Does the Pulse & Glide technique work....

This exactly the point I tried to make in my post above. Prius makes it difficult to go into the "neutral" glide without using N as one has to keep pressing gas slightly while watching the display. Distracts me from watching traffic ahead. I would prefer if lifting of gas pedal would not produce coasting with regenerative braking.

 

Me too, friendly. But with practice you can find the glide by feel and confirm with a glance as you scan the instrument panel normally.

 

^^^ This. After a while you can glide by feel with only an occasional glance at the display to confirm that you're not using the battery.

 

Am I doing it right?

-Iain

 

Awesome! Thanks for the feedback It was a 60 km/h zone with no traffic behind me. I was doing between 35 and 40 mi/h because off the top of my head I seemed to recall that range being suggested somewhere. I imagine that the greater the breadth of that range, the greater the gain is lower consumption.

My commute is 20 km and I've endured a batch of 5 l/100 km tanks with the cold. So I am motivated.

-Iain

 

After watching the video I may be gliding incorrectly. I usually glide with the the indicator invisible that is no chargeing and no electric propulsion. That is the indicator is gone. Should I have some electric propulsion during the glide?

 

It works for me.

 

Awesome. Thanks for the advice.

I set the trip A when I start up each morning. I drive short trip moving kids around and myself. Trips are never longer than 11 miles. So that is tough. I'm really getting a solid understanding of how temperature affects indicated mpgs. If it is single digits 50 is not really a possibility. 10-20 degrees F I can get 50. 20 - 30 50 is doable. 30 and above it gets much easier. I had the block heater installed and it has helped. I can get the ICE to turn off in about .75 miles. I need to work on my P&G technique to maintain 35-40 mph. I always end up slower. Will P&G allow me 50 mpg in 15-20 degree F at average 35 mph? Now my average mph's are 22-25.

Thanks again for the comments.

 

How does this pulse and glide work though? As I see it, it takes a certain amount of energy to propel the vehicle at a particular speed. If that energy is coming from the battery with the ICE off, when the battery is flat, the ICE kicks in and has to deliver the same amount of energy as the battery did to keep the vehicle moving AND recharge the battery at the same time, ie use a bit more energy on top. Since nothing is 100% efficient there will be losses when charging the cells too so the net result is surely more energy used than driving normaly as Toyota recommend.

I cannot help wondering if just feathering the accelerator wouldn't be just as efficient if not ever so slightly more so that pulse and glide techniques.

And what about the extra wear and tear with the extra starting and stopping of the ICE? What will that cost?

Anybody care to tell me what I am missing?

 

First, when you do the pulse and glide thing you're not actually propelling the car at a constant speed... You use the ICE to get up to speed, then you coast for a little while with the ICE off and your speed drops while you coast. Then you turn the ICE on again and speed up, then coast again with the ICE off... And repeat... You shouldn't be draining and recharging the battery if you're doing this right.

The reason P&G works is that all engines are more efficient at certain RPM levels. Feathering the pedal and maintaining a set speed won't allow the engine to operate in it's most efficient range. Instead, you try to run the engine in the efficient range during the pulse and shut it off for the glide. When done right this works and will definitely save gas.

The prius, with it's electric motor makes things a bit more confusing as you do lose energy during the conversions. However, it can still be more efficient overall to run in electric mode at slower speeds where the ICE would be less efficient and allow it to recharge later when it's running in it's efficient range. You also get some energy from the regenerative breaking that otherwise would have been lost.

 

Ok, I will give it a go when My Prius arrives.

 

cbc, welcome! You'll love your Prius.

When your speed/terrain makes efficient use of the ICE output, then steady state is fine. But otherwise, as stated by Brett, P&G **avoids** the conversion losses you accurately point out. Glide is not EV power, but inertia power. Feels as if you put it in neutral (no drag).

Remember that gliding requires slight throttle input to cancel the regen toyota put in at 0 throttle. Foot off the gas (0 throttle) is best referred to as coasting (useful if you need to shed speed for stoplight timing), and is not part of P&G.

 

while gliding, a small amount of battery still gets consumed i.e. a/c, audio equipment and headlights usage.. i.e. after 2 cycles of gliding, one bar of battery gets dropped and consequently on 7-8 cycles of pulse and glide, battery gets to 3 bars and then i intentionally try not to p&g but to keep running ICE with very little pressure on the pedal to consume less gas.. and one the batter gets back to almost full state, i pulse and glide again .. the loop continues.. and i hope its not bad for the battery :S

 

IMO, everything is normal. If you will try to limit your usage of the electricity in the traction battery by turning off some of the accessories, you might find that the traction battery will hold the SOC a while longer.

The Gen II was worse about what you describe than the Gen III Prius. However I have found I can P&G all day long if I keep the A/C off and very rarely have to use the ICE to recharge the traction battery. But if I turn the A/C on, all bets are off at that point.

Have a great day. Interesting string too!

Ron (dorunron)

 

To the OP.

Do not make yourself crazy driving this car. DO NOT practice P&G, when you first get it, in traffic. I found out how good the ABS brakes work by trying this a few times. I easily get low 50's in the city and mid 50's on the highway when I use cruise control. With P&G you will, realistically, pick up a few mpg's while driving with the alertness of everyone around you like your were intoxicated or texting while driving.

You will find this all out when you get your first insurance premium statement. My wife, my 22 yr old son and I haven't had an accident or citations in years but my auto insurance went up almost $100.00 per month when I told my agent what I bought (I'm pretty AAA had something to do with that in a scathing report on hypermile driving techniques).

Drive it like a car and not a helicopter with unlimited airspace. There are others on the road as well.