Thanks to everyone who helped me with my queries and for folks who are posting questions and responses. It really helped to read the information on this site. I've been waffling about where, when, and what to buy, but I finally made the big decision today. Very happy with my Prius III with no nav, blizzard pearl exterior, beige interior. My soon-to-be 8 year old is getting a kick out of the bluetooth phone as well as the one-touch open/lock function! I'm learning how to drive in eco mode!
i hear power mode is the best as it gives more power which allows you to coast more... closer to a true pulse and glide...
Maximum accelerator pedal equals maximum throttle in both eco and power modes. Power is therefore exactly the same. Nor does more power allow more coasting (how would that work anyway?). Nor is the point of pulse and glide to use more power to get to speed, rather it is get to speed as efficiently as possible. To the OP, enjoy your new ride. Get used to the car before worrying about modes for now.
Not exactly. The point of pulse and glide is to maximize MPG during the combination of the pulse and the glide phase. Because the ICE runs inefficiently (in terms of converting gas to momentum) at low throttle openings, one uses a fairly large throttle opening during the pulse phase to accelerate the car. Accepting that one burns more fuel than one would at constant speed in exchange for using that fuel more efficiently. Then during the glide the ICE is at idle (or preferably off) so that it burns little or no fuel. Overall MPG is the combination of the two phases. It seems to work best with a "brisk" (not WOT) pulse so that the glide is longer than the pulse. If there are elevation changes, it helps to pulse on uphills (adding in the load of gaining elevation) and glide downhills (extending the glides). I've used P&G on conventional vehicles for several years with good results. Haven't had much luck with the Prius. STM it's hard to avoid using battery on the pulse and getting the drag of regen on the glide, thus shortening it. Takes a delicate throttle foot to just balance out regen on the glide. I agree, it's pointless to worry about modes until the OP gets a feel for the Prius. P.S. I once drove a diesel GMC Suburban which had a "freewheel" AT. When I took my foot off the throttle, RPM's would drop to idle, zero engine braking. Perfect for P&G, though I doubt GM had that in mind when they designed it!
Rather than using a meaningless term like 'brisk', why not go look at a power curve graph for the car? As you say what matters is the combination of pulse and glide, it matters not at all whether the glide is longer than the pulse. The glide from a certain speed is always the same length regardless of how quickly you got to that speed. So what matters is how much gas you use getting to that speed. Which is precisely what I said.
It's actually more useful to look at LOD readings on the ScanGauge and determine what works experimentally rather than theoretically. Most people don't have ScanGauges so "brisk" is a rough approximation: more than "like there's an egg under your foot" and less than "like you stole it". I probably should have said that. Nope. If you fit your glides to the terrain they can be longer. Gliding uphill just doesn't work well, I tried it. It also helps to fit glides to traffic, gliding in gaps between groups of cars so that glides don't have to be shortened because someone is riding your rear bumper. Idealized straight and level scenarios, power curves, etc aren't very useful because driving is a dynamic environment. What works better is to monitor MPG, try different things, and learn what works in the particular real situation one is in. This is why people commuting over the same route daily can learn efficient driving - and then can apply their empirical experience to other trips they make. Forgot: P&G is described in more detail here: http://www.cleanmpg.com/forums/showthread.php?t=1510 (see Section IV) and for the Gen 2 Prius here (might be somewhat relevant for the Gen 3 Prius): http://www.cleanmpg.com/forums/showthread.php?t=1224
Even more useless than 'brisk'. That sounds to me like saying you want your amp volume more than 0 and less than 11. The actual value really does matter, and I invite anyone interested to search for the articles by people who have spent years studying it (like Hobbit). Do I really need to say 'all else being equal' in every sentence? The point being that the how you got to that initial speed has NO effect on how long the glide is. Fine, but if you don't understand the ideal situation, you have no hope of understanding the more complicated dynamic environment.
Yes I know Hobbit and rode with him several years ago. You're overly preoccupied with the idea that there is an ideal acceleration rate: "P&G is not just about a speed range nor is it about an acceleration rate. It is a combination of a given amount of fuel consumed and distance traveled in the “Pulse†phase vs. the distance traveled in the “Glide†phase. If you “Pulse†for .3 miles at 35 MPG , you need to “Glide†at least twice the distance covered during the “Pulse†(.6 miles) to achieve 105 MPG average over .9 miles." (from the cleanmpg article referenced above) Actually it does, in anything but absolutely flat terrain, and most terrain is not absolutely flat. Pulses need to be timed and modified as necessary to maximize glide (while minimizing fuel usage during the pulse). A badly timed pulse may put you at the target speed while still on an uphill, which may mean a shortened pulse. Understanding an "idealized" situation can be useful, but it's equally important to understand the magnitude of other factors. AND to apply that understanding. This has drifted far from the OP's post, so I'll just congratulate him/her and move on.
Not sure where you get this from. You make it sound like that example is in some way a benchmark. The objective is to minimize gas consumed per mile traveled. Since a glide is the conversion of kinetic energy and potential energy (from hills) into distance traveled, and those things are completely set at the time of start of the glide, nothing that happens before that affects the glide distance. You already used that. No amount of adding complications will make simple wrong things said about the simple case any less wrong. Which to refresh memories was: "it gives more power which allows you to coast more... closer to a true pulse and glide..." unless you are pulse and gliding at maximum speed, having more power will not allow you to coast more. The pulse should be done in the most efficient way possible, not the most powerful way possible. And for a given (exactly the same) scenario, the glide will be the same regardless of the power levels used in the pulse.
Are you able to discuss the price you paid for your Prius? I am in the market for one and am trying to get the best deal, but I am not sure what the best deals are these days. Thanks!
