"Hype" and P&G - venting - Page 2 - GreenHybrid

bwilson4web · #11 (**permalink**) 06-26-2007, 03:04 PM

Quote:

Originally Posted by laurie

you say TOMATO, i say TOMAHTOH

That is why the term "P&G" often sounds more like 'art' instead of a well defined way of driving. I've seen cases where the P&G description was along the lines of "driving up hills slowly and gliding down the back side", which is actually topology driving . . . something entirely different.

Bob Wilson

"'When I make a word do a lot of work like that,' said Humpty Dumpty, 'I always pay it extra.'" - Lewis Carroll

Delta Flyer · #12 (**permalink**) 06-26-2007, 03:07 PM

Something seems very odd about making something a lot older than 17 years old (pulse and glide) and claiming this is a Prius invention that can't be varied.

bwilson4web · #13 (**permalink**) 06-26-2007, 03:40 PM

Quote:

Originally Posted by Delta Flyer

. . . P&G on the grandest scale of all. . . .

Rocket powered P&G. But NASA continues to investigate better spacecraft systems:

http://www.nasa.gov/lb/centers/glenn.../ds1opseq.html

Quote:

. . . the operational sequence used to validate the in-flight performance of the ion engine and complete the mission objectives for DS1.

Ion engine is a constant, steady powered mode, no ballistics glide or 'drafting planets' with the engine off.

Bob Wilson

Delta Flyer · #14 (**permalink**) 06-26-2007, 03:44 PM

I look forward to more advances in ion technology, although it's premature to say this new breed of propulsion will never use gravity assists.

Mr. Kite · #15 (**permalink**) 06-26-2007, 04:13 PM

I'm really not sure what the problem is. It has always seemed to me that P&G was an advanced and specialized technique. For most commuters, P&G just doesn't fit into their commute. Lots of other things are first emphasized to new members to increase their fuel economy.

Quote:

That is why the term "P&G" often sounds more like 'art' instead of a well defined way of driving.

I guess you do not like arts. Not all people are willing to drive based upon your graphs. Sometimes you just have to let go.

Use the force, Bob!

bwilson4web · #16 (**permalink**) 06-26-2007, 04:30 PM

Quote:

Originally Posted by Mr. Kite

I'm really not sure what the problem is.

It has to do with what appears to be a poorly defined term being given supernatural powers. <grins>

Quote:

Originally Posted by Mr. Kite

Use the force, Bob!

Obi-won Ke-Newton

Bob Wilson

Delta Flyer · #17 (**permalink**) 06-26-2007, 06:06 PM

Quote:

Originally Posted by Mr. Kite

I'm really not sure what the problem is.

I can't help but to agree with you.

On my work commute some parts lend itself to a steady cruise while others are more effective with pulse and glide. Along with others, I enjoy saving money, emissions, gas, and having some fun in the process. I find it odd that any of this would be the least bit controversial at a site named www.greenhybrid.com - it never should be (again, ibrands wants to interview hypermilers - see earlier post). So what if some hypermilers don't drive hybrids?...they are probably the most likely demographic to get one next.

bwilson4web · #18 (**permalink**) 06-27-2007, 01:34 AM

Quote:

Originally Posted by Delta Flyer

I can't help but to agree with you.

On my work commute some parts lend itself to a steady cruise while others are more effective with pulse and glide. Along with others, I enjoy saving money, emissions, gas, and having some fun in the process. I find it odd that any of this would be the least bit controversial at a site named www.greenhybrid.com - it never should be (again, ibrands wants to interview hypermilers - see earlier post). So what if some hypermilers don't drive hybrids?...they are probably the most likely demographic to get one next.

Don't overlook the obvious:

No form of P&G can overcome the missing tires. To achieve maximum efficiency, everything from the road rubber to tank and air inlet to exhaust needs to be optimized. Being fixated on P&G to the exclusion of all others risks missing the obvious.

Sad to say but 'hypermiler' has become the 'Hells Angel' variant of motorcycle rider. It has led truck drivers to visit GreenHybrid to caution against tailgating even though no one here advocates that approach. Efficient driving is pretty boring thanks to modest speeds, using slow traffic lanes, predictive braking and use of fuel efficient routes but the media likes to include spicy tidbits from the Mother Jones article.

Bob Wilson

Mr. Kite · #19 (**permalink**) 06-27-2007, 03:22 AM

Quote:

Originally Posted by bwilson4web

Don't overlook the obvious:
No form of P&G can overcome the missing tires. To achieve maximum efficiency, everything from the road rubber to tank and air inlet to exhaust needs to be optimized. Being fixated on P&G to the exclusion of all others risks missing the obvious.

Who is fixated on P&G? Bob.

Don't worry. Your graphs can coexist with P&G.

spartybrutus · #20 (**permalink**) 06-27-2007, 03:53 AM

Quote:

Originally Posted by bwilson4web

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

Bob - thanks for the DATA above. Part of what is mysterious about P%G is that I seldom see anyone describe:
- min, max and ave speeds.
- max rpms on the pulsse
- rate of rpm increase or duration of the pulse
- rate of or duration of speed bleed off before next pulse

your chart DATA gets at this.

Certainly I am a newbie in my HCH2 and started with CC at the speed limits since it was "easy" to practice. Doing better than I had hoped at 54.1mpg lifetime. Now, I am trying to determine where P&G fits into the driving regimine and HOW specifically to do it.

Yep - a side by side comparison of CC vs P&G (including details of the P&G) at same average speeds would be handy.

Best regards,
Carl