Pulse and Glide Strategies

[MPGranger]

With my manual truck, I've been P&Ging from 65MPH to 40MPH which is the speed limits for the roads I use. But how do others execute their P&G? I've been accelerating to 65 and then coasting down to 40, but should I be focusing more on the geography for my P&G?

[5speed5]

I definitely use geography when P&Ging. I pulse up hills then begin gliding just prior to cresting the hill. I don't really use P&G on the pure flat sections of road (of course there's not much of that around here).

(BTW, I just got my HHR and have only started hypermiling with it. The average you see in my signature is from two tankfuls driving 70-75 mph to get the HHR home before dark (bought it in Phoenix, AZ). I've now got ~470 miles on this tank and my car's computer says 41.1 mpg which is getting near double the EPA combined mpg. With a 16 gallon tank, I should have no problem getting over 600 miles on this tank.)

[Vekke]

I would not Push so high speed, because in most cases you come down from 65 very fast. My usual push top speed is 55 MPH and the low figure 47 MPH. If you are in a downhill you can make the push little bit higher speeds.

I have also find it like so that I try avoid doing pushes in "steep" uphills. I usually try to glide them up with minimum load. If I do a push in a uphill I try to do it in the centre of the hill so I only need one push.

I would also suggest trying out the search button. There are lots similar topics already .

[PaleMelanesian]

25 mph is an awfully wide speed range. I like a 15 mph range better - like 40-55 or 45-60. With a truck's aerodynamics, 65 is going to be dragging you down a lot.

Do you have a gauge (scan or ultra)? They help immensely for fine-tuning p&g. If you do, use ~75 LOD for the pulses. Focus on keeping the trip average ticking up with each p&g cycle.

I generally do uphill pulses, like 5speed5 described. I start pulsing at the bottom right as the hill starts to drop your speed. Start coasting just before the crest. You can maintain a more steady speed this way. You're pulsing and gliding your potential energy instead of kinetic energy.

[NeilBlanchard]

I'll add the idea of "swooping", which is accelerating as you near the bottom of a hill *if* it is followed by an uphill; or a long glide. Climbing hills is best with holding the throttle constant (if possible) and let your speed drop as you climb. Think of how you would ride a bicycle.

So, for me accelerating uphill is not good. So, using elevation changes is great to extend the glide, but depending on the type of driving, I'd add swooping when appropriate.

[PaleMelanesian]

I won't necessarily accelerate up the hill, but power up the hill at optimum BSFC. If that means accelerating, then I put in some glides as appropriate. If it means losing speed, I do that. If it means losing too much speed, downshift and attack the hill faster next time.

[Diesel_Dave]

As someone who grew up in the Appalachians and now lives in central Indiana, I think it's important for this discussion to remember that different people have different definitions of the word "hill".

I suggest that one should probably drive steep hills differently than lesser grades (such as a overpass).

Where I drive here in IN, all we have a those lesser grade, and most of the time it's level-up-down-level again. Here's my philosophy as far as those go: I try to maximize the amount of "pulse" I have on the upward grade and maximize the amount of "glide" I have on the downward grade. Generally that means timing things so I end my pulse at the top of the "hill". Depending on the length of the "hill" that may mean starting a pulse at the bottom or maybe not.

Of course, all this depends on traffic too.

[euromodder]

Originally Posted by NeilBlanchard

I'll add the idea of "swooping", which is accelerating as you near the bottom of a hill

I do that when approaching bridges or overpasses.
Accelerate on flat grond, coast up trading speed for height, and then down again picking up speed for a long coast.

[F8L]

I use the same technique as euromodder. With enough overpasses on your commute this can dramatically enhance your overall mpg for that tank.

[SentraSE-R]

60-45, or 55-40. Better yet, find roads where you can P&G 40-25.