pulse-n-glide: what speeds can you maintain?

You are not gliding. Gliding should be down near (but not in) the regen area, say the 1st quarter of the ECO band, whereas you are applying power near the middle of the ECO band. Gliding and maintaining speed are fundamentally different things. Gliding is at the whim of the rolling resistance, air resistance, and gravity (like being in neutral).

The car decides when to tap the ICE versus the batteries versus both based on factors such as power needed (speed, wind, etc), SOC, warm-up stage, climate control setting, mode selection, etc. So there is no single speed that keeps the ICE off.

P&G is a cycle, done in a band (e.g., 40 to 35 mph). Accelerate to 40, glide to 35, repeat. In the right setting, this gives great fuel economy, as opposed to steady speed near the middle of the ECO band of HSI.

 

You guys crack me up.

Let's say you hypermilers increase your average MPG from 50 to 55. A person driving 15k miles will save 27 gallons PER YEAR. At $3 per gallon gas prices (we seem to be headed there), that's $81 PER YEAR!

Don't you think you're already doing enough by driving a car that does a GREAT job of helping us preserve our planet's oil reserves, reduce our dependency on foreign oil, AND is very kind to the environment with minimal emissions?

Stop driving yourselves crazy (pun intended). Just drive the car and enjoy it.

 

No, we aren't yet doing enough, and by a very wide margin.

 

Jim, I don't mind if others choose not to P&G, nor do I always do so myself. Just pointing out that the driving described had nothing to do with that technique. I still pick up abandoned coins, too. It's just in my genes, and I enjoy the challenge for the high FE, not to mention a fundamental objection to buying oil from people who wish me and my loved ones death.

Don't be deceived into thinking it 55 vs 50. More like 75+ vs 50.

 

My apologies OP. 25% should bleed down to parking lot speed, but slowly. 40-48% is probably 30-35 mph as you suggested in post 1.

5 mph band for P&G is kind of low, and, if combined with placard psi, will require annoyingly frequent pulses. I just try to fit the conditions. For example, my commute has a light followed by a flat 1/2 mile to another light where I turn left and usually have to wait. I pulse up to 40 at 100% ECO or barely into PWR band, then glide over 1/4 mile into light. After turn, I have a flat 1/4 mile where I pulse back to 40, then it glides (at 0-10% of ECO) down to a creekbed and up to a light, so easily 3/4 mile glide down to around 20 mph. Basically, pulse every 1/2 to 1 mile absent longer descents. I try not to accelerate going up hill, so I may accelerate harder pre-climb or stay in that 50% ECO area if I want to hold speed to the crest, then start a glide. I glide between 25% and 0% of ECO, depending on whether the terrain needs an extended glide or pure glide. I will pulse anywhere between 75% ECO and well into PWR, but usually near 100% ECO.

If I have to pulse more than once or twice in a mile, I tend not to P&G there.

All of this is subject to traffic courtesy, of course. These are multi-lane areas without heavy traffic.

If you edge your psi upward from placard toward max sidewall, you will be happier with gliding and mpg. My psi has increased as my comfort level grew, to the point that I go max sidewall unless I know I need a softer ride for rough sections or something. Even then, I don't go down all the way to placard, which I've come to regard as the manufacturer's soft ride level that assumes I drive hard, while the tire company's maximum improves tire life, handling, and FE.

Others can add nice scientific answers, but I do not have that data. Good luck.

 

At 48mph or higher, I find the best approach is to get to speed a little over the Eco range, and once up to speed reduce to around 50%, which will peg the MPG at 100mpg and apply power as needed to maintain speed, keeping mpgs between 50 and 100mpg. If I get to a hill, I can approach the top of the Eco Range or even exceed it if necessary. When coming down hills I can glide (at the bottom of the Eco Range but not recharging). When driving this way, the ICE is running all the time.

Under 48mph, I do P&G by going back and forth between 75% or higher and down to the bottom of the Eco range, but again not recharging.

Using these two techniques, I have been averaging 55-58mpg in the 15- 30 degree weather we've been having using factory recommended tire pressures...can't wait for warmer weather to see how she does.

 

I have an exit ramp that I use every day coming home from work with about a 3 mile, 45 mph flat street where I can usually glide and gain about 0.5 mpg. In order to keep flow with the heavy traffic, I just try to do what the OP is asking and keep the HSI just to the left of the center bar to keep the ICE off as long as possible. I will glide to about 40 mph and then have to ramp back up to 45 and glide some more. I can normally do this about twice during the 3 mile stretch.

Does this help with your question ?

 

Read these two articles.

They will give you a good start.

Beating the EPA - The Why’s and How to Hypermile - CleanMPG Forums

Pulse and Glide in the Prius II

 

I don't have any problem with hypermilers or people employing hypermiling techniques, as long as they aren't endangering themselves or others and/or hampering the traffic around them.

I think the nature of The Prius Hybrid invites, encourages hypermiling. Sure you can choose to "just drive it" but the technology rewards non-agressive driving. This is definently a Chicken after the egg type of thing. People have developed techniques to apply to the use of the machine. Hanging around this forum I tried employing just a few of the driving techniques of hypermiling to my full ICE Honda and was suprised at how much further I got on a tank of gas. Although I admit, I'm just not disciplined enough to apply those techniques all the time.

I wonder as the technology improves. As we advance to "Plug-In" Prius, and full electrics and other unseen, unknown advancements that make hypermiling less necessary as the efficiency becomes more and more automatic, I think someday we will look back at all the "Hypermiling" techniques early adopters and current drivers were employing and they will seem quaint and strange. So I say (Safely) Pulse and Glide now, because someday you won't have to.

 

This is already happening. My GenIII beats its EPA rating by less than its nonhybrid predecessors, mainly because some of the savings I could achieve on the old ones is automatically harvested by the Prius and rolled into its EPA sticker. Of course, this is a very good thing.

 

We don't have to now. For me, it's purely a game. And with the new EV and PHEV cars right around the corner, this is all speculation but behaps P & G will still be a game. We will pulse our EV cars up to speed and glide back down, just like we do now, but with the objective of getting 125 mile range out of a charge instead of the advertised 100 miles by cars like the Nissan Leaf.
Just a thought....

 

Correct and exactly. Every time you draw from the pack, you are using energy that was captured from the ICE burning gas or from regen of momentum (momentum created by burning gas). Each conversion of energy is less than 100% efficient. So while the pack helps us recover significant energy wasted in non-hybrids, its use takes us further from the theoretical efficiency of the vehicle. It also allows more total power when needed, so the ICE is smaller than a non-hybrid with the same total power, which is fantastic.

So use the pack, but don't over use it. When you can P&G, glide is ideally without amps from the pack.

 

If you are getting that kind of difference I can guarantee one thing. You are driving every other driver on the road around you nuts.