Finally P&G

<div class='quotetop'>QUOTE(powphilprius @ Jun 7 2007, 08:00 PM) [snapback]457779[/snapback]</div>

So how high do you pulse to before you glide? 5 mph differential? 10? Or????

 

<div class='quotetop'>QUOTE(apriusfan @ Jun 7 2007, 11:30 PM) [snapback]457807[/snapback]</div>

This really depends on the terrain, traffic, traffic lights, predicting what's ahead etc...

There are some pretty good mild downhill stretches on my way to work that I have managed 63mpg over 8 miles and 20 minutes (with about 10-15 traffic stops) but going back uphill I get about 45mpg or so. It frustrates me and I don't know how to get over it, 45mpg uphill grrrr.

 

I would agree that the actual speeds you use as your upper and lower limit depend on traffic conditions, terrain, lights, etc. The key is to maintain your buffers (keep a good distance between you and the traffic ahead) and attempt to time lights (so you don't have to come to a stop) so that you can get uninterrupted glides. If traffic is very heavy, your target speeds will need to be much lower to maintain those buffers.

The differential between the two speeds should probably be at least 10 MPH, though. If you want to get the MPG benefit, the glide portion has to be longer than the pulse portion of the cycle. This is the formula for P vs. G distances posted by Wayne Gerdes (god of hypermiling) over at cleanmpg.com:

"The following equation will show you what you will need to achieve for a given target FE.
Pulse distance * [(Target FE mpg/Average Pulse Rate in mpg) – 1] = Glide distance needed to achieve target.
For a 100 mpg target goal, the following equation and examples of differing Pulse rates (Average FE during the Pulse) will give you your glide distances needed to achieve your 100 mpg goal!
Pulse Distance (miles) * [(100 mpg/20 mpg) – 1)] = Glide Distance (miles) needed to achieve target.
Pulse at a 20 mpg rate of acceleration over .2 miles:
.2 miles * [(100 mpg/20 mpg) – 1] = .8 miles of Glide to achieve 100 mpg over a total distance of 1 mile.
.2 miles of Pulse at a 20 mpg pulse rate with .8 miles of Glide will give you a 100 mpg.
Pulse at a 30 mpg rate of acceleration over .3 miles:
.3 miles * [(100 mpg/30 mpg) – 1] = .7 miles of Glide to achieve 100 mpg over a total distance of 1 mile.
.3 miles of Pulse at a 30 mpg pulse rate with .7 miles of Glide will give you 100 mpg.
Pulse at a 40 mpg rate of acceleration over .3 miles:
.3 miles * [(100 mpg/40 mpg) – 1] = .45 miles of Glide to achieve 100 mpg over a total distance of .75 miles.
.3 miles of Pulse at a 40 mpg pulse rate acceleration with .75 miles of Glide will give you 100 mpg.
Pulse at a 50 mpg rate of acceleration over .4 miles:
.4 miles * [(100 mpg/50 mpg) – 1] = .4 miles of Glide to achieve 100 mpg over a total distance of .8 miles.
.4 miles of Pulse at a 50 mpg pulse rate with .4 miles of Glide will give you 100 mpg."

I'm resetting the Consumption screen after each trip at this point, because I'm still learning and I want to see how I do on each trip. Here's my best run so far:

[attachmentid=8719]

Now, Gerdes can get that over a whole tank, and I'm certainly not there yet, but it shows how well you can do if conditions are right.

Good luck!