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Old 06-26-2007, 01:55 PM
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bwilson4web bwilson4web is offline
Engineering first
 
Real Name: Bob
Location: Huntsville, AL
Hybrids: Prius Classic 03
Posts: 5,035
Wink Re: "Hype" and P&G - venting

Quote:
Originally Posted by FastMover View Post
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. . . .

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

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Last edited by bwilson4web; 06-26-2007 at 02:00 PM.
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