Pulse and Glide plus Warp Stealth in the Prius II for maximum FE …

[dyoungerman]

Hello all,

I am the proud owner of a new 2007 Prius Touring (Pkg. #3) for 4 whole days and counting. (Yay!) This online community of "Prii People" and technical information is kind of overwhelming, but it's great for newbies like me to have resources to go to.

I'm averaging 47-50 mpg on my 35 mile each-way commute. It's mostly through small towns, on back roads, and on state routes, but it's hilly. So far, I'm quite pleased and I'm finding this mileage thing quite addictive.

Here's my question, though. Is my car a Prius II that you speak of? (I was told that my car is the 4th generation of the Prius that Toyota has made?) Can I follow the same rationale/procedures listed in this thread? I've tried coasting techniques down hills and on flat sections of road and I can't get the display to show no energy flow arrows. My Prius has the Hybrid Synergy Drive and the CVT transmission. I think it might be behaving differently than models with prior generation technology, but I dunno.

Thanks much!
dyoungerman

[JimboK]

Originally Posted by dyoungerman

Hello all,

I am the proud owner of a new 2007 Prius Touring (Pkg. #3) for 4 whole days and counting. (Yay!) This online community of "Prii People" and technical information is kind of overwhelming, but it's great for newbies like me to have resources to go to.

I'm averaging 47-50 mpg on my 35 mile each-way commute. It's mostly through small towns, on back roads, and on state routes, but it's hilly. So far, I'm quite pleased and I'm finding this mileage thing quite addictive.

Here's my question, though. Is my car a Prius II that you speak of? (I was told that my car is the 4th generation of the Prius that Toyota has made?) Can I follow the same rationale/procedures listed in this thread? I've tried coasting techniques down hills and on flat sections of road and I can't get the display to show no energy flow arrows. My Prius has the Hybrid Synergy Drive and the CVT transmission. I think it might be behaving differently than models with prior generation technology, but I dunno.

Thanks much!
dyoungerman

Welcome to CleanMPG and congrats on your purchase, dyoungerman! The masters (not me, though I'm working on it) are here to teach you!

Yes, yours is what many refer to as the Prius II, which began with the 2004 model year. It's actually the third generation, which leads to confusion as you've seen. Here's a good overview of the Prius models' history. To eliminate confusion in discussions where multiple models are discussed, many use the actual Toyota model numbers, NHW10, NHW11, and NHW20. IMHO, just stating your model year is sufficient.

I don't know all the differences between the Touring model and the basic model, but the hybrid propulsion system is the same. I'm sure the Touring package could affect fuel economy in small ways -- different tires, for example -- but I believe you should still get good hypermiling results if you apply what's taught here and on the Prius forums.

In particular, keep working on your glides. As long as you're at 40 MPH and below, completely let off the pedal for a second or two, allowing the ICE to shut down and green arrows to appear, and then feather the pedal ever so slightly until the arrows disappear. Once you're able to call that up on demand, you're on your way. If you can't safely stay at those speeds, then at higher speeds "warp stealth" produces mostly the same effect. The technique is the same. The visible difference is that you won't provoke a "no arrows" state, and instead the slight pedal feathering produces orange arrows.

It takes practice and patience with these and many of the hypermiling techniques described on this site. I suggest you take a couple of them at a time, get good at them, and then progressively add more. I've had my car for over a year, and it's been only recently that I've started even to come close to what the experts have done.

[JimboK]

About time to bring this thread back to life ....

I've been wondering something recently: With the experience we Prius drivers now have under our collective belt, is there a consensus on optimal P&G speeds and ranges? And a related question: Are there inefficiencies in the ICE starting and stopping during P&G? It would seem intuitive (to me anyway) that there would be.

Wayne's experience (described earlier in this thread) suggests wide P&G speed ranges get better results than narrow ones. Inefficiencies in ICE shutdowns and restarts would help explain his results. On the other hand, I remember Diamondlarry suggesting recently that he was experimenting with narrower speed ranges (5 MPH??), but I didn't see any report of his conclusions.

I began some controlled testing last year on various combinations of P&G speeds and ranges:

• 15-25 MPH
• 15-30 MPH
• 15-35 MPH
• 20-30 MPH
• 20-35 MPH
• 25-35 MPH

The tests were never completed because of the unanticipated need to replace my tires partway through. I plan to begin testing anew sometime this spring, and will include comparisons to steady-state driving. (Results will be posted.) But the incomplete results suggested that range had no effect; instead, results improved as the overall average speed dropped.

So, what's the current thinking among those of you smarter than me?

[bestmapman]

Hi Jim,

I think this would be a great study. Maybe I could participate with you. If you give me the parameters you are using (distance, terrain, etc.) I could duplicate your efforts and we could duplicate the data.

Now that I have a scangauge, we could duplicate things such as tps and ign.

[diamondlarry]

Originally Posted by JimboK

About time to bring this thread back to life ....


Wayne's experience (described earlier in this thread) suggests wide P&G speed ranges get better results than narrow ones. Inefficiencies in ICE shutdowns and restarts would help explain his results. On the other hand, I remember Diamondlarry suggesting recently that he was experimenting with narrower speed ranges (5 MPH??), but I didn't see any report of his conclusions.



So, what's the current thinking among those of you smarter than me?

Oops! I did mention that didn't I. I will be doing some driving on Monday and I may be able to test that out. Today, I was experimenting with 25-35 or so on some country roads. I also did a little bit with 30-40 or less. I did notice that the lower end target speeds that were closer to 30 mph seemed to have a higher impg number, ie. going from 30 mph or above to 35 mph or so. I went from my mom's house to a Sunday School class party that was a distance of 13.3 miles and, at ~40F I ended up with 82.2 mpg. Now, if I could just remember exactly what I did...

I have a little story that is slighty off-topic for this thread but is related to mpg. When I got to the party, one of the guys asked me, "What kind of mileage are you getting in your car, 60 mpg?" I just smiled and said, "Maybe on a bad day." Then they looked at me in shock when I told them that I may drive a little slow but I did get 82 mpg coming here. That brought on a short discussion on my P&G techniques; very short.

[Dan]

I'm posting from my phone so I've only skimmed the topic revival.

Now i have done some work this winter on shutoff and ice light losses. all done at lower speeds with am ev button.

On steady state I think ign14 should stablize around 70 mpg @ 46 mph. i think that will be the best.

if you test below 45 mph it well need to be done over many miles with start soc = end soc. If you get good numbers by canniblizing soc its invalid.

11011011

[diamondlarry]

I have found on my highway trips to Chicagoland and beyond that when the speed drops much below 50 mph that the IMPG numbers usually start to fall. At 50-55 the number will bounce around from 80-85 or greater but will drop to the 70's when below 50 mph. They really start to drop off when below 45 mph. It must be that when rpm's stay the same that a higher speed will cause a higher calculated FE number. There will, of course, be limits to this because of aerodynamic drag if the speed is too high.

[bhchan]

New Prius owner. thanks for all the info. this is gonna be fun to incorporate.
________
AnalDreams21

[lyekka]

Originally Posted by JimboK

About time to bring this thread back to life ....

I've been wondering something recently: With the experience we Prius drivers now have under our collective belt, is there a consensus on optimal P&G speeds and ranges? And a related question: Are there inefficiencies in the ICE starting and stopping during P&G? It would seem intuitive (to me anyway) that there would be.

I have been wondering this since I learned about P&G.... Would it vary with the seasons also? I try to extend the P&G and sometimes I think I did too much as the ICE seems to get cold and does not want to glide.

[Dan]

Originally Posted by lyekka

I have been wondering this since I learned about P&G.... Would it vary with the seasons also? I try to extend the P&G and sometimes I think I did too much as the ICE seems to get cold and does not want to glide.

1. Slower is better than faster
2. Ultra low speed ICE-on is bad.
3. As few lights as possible is good.
4. Regen is bad
5. Assit is bad

DISCLAIMER: I use metric, so don't freak out.

OK... culling all that together, here's what I decided (the world according to 11011011). So basically we are asking the pulse entry point (at what speed you light the engine) and your glide entry point (at what speed you cut the engine). So looking at point 1, I decided that a low glide entry point was good. Looking at point 3, I want to have at least a 35 kph (21 mph) delta between my pulse entry and my glide entry velocities. Also looking at point 2 I don't want to dip below 20 kph (12 mph). So my "competition" window is:

Pulse Entry: 20kph (12 mph)
Glide Entry: 55kph (34 mph)

Now to satisfy point 4 and 5, I try to do all my pulse and glide transitions via an instantaneous EV switch (Radio Shack or Factory EV).

Now based on my SHM research, I really like to see my IGN around 14,15, or 16. So my pulse RPM is usually dialed in at 1600 RPM. Easy.

Outside of "competition" mode I bump my Pulse entry up to 45 kph (28 mph) or 30 kph (19 mph) if no one is around.

Hope that helps

11011011