Hi folks,

I'm venting but every time I see someone touting "P&G" and "hype" anything, this photo springs to mind as the perfect reply:


The butt of my joke has to do with the "hyped" properties of P&G that appears to suck the air out of all other considerations for efficient driving. Things like block heaters, route planning and other solutions are ignored because "P&G" is the one and only answer in all cases. The hype has reached the point where P&G is touted as if it has replaced the ordinary laws of Newtonian physics and a Nobel Prize awaits the inventor of P&G. Mostly, I'm tired of the "hype" about "hypermiling" and "pulse and glide" but there is a selfish reason for my disapproval.

When Mother Jones prints an article about extreme hypermiling, someone in an insurance company begins thinking, "You know these hybrid owners are dangerous" and the Traveller's 10% hybrid discount is at risk. Sensible hybrid drivers who give excellent interviews find their stories often have extra stuff about the extreme 'turning off engines' and 'tailgating trucks.' Hypermiler has become to efficient driving what 'Hells Angles' are to motorcycling, the wrong image.

So if you see a few 'joke' replies to future threads about "hypermiler" and "P&G," understand it is just swinging a "clue by four." I love irony and hopefully a little humor will help folks move beyond the hype to efficient driving and vehicle improvements.

Bob Wilson

 

Bob, you can't dislike P&G too much....after all I believe your employer is associated with NASA who does P&G on the grandest scale of all. For example the New Horizons mission:

• Earth to Low Orbit - 15 minutes
• "glide" 15-20 minutes in orbit
• 7-8 minute burn to leave Earth
• "glide" for a year
• "draft" Jupiter (gravity assist). New Horizons gains nearly 9,000mph
• "glide" nine years
• fly-by Pluto/Charon

Along with Voyager, Pioneer, Gaileo, Cassini–Huygens, to name a few, these deep-space probes are a remarkable feat of engineering.

P.S. I really can't think of anybody that uses P&G to the exclusion of everything else behind the wheel

Remember you are including laurie and Hot Georgia to name a couple with that broad brush.

As Jack Webb said on Dragnet - "Just the facts, please."

Lots of articles since Mother Jones have been published on hypermiling since (around a couple of dozen including this one), most of them espousing many of the techniques you also advocate....there has been to coin a phrase you used - "swift boat tatics". I have done a couple of interviews that have been printed - the legal department will insert after the editor's story in close drafting, etc at the end to enhance this misperception this is often done. I know this has been done to a couple of other people that have been interviewed as well, including laurie.

 

I think P&G is the most commonly misunderstood term on hybrid forums and is often cited in situations where the reference is incorrect. Don't misunderstand me, P&G is a proven and valid technique for improved FE. It's just that I think it has limited applicability in typical commuter traffic conditions. If you try to use it in heavy traffic, then IMHO you chance the frustration and ill-will of drivers behind you, and that sets a bad tone relaive to the hybrid community for these drivers. If the objective here is to expand the hybrid community -- for whatever reasons each of us harbors, then this action is contrary to that goal.

With my new TCH, I am rapidly discovering that the "heretical mode" is a far more practical technique to achieve vastly improved FE anyway. I do not know if a parallel situation exists in non-toyota hybrids, but this electronic recirculation mode has proven to me to be most useful in heavy commuter traffic moving in the 40 to 55 mile speed range (which is most of the time in my own commute). This operating state maintains those speeds over reasonably level terrain for extended periods with the MPG indicator either pegged at 60 or on mild uphill grades moving up (down) to 45 or so. That is great mileage for a mid-range speed in my middle weight hybrid. It is also reasonably compatible with traffic flow, so no-one gets held up behind me.

 

Exactly!

Efficient driving is a string of elements that all need to be addressed since any one can throw the results out:

1. Warm-up technologies such as block heaters and thermistor hacks
2. Warm-up driving such as first mile at low speeds
3. Cool-down or end of trip, EV speeds
4. Tires both the grade and inflation
5. Lubricants both grade and level
6. Use of air conditioner and heater including parking for savings
7. Route planning for topology and speed driving
8. Speed ranges to use and avoid
9. Higher energy gasolines
10. Other maintenance items
11. Vehicle instrumentation to optimize operating range
12. Appropriate highway driving techniques
13. Appropriate urban driving techniques, including P&G

The problem is P&G is seldom described as min, max and the equivalent, steady-state or block speed. The car might as well be on blocks if someone simply states "P&G" without the at least the min and max speeds and to be complete, the equivalent steady-state speed. BTW, it turns out there are some steady-state speeds that exceed the performance of the equivalent, block-speed, P&G protocols.

Bob Wilson

 

bob, as one of those who had "excessive techniques" added to the AP interview i gave, i would like to hear your description of P&G before i comment further. please tell me how you consider it to be used.

 

Sure, 25-43(34)P&G means:

• 25 mph minimum glide speed
• 43 mph maximum pulse speed
• 34 mph average speed on level ground
• P&G is pulse and glide

This defines P&G in a form that anyone can replicate. It also means that with a steady-state, MPG vs MPH chart, we can evaluate the effectiveness of P&G versus just setting the cruise control to the same speed:


I have found only one practical use of P&G with my NHW11 Prius, during the warm-up phase. Using a block heater or thermistor hack eliminates this very limited, 3-5 minutes. In all other cases, it is as or even more efficient to use steady-state speeds for 35-38 mph. I simply choose routes that have 4-lanes and maximum speed limits of 40-45 mph. Huntsville is fortunate to only have a 'rush minute'. But rush hour congestion works just fine for a Prius if all of the other elements have been addressed.

Bob Wilson

 

nice chart, however, i have another version of it that's not quite so technical, and still serves me well.

i have mentioned many times (ad nauseum, i am sure), that i drive 40 miles to work. when i don't take the more relaxing backroads, i drive a 4 lane rural 65MPH highway. i have noticed through 6 years of this commute there is a definite traffic pattern consisting of my being nearly alone on a segment of road......traffic catches up and passes me (while i drive 60 in the RIGHT lane).....after a few moments, i am basically by myself again.

therefore, part of my P&G technique consists of slowing down to a more fuel efficient speed when there is nobody behind me, to moving back to 60 when traffic approaches. this way i avoid most threats of being rundown for interfering with someone's god-given right to speed, though of course there are always those who i will never please. in between i can slow down to perhaps 50 and keep my FE intact.

if you think it doesn't work, you can look at my stats. my last couple of fills have been 60MPG and above, plus i threw in one 800 mile tank. on an HCH I. more than one way to skin a cat.

 

I'd be interested in your chart too. IMHO we don't do a good job of sharing the steady-state characteristics of our respective vehicles.

As for driving style, my understanding is any 'n-m(a)P&G' entails a pattern of acceleration and 'gliding' so the speed looks like a saw-tooth. If you're just backing down to a more fuel efficient speed range that you hold, that wouldn't be a P&G pattern like this:


In this test, there was no other traffic until the intersection when I drove in a more predictable pattern. Here is the same data with each P&G cycle laid upon the other:


I used this chart to determine that this is a "25-43(34)P&G" cycle. I could then perform a set of 34 mph runs and compare the results.

Bob Wilson

 

you say TOMATO, i say TOMAHTOH

and by the way, i do your version of it on the backroads going home. i don't know that it makes much difference in what the speed differential is, as long as the end result is higher fuel economy, yes?

 

Just a little observation: the driving style described as pulse and glide has been going on for decades. Therefore, it would not seem propriatry to the Prius, esp when it was done well before it existed. Of course there are variations of it.

Another observation - check out a few ibrands (GH owner) threads:
Why would anyone want to diss hypermiling if ibrands is wanting to interview them?