off (blank screen). Ideally you minimize the brief period of regeneration arrows. The range of pulsing and gliding is up to you. 20-->40-->20mph or 33-->38-->33mph, whatever. Teddy Girl of the longest tank fame used 31 or 34 down to 19 or 21mph... never going past a delta (change from pulse to glide of 12mph).

9G-man · Aug 23, 2008

kscableguy said: ↑

so when you all are P&G'ing, you are basicly speeding up over the speed limit (5-10mph over) and then just taking your foot off the gas and letting the car coast until you are about 5-10mpg under the speed limit? Am I understanding this right????
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No, that's not right. Go back to the beginning of this thread and read.
Coasting does not apply to the Prius. It's Regen, Glide, stealth or (above 42MPH) warp stealth.
You fully control it with your right foot.
Try to apply the glide whenever possible and reasonable.
ie; anytime slowing down in necessary, maintaining speed is not necessary, traveling down hills etc.
Since you have a car that can run on no gas, the idea is to maximize the amount of time its doing just that.

fishinmyeye · Aug 23, 2008

efusco said: ↑

But I think the lack of being in S4 is probably the main issue.
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what is S4?

JimboK · Aug 23, 2008

fishinmyeye said: ↑

what is S4?
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It's the final stage of the Prius warmup cycle. The warmup stages are described here.

How to Pulse and Glide with pictures...

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How to Pulse and Glide with pictures...

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